JP4684838B2 - Lighting device, light control measurement structure and image display device using them - Google Patents

Lighting device, light control measurement structure and image display device using them Download PDF

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JP4684838B2
JP4684838B2 JP2005293549A JP2005293549A JP4684838B2 JP 4684838 B2 JP4684838 B2 JP 4684838B2 JP 2005293549 A JP2005293549 A JP 2005293549A JP 2005293549 A JP2005293549 A JP 2005293549A JP 4684838 B2 JP4684838 B2 JP 4684838B2
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JP2007103226A (en
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伊久雄 大西
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株式会社クラレ
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  The present invention relates to an illuminating device composed of a plurality of linear light sources, a structure having two types of light direction control means used therefor, and an image display device using the same, and is particularly large in size, high luminance and luminance uniformity. The present invention relates to an illumination signage device that is required for use in an illumination signage device, a liquid crystal display device and the like, a structure having two types of light beam direction control means, and an image display device.

  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 equalizes it with a diffusion sheet, 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 back 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 a mobile phone and a mobile personal computer.

  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, the edge light method reduces the ratio of the length of the peripheral portion to the display area where the light source can be arranged, so that 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 cost increase 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 become difficult for the edge light system to respond to 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. 26 shows an example of this type of lighting device. In this example, the illumination device has a rectangular emission surface composed of an X direction and a Y direction perpendicular to the X direction, and includes a plurality of linear light sources 1, a light diffusion plate 5, and a reflection plate 4. The linear light source 1 is arranged in one imaginary plane parallel to the X direction and the Y direction, and the linear light source 1 has a longitudinal direction arranged parallel to the Y direction, and the X direction. The light diffusing plates 5 are arranged on the emission surface side of the arranged linear light sources 1, and the main surface is the virtual plane on which the linear light sources 1 are arranged. The reflecting plate 4 is positioned on the opposite side of the light diffusing plate 5 with the arrayed linear light sources 1 sandwiched therebetween, and the main surface of the reflecting plate 4 is arranged with linear light sources. Parallel to the virtual plane. In addition, the light diffusing plate 5 usually has a light diffusing material uniformly dispersed therein and has a uniform optical performance within the main surface.

  A rectangular exit surface is most common in many applications of the present lighting device, such as image display devices and lighting signs.

  Also, the linear light source is the most common light source for these lighting devices because it is easier to eliminate luminance unevenness than the point light source and the wiring is short and easy. 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, however, the linear light source is oriented parallel to the long side of the output surface rectangle. It is desirable that the number of linear light sources can be reduced. In addition, by arranging linear light sources at equal intervals in the same plane, luminance unevenness, which is a problem, becomes periodic due to the arrangement of linear light sources, and it is a problem with light diffusing plates that have uniform optical performance within the main surface. Elimination of uneven brightness becomes easy. 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 requires the use efficiency of the light emitted from the light source, that is, the ratio of the light flux emitted from the light exit surface is high, and the number of light sources can be increased freely. 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 an application for observing an illumination surface such as an image display device or an illumination signboard, 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 in the edge light system, it is difficult to eliminate it by means such as a diffusion film in which a light diffusing material is applied to the surface of a film conventionally used in the edge light system. Therefore, a light diffusing plate in which a light diffusing material 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. In order to obtain good diffusibility and light utilization efficiency, various light diffusing materials such as inorganic fine particles and crosslinked organic fine particles have been studied (for example, see Patent Document 2). However, these methods using a light diffusing material are not preferable from the viewpoint of energy saving because they absorb light into the light diffusing material 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 shape of the reflector may hinder thinning.

  In addition, a method of installing 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 (for example, see Patent Document 5), etc. However, similarly, since the exact alignment of a member and a light source is required, the subject that productivity is inferior arises.

  Further, a light diffusing plate having irregularities on the surface has been proposed (see, for example, Patent Document 6). These diffusing plates can obtain the desired diffusibility while avoiding or reducing the use of the diffusing material, 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 having a triangular or corrugated cross section and continuously extending in one direction. However, since these prism sheets aim to reduce the light loss by directing the diffused light to the front, it is impossible to eliminate the lamp image generated in the direct system.

  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 diffusing plate or reducing the number of optical films. In order to realize energy saving, it is necessary to increase the light utilization efficiency. The direct method can increase the number of linear light sources and easily obtain high brightness as described above. However, from the viewpoint of energy saving, use of light by using a large amount of light diffusing material to eliminate the lamp image. Decreasing efficiency must be suppressed.

Japanese Patent Laid-Open No. 2-17 JP 54-155244 A Japanese Patent No. 2852424 JP 2000-338895 A JP 2002-352611 A JP-A-10-123307 Patent No. 3455884

  Therefore, in the present invention, high luminance, particularly high front luminance, high light use efficiency, easy response to the increase in size of the device, and uneven luminance in the front direction without strict alignment between the light source and other members. An object of the present invention is to provide an illuminating device that is advantageous for productivity and thinning, a structure having first and second light direction control means provided in the illuminating device, and an image display device using the same. To do.

  Therefore, the present inventors have replaced the light diffusing plate of the general direct illumination device as illustrated in FIG. 26 with the first light direction control means and the second light direction control means proposed by the present inventors. I found that I could solve the problem. In order to solve the above problems, in the present invention, the use of the light diffusing material can be avoided or greatly reduced by the second light beam direction control means, and the light use efficiency can be improved, and the first light beam direction control means. Thus, by converging the viewing angle in the Y direction and concentrating the outgoing energy in the front direction, it is possible to achieve high brightness, particularly improvement of front brightness useful for many applications. Further, the second light beam direction control means has a plurality of protrusions on the ridge, and the cross-sectional shape thereof is optimized, so that the light emitted from the incident light at all points on the surface where light enters the second light beam direction control means. It can have a uniform property of controlling the direction in the same way, and is not only advantageous for changing the size, 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 eliminating uneven brightness and improving brightness can eliminate or reduce the use of other functional optical films, which is advantageous in terms of 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 emission side of these illumination devices.

  An illuminating device provided in the present invention is an illuminating device having a rectangular emission surface composed of an X direction and a Y direction perpendicular to the X direction, and the illuminating device includes a plurality of linear light sources and a first light beam direction. Control means and second light direction control means, the second light direction control means is a member for narrowing the viewing angle characteristics in the Y direction, and the second light direction control means reduces the luminance unevenness in the front direction. It is a member for eliminating.

  If the distribution of the outgoing light intensity is substantially 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 distribution of the light output intensity of each linear light source, and if the distribution becomes almost constant at an arbitrary position on the exit surface side, the luminance Unevenness is eliminated.

  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 small solid angle centered on the normal direction of the main surface of the second light direction control means.

The means provided by the present invention will be described in detail below.
The invention according to claim 1 has a rectangular emission surface composed of an X direction and a Y direction perpendicular to the X direction,
A lighting device comprising a plurality of linear light sources, a first light beam direction control means, a second light beam direction control means, and a reflector,
The linear light sources are arranged in parallel and at equal intervals in a virtual plane parallel to the Y axis and the X axis that intersect perpendicularly.
And arranged along the X-axis parallel to the Y-axis,
The reflecting plate is arranged in parallel to the X direction and the Y direction on the side facing the light emitting surface with respect to the linear light source,
The first light beam direction control unit and the second light beam direction control unit are closer to the emission surface than the virtual plane on which the linear light source is arranged.
The light from the light source is arranged to be received by both the first light direction control means and the second light direction control means,
The first light beam direction control means refracts the received light, condenses the dispersion in the Y-axis direction of the light, and passes it to the exit surface side,
The second light beam direction control means is an illuminating device characterized in that the received light is reflected and refracted to improve the positional uniformity of the light in the X-axis direction and pass to the exit surface side.

  The reflector receives and reflects light from the linear light source and makes it enter the light control member as diffused light, and receives and reflects the reflected light from the light control member and makes it enter the light control member again as diffused light. Fulfill. With this configuration, the luminance unevenness in the front direction due to the arrangement of the linear light sources can be eliminated, and the luminance uniformity and high brightness in the front direction, which are the most important, can be realized by focusing in the front direction.

Furthermore, the invention of claim 1
Before Stories second light beam direction control means is in the plate-like structure,
The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
The second light beam direction control means comprises a plurality of hook-shaped convex portions parallel to the Y axis of the surface on the exit surface side of the plate-like structure,
The distance between the centers of the linear light sources is D, the distance between the center of the arbitrary linear light source and the plate-like structure having the second light beam direction control means is H, and the distance from the one linear light source to the second. F (X) is a function representing the intensity of light emitted in the normal direction of the exit surface at the position coordinate X in the X direction (the light source position is X = 0) of the light incident on the light direction control means,
g (X) = f (X−D) + f (X) + f (X + D) (1)
When
In the range of −D / 2 ≦ X ≦ D / 2,
The ratio g (X) min / g (X) max of g (X) min that is the minimum value of g (X) and g (X) max that is the maximum value is 0.6 or more,
The minimum value X min of X is in the range of −3.0D ≦ X min ≦ −0.5D, and the maximum value X max is in the range of 0.5D ≦ X max ≦ 3.0D (where X min and X max is the attenuation at the vicinity of the linear light source where the value of f (X) is X = 0, and the coordinates of both ends when it becomes substantially 0),
An X-direction cross-sectional shape of an arbitrary convex portion is composed of (2N + 1) different regions −N to N expressed by the following formulas (2) to (8). .
δ = (X max −X min ) / (2N + 1) (2)
X i = i × δ (3)
α i = Tan −1 (X i / H) (4)
β i = Sin −1 ((1 / n) sin α i ) (5)
γ i = Sin −1 ((1 / n 2 ) sin α i ) (6)
a i αf (X i + T · tanγ i) · cosΦ i · cosβ i / cosα i / cos (Φ i -β i) (7)
Φ i = Tan −1 ((n · sin β i ) / (n · cos β i −1) (8)
However,
N: natural number i: an integer from −N to N n: refractive index n 2 of the convex portion of the light control member: refractive index a i of the base material of the light control member: width Φ i of the region i in the X direction: Slope inclination T with respect to the exit surface: thickness from the entrance surface of the plate-like structure having the second light beam direction control means to the bottom of the convex portion

  Since the main surface of the plate-like structure having the second light direction control means and the virtual plane on which the linear light source is arranged are parallel, the distance from the linear light source to the second light direction control means is uniform. Therefore, the distribution of the incident light intensity to the second light direction control means of each linear light source becomes uniform, and the distribution of the entire incident light intensity is along the X direction, which is the arrangement direction of the linear light sources, Since the distribution is periodic according to the position of the linear light source, it is easy to eliminate luminance unevenness.

