JP2013068855A - Optical path control filter and image display unit including the same - Google Patents

Abstract

An optical path control filter that prevents moiré due to interference with a pixel array of a display panel and a display device using the same are provided.
An optical path control filter 10 includes an optical path control layer 1 in which light absorbing portions 1a and light transmitting portions 1b are alternately arranged in a stripe shape. A light shielding pattern 1P when the light absorbing portion 1a is viewed from above is generated from the seed pattern 2P, and this seed pattern extends between the two branch points B and becomes a source of a transmission region corresponding to the light transmission portion. An average value N of the number of boundary line segments formed from a large number of boundary line segments L that define the open region A as a closed region and extending from one branch point is 3.0 ≦ N <4.0. The area and the shape of the opening region having the same number of boundary line segments surrounding the region include regions where the number and the shape are not constant. A parallelogram generation amount region is defined in this seed pattern, and a boundary line segment connecting the right and left sides from the shortest distance is extracted as a connecting line segment Lc in order from the top to obtain a light shielding pattern.
[Selection] Figure 1

Description

  The present invention relates to an optical path control filter that controls the path of light as an optical filter that is preferably applied to a display panel, and an image display apparatus including the same. In particular, the present invention relates to an optical path control filter that does not cause moire (striped pattern) due to interference with the pixel array period of the display panel when combined with a display panel, and an image display apparatus including the same.

In recent years, various image display devices using various display panels, such as televisions, electronic signboards, and multifunctional portable information terminals, have been put into practical use. Further, an optical path control filter for appropriately diffusing or condensing the traveling direction of light is incorporated on the observer side of the display panel in order to effectively deliver the image light of the display panel to the observer ( Patent Document 1).
The optical path control filter appropriately diffuses and condenses image light and absorbs unnecessary external light to improve the front brightness and the viewing angle control function to appropriately expand or converge the viewing angle. Etc. have an optical path control function.

  In such an optical path control filter, a large number of columnar light absorbing parts that absorb unnecessary light are arranged in a stripe or lattice form at regular intervals along the layer surface, and light that transmits necessary light between the light absorbing parts. An optical path control layer having a structure provided with a transmission part is provided.

By the way, in the conventional optical path control filter, since the light absorption parts are arranged at a constant repetition period, when the image display device is combined with the display panel, the arrangement period of the pixels constituting the display panel Moire (striped pattern) may occur due to interference.
Therefore, as disclosed in Patent Document 1, it is known to provide a bias angle by inclining the arrangement direction of the light absorbing portions extending linearly or wavely with respect to the arrangement direction of the pixels constituting the display panel. The method of providing a bias angle for preventing such moire is not limited to the optical path control filter, and in the display-related case, the electromagnetic mesh filter for the front surface of the plasma display panel also has an opening portion of the conductor mesh as in Patent Document 2. It is known to provide a bias angle in the arrangement direction.

JP 2006-313360 A JP 61-200783 A

  However, in order to prevent moiré, the bias angle setting method is such that the optimal bias angle to be set is the pixel size of the display panel, the inter-pixel size, the pixel arrangement period, the size of the light absorbing portion in the optical path control filter, and the light. All of the dimensions between the absorption parts and the arrangement period of the light absorption parts are related. For this reason, each screen size of the display panel to be combined is designed, and a large number of optical path control filters are required, resulting in a decrease in product yield. In addition, since it cannot be manufactured as a general-purpose product, the production efficiency is poor, which hinders cost reduction.

As a certain improvement measure for this point, the bias angle is not determined for each product during the manufacturing process, and as shown in FIG. 14, the extending direction of the light absorbing portion 41 is a continuous belt shape (web shape) and the flow direction is the flow direction. A sheet-like optical path control filter 40 is cut out obliquely with respect to the flow direction MD according to a required bias angle θ from an intermediate product 40w parallel to MD (the arrangement direction having a repetition period is parallel to the width direction TD). There is also a method.
However, this method has a problem that there are many useless portions 42 as can be seen from FIG.

  That is, an object of the present invention is to provide an optical path control filter capable of preventing moire even without providing a bias angle, and an image display device including the same.