  The main surface of the plate-like structure having the second light direction control means is composed of an incident surface that faces the linear light source and receives light from the linear light source, and an output surface that emits light received by the incident surface. Become. The emission surface has a plurality of hook-shaped protrusions on the surface, and the protrusions have hook-shaped ridgelines corresponding to the tops formed in parallel to the Y direction and arranged along the X direction. . The convex portion serves to control the light from the linear light source and to make the distribution of the emitted light intensity in the front direction of the emitted light constant. The ridge-shaped ridgeline corresponding to the top of the convex part is arranged in parallel to the Y direction, that is, the convex parts are located in parallel, and the incident surface and the outgoing surface, which are the main surfaces of the second light beam direction control means, are lines. Since the light source from the linear light source is efficiently received by the main surface, the direction control of the light in the X direction in which the luminance unevenness is remarkable can be performed. In the direct illumination system, the luminance unevenness is most remarkable in the X direction perpendicular to the longitudinal direction of the linear light source. On the other hand, the illumination apparatus of the present invention has a preferable shape of the convex portion of the second light direction control means. By making the distribution of the intensity of light emission in the front direction constant, it is characterized by eliminating luminance unevenness in the front direction, and its ability is the highest in the direction where the width of the convex portion is the smallest. By providing the ridge-shaped ridge line corresponding to the top of the convex part in parallel with the linear light source, that is, in parallel with the Y direction, uneven luminance can be efficiently eliminated.

  Further, by arranging the convex portions having the same shape in parallel, the optical properties of the second light direction control means are uniform, so that alignment is not required, and the display size, the number of linear light sources and the arrangement of the linear light sources are not required. The lighting device can be manufactured with high productivity because it can respond immediately to changes. Therefore, for example, since it is possible to cut out an arbitrary position of a large plate-shaped molded article having a desired convex portion created by a large extrusion molding machine or the like to an arbitrary size, the second light beam direction control means is advantageous in production. In addition to this, it is possible to easily cope with a change in the size of the lighting device.

The light from the linear light source and the light from the linear light source reflected by the reflecting plate are incident on the incident surface of the second light direction control means. Among these, for the light incident on the second light source direction control means from the linear light source, the distance between the centers of the linear light sources is D, the center of the arbitrary linear light source, the second light direction control means, Where H is the position coordinate X in the X direction of the light incident on the second light direction control means from the linear light source, and the light output intensity in the normal direction of the exit surface, which is the front direction, A function expressing the light source position as X = 0 is f (X),
g (X) = f (X−D) + f (X) + f (X + D) (1)
When
In the range of −D / 2 ≦ X ≦ D / 2,
The ratio g (X) min / g (X) max of g (X) min that is the minimum value of g (X) and g (X) max that is the maximum value is 0.6 or more. .

  In the illumination device of the present invention, the same linear light source is used. Therefore, the function g (X) is the sum of f (X) for three adjacent linear light sources. The range of −D / 2 ≦ X ≦ D / 2 is a range up to an intermediate point between each of the central linear light source and the adjacent linear light source, and g (X) regarding any three adjacent linear light sources. When the above condition is satisfied, the luminance unevenness in the front direction can be eliminated over the entire surface.

  Since light is received under the same conditions for each period of the linear light source, and the second light direction control means controls the same light output direction for light incident on an arbitrary point on the incident surface, it is for one period. By controlling the distribution of the light emission intensity in the range of D / 2 ≦ X ≦ D / 2, the entire light emission intensity distribution can be controlled. Further, as described above, the distribution of the light intensity is the sum of the distributions of the light intensity of the respective linear light sources. If the distribution becomes almost constant at any position on the observation surface side, the luminance unevenness is eliminated. 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.

Since the light intensity of the linear light source is inversely proportional to the distance, the influence of the light from the distant linear light source is small. For this reason, by setting the function g (X) considering only the light output intensities from the three adjacent linear light sources within an appropriate range, the distribution of the light output intensity in the front direction can be controlled, and the luminance unevenness in the front direction can be reduced. Can be resolved. By setting g (X) to a range in which the ratio g (X) min / g (X) max of g (X) min that is the minimum value and g (X) max that is the maximum value is 0.6 or more, Due to the effect of the reflector, the actual light intensity distribution is made more uniform, and the sum of the light intensity distributions in the front direction of each linear light source is almost constant at any position on the observation surface side. Can be resolved.

  FIG. 9 is a diagram showing f (X) and g (X) of the illumination device of the present invention in which linear light sources are arranged with D = 30 mm shown for f (X) in FIG. The position coordinate in the X direction of the linear light source located at the center is set to 0, and the distance (mm) in the X direction is set to the X coordinate.

Furthermore, the present inventors have found out the shape of the convex portion for making the distribution of the light emission intensity in the front direction substantially uniform. That is, in the present invention, the minimum value X min of the minimum value Xmin of X is X is in a range of -3.0D ≦ X min ≦ -0.5D, the maximum value X max is 0.5 D ≦ X max ≦ 3. It is a range of 0D, and the cross-sectional shape in the X direction of the convex part is composed of (2N + 1) different regions −N to N expressed by the following formulas (2) to (8). . Of these, the region 0 has an inclination of 0, that is, parallel to the incident surface, and can efficiently emit light incident from directly below in the front direction.

δ = (X max −X min ) / (2N + 1) (2)
X i = i × δ (3)
α i = Tan −1 (X i / H) (4)
β i = Sin −1 ((1 / n) sin α i ) (5)
γ i = Sin −1 ((1 / n 2 ) sin α i ) (6)
a i αf (X i + T · tanγ i) · cosΦ i · cosβ i / cosα i / cos (Φ i -β i) (7)
Φ i = Tan −1 ((n · sin β i ) / (n · cos β i −1)) (8)
N: natural number i: integer from −N to N n: refractive index n 2 of the convex portion of the second light direction control means: refractive index a i of the base material of the second light direction control means: in the X direction of the region i Width Φ i : Slope inclination with respect to the exit surface of the region i T: Thickness from the entrance surface of the plate-like structure having the second light beam direction control means to the bottom of the convex portion Here, α, β, γ, Φ, etc. All of the angles have an absolute value of less than 90 °, the angle formed clockwise with respect to the reference line is positive, and the angle formed counterclockwise is negative.

First, equation (7) will be described with reference to FIG.
X min and X max are the coordinates of both ends when the value of f (X) attenuates around the vicinity of the linear light source where X = 0 and becomes substantially zero. When X min to X max are equally divided (2N + 1), the width δ of each divided element is expressed by Expression (2). At this time, the center coordinates X i of an arbitrary element are expressed by Expression (3). The incident angle from the linear light source at the position of X = 0 to the incident surface of the second light direction control means of the coordinate X i is an angle α i represented by the equation (4) with respect to the normal direction.

Here, the light is refracted and travels inside the second light beam direction control means at an angle γ i shown in Expression (4) with respect to the normal direction. When it reaches the bottom of the convex part, it is refracted again, travels inside the second light beam direction control means at an angle β i shown in Formula (5), and enters the convex part 2. Here, the convex portions of the second light beam direction control means and the base material on which the convex portions are provided may have the same refractive index. In this case, the refractive index is not refracted at the bottom of the convex portions, and β i = γ i Become. Among them, only the light that has reached the slope of the inclination Φ i with respect to the emission surface represented by the equation (8) is directed in the front direction.

Here, the length of the slope of the region i occupied by the slope of the angle Φ i is b i, and the projection length from the slope of the region i to the direction perpendicular to the light ray direction inside the convex portion of the second light ray direction control means When the height is e i , the angle of the slope of the region i in the cross section parallel to the X direction and the normal direction of the principal surface of the second light direction control means is the light ray inside the convex part of the second light direction control means. Since the angle ξ i formed with respect to the angle perpendicular to the direction is (Φ i −β i ),
e i = b i · cos (Φ i −β i ) (9)
It becomes.

Here, if the length of the projection onto the plane parallel to the incident surface of the region i occupied by the slope of the angle Φ i , that is, the width of the region i in the X direction is a i ,
b i = a i / cosΦ i (10)
It is.
From equation (9) and equation (10), e i = a i / cosΦ i · cos (Φ i −β i ) (11)
It becomes.
Here, as shown in FIG. 13, when the width in the X direction of the convex portion, that is, the sum of a i is P, it is incident on the second light direction control means 2 at an angle α i and passes through the second light direction control means. Thus, the proportion of the light 9 traveling toward the region i out of the light 9 traveling toward the convex portion 2 is e i / (P · cos β i ).

On the other hand, the intensity of light incident on the second light direction control means at the angle α i , that is, the illuminance, is proportional to cos 2 α i as described later.

Further, as shown in FIG. 14, the angle [Delta] [alpha] i anticipating the diameter of the light source in the point of coordinates X i is proportional to cos [alpha] i. Accordingly, the intensity of light per unit area unit angle incident on the coordinate X i is proportional to cos 2 α i / Δα i , and from this, is proportional to cos 2 α i / cos α i , that is, cos α i . In other words, the light from the linear light source per unit angle of the light incident on the unit convex portion at the point of the coordinate X = X i with respect to the intensity per unit angle of light incident on the unit convex portion at the point of X = 0. The intensity ratio is cosα i . Thus, the light exiting the front is cosα i · e i / (P · cosβ i), a i / cosΦ i · cos (Φ i -β i) from equation (11) · cosα i / ( P · cosβ i ).

When the thickness from the incident surface of the plate-like structure having the second light beam direction control means to the bottom of the convex portion is T, the light is emitted in coordinates (X i + T · tan γ i ). The intensity of light emission is f (X i + T · tan γ i ).

Furthermore, since the light emission intensity in the front direction is proportional to the emission intensity of the linear light source and the emission ratio in the front direction,
f (X i + T · tanγ i) αa i / cosΦ i · cos (Φ i -β i) · cosα i / (P · cosβ i) (12)
According to
a i αP · f (X i + T · tanγ i) · cosΦ i · cosβ i / cosα i / cos (Φ i -β i) (13)
It becomes. Here, if the width of the convex portion 2 is P, the sum of a i becomes the width P of the convex portion.