Therefore, in the present invention, an optical path control filter and an image display device having the following configuration are provided.
(1) Optical path control provided with an optical path control layer having a columnar light absorbing portion arranged in a plurality of stripes spaced apart from each other along the filter surface, and a light transmitting portion between the light absorbing portions. A filter,
A light-shielding pattern having a planar view shape when the light absorbing portion is viewed from the normal direction of the filter surface and having the light transmitting portion as a transmission region is generated from a seed pattern,
This kind of pattern is
An average value N of the number of boundary lines extending from one branch point is formed from a number of boundary lines extending between two branch points and defining an opening region that is the base of the transmission region as a closed region. 3.0 ≦ N <4.0, and a pattern including a region where the area and shape of the opening region having the same number of boundary line segments surrounding the periphery are not constant,
The shading pattern is
For the seed pattern, a parallelogram whose opposing opposite sides are parallel to each other is defined as a generation region for generating the light-shielding pattern, and a first direction parallel to any side of the parallelogram with respect to the generation region And a second direction parallel to the side intersecting with the arbitrary side,
A light shielding pattern extending globally in the first direction,
In order from one end to the other end of the generation region in the second direction, the boundary line segment starts from an intersection with one of two sides parallel to the second direction of the generation region. And set the intersection with the other side as the end point,
In order from the one end to the other end in the second direction, a boundary line segment connecting the start point and the end point with the shortest distance is selected as a connection line segment, and the boundary line deviated from the connection line segment By erasing the minutes and connecting the opening regions facing each other across the boundary line segment to form the transmission region extending in the first direction,
It is generated as a light-shielding pattern consisting of connecting line segments corresponding to the light absorption part,
Optical path control filter.
(2) The optical path control filter according to (1), wherein a transparent base material is laminated on the optical path control layer.
(3) An image display device comprising a display panel and the optical path control filter of (1) or (2).

  According to the present invention, the line segment of the light shielding pattern included in the optical path control layer that controls the path of the light beam is a line segment that is not a straight line but a random shape, and there is no periodicity in the arrangement of the line segment. Even without setting the bias angle, the occurrence of moire can be prevented very effectively.

The top view (A) which shows the light shielding pattern in one Embodiment of the optical path control filter of this invention, sectional drawing (B) of an optical path control filter, and the top view (C) which shows the seed pattern of a light shielding pattern. Sectional drawing which shows another one Embodiment (with a transparent base material) of the optical path control filter by this invention. The top view which shows an example of a seed pattern. The top view explaining that the direction which has periodicity does not exist in arrangement | positioning of the opening area | region defined by a seed pattern. The figure which shows the method of determining a generating point in the method of designing a seed pattern. The figure which shows the method of determining a generating point in the method of designing a seed pattern. The figure which shows the method of determining a generating point in the method of designing a seed pattern. The figure explaining the degree of dispersion | distribution of the determined mother point group by an absolute coordinate system and a relative coordinate system. The figure which shows the method of creating a Voronoi diagram from the determined generating point and determining a seed pattern. The figure which shows the method of producing | generating the light-shielding pattern from a seed pattern. Sectional drawing which shows the various examples of the main cut surface shape of a light absorption part. The top view which shows an example by which the seed pattern was repeated as a unit pattern area | region of the magnitude | size of 1/3 or more of the dimension of an optical path control filter. 1 is a cross-sectional view showing an embodiment of an image display device according to the present invention. The top view explaining the waste which arises when cutting out a thing with a bias angle because the conventional optical path control filter has a repetition period.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relations, aspect ratios, and the like of components may be exaggerated as appropriate for convenience of explanation.

[A] Definition of terms:
Hereinafter, definitions of main terms used in the present invention will be described here.

The “sheet surface” means a surface coinciding with the planar direction of the optical path control filter 10 when the sheet-like optical path control filter 10 is viewed as a whole and as a whole. Usually, it is a surface parallel to the front surface, back surface, or both front and back surfaces of the optical path control filter 10. In FIG. 1, it is an XY plane or a plane parallel thereto.
The “main cut surface shape” is defined as a cross section orthogonal to the extending direction of the light absorbing portion 1a or the target portion of the light shielding pattern 1P among the cross sections parallel to the normal line n set on the “sheet surface”. This means the shape at the “main cut surface”.
The “planar shape” means a shape in a plane parallel to the “sheet surface”. In other words, the “planar shape” means a shape viewed from the direction of the normal line set on the “sheet surface”.
The terms “sheet”, “film” and “plate” are not distinguished from each other based solely on the difference in designation. Therefore, for example, a “sheet” is a concept including a member that can also be called a film or a plate.