It becomes.
P is the convex width and is a constant.
a i αf (X i + T · tanγ i) · cosΦ i · cosβ i / cosα i / cos (Φ i -β i) (7)
The convex portion has a shape composed of a region i having a width a i that satisfies the relationship of (Expression 7). As is well known, since the proportional reduction optical system exhibits almost the same directivity characteristics, the pitch of the convex portions can be freely selected.

Here, the relationship between the incident angle to the second light beam direction control means and the incident intensity will be described with reference to FIG.
Considering the minute angle Δθ centered on the incident angle θ from the linear light source to the second light direction control means, when Δθ is sufficiently small, the following equations (15), (16), and (17) are obtained. It holds.
U = H '· Δθ (15)
H ′ = H / cos θ (16)
V = U / cos θ (17)
Therefore, V = H · Δθ / cos 2 θ (18)
It is. That is, since V is inversely proportional to cos 2 θ, the intensity of incident light per unit area to the second light direction control means when the intensity of the emitted light within Δθ from the linear light source is constant regardless of θ. Is proportional to cos 2 θ.

Next, equation (8) will be described.
FIG. 6 shows the principle of directing light to the front in the lighting device of the present invention.
Incident light 7 entering the second light beam direction control means 2 having a refractive index n from the linear light source is refracted at the incident surface 6 of the second light beam direction control means and passes through the inside of the plate-like structure. Further, the light 9 is refracted by the convex portion 2 on the emission surface side and is emitted to the observation surface side. At this time, the emission light 8 is emitted in the front direction at the angle Φ where the inclination is desirable in the convex portion 2. Is the case. In the present invention, the light emission intensity in the front direction can be adjusted by adjusting the ratio of the angle Φ so that the light emission intensity in the front direction is constant in consideration of the distribution of α based on the arrangement and the intensity of the incident light 7.

The inclination Φ of the projection 2 on the exit surface for directing the incident light 7 to the front is determined by the refractive index of the second light direction control means 2 and the incident angle of the light to the second light direction control means 2. The incident angle of light on the incident surface 6 with respect to the normal of the incident surface 6 is α, and the light that is refracted by the incident surface 6 and passes through the convex part 2 inside the second light beam direction control means is normal to the incident surface 6. Is the angle formed with respect to the normal of the slope on the exit side and ε is the angle of the light traveling through the second light beam direction control means, and the light refracted on the exit side slope and emitted to the observation surface side The angle formed with respect to the normal of the slope is ω, and the refractive index of the second light direction control means is n. At this time, let Φ be the angle of the slope of the convex portion so that the light exiting the exit surface travels in the front direction, which is the normal direction of the entrance surface.
At this time, the following relationship is established.
β = Sin −1 (1 / n · sin α) (5) ′
Φ = β−ε (19)
−n · sinε = −sinω = sinΦ (ω = −Φ) (20)
From equation (19) and equation (20),
−n · sin (β−Φ) = sinΦ (21)
−n · {sinΦ · cosβ−cosΦ · sinβ} = sinΦ (21) ′
Dividing both sides of equation (21) 'by cosΦ (since sinΦ / cosΦ = tanΦ)
−n {tanΦ · cosβ−sinβ} = tanΦ (21) ”
From this, Φ can be expressed as follows.
Φ = Tan -1 (n · sinβ) / (n · cosβ-1)) (21) '''
From Equation (5) 'and Equation (21)''', Φ = Tan -1 · (sinα / (n · cos (Sin -1 ((1 / n) sinα))-1)) (21) ''''

α, n, and Φ have such a relationship, and light having a desired incident angle α can be emitted in the front direction by the refractive index n of the second light direction control means 2 and the inclination Φ of the convex portion 2. . By the equation (21) ′ ″, the inclination Φ i of each region of the convex portion satisfies the equation (8), so that the light incident on the incident surface at the angle α i is emitted in the front direction from the region i of the convex portion. Can explain what can be done.

As described above, the slope Φ i of the convex region i and the width a i in the X direction occupied by the convex region i, which are important factors that determine the shape of the convex portion, in the distribution f (X) of the desired intensity of light emission in the front direction are as follows. The linear light source is selected based on the arrangement of the linear light source and the refractive index of the second light direction control means.

The invention according to claim 2 is characterized in that the first light direction control means is in a plate-like structure,
The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
The first light beam direction control means comprises a plurality of hook-shaped protrusions parallel to the X axis of the surface on the exit surface side of the plate-like structure, and has a cross section perpendicular to the X axis and parallel to the Y axis. an illumination device according to claim 1 or 2, wherein the tilt Kino maximum value of the shape is 30 ° or more and 60 ° or less.
By making the first light direction control means a plate-like structure, mechanical strength can be ensured, and the change in the optical characteristics caused by warping in the film state can be reduced.

The operation of the first light direction control means will be described with reference to FIG. Consider light propagation in a plane perpendicular to the X direction.
The light incident from the surface on the linear light source side of the plate-like structure constituting the first light beam direction control means is refracted on the surface on which the light is incident, and the refraction of the convex slope provided on the exit surface side. However, light is emitted at an angle whose absolute value is small. That is, it is possible to narrow the emission angle distribution. Depending on the shape of the convex portion, light may be reflected again to the light source side by total reflection on the convex slope. The reflected light is reflected by the reflecting plate provided on the back surface of the light source, is incident again on the first light beam direction control means, and the above phenomenon is repeated.

  The maximum inclination angle of the convex slope is preferably 30 ° to 60 °. If it is 30 ° or less, the light refracted in the front direction is reduced and the light collecting function is lowered, and if it is 60 ° or more, the emitted light in the oblique direction is increased, so that the light collecting function is similarly lowered.

The invention according to claim 3
The first beam direction control means is in a plate-like structure;
The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
The first light direction control means includes a plurality of hook-shaped protrusions parallel to the X-axis of the surface on which light of the plate-like structure is incident, and is perpendicular to the X-axis and parallel to the Y-axis. an illumination device according to claim 1 or 2, wherein the tilt Kino maximum value of the shape of the cross section is not more than 10 ° and not more than 40 degrees.

  The main surface of the plate-like structure is composed of an incident surface on which the first light beam direction control means is provided and an exit surface opposite to the incident surface.

  The operation of the first light direction control means will be described with reference to FIG. Consider the progress of light in a plane parallel to the normal direction and the Y direction of the plate-like structure. Here, for convenience of explanation, one of the Y directions is positive and the other is negative. In FIG. 20, the right direction indicates plus and the left direction indicates minus. Further, let s be the region in the plus direction with the top of the convex portion W as the ridge, and t be the region in the minus direction.

  The surface on which light enters when entering the region s when incident in a direction positive to the normal direction of the second light direction control means within a plane parallel to the normal direction of the second light direction control means and the Y direction. The light is emitted at an angle closer to the normal direction than the incident angle due to the refraction action. On the other hand, when it enters the region t, it is emitted at an angle away from the normal direction.

  Adjustment of the angular distribution of light passing through the first light direction control means is possible by adjusting the shape of the convex portion W. That is, by selecting a suitable shape, the angular distribution of the emitted light can be narrowed. Further, when the incident angle of the plate-like structure on the light incident surface side is increased, the light is reflected again to the light source side by total reflection on the emission surface. The reflected light is incident again on the second light beam direction control means by the reflecting plate provided on the back surface of the light source, and the above phenomenon is repeated.

  Therefore, the formation of the ridge-shaped convex portion W parallel to the Y direction on the surface side where the light from the second light direction control means is incident can narrow the outgoing light angle distribution in the X direction and increase the luminance in the front direction. it can. When the height of the convex portion W increases, the ratio of the region s when observed obliquely in the X direction decreases, and conversely, the ratio of the region t increases. In other words, if the height of the convex portion becomes too high, the light is not collected, and the emitted light distribution becomes wider, and conversely, the luminance in the front direction decreases.

  The maximum inclination angle of the convex portion W slope is preferably 10 ° to 40 °. Further, 20 ° to 30 ° is more preferable. Moreover, it is preferable that the top of the cross-sectional shape in the Y-axis direction of the convex portion W is a curved surface. This is because if the top of the cross-sectional shape is formed in a straight line, chipping and collapse are likely to occur, and the appearance quality deteriorates due to the bright spots and black spots associated therewith.

  Further, it is desirable that the cross-sectional shape of the convex portion W in the Y-axis direction is a line-symmetric shape with the normal line of the main surface of the second light direction control means passing through the top as the center. Thus, the outgoing light angle distribution in the X direction can be made symmetrical in the plus and minus directions with the 0 ° direction as the center, so that viewing angle characteristics balanced in the plus and minus directions can be obtained.

The invention according to claim 4 is characterized in that the first light beam direction control means and the second light beam direction control means provided on the surface on which the light projection is incident are in the same plate-like structure. To do. Thereby, the interface between the members having the first light direction control means and the second light direction control means can be eliminated, and light loss due to reflection at the interface can be reduced.

According to a fifth aspect of the invention, an illumination device according to claim 1, X-direction of the cross-sectional shape of the convex portion forms a convex portion (2N + 1) numbers of at least one pair of inclination different areas It is the illuminating device characterized by being the shape which approximated the shape of two adjacent area | regions of a curve with the curve. The convex portion described in claim 1 is composed of (2N + 1) inclined surfaces having an angle Φi, and shows a shape obtained by approximating the shape of at least one pair of two adjacent regions by a curve. This is desirable because the distribution of the light emission intensity in the front direction and the distribution of the light emission angles become smoother. Moreover, since it is easier to shape, it is advantageous and desirable when producing the second light beam direction control means. Furthermore, it is also desirable that the bonded portion of the region is not easily broken because it is not a sharp shape. The breakage of the joint is undesirable because it may cause a change in the light emission direction and unnecessary scattering.

A sixth aspect of the present invention is the lighting device according to any one of the first to fifth aspects, wherein the plate-like structure is a transparent thermoplastic having a water absorption of 0.5% or less in an atmosphere of 60 ° C. and 80%. It consists of resin. By forming irregularities on the surface of the plate-like structure, the surface area is different between the light incident surface and the light exit surface, but by making the water absorption rate below 0.5% under the above atmosphere, the difference in expansion due to water absorption It is possible to reduce the warpage generated by the above.