[B] Optical path control filter:
FIG. 1 shows an optical path control filter 10 according to an embodiment of the present invention. The optical path control filter 10 in the present embodiment has a sheet-like shape, and the sheet surface that is also the filter surface is a plane parallel to the XY plane, which is a light incident surface and a light exit surface, and is normal to the sheet surface. The (n) direction is the Z-axis direction. 1A and 1C are plan views, and FIG. 1B is a cross-sectional view in a plane parallel to the Y-axis direction of FIG.

The optical path control filter 10 includes a columnar light absorbing portion 1a arranged in a large number in stripes at intervals along the filter surface 1s, and a light transmitting portion 1b between the light absorbing portions 1a. An optical path control layer 1 is provided. The light absorbing portion 1a is made of a light absorbing material, and the light transmitting portion 1b is made of a light transmitting material.
The light absorbing portion 1a has a planar view shape when the light absorbing portion 1a is viewed from the normal direction of the filter surface 1s, and a light shielding pattern 1P having the light transmitting portion 1b as a transmission region T is shown in FIG. It is generated from the seed pattern 2P shown in the plan view.

The seed pattern 2P is formed from a number of boundary line segments L that extend between two branch points B and define an open region A that is the origin of the transmission region T as a closed region. The average value N of the number of extending boundary line segments L is 3.0 ≦ N <4.0, and the area and shape of the opening region A having the same number of boundary line segments L surrounding the periphery are not constant. . In addition, the arrangement of the opening regions A is a pattern in which there is no direction having periodicity.
In FIG. 1C, a boundary line segment L indicated by a dotted line indicates a line segment that is not employed in the light shielding pattern 1P among the boundary line segments L in the seed pattern 2P.

Therefore, the light absorbing portion 1a exhibiting the light shielding pattern 1P generated from the seed pattern 2P has a shape in the extending direction that is not a linear shape but a random, irregular broken line shape and an aperiodic shape, There is no periodicity in the array period.
For this reason, the optical path control filter 10 according to the present embodiment can extremely effectively prevent moiré due to interference with the pixel arrangement period of the display panel without setting a bias angle.

  In the present invention, like the optical path control filter 10 of the embodiment shown in the cross-sectional view of FIG. 2, the optical path control layer 1 is formed by laminating the transparent substrate 3 for the purpose of reinforcing mechanical strength. Various modifications can be made.

  Hereinafter, the optical path control layer having the light shielding pattern 1P characteristic of the present invention will be described in detail.

(Optical path control layer)
The optical path control layer 1 includes a columnar light absorbing portion 1a having a light shielding pattern 1P having a specific shape as described above in plan view, and a light transmitting portion 1b occupying a portion other than the light absorbing portion 1a. The light absorption unit 1a absorbs unnecessary light, and the light transmission unit 1b transmits the necessary light. The light absorbing portion 1a has a columnar shape of random lines or broken lines, and a large number of stripes are arranged along the filter surface at intervals from each other with the general extending direction thereof being substantially parallel. A space between the light absorbing portions 1a is a light transmitting portion 1b. As a result, the light absorbing portion 1a and the light transmitting portion 1b are alternately arranged in a stripe shape, which is the same as the conventional optical path control layer, but the irregularity of the light shielding pattern 1P having a planar view shape. However, the present invention is different.

  The light absorption part 1a and the light transmission part 1b which comprise the optical path control layer 1 can be based on a conventionally well-known material and formation method. Therefore, these will be described later. First, the light shielding pattern 1P exhibited by the light absorbing portion 1a, which is a characteristic requirement of the present invention, will be described.

[Shading pattern]
The light shielding pattern 1P has a planar view shape of the light absorbing portion 1a, and is a pattern in which a large number of random and irregular line segments are spaced apart from each other and arranged aperiodically. The light shielding pattern 1P is a pattern generated from the seed pattern 2P.

[Seed pattern]
The seed pattern 2P is a mesh pattern, whereas the light shielding pattern 1P is a stripe pattern.

[Seed pattern and opening area defined by this]
The seed pattern 2P is a pattern that is the basis of the light shielding pattern 1P that is the planar view shape of the light absorbing portion 1a when the light absorbing portion 1a is observed from the normal direction of the sheet surface (Z-axis direction in FIG. 1). is there. Hereinafter, the seed pattern 2P will be described with reference mainly to FIG. 3 and FIG.

As shown in FIG. 3, the seed pattern 2 </ b> P is formed from a large number of boundary line segments L that extend between the two branch points B and define the opening region A. An average value N of 3.0 ≦ N <4.0, that is, 3.0 or more and less than 4.0, and the number of boundary line segments L surrounding the periphery of the opening region A is the same. The area and shape are non-constant patterns. In addition, the arrangement of the opening regions A is a pattern in which there is no direction having periodicity.
In the present invention, the fact that there is no direction having periodicity in the arrangement of the opening region A is also referred to as an arrangement in which the direction in which the opening region A has a repeating period does not exist.

  As shown in FIGS. 3 and 9, the line portion Lt of the seed pattern 2P includes a large number of branch points B. The line portion Lt of the seed pattern 2P is composed of a large number of boundary line segments L that form branch points B at both ends. That is, the line portion Lt of the seed pattern 2P is composed of a number of boundary line segments L extending between the two branch points B. Then, at the branch point B, the boundary line segment L is connected, so that the opening region A is defined. In other words, an opening area A as a closed area is defined by being surrounded by a boundary line segment L and partitioned.

  Note that the seed pattern 2P is an array in which the opening area A does not have a direction having a repetition period, and in order to sufficiently exhibit the effect of preventing moire, the number of boundary line segments L surrounding the periphery is small. It is preferable to use a pattern in which the area and shape of the same opening region A are not constant. Preferably, 50% or more of the opening regions A having the same number of boundary line segments L surrounding the periphery have different areas and shapes. More preferably, the opening areas A having the same number of boundary line segments L surrounding the periphery are spread over the entire area of the seed pattern 2P so that the areas and shapes thereof are all different from each other. In other words, among the opening regions A included in the seed pattern 2P, the shapes and areas of the opening regions A in which the number of boundary line segments L surrounding the periphery are the same are not all the same, and at least some of the other regions Means that it will be different. Here, the number of boundary line segments L surrounding the periphery is the same as the number of corners (or the number of sides) of the polygon when the opening region A is a polygon. In addition, in the above description, even when the two opening areas A are congruent figures and have different directions, it is considered that the shapes of the two opening areas A are different from each other.

  As shown in FIGS. 3 and 9, since the line portion Lt is composed only of the boundary line segment L, there is no line portion Lt that extends into the opening region A and becomes a dead end. According to such an aspect, it is possible to effectively realize the optical path control layer 1 having a sufficient unnecessary light absorption function and a high necessary light transmission function at the same time.

  On the other hand, in order to prevent the occurrence of moire, the seed pattern 2P corresponding to the generation of the entire region of the light shielding pattern 1P does not seem to have a constant area and shape of the opening region A having the same number of boundary line segments L surrounding the periphery. It has become. In order to eliminate moiré with certainty, it is preferable that the entire region of the seed pattern 2P is composed only of such regions. The present embodiment has such a configuration. As a result of intensive research, the inventors of the present invention do not simply irregularize the pattern of the seed pattern 2P, but the opening area A of the seed pattern 2P has the same number of boundary line segments L surrounding the periphery. The area and shape of the opening area A of the display area are not constant, and the pattern of the seed pattern 2P is defined so that there is no periodic direction in the arrangement of the opening area A, thereby interfering with the pixel arrangement of the display panel. It has been found that the moiré that can be caused by the can be made very effectively inconspicuous.

[No repeat cycle]
In FIG. 4, the area and shape of the opening area A in which the number of boundary line segments L surrounding the opening area A defined by the seed pattern 2P is the same. Then, there is no region arranged in the opening region A with a constant period, and there is no repetition period, in other words, there is no direction having periodicity in the arrangement of the opening region A. It is a top view in the sheet surface parallel to a plane. Within the plane of the sheet surface, in the figure, one virtual straight line di that faces an arbitrary direction at an arbitrary position is selected.
This one straight line di intersects with the boundary line segment L of the line portion Lt to form an intersection. The intersections are shown as intersections c1, c2, c3,..., C9 in order from the lower left in the drawing. The distance between adjacent intersections, for example, the intersection c1 and the intersection c2, is a dimension t1 on the straight line di of the certain opening region A. Next, the dimension t2 on the straight line di is similarly determined for another open area A adjacent to the open area A having the dimension t1 on the straight line di. Then, with respect to a straight line di in an arbitrary direction at an arbitrary position, from the boundary line segment L intersecting with the straight line di, a large number of opening regions A that encounter the straight line di in an arbitrary direction at an arbitrary position, t1, t2, t3,..., t8 are determined. And the sequence of numerical values of t1, t2, t3,..., T8 has no periodicity.
In FIG. 4, t1, t2, t3,..., T8 are drawn separately from the seed pattern 2P along with the straight line di at the bottom of the drawing for easy understanding.