The invention of claim 7 is a structure having a first light beam direction control means and the second light beam direction control means for lighting apparatus has according to any of claims 1-6. The structures constituting the first light direction control means and the second light direction control means partially reflect the light incident on the incident surface from the incident surface side and partially transmit the light. By this function, the luminance unevenness of the emitted light is reduced. Further, the light transmitted through the incident surface of the structure constituting the second light direction control means is refracted at the incident surface, condensed near the normal direction of the incident surface, and travels toward the exit surface. The light that has passed through the incident surface of the structure constituting the second light direction control means and directed toward the convex portion of the output surface is refracted according to the inclination of each region of the convex portion. Light that is directed to an area of the appropriate angle is directed in the front direction. Further, by appropriately selecting the ratio of each region of the convex portions having different inclinations, it is possible to make the light emission intensity in the front direction at a point on an arbitrary light exit surface constant. Due to the functions of the entrance surface and the exit surface convex portion described above, it is possible to eliminate uneven brightness of the exit light in the front direction, which is the normal direction of the exit surface, with various configurations in which a linear light source is disposed on the entrance surface side.

The invention described in claim 8 is an image display device characterized in that a transmissive display element is provided on the exit surface side of the illumination device according to any one of claims 1 to 6 . The illuminating device is an illuminating device having a high front luminance and a uniform luminance distribution in the front direction, and can be used as a preferable image display device by providing a transmissive display element on the emission side. Here, the image display device refers to a display module in which a lighting device and a display element 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.

  In the present invention, in the direct system, lighting efficiency is high, and the distribution of the intensity of emitted light in the front direction is constant, so that there is no uneven brightness in the front direction such as a lamp image and the brightness in the front direction is high. Providing equipment. Moreover, it can respond also to thickness reduction by making a linear light source and another member close, or simplifying a film structure. Furthermore, since the same optical control can be performed on the first light beam direction control means, the second light beam direction control means, and the light incident on the reflecting plate at any place, the linear light source and the like An illumination device that can be manufactured with high productivity and that can immediately respond to changes in the display size and the number and arrangement of linear light sources is not required. Moreover, the structure which has a 1st light direction control means and a 2nd light direction control means is provided. Furthermore, an image display apparatus using the same is provided.

  Examples of the first light direction control means include a plurality of lenses disposed on an incident surface, which is a surface on which light is incident, a plurality of lenses disposed on an exit side, and a plurality of prisms. The second light direction control means includes a plurality of lenses or polyhedrons arranged on the exit surface side.

  FIG. 1 shows an example of the best mode of a lighting device provided by the present invention. An illumination device having a rectangular emission surface composed of an X direction and a Y direction perpendicular to the X direction, wherein the linear light source 1 is arranged in a Y virtual direction in one virtual plane parallel to the X direction and the Y direction. And parallel to the X direction.

  Here, the second light beam direction control means is arranged on the emission surface side of the arrayed linear light sources, and the second light beam direction control means is a bowl-shaped convex part, and the structure constituting the bowl-shaped convex part The main surface is parallel to the virtual plane on which the linear light sources 1 are arranged, and a plurality of convex portions 2 are formed on the surface on the exit surface side. It is the illuminating device which is formed in parallel with the direction and is arranged along the X direction.

  It is desirable that the reflectance of the reflector 4 arranged on the back surface in parallel with the X direction and the Y direction is 95% or more. By reflecting the light traveling from the linear light source 1 to the back surface and the light reflected by the light control member 2 and traveling toward the back surface further to the emission side, the light can be used effectively, so that the light utilization efficiency is increased. Examples of the material of the reflecting plate include metal stays such as aluminum, silver, and stainless steel, white coating, and foamed PET resin. A reflector having a high reflectance is desirable for improving the light utilization efficiency. From this viewpoint, silver, foamed PET resin, and the like are desirable. Further, it is desirable to diffuse and reflect light in order to improve the uniformity of the emitted light. From this viewpoint, foamed PET resin and the like are desirable.

Since the linear light source of the present invention is arranged so as to be sandwiched between the reflector and the light control member, about half of the light emitted from the linear light source is directed toward the light control member, and the remaining half is Head in the direction of the reflector. Of these, the light diffusely reflected by the reflecting plate toward the reflecting plate enters the light control member as diffused light. A part of the light incident on the light control member from the linear light source is totally reflected and travels toward the return reflector. The light emitted from the linear light source toward the reflection plate and the light totally reflected by the light control member and directed toward the return reflection plate are diffusely reflected by the reflection plate and enter the light control member again as diffused light. . The incident light as the diffused light is emitted as light having the same front luminance and angular distribution at all points on the emission surface of the light control member. Accordingly, the ratio G (X) min / G (X) between the minimum value G (X) min and the maximum value G (X) max of the outgoing light intensity in the front direction when the diffused light is included in the state where the reflector is disposed. max is larger than the ratio g (X) min / g (X) max when no reflected light is included. Further, by appropriately selecting the reflector, 50% or more of the light incident on the light control member becomes diffuse light.

The effect of the reflecting plate varies depending on the reflectance of the reflecting plate, the diffusion performance, and the linear light source arrangement, but the brightness unevenness eliminating effect by the reflecting plate is simply estimated below. It is assumed that 50% of the light emitted from the linear light source is diffusely reflected by the reflector and then enters the light control member. If the reflectance of the reflector is 95%, 95% of the same amount of light emitted from the linear light source toward the light control member in the front direction is reflected by the reflector from the linear light source and then diffused light The light enters the light control member and exits in the front direction. Assuming that the light emitted from the linear light source toward the light control member in the front direction is the average of g (X) max and g (X) min , (g (X) max + g (X) min ) / 2 × 0.95 is reflected by the reflector from the linear light source, enters the light control member as diffused light, and exits in the front direction. This is added to g (X) max and g (X) min , respectively, and G (X) min which is the minimum value of the light output intensity when the reflector is arranged, G (X) max which is the maximum value and When the ratio ratio G (X) min / G (X) max is obtained, it is as follows.

G (X) max = g (X) max + (g (X) max + g (X) min ) /2*0.95 (22)
G (X) min = g (X) min + (g (X) max + g (X) min ) /2×0.95 (23)
G (X) min / G (X) max = {g (X) min + (g (X) max + g (X) min ) /2×0.95} / {g (X) max + (g (X ) Max + g (X) min ) /2×0.95} (24)
In order for the ratio G (X) min / G (X) max to be 0.8 or more,
g (X) min / g (X) max ≧ 0.65 (25)
It becomes.
As described above, since the diffused light component is actually 50% or more of the incident light to the light control member,
g (X) min / g (X) max > 0.6 (26)
And it is sufficient.

  FIG. 27 is a diagram illustrating the relationship between the light output intensity in the front direction and the position of the linear light source when the linear light sources are arranged in parallel. As shown here, in an illuminating device in which a plurality of linear light sources 1 are arranged, the intensity of light emitted in the front direction (up in the drawing) is the portion directly above each linear light source 1 and the portion directly above it. And the portion directly above each of the adjacent linear light sources 1 (an oblique upper portion) is greatly different. This means that in the illuminating device of the present invention, the incident intensity in the front direction on the incident surface of the second light direction control means is greatly different between the portion directly above each linear light source 1 and the obliquely upper portion.

  FIG. 2 is a diagram showing the relationship between the position of the linear light source and the intensity of light emitted in the front direction in the illumination device of FIG. As described above, since the distribution of the intensity of light emission in the front direction is substantially constant, the luminance unevenness in the front direction is eliminated.

  FIG. 3 is a diagram showing the position of the linear light source and the distribution of the light output intensity in the front direction when the three adjacent linear light sources are arranged. If these sums are almost constant, it can be said that the luminance unevenness in the front direction has been eliminated. As shown in FIG. 2, the light intensity distribution in the front direction becomes substantially constant by the second light direction control means 2 of the present invention, so that luminance unevenness in the front direction is eliminated.

FIG. 7 shows an example of the distribution in the X direction of the intensity of light emitted in the front direction by light from any one linear light source of the illumination device of the present invention in which linear light sources are arranged with D = 30 mm. Light emitted in the front direction by light from one linear light source is in the range of X min to X max . In the case of showing gentle attenuation as shown in FIG. 7, for example, the value of X when the value of f (X) becomes 1/100 of the maximum value can be substituted. The values of f (X) for determining X min and X max are preferably the same, and if it is 1/20 or less of the maximum value, there is no problem, and 1/100 or less is more desirable. In FIG. 7, X min = −3D and X max = 3D, and f (X min ) = f (X max ) is 1/100 or less of f (X). In such a shape, since the intensity of light emission in the front direction is not strictly determined by the sum of only three adjacent ones, g (X) is not constant but g (X) near the center where X = 0. It is desirable that is slightly higher than the surrounding area.

In FIG. 8, linear light sources are arranged with D = 30 mm as in FIG. 7, and the light from any one linear light source in the illumination device of the present invention using another second light beam direction control means is used. An example of the distribution in the X direction of the light output intensity in the front direction is shown. In this example, X min = −D and X max = D. Depending on the shape of the convex portion, which is the second light direction control means, light with a certain incident angle or more does not advance to the front, and thus the light output intensity suddenly decreases at a part away from the linear light source. . In such a shape, since the intensity of light emission in the front direction is determined by the sum of only three adjacent ones, it is most desirable that g (X) is constant. At this time, light exits in the front direction in the range of X min to X max , and its distribution is f (X). When the case where X min = −3D and X max = 3D shown in FIG. 7 is compared with the case where X min = −D and X max = D shown in FIG. 8, the convexity which is the second light direction control means is compared. Since the part width is limited, the distribution of the light emission intensity in the front direction is determined by the distribution of the inclination angle Φ of the slope. As shown in FIG. 8, the convex shape has a slope angle that directs light with low energy incident in an oblique direction from a far direction to the front direction, but an angle Φ that directs light from a far direction to the front as shown in FIG. Instead, the front luminance is improved in the convex shape formed by the angle Φ in which only the light incident in the range of −D <X <D is directed to the front. Thus, reducing the width of X max to X min has the effect of increasing the ratio of light emission in the front direction by efficiently directing stronger light to the front.

On the other hand, increasing the width of X max to X min has the effect of increasing the light emission ratio in the front direction by directing the light of a distant linear light source to the front. Therefore, in order to increase the front luminance, it is desirable that the width of X max to X min be in an appropriate range. Desirable widths of X max to X min vary depending on f (X), but for example, a range of X in which the light emission intensity is ½ or more of the maximum value can be used as a guide. It is desirable to take the width of this range is large when the X max to X min relatively large, it is desirable to take small smaller. Width of the thus X max to X min can increase the front luminance in suitably determined that the.