When this straight line di is rotated at an arbitrary angle from the one shown in FIG. 4 to obtain the dimensions t1, t2,... Of each opening region A in another direction, the straight line is again the same as in FIG. There is no repetitive periodicity in the di direction.
That is, there is no direction having a repetition period in the opening area A defined by the boundary line segment L as in the sequence of numerical values of t1, t2, t3,.
In other words, in the arrangement of the opening area A, a number sequence of the arrangement of the dimensions ti of the opening area A on the virtual line segment di in an arbitrary direction passing through an arbitrary position becomes an aperiodic function. That is, there is no M that satisfies t (i) = t (i + M) (i and M are independent positive integers).
Thus, the absence of a direction having periodicity in the arrangement of the opening areas A is expressed as the absence of a direction in which the opening areas A are arranged at a constant repetition period.

  Furthermore, in the seed pattern 2P that is the basis of the light shielding pattern 1P included in the optical path control layer 1 of the optical path control filter 10 according to the present embodiment, the average value N of the number of boundary line segments L extending from one branch point B is 3. 0 ≦ N <4.0. Thus, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, the straight line extends the array pattern of the seed pattern 2P. It is possible to make the pattern greatly different from a square lattice pattern (N = 4.0), which leads to generation of a simple stripe pattern in which directions are parallel to each other and periodically arranged at regular intervals. In addition, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0, it is also large from the honeycomb arrangement (N = 3.0). Different patterns can be used. Then, after setting the average value N of the number of boundary line segments L extending from one branch point B to 3.0 ≦ N <4.0, the arrangement of the opening regions A is made irregular, It has been confirmed that the direction having periodicity in the arrangement can be prevented from being stably present, and as a result, the moire can be made extremely inconspicuous.

  The average value N of the number of boundary line segments L extending from one branch point B is strictly determined by checking the number of boundary line segments L extending for all branch points B included in the seed pattern 2P. The average value is calculated. In practice, however, the total number of boundary line segments L extending from one branch point B is considered in consideration of the size of the opening area A per line defined by the line portion Lt. It extends about a branch point B included in a section having an area that can be expected to reflect a tendency (for example, a 10 mm × 10 mm portion in the seed pattern 2P in which an opening region A is formed in a dimension example described later). The number of boundary line segments L to be output is checked to calculate the average value, and the calculated value is handled as the average value N of the number of boundary line segments L extending from one branch point B for the seed pattern 2P. May be.

  Actually, in the seed pattern 2P shown in FIG. 3, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0. For example, in the case of the seed pattern 2P of FIG. 3, when a total of 387 branch points B are measured, the boundary line segment L has three branch points B and the boundary line segment L has four branches. The number of point B is 14 (the number of branch points where the number of boundary line segments L to branch is 5 or more is 0), and the average number of boundary line segments L coming from the branch point B (average branch number) is 3.04 Met.

[Method for creating seed pattern pattern shape]
Here, an example of a method for creating the pattern of the seed pattern 2P unique to the present invention will be described below.

  The method described here includes a step of determining a generating point, a step of creating a Voronoi diagram from the determined generating point, and a boundary line segment extending between two Voronoi points connected by one Voronoi boundary in the Voronoi diagram. A step of determining a path of L, and a step of determining a thickness of the determined path to define each boundary line segment L to determine a pattern of the seed pattern 2P (line portion Lt). . Hereinafter, each step will be described in order. Note that the pattern shown in FIG. 3 described above is a pattern actually determined by the method described below.