FIG. 10 shows g (X) of the illumination device shown for f (X) in FIG. As already shown, if g (X) is constant within the range of −D / 2 ≦ X ≦ D / 2, which is one cycle of the linear light source, the luminance unevenness in the front direction is eliminated, and X min , X max is optimal, the light with high energy in the vicinity of the linear light source is directed to the front, and thus the brightness in the front direction is higher.

The arrangement order of the regions -N to N is not necessarily along the X axis. However, if this is not the case, an inflection point exists in the convex portion, which is the second light direction control means, depending on how the regions are arranged, and the convex portion with the angle Φ i that directs the incident light at the angle α i to the front. rays direction depends reach refracted or reflected on the slopes of different angle before reaching the slope parts, it may not reach the slant angle [Phi i, or reach the slope angle [Phi i an undesirable angle As a result, it becomes difficult to control the light emission direction, and the performance may be insufficient. When the -N to N regions are arranged in the order of the X-axis position coordinates, the shape of the convex portion which is usually the second light direction control means is a shape having no inflection point, and the entire convex portion is substantially convex. Shape. In the case of such a shape, the direction of the light beam usually does not change due to reflection or refraction by reaching the region on another convex part before the light reaches the region on the desired convex part. This is easy and advantageous.

Further, the width a i in the X direction of each region of the convex portion which is the second light direction control means is f (X i + T · tan β i ) · cosΦ i · cos β i / cos α i / cos (Φ i −β i ). Although the proportionality is a feature of the lighting device of the present invention, the preferred width may be slightly shifted due to the influence of the height from the bottom of the convex portion to the surface, but there is no significant influence.

  Here, FIG. 12 is a sectional view showing the arrangement of the second light direction control means 2 and the linear light source 1. In the figure, the thickness T from the incident surface 6 to the bottom of the convex portion which is the second light direction control means, the distance H from the center of the linear light source 1 to the incident surface 6 of the second light direction control means 2, and the linear light source. 1 shows the distance D between the centers of 1. The thickness T from the incident surface 6 to the bottom of the convex portion is preferably 1 mm to 3 mm. If T is small, the thickness of the second light direction control means becomes thin and the thickness of the lighting device is also thin, which is desirable. However, if it is too thin, the strength will be weak, so that the light emission direction will change and control will not be possible. Brightness unevenness occurs. In addition, the mechanical strength is weakened and there is a possibility of breakage. On the other hand, if the thickness is too large, the thickness of the lighting device is increased, which is not desirable because it is contrary to the demand for thickness reduction.

  N is preferably 2 or more. When N is large, the convex portion has a complicated shape composed of many inclinations. When the number of inclinations is large, the light emission in the front direction can be controlled efficiently and accurately, and the uniformity of the light emission intensity distribution in the front direction is high. In terms of accuracy, N should be large, but if it is too large, the shape becomes complicated and it becomes difficult to produce. From the viewpoint of ease of creation, N is preferably 100 or less, and more preferably 10 or less.

  You may approximate the shape of at least 1 set of adjacent area | regions among the area | regions which form the convex part which is a 2nd light direction control means with a curve. Further, the shape of two or more adjacent regions may be approximated by a curve. Further, the shape of three or more adjacent regions may be approximated by a curve, and the shape of the entire convex portion may be approximated by a curve. FIG. 11 is a diagram showing an example of the cross-sectional shape in the X direction of the second light direction control means when the shape of the entire region of the convex portion is approximated by a curve. Approximating the shape of many areas with a curve approximates the shape of adjacent areas such as smoothing out the light intensity distribution and light angle distribution in the front direction, easy to shape, and difficult to break. This is more effective and desirable. The approximation method to the curve is not particularly limited, and a generally well-known least square method, spline interpolation method, Lagrange interpolation method, or the like can be used. As the points used for approximation, at least one point is selected from the approximated region. Usually more than the number of approximated areas. For example, it is possible to select both ends of a plurality of continuous regions and contact points of each region. In addition, the midpoint of each region can be used for approximation.

  As shown in FIG. 12, in the illuminating device of the present invention, the linear light sources are arranged in the same plane at a distance D parallel to the Y direction, and the incident surface of the second light direction control means is arranged at a position separated by H. ing. Here, a smaller D is desirable because the distribution of the intensity of light emission in the front direction is constant. However, if D is too small, the number of linear light sources increases and energy consumption increases when the screen size is the same. A desirable range of D is 10 mm to 100 mm, and a more desirable range is 15 mm to 50 mm. Further, it is desirable that H is large because the distribution of the light emission intensity in the front direction is constant. However, if H is too large, the thickness is increased, which is not desirable because it is contrary to the thinning required for the lighting device. A desirable range of H is 5 mm to 50 mm, and a more desirable range is 10 mm to 30 mm. Further, the ratio D / H is preferably 0.5 to 3 and more preferably 1 to 2 in view of the balance between D and H.

  As for the height of the convex part which is a 2nd light direction control means, 1 micrometer-500 micrometers are desirable. If it is larger than 500 μm, when the exit surface is observed, the convex portion which is the second light direction control means is easily confirmed, so that the quality is lowered. On the other hand, if 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 device element, the width P of the convex portion in the X direction is 1/100 to 1 / 1.5 of the pixel pitch of the liquid crystal. It is desirable. If it is larger than this, moire occurs with the liquid crystal panel, and the image quality is greatly reduced.

  Although there is no restriction | limiting in shaping | molding the shape to the convex part which is a 2nd light direction control means, Extrusion molding, injection molding, 2P shaping | molding using an ultraviolet curable resin, etc. are mention | raise | lifted. 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, although the convex part which is a 2nd light direction control means is normally 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. In addition, since the light directly above the linear light source is emitted in the front direction, it is effective 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 the light can be controlled by the inclination angle of the slope of the convex part, so that the light intensity distribution in the front direction becomes uniform.

  Moreover, it is desirable that the convex portions as the second light direction control means have the same 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 manufacture the lighting device with high productivity. be able to.

  Further, when the second light beam direction control means is on the plate-shaped member and the second light beam direction control means is a convex portion formed on the exit surface, the plate-shaped member may be made of the same material as the second light beam direction control means. Any material that is usually used as a base material for optical materials can be desirably used, and a translucent thermoplastic resin is usually used. For example, methacrylic resin, polystyrene resin, polycarbonate resin, cycloolefin resin, methacryl-styrene copolymer resin, cycloolefin-alkene copolymer resin and the like can be mentioned.

  The second light direction control means of the present invention can be made using a plurality of different materials as required. For example, after forming the convex part which is a 2nd light direction control means on a film, a support plate can be match | combined with the film surface in which the convex part is not formed, and it can also be set as a light expansion control member. For example, in the case of using an ultraviolet curable resin for forming the convex portion, it is possible to reduce the amount of the expensive ultraviolet curable resin used by using a general-purpose translucent resin other than the vicinity of the convex portion.

Further, by providing the light diffusing means, it is possible to further improve the uniformity of luminance.
As the light diffusing means, a method of providing random irregularities such as embossing or embossing on the main surface of the plate member, a method of dispersing a small amount of light diffusing material inside the structure, a diffusion sheet on the incident side of the light control member and / or Or the method of providing in the output side, or the method of combining these is mentioned. The formation of random irregularities can be realized by applying a solution in which fine particles are dispersed to the main surface or transferring from a mold having irregularities. These are preferably provided on the exit surface side rather than the light source side, and can be provided on the light source side and / or the exit surface side of the light control member. As for the degree of unevenness, the arithmetic average roughness Ra is desirably 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 to some extent near the front due to refraction at the incident surface when entering the light control member. As a result, the light emission ratio in the front direction is increased. 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 by an unevenness | corrugation similarly may be reduced by being refracted by an uneven surface. It can be adjusted to a range desired for the intended use from the balance between the obtained diffusibility and luminance unevenness eliminating effect and front luminance.

  When the light diffusing material is dispersed inside the structure, the concentration of the light diffusing material can be kept relatively low. Thereby, it is possible to suppress a decrease in transmittance and front luminance. Although the suitable concentration of the light diffusing material varies depending on the material, transmittance and haze can be used as a guide. It is desirable to use at a concentration such that the transmittance is 80% or more and the haze is 50% or less. For example, the MS polymer having a thickness of 2 mm contains 0.04 Wt% of siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicone Co., Ltd., number average particle diameter 2 μm, CV value 3%) as a light diffusing material. A molded plate or the like can be used.

  When the light diffusion means is in a plate-like member and the first light direction control means and the second light direction control means are in a plate-like structure, they may be the same plate.

  In the case of applying the light diffusing material, it is more preferable to apply it on the exit surface side. As the light diffusing material, inorganic fine particles and cross-linked organic fine particles conventionally used for light diffusing plates and diffusion sheets can be used. The amount used is very small compared to a conventional general light diffusion plate, and a diffusibility equal to or higher than that can be obtained, and the transmittance is also very high.

When using a support plate, there is no problem even if the base material portion of the second light direction control means and the members arranged on the linear light source side of the second light direction control means are a plurality of types of plates having different refractive indexes. . In this case, a i can be obtained by deriving an expression corresponding to Expression (7) in accordance with the idea described so far. However, when the variation of the respective refractive indexes is within 90%, the refractive index n 2 can be approximated according to the ratio of the respective plate thicknesses to derive the equation (7). For example, the members disposed on the base material portion and the linear light source side have three refractive indexes of n ′, n ″, n ′ ″ and plate thicknesses of T ′, T ″, T ′ ″, respectively. In the case of a plate, n 2 can be approximated by a value of (n ′ · T ′ + n ″ · T ″ + n ′ ″ · T ′ ″) / T.

  Further, when light diffusing materials having different refractive indexes are dispersed, the amount of the light diffusing material used is extremely small in the present invention, and therefore the influence of the refractive index need not be considered.

  Further, the first light beam direction control means is arranged on the emission surface side of the arranged linear light sources, and the main surface of the structure constituting the first light beam direction control means is the virtual light source in which the linear light sources 1 are arranged. A plurality of convex portions are formed on the surface on the exit surface side or the surface side on which light is incident, and the convex portions have a bowl-shaped ridge line corresponding to the top portion formed in parallel with the X direction; and , Arranged along the Y direction.

  The reflection plate 4 arranged on the back surface reflects the light directed from the linear light source 1 to the back surface, the light reflected by the first light beam direction control unit and the second light beam direction control unit, and further reflected toward the back surface to the emission side. Since light can be used effectively, light utilization efficiency is increased.