  First, the process of determining a generating point will be described. First, as shown in FIG. 5, an absolute coordinate system O-X-Y (this coordinate system O-X-Y is a normal two-dimensional plane. The first generating point (hereinafter referred to as “first generating point”) BP1 is arranged at an arbitrary position of “. Next, as shown in FIG. 6, the second generating point BP2 is arranged at an arbitrary position separated from the first generating point BP1 by a distance r. In other words, at any position on the circumference of a circle with a radius r centered on the first generating point BP1 on the absolute coordinate system XY (hereinafter referred to as “first circumference”), the second A generating point BP2 is arranged. Next, as shown in FIG. 7, the third mother point BP3 is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the second mother point BP2 by the distance r or more. Thereafter, the fourth generating point is arranged at an arbitrary position separated from the first generating point BP1 by the distance r and from the other generating points BP2 and BP3 by the distance r or more.

  In this way, the mother point is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the other mother points until the next mother point cannot be arranged. Go. Thereafter, this operation is continued based on the second generating point BP2. That is, the next generating point is arranged at an arbitrary position separated from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Based on the second generating point BP2, until the next generating point cannot be arranged, it is at an arbitrary position away from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Place the mother point. Thereafter, the base point as a reference is sequentially changed, and the base point is formed in the same procedure.

  With the above procedure, the mother point is arranged until it becomes impossible to arrange the mother point in the region where the seed pattern 2P is to be formed. When the mother point cannot be arranged in the region where the seed pattern 2P is to be formed, the step of producing the mother point is completed. By the processing so far, the mother point groups irregularly arranged on the two-dimensional plane (XY plane) are uniformly dispersed in the region where the seed pattern 2P is to be formed.

With respect to the generating point groups BP1, BP2,..., BP6 (see FIG. 8A) distributed in the two-dimensional plane (XY plane) in such a process, the distances between the individual generating points are not constant. Have However, the distribution of the distance R between any two adjacent generating points is not a complete random distribution (uniform distribution), but a range ΔR between the upper limit value R _MAX and the lower limit value R _MIN with the average value R _AVG in mind. = R _MAX -R _MIN is distributed. Note that, here, two Voronoi regions XA are adjacent to each other, but when two Voronoi regions XA are adjacent after generating a Voronoi diagram from the generating point groups BP1, BP2,... It is defined that the generating points of are adjacent to each other.

That is, the generating point group described here is referred to as a coordinate system having each generating point as an origin (referred to as a relative coordinate system oxy, while a coordinate system defining an actual two-dimensional plane is referred to as an absolute coordinate system O. 8 (B), FIG. 8 (C),..., In which all the generating points adjacent to the generating point placed on the origin are plotted are obtained for all generating points. Then, when the graph of the adjacent generating points on all the relative coordinate systems is displayed with the origin o of each relative coordinate system superimposed, a graph as shown in FIG. 8D is obtained. The distribution pattern of adjacent mother point groups on the relative coordinate form is not a uniform distribution in which the distance between any two adjacent mother points constituting the mother point group is 0 to infinity, but the distance from the origin o. Is distributed in a finite range from R _AVG −ΔR to R _AVG + ΔR (a donut-shaped region from radius R _MIN to R _MAX ).
As can be seen from FIG. 8D, the orientation (angle) distribution of another generating point BP viewed from an arbitrary generating point BP is isotropic (or substantially isotropic). This corresponds to the fact that the orientation (angle) distribution of the opening region A in the seed pattern 2P generated from the mother point (group) BP is isotropic (or substantially isotropic). .

  As described above, by setting the distance between each generating point, the Voronoi region XA obtained from the generating point group by the method described below, and the size of the opening region A obtained from this (or from The distribution of the area of the opening region A) is not a uniform distribution (completely random) but is distributed within a finite range.

By comprising in this way, the surface distribution of the total area which totaled the area of each of several opening area | region A which occupies in the arbitrary fixed small area in the seed pattern 2P becomes more uniform, and brightness / darkness unevenness is prevented. . In order to make the unevenness of light and darkness caused by insufficient surface uniformity of the surface distribution substantially invisible and compatible with the anti-moire due to the non-periodicity of the seed pattern 2P, the maximum size D of the opening region A When the value is D _MAX and the minimum value is D _MIN , the distribution range ΔD = D _MAX −D _MIN of the size D is the average value D _AVG of the size D,
0.1 ≦ ΔD / D _AVG ≦ 0.6
More preferably,
0.2 ≦ ΔD / D _AVG ≦ 0.4
And

Here, the size D of the opening area A is defined as follows for all the opening areas A.
(1) When a circle passing through all the branch points B (all vertices in the case of a polygon) belonging to a certain opening area A can be drawn, the size D is determined by the circumscribed circle diameter of the opening area A. And
(2) If a circle passing through all the branch points B (all vertices in the case of a polygon) belonging to a certain opening area A cannot be drawn, the maximum distance between the two branch points B belonging to this opening area A The value (maximum diagonal length in the case of a polygon) is taken as the size D.