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

  FIG. 15 shows a configuration example in which the second light direction control means is in a plate-like structure and the first light direction control means is composed of a plurality of hook-shaped convex portions parallel to the X axis of the surface on the exit surface side. . In this case, the second light beam direction control means is disposed closer to the light source than the first light beam direction control means. In the present configuration, the first light direction control means may be formed on a plate or a film.

  Further, in FIG. 17, the first light direction control means is provided in the plate-like structure, and the first light direction control means is composed of a plurality of hook-shaped protrusions parallel to the X axis of the surface on the exit surface side of the plate-like structure. An example of the configuration is shown. In this case, the plate-like structure is disposed closer to the observation side than the first light beam direction control means. In this configuration, the second light direction control means may be formed on a plate or a film.

  In FIG. 19, the first light beam direction control means is in the plate-like structure, and the first light beam direction control means is a plurality of hook-shaped protrusions parallel to the X axis of the surface on which the light of the plate-like structure is incident. A configuration example in the case of consisting of: In this case, the plate-like structure is disposed closer to the light source than the first light beam direction control means. In this configuration, the second light direction control means may be formed on a plate or film.

  In FIG. 21, the second light beam direction control means is in the plate-like structure, and the first light beam direction control means is a plurality of hook-shaped protrusions parallel to the X axis of the surface on which the light of the plate-like structure is incident. A configuration example in the case of consisting of: In this case, the plate-like structure is disposed closer to the light source than the first light beam direction control means. In this configuration, the first light direction control means may be formed on a plate or film.

  As for the height of the convex part of a 1st light direction control means, 1 micrometer-500 micrometers are desirable. When the thickness is larger than 500 μm, the convex portion is easily confirmed when the emission surface is observed, and the quality is deteriorated. On the other hand, if 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 device element, the width of the convex portion in the Y direction is 1/100 to 1 / 1.5 of the Y direction pixel pitch of the liquid crystal. It is desirable to be. If it is larger than this, moire occurs with the liquid crystal panel, and the image quality is greatly reduced.

When the first light direction control means and the second light direction control means are convex portions, the first light direction control means and the second light direction control means can be desirably used as long as they are materials that are usually used as optical materials. Usually, a translucent thermoplastic resin is used. For example, methacrylic resin, polystyrene resin, polycarbonate resin, cycloolefin resin, methacryl-styrene copolymer resin, cycloolefin-alkene copolymer resin and the like can be mentioned. It is also possible to 2P molding the first light beam direction control means to the film or sheet as a base material by an ultraviolet curable resin (P hoto P olymerization Process).

  Furthermore, when the first light direction control means or the second light direction control means is a convex part and the structure having the convex part is plate-like, the surface area and light of the surface on which the light of the plate-like structure is incident are reduced. The surface area of the outgoing surface is different. When the plate-like structure expands due to water absorption or the plate-like structure shrinks due to dehydration, the expansion rate or contraction rate of the light incident surface and the light emission surface differs due to the difference in surface area, and the plate structure Warping occurs. The warpage can be reduced when the plate-like structure is made of a transparent thermoplastic resin having a water absorption rate of 0.5% or less in an atmosphere of a temperature of 60 ° C. and a humidity of 80%. If the water absorption rate exceeds 0.5% under the same conditions, the amount of warpage becomes excessive and the appearance quality is degraded.

  Also, a hook-shaped convex portion, which is the first light beam direction control means, is formed on the surface on which the light of the plate-like structure is incident, and a hook-shape, which is the second light beam direction control means, is formed on the surface from which the light of the same plate-like structure is emitted When a convex part is formed, the surface area difference between the surface where light enters and the surface where light exits is small, which is advantageous for warping. In addition, when the direction formed by the ridge-up convex portion that is the first light beam direction control means and the direction formed by the heel-up convex portion that is the second light beam direction control means are orthogonal to the warp to increase the rigidity of the plate-like structure. More advantageous.

  As shown in FIG. 22, when the first light beam direction control means is a convex portion formed on the surface on which the light of the plate-like structure is incident, it is preferably in the same structure as the second light beam direction control means. . Compared with the case where the first light direction control means and the second light direction control means are separated, two interfaces with air can be eliminated, and the efficiency of emitted light can be improved.

  When the first light direction control means and the second light direction control means are in the same plate-like structure, first, a plate-like structure in which the first light direction control means or the second light direction control means was formed was produced. Thereafter, the first light direction control means or the second light direction control means can be formed on the opposite surface by 2P molding or the like.

  Furthermore, it is also possible to prepare a female mold of the first light direction control means and a female mold of the second light direction control means and mold them simultaneously by injection molding or the like.

  FIG. 23 shows an example in which the first light direction control means and the second light direction control means are convex portions formed on the surface from which the light of the same plate-like structure is emitted. The first light ray direction control means is a portion in which the normal direction of the surface of the convex portion is perpendicular to the X direction and not perpendicular to the Y direction, and controls the direction of the light ray in the Y direction. The second light direction control means is a portion in which the normal direction of the surface of the convex portion is perpendicular to the Y direction and not perpendicular to the X direction, and controls the direction of the light in the X direction. In the case of such a configuration, first, a female die having both the first light direction control means and the second light direction control means is prepared, and then formed by 2P molding or the like on the surface of the plate member. Can do.

  Furthermore, it is possible to prepare a female mold and mold it by injection molding or the like. The shape of the cross section perpendicular to the Y coordinate of the second light beam direction control means shown in FIG. 23 differs depending on the Y coordinate. Since the principle of eliminating the lamp image in the front direction depends on the ratio of the inclination of the second light direction control means, the average inclination distribution obtained by averaging the inclination distributions of the cross-sectional shapes may be a desired inclination distribution. Desirable inclination distribution means that the second light direction control means is the same as the case where the second light direction control means is not on the same plane as the first light direction control means. For example, the shape shown in claims 2 and 6 is desirable.

  A light diffusing sheet having a light diffusing function may be provided on the exit surface side of the second light direction control means. A more uniform front luminance distribution can be obtained by diffusion using the light diffusion sheet.

  As shown in FIG. 18, it is preferable that a plurality of substantially hemispherical minute irregularities are formed on the surface of the first light beam direction control means, and are arranged closer to the exit surface than the second light beam direction control means. As described above, the light incident in the oblique direction with respect to the second light direction control means emits light in the front direction from a part of the convex portion of the second light direction control means. That is, when the convex portion of the second light direction control means is observed in detail, fine light and darkness parallel to the X direction is generated. The fine brightness and darkness can be eliminated by dispersing the angular distribution in the Y direction by the minute unevenness. Further, it is desirable that the minute irregularities are randomly arranged. When an LCD panel or the like is provided on the light emitting surface, the moire caused by the interference between the pixels having periodicity and the arrangement period of the convex portions of the second light direction control means should be reduced by the scattering effect due to the randomly arranged micro unevenness. Can do.

  The fine irregularities are formed by forming a convex portion of the first light direction control means, applying a solution in which fine particles are dispersed by spraying, or preparing a roll-shaped female mold and extruding a resin in which fine particles are dispersed, It can be obtained by preparing a flat female mold and performing 2P molding using an ultraviolet curable resin in which fine particles are dispersed.

  In this case, the difference between the refractive index of the fine particles and the refractive index of the first light beam direction control means convex portion Z is preferably 0.1 or less. Furthermore, it is more preferable that it is 0.05 or less. This is because if it exceeds 0.1, the light condensing function is lowered due to the scattering action due to the difference in refractive index.

  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 element includes a transmissive liquid crystal panel, An image display device having excellent luminance uniformity on the display surface can be obtained.

The form of the Example of this invention is shown below.
The configuration of the illumination device of the present embodiment is shown by the schematic diagram of FIG.
First, a Y direction length 458 mm, an X direction length 730 mm, a thickness direction length 35 mm perpendicular to the Y direction and the X direction, a Y direction length 698 mm, and an X direction length (not shown) A rectangular parallelepiped white ABS resin housing having a rectangular opening of 416 mm is prepared.
Next, the reflection plate 4 made of foamed PET resin and having a reflectance of 95% is disposed so as to cover the bottom portion at a position facing the opening on the emission side of the housing.

  Next, a linear light source is arranged in parallel with the reflecting plate with an interval of 2 mm on the exit side of the reflecting plate. As the linear light source 1, a plurality of cold cathode tubes having a diameter of 3 mm and a length of 700 mm are arranged with the longitudinal direction parallel to the Y direction and arranged along the X direction. In Examples other than Example 9 and Comparative Examples, 16 cold cathode fluorescent lamps are arranged at intervals of 22 mm. In Example 9, twelve cold cathode tubes are arranged at intervals of 30 mm.

  Next, the second light direction control means 2 is arranged so as to cover the opening. The second light direction control means is parallel to the reflecting plate 4 with an interval of 14 mm on the emission side of the linear light source 1. The second light direction control means has a length of 707 mm in the X direction and a length of 436 mm in the Y direction, and a thickness not including the height of the convex portion in the thickness direction perpendicular to the Y direction and the X direction is 2 mm. is there.

  H from the center of the linear light source 1 to the second light beam direction control means 2 is 15.5 mm, and the distance D between the centers of the adjacent linear light sources 1 is in Examples and Comparative Examples except Example 9 and Comparative Example 3. 25 mm, 33 mm in Example 9 and Comparative Example 3.

  The 2nd light direction control means of Examples 1-3, 5-13, and 15 was produced in the following procedures. The bowl-shaped convex part 2 formed on the emission surface is formed by using a mold in which groove-shaped concave parts having a width of 0.3 mm are continuously formed in parallel by cutting. An ultraviolet curable resin having a refractive index of 1.55 was applied to the cutting surface of the mold, and a methyl methacrylate-styrene copolymer having a refractive index of 1.549 and a length of 436 mm, a width of 707 mm, and a thickness of 0.1 mm were formed thereon. The transparent resin film (except for Example 15) was stacked, and the ultraviolet curable resin was cured by irradiating the transparent resin film with ultraviolet rays.

  Moreover, the 1st light direction control means of Examples 1-3, 5-13, and 15 was produced in the following procedures. The first light direction control means 3 is formed by using a mold in which groove-shaped concave portions having a width of 0.1 mm are continuously formed in parallel by cutting. An ultraviolet curable resin having a refractive index of 1.55 was applied to the cutting surface of the mold, and a methyl methacrylate-styrene copolymer having a refractive index of 1.549 and a length of 436 mm, a width of 707 mm, and a thickness of 0.1 mm were formed thereon. The transparent resin film was stacked, and the ultraviolet curable resin was cured by irradiating the transparent resin film with ultraviolet rays.

  In the case of a plate-like structure, a film in which the first light beam direction control means is formed on the surface of a resin plate having a thickness of 2 mm on one side or a film in which the second light beam direction control means is formed is provided on the surface of the resin plate. It was obtained by optically adhering both the film on one side or the film on which the first light direction control means was formed and the film on which the second light direction control means was formed. In addition to Example 15, a transparent acrylic plate was used.

  Example 15 uses 0.04 Wt of siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicone Co., Ltd., number average particle diameter 2 μm, CV value 3%) as fine particles of the light diffusing material instead of the transparent resin plate. The member which has a 1st light direction control means is produced using the shaping | molding board containing%.

The molded plate containing the light diffusing material is produced as follows.
In the other examples, the same methyl methacrylate-styrene copolymer resin pellets as the material of the transparent resin plate used for the production of the light control member, the light diffusing material, and 2- (5-methyl-) which is a purple ray absorbent 2hydroxyphenyl) benzotriazole (0.1% by mass) is mixed with a Henschel mixer and then melt-kneaded using an extruder to produce a molded plate having a width of 1000 mm and a thickness of 2 mm at an extrusion resin temperature of 200 ° C. By cutting this, it is set to 436 mm long and 707 mm wide.

  The first light direction control means and the second light direction control means of Example 4 and Example 14 were produced by the following procedure. First, a groove-shaped recess having a width of 0.1 mm is continuously formed in parallel by cutting a female mold in which the first light direction control means is reversed. A female mold having the second light beam direction control means inverted in a direction perpendicular to this is continuously formed by cutting to form a 0.3 mm groove-shaped recess. An ultraviolet curable resin having a refractive index of 1.55 was applied to the cutting surface of the mold, and a methyl methacrylate-styrene copolymer having a refractive index of 1.549 and a length of 436 mm, a width of 707 mm, and a thickness of 0.1 mm were formed thereon. The transparent resin film was stacked, and the ultraviolet curable resin was cured by irradiating the transparent resin film with ultraviolet rays. Thereafter, the film on which the first light beam direction control means and the second light beam direction control means were formed was optically adhered to the surface of a transparent acrylic plate having a thickness of 2 mm via an adhesive.

The shape of the grooves of the mold shown in also Table 1 the regions -N~N with N, f (X), Y min, Y max, thus determined is the gradient Φ and X direction width a shown in Table 1 It is produced so as to be arranged according to the order of the regions.

  In Examples 1 to 13, the entire region of each convex portion is approximated to a curve by the least square method. The points at both ends of all line segments are taken to approximate the vertices of at least two adjacent line segments.

(Comparative example)
As Comparative Examples 1 to 4, the results of arranging the light control member having only the second light direction control means are shown in Table 1. As a result of observation from the front direction, the luminance in the front direction decreases.

  As Comparative Example 5, a prism sheet in which a prismatic prism having an apex angle of 90 ° is formed on the exit surface is arranged so that the prism is parallel to the linear light source. As a result of observing from the front direction, the luminance is greatly reduced in the portion directly above the linear light source, and the in-plane luminance unevenness is increased.

  Table 1 shows the configuration of each example and each comparative example and the results of luminance measurement.

  24 and 25 show the principle of light control of the sheet. As shown in FIG. 24, all the light 7 incident on the incident surface of the prism sheet 11 from the normal direction is totally reflected and returns to the light source side as reflected light 10, so that the total light transmittance in this region is 0 in principle. Yes, the measured value is very low at 5%. On the other hand, as shown in FIG. 25, the light 7 incident from an oblique direction is refracted by the convex portion and travels to the vicinity of the front surface, and thus exhibits a high total light transmittance. In the implemented configuration, it was 90%. In this example, luminance unevenness is not eliminated.

  In addition, a transmissive liquid crystal panel is mounted on the exit side of the illumination device to form an image display device, which is observed from the front. As a result, luminance unevenness is remarkable in the obtained image.

  As Comparative Example 6, an evaluation is carried out when a light diffusion plate containing ordinary fine particles is used in place of the light control member. In this case, the luminance in the front direction decreases. In addition, a transmissive liquid crystal panel is mounted on the exit side of the illumination device to form an image display device, which is observed from the front. As a result, it can be seen that the obtained image is considerably darker than the case of using the illumination device of Example 1.

  In addition, after producing the female mold having the unevenness of the exit surface and the unevenness of the entrance surface of Example 3, a material having a water absorption rate of 0.4% and a material having 2% in an atmosphere at a temperature of 60 ° C. and a humidity of 80%. A plate-like structure having a thickness of 2 mm shown in FIG. 22 was produced by injection molding. As a result of leaving two plate-like structures in an atmosphere of 45 ° temperature and 90% humidity, the amount of warpage of a plate-like structure made of a material having a water absorption rate of 2% is 1.9 mm. The amount of warpage of the plate-like structure made of a material having a rate of 0.4% was 0.8 mm. Here, the amount of warpage is the maximum height from the flat plate of the surface facing the flat plate when the object to be measured is placed on the flat plate.

It is the schematic of the suitable example of the illuminating device of this invention. It is a figure which shows the relationship between the position of a linear light source, and the emitted light intensity to a front direction of the illuminating device of FIG. It is a figure which shows distribution of the light emission intensity | strength to the position of each linear light source, and each front direction when arrange | positioning three adjacent linear light sources. The incident angle alpha i of the light from the linear light source is a diagram showing the relationship between the X-direction of the width a i angle [Phi i and region i of slope of the slope of the area i of the convex portion. It is a figure explaining the relationship between the incident angle to a light control member, and incident intensity. It is a figure which shows the principle which directs light to the front with the illuminating device of this invention. It is a figure which shows one example of distribution of the X direction of the emitted light intensity to the front direction by the light from one linear light source. It is a figure which shows one example different from FIG. 7 of the distribution of the X direction of the emitted light intensity to the front direction by the light from one linear light source. It is a figure which shows f (X) of the illuminating device shown in FIG. 7, and g (X) corresponding to it. It is a figure which shows f (X) of the illuminating device shown in FIG. 8, and g (X) corresponding to it. It is a figure which shows the example of the cross-sectional shape of the X direction of the light control member at the time of approximating the shape of the whole area | region of a convex part with a curve. It is the figure which showed arrangement | positioning of the light control member and linear light source which can be used for this invention. It is a figure which shows the ratio of the light which goes to the area | region i among the lights which go to a convex part with angle (alpha) i . Is a diagram showing an angle anticipating the linear light source in the coordinate X i. It is a block diagram at the time of arrange | positioning the structure which has arrange | positioned the 2nd light direction control means to the output surface side at the output surface side of a 2nd light direction control means. It is a figure which shows the principle of the condensing effect | action when the 1st light beam direction control means is arrange | positioned at the output surface side. It is a block diagram at the time of arrange | positioning the plate-shaped structure which has arrange | positioned the 2nd light beam direction control means to the output surface side at the entrance plane side of a 1st light beam direction control means. It is a block diagram at the time of arrange | positioning the 2nd light beam direction control means to the output surface side, and arrange | positioning the structure in which the 2nd light beam direction control means surface has a random unevenness | corrugation to the output surface side of a 2nd light beam direction control means. . It is a block diagram at the time of arrange | positioning the plate-shaped structure which has arrange | positioned the 2nd light beam direction control means to the entrance plane side at the entrance plane side of the 2nd beam direction control means. It is a figure which shows the principle of the condensing effect | action when the 1st light beam direction control means is arrange | positioned at the entrance plane side. It is a block diagram at the time of arrange | positioning the structure which has arrange | positioned the 2nd light beam direction control means to the incident surface side at the output surface side of a 2nd light beam direction control means. It is a block diagram at the time of forming the 1st light beam direction control means and the 2nd light beam direction control means in the entrance plane and exit surface of the same plate-shaped structure, respectively. It is a block diagram at the time of forming a 1st light beam direction control means and a 2nd light beam direction control means in the output surface of the same plate-shaped structure. It is a figure which shows a mode that the light progresses when the light of a linear light source injects perpendicularly on the smooth surface of the prism sheet of the comparative example 4. It is a figure which shows a mode that the light advances when the light of a linear light source injects into the smooth surface of the prism sheet of the comparative example 4 from the diagonal direction. It is the schematic of the conventional illuminating device of a direct system. It is a figure which shows distribution of the emitted light intensity to the front direction from the linear light source arranged in parallel.

Explanation of symbols

1: linear light source, 2: second light beam direction control means, 3: first light beam direction control means, 4: reflector, 5: light diffusion plate, 6: incident surface 7: incident light, 8: outgoing light, 9 : Light passing through the plate-like structure, 10: reflected light 11: prism sheet

D: Distance between the centers of adjacent linear light sources H: Distance between the center of the linear light sources and the incident surface of the light control member f (X): Arrangement direction X of the linear light sources and any one of the illumination devices Function of distribution of light from linear light source and intensity of light emitted from convex part of light control member in front direction N: natural number n: refractive index n 2 of convex part of light control member: base material of light control member the refractive index of X max: positive direction of the X-coordinate at which f (X) is 0 X min: f the negative direction when (X) is 0 X-coordinate g (X): f (X -D) + F (X) + f (X + D)
Function g (X) min : Xmin ~ of the distribution between the arrangement direction X of the linear light sources and the intensity of the light emitted from the adjacent three linear light sources in the front direction emitted from the convex portion of the light control member minimum value g (X) max of g (X) between the X max: maximum value of X min to X max between the g (X) δ: δ = satisfy (X max -X min) / ( 2N + 1) Micro section Φ i : slope slope X i of the convex area i with respect to the exit surface X i : center value X i of each element when X min to X max are equally divided by (2N + 1) a i : convex area i width X in the X direction: thickness from the incident surface of the light control member to the bottom of the convex portion α i : incident from a linear light source in a cross section parallel to the normal direction of the X direction and the main surface of the light control member angle of the light incident on the surface is emitted from the area i through the interior light control member, the ray direction from the linear light source forms with respect to the normal line of the incident surface beta i: the main surface of the X direction and the light control member In the cross section parallel to the normal direction, the light ray direction inside the convex portion of the light control member of the light incident on the incident surface from the linear light source and exiting from the region i through the light control member is represented by the incident surface. The angle γ i formed with respect to the normal line of the region: the region i that enters the incident surface from the linear light source and passes through the light control member in a cross section parallel to the X direction and the normal direction of the main surface of the light control member The angle b i of the light emitted from the inside of the base material of the light control member with respect to the normal of the incident surface is in the cross section parallel to the X direction and the normal direction of the main surface of the light control member in the length of the slope areas i e i: in the X direction and the light control member in the cross section parallel to the normal direction of the principal surface, through the inside the light control member and incident on the incident surface from the normal direction source Projection length ξ i of light emitted from region i in a direction perpendicular to the direction of the light beam inside the light control member ξ i : Angle θ formed by the angle of the slope of the region i in the cross section parallel to the normal direction of the X direction and the main surface of the light control member with respect to the angle perpendicular to the light ray direction inside the convex portion of the light control member : From the linear light source, the light that enters the incident surface from the linear light source and exits from the exit surface through the inside of the light control member in a cross section parallel to the X direction and the normal direction of the main surface of the light control member The incident angle Δθ formed with respect to the normal of the incident surface is a minute range centered on the light of the incident angle θ in the cross section parallel to the X direction and the normal direction of the main surface of the light control member. Angle H ′ formed with the center of the linear light source: a light control member through which light emitted from the linear light source at an angle (θ−Δθ) passes in a cross section parallel to the X direction and the normal direction of the main surface of the light control member The trajectory connecting the point on the incident surface of the light source and the center of the linear light source is projected onto the trajectory through which the light emitted from the linear light source at an angle θ passes. The length (approximately equal to the distance between the center point on the incident surface of the light control member through which light emitted by the linear light source angle θ and the linear light source)
V: in a region on the incident surface of the light control member through which light of Δθ around the incident angle θ from the linear light source passes in a cross section parallel to the X direction and the normal direction of the main surface of the light control member Length U: On the incident surface of the light control member through which light of Δθ from the linear light source passes in a cross section parallel to the X direction and the normal direction of the main surface of the light control member Projection of the line segment of the length V of the region to an angle perpendicular to the incident angle θ α: light incident on the light control member in a cross section parallel to the X direction and the normal direction of the main surface of the light control member The incident angle β with respect to the normal of the incident surface β: in the cross section parallel to the X direction and the normal direction of the main surface of the light control member, is incident on the incident surface from the linear light source and passes through the light control member. The angle γ of the light emitted from the convex portion inside the convex portion of the light control member with respect to the normal of the incident surface γ: the X direction and the optical control Light within the substrate of the light control member that is incident on the incident surface from the linear light source and exits from the convex portion through the light control member in a cross section parallel to the normal direction of the main surface of the member The angle ε with respect to the normal of the incident surface ε: The light source enters the incident surface from the linear light source in a cross section parallel to the X direction and the normal direction of the main surface of the light control member. The angle ω of the light ray direction inside the light control member passing through the convex portion with respect to the normal line of the slope of the convex portion passing through the X direction and the normal direction of the main surface of the light control member In the parallel cross section, the direction of the light ray emitted from the convex portion of the light incident on the incident surface from the linear light source and passing through the inside of the light control member is normal to the slope of the convex portion through which the light passes. an angle formed with respect to P: in the X direction and the light control member in the cross section parallel to a normal direction of a principal face, the width of the convex portion [Delta] [alpha] i: the seat Angle anticipating the diameter of the linear light source than X i

Claims (8)

  1. It has a rectangular exit surface composed of an X direction and a Y direction perpendicular to the X direction,
    An illumination device comprising a plurality of linear light sources, first light beam direction control means, second light beam direction control means, and a reflecting plate,
    The linear light sources are arranged in parallel and at equal intervals in a virtual plane parallel to the Y axis and the X axis that intersect perpendicularly.
    And arranged along the X-axis parallel to the Y-axis,
    The reflecting plate is disposed in parallel to the X direction and the Y direction on the side facing the light emitting surface with respect to the linear light source,
    The first light direction control means and the second light direction control means are closer to the exit surface than the virtual plane on which the linear light source is arranged.
    The light from the light source is arranged to be received by both the first light direction control means and the second light direction control means,
    The first light beam direction control means refracts the received light, condenses the dispersion in the Y-axis direction of the light, and passes it to the exit surface side,
    The second light direction control means reflects and refracts the received light to improve the position uniformity of the light in the X-axis direction and pass it to the exit surface side ,
    Before Stories second light beam direction control means is in the plate-like structure,
    The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
    The second light beam direction control means comprises a plurality of hook-shaped convex portions parallel to the Y axis of the surface on the exit surface side of the plate-like structure,
    The distance between the centers of the linear light sources is D, the distance between the center of the arbitrary linear light source and the plate-like structure having the second light beam direction control means is H, and the distance from the one linear light source to the second. F (X) is a function representing the intensity of light emitted in the normal direction of the exit surface at the position coordinate X in the X direction (the light source position is X = 0) of the light incident on the light direction control means,
    g (X) = f (X−D) + f (X) + f (X + D) (1)
    When
    In the range of −D / 2 ≦ X ≦ D / 2,
    The ratio g (X) min / g (X) max of g (X) min that is the minimum value of g (X) and g (X) max that is the maximum value is 0.6 or more,
    The minimum value X min of X is in the range of −3.0D ≦ X min ≦ −0.5D, and the maximum value X max is in the range of 0.5D ≦ X max ≦ 3.0D (where X min and X max is the attenuation at the vicinity of the linear light source where the value of f (X) is X = 0, and the coordinates of both ends when it becomes substantially 0),
    An illuminating device characterized in that a cross-sectional shape in the X direction of an arbitrary convex portion is composed of (2N + 1) different regions −N to N expressed by the following formulas (2) to (8).
    δ = (X max −X min ) / (2N + 1) (2)
    X i = i × δ (3)
    α i = Tan −1 (X i / H) (4)
    β i = Sin −1 ((1 / n) sin α i ) (5)
    γ i = Sin −1 ((1 / n 2 ) sin α i ) (6)
    a i αf (X i + T · tanγ i) · cosΦ i · cosβ i / cosα i / cos (Φ i -β i) (7)
    Φ i = Tan −1 ((n · sin β i ) / (n · cos β i −1) (8)
    However,
    N: natural number i: an integer from −N to N n: refractive index n 2 of the convex portion of the light control member: refractive index a i of the base material of the light control member: width Φ i of the region i in the X direction: Slope inclination T with respect to the exit surface: thickness from the entrance surface of the plate-like structure having the second light beam direction control means to the bottom of the convex portion
  2. The first beam direction control means is in a plate-like structure;
    The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
    The first light beam direction control means includes a plurality of hook-shaped convex portions parallel to the X axis of the surface on the light emitting side of the plate-like structure, and is perpendicular to the X axis of the convex portion and parallel to the Y axis. the lighting device according to claim 1, inclined Kino maximum value of the shape of the cross section and wherein the at least 30 ° and 60 ° or less.
  3. The first beam direction control means is in a plate-like structure;
    The plate-like structure is arranged in parallel with a virtual plane on which the linear light source is arranged;
    The first light direction control means includes a plurality of hook-shaped protrusions parallel to the X-axis of the surface on which light of the plate-like structure is incident, and is perpendicular to the X-axis and parallel to the Y-axis. the lighting device according to claim 1, inclined Kino maximum value of the shape of the cross section is equal to or less than 10 ° and not more than 40 degrees.
  4. The lighting device according to any one of claims 1 to 3, the first light beam direction control means and the second light beam direction control means and wherein the Ru same plate-shaped structure near.
  5. 2. The lighting device according to claim 1 , wherein a cross-sectional shape of the convex portion in the X direction is a shape of at least one pair of adjacent two regions among (2N + 1) different regions forming the convex portion. Is a shape approximating with a curve.
  6. The lighting device according to any one of claims 1 to 5 , wherein the plate-like structure is a transparent thermoplastic resin having a water absorption of 0.5% or less in an atmosphere at a temperature of 60 ° C and a humidity of 80%. A lighting device comprising:
  7. The structure which has a 1st light direction control means and a 2nd light direction control means with which the illuminating device of any one of Claims 1-6 is provided.
  8. The image display apparatus being characterized in that a transmission type display element provided on the exit surface side of the lighting device according to any one of claims 1-6.
JP2005293549A 2005-10-06 2005-10-06 Lighting device, light control measurement structure and image display device using them Active JP4684838B2 (en)

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JP2005293549A JP4684838B2 (en) 2005-10-06 2005-10-06 Lighting device, light control measurement structure and image display device using them
EP20060767315 EP1900996B1 (en) 2005-06-29 2006-06-26 Lighting device with light control member and image display unit using the above
KR20087002272A KR100928171B1 (en) 2005-06-29 2006-06-26 The light control member and the image display apparatus using them that are used in lighting equipment and lighting equipment
US11/994,377 US7744235B2 (en) 2005-06-29 2006-06-26 Lighting device and light control member used therefor and image display device using the lighting device and the light control member
PCT/JP2006/312698 WO2007000962A1 (en) 2005-06-29 2006-06-26 Lighting device and light control member used for this and image display unit using these
TW95123254A TWI417612B (en) 2005-06-29 2006-06-28 Lighting apparatus and image display apparatus using the same

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KR20090085099A (en) * 2006-11-15 2009-08-06 쓰리엠 이노베이티브 프로퍼티즈 컴파니 Back-lit displays with high illumination uniformity
JP5246160B2 (en) * 2007-06-29 2013-07-24 凸版印刷株式会社 Lens sheet, optical sheet for display, backlight unit using the same, and display device
US7753544B2 (en) * 2007-06-29 2010-07-13 Sumitomo Chemical Company, Limited Light control plate, surface light source device and transmissive image display device
US8848132B2 (en) * 2008-02-07 2014-09-30 3M Innovative Properties Company Hollow backlight with structured films
KR101506498B1 (en) * 2008-12-15 2015-03-30 엘지디스플레이 주식회사 Backlight unit for liquid crystal display device

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JP2002040564A (en) * 2000-07-25 2002-02-06 Toppan Printing Co Ltd Transmission-type screen
JP2007041172A (en) * 2005-08-02 2007-02-15 Dainippon Printing Co Ltd Light control sheet and surface light source device

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Publication number Priority date Publication date Assignee Title
JP2002040564A (en) * 2000-07-25 2002-02-06 Toppan Printing Co Ltd Transmission-type screen
JP2007041172A (en) * 2005-08-02 2007-02-15 Dainippon Printing Co Ltd Light control sheet and surface light source device

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