  In the step of determining the generating point, the size D of the opening area A can be adjusted by changing the size of the distance r. Specifically, by reducing the size of the distance r, it is possible to reduce the size D of the opening area A, and conversely, by increasing the size of the distance r, The size D of the opening area A can be increased.

  Next, as shown in FIG. 9, a Voronoi diagram is created based on the arranged generating points. As shown in FIG. 9, the Voronoi diagram is composed of line segments that are drawn at the intersection of two bisectors by drawing a perpendicular bisector between two adjacent generating points BP and BP. FIG. Here, the line segment of the bisector is called Voronoi boundary XB, the intersection of Voronoi boundary XB forming the end of Voronoi boundary XB is called Voronoi point XP, and the area surrounded by Voronoi boundary XB is Voronoi area XA Call it.

  In the Voronoi diagram created as shown in FIG. 9, each Voronoi point XP forms a branch point B of the seed pattern 2P. Then, one boundary line segment L is provided between two Voronoi points XP forming the end of one Voronoi boundary XB. At this time, the boundary line segment L may be determined so as to extend linearly between the two Voronoi points XP as in the example shown in FIG. Various paths (for example, circle (arc), ellipse (arc), fence line, hyperbola, sine curve, hyperbolic sine curve, elliptic function curve, Bessel function curve, etc.) between the two Voronoi points XP without It may be extended by a broken line or the like. When the boundary line segment L is determined to extend linearly between two Voronoi points XP as in the example shown in FIG. 3, each Voronoi boundary XB defines the boundary line segment L. It becomes like this.

  After determining the path of each boundary line segment L, the line width (thickness) of each boundary line segment L is determined. The line width of the boundary line segment L is determined in consideration of unnecessary light absorption performance and necessary light transmission function performance obtained by the optical path control layer 1 exhibiting the light shielding pattern 1P generated from the created seed pattern 2P. . As described above, the pattern of the seed pattern 2P can be determined.

[Generation of shading pattern from seed pattern]
A method of generating the light shielding pattern 1P from the seed pattern 2P will be described with reference to FIG.
First, for the seed pattern 2P, a parallelogram whose opposing opposite sides are parallel to each other is defined as a generation region W for generating the light shielding pattern 1P. In the present embodiment, a rectangle is adopted as the parallelogram of the generation region W.
The generation region W corresponds to the shape of one optical path control filter 10 (one unit of use) when the obtained light shielding pattern 1P is used as the optical path control filter 10.
Next, a first direction d1 parallel to an arbitrary side of the parallelogram with respect to the generation region W and a second direction d2 parallel to the side intersecting with the arbitrary side are determined. In the present embodiment, the first direction d1 is the horizontal direction in the drawing (horizontal direction), and the second direction d2 is the vertical direction in the drawing (vertical direction). In addition, since the generation area W is a rectangle, the first direction d1 and the second direction d2 are orthogonal to each other.

Next, the light shielding pattern 1P extending globally in the first direction d1 is generated as follows.
First, an intersection between one side W2c and the boundary line segment L of the two opposite sides W2c and W2d parallel to the second direction d2 is set as a start point Ps, and an intersection between the other side W2d and the boundary line segment L is set as an intersection. It is determined as the end point Pe. In the figure, Ps1, Ps2,... Are determined in order from the one end W2a side to the other end W2b of the generation region W as the start point Ps, and similarly, Pe1, Pe2,. Determined.
Next, in order from the one end W2a to the other end W2b in the second direction d2, a set of boundary line segments L that connect each start point Psi and each end point Pei with the shortest distance is sequentially selected as a connection line segment Lci. Go. Here, i = 1, 2, 3,... Is a natural number representing the order. In the figure, the connecting line segment Lc1 connecting the start point Ps1 and the end point Pe1 is selected, and then the connecting line segment Lc2 connecting the start point Ps2 and the end point Pe2 is selected.
Thus, finally, the boundary line segment L deviating from the connection line segment Lc is erased, and the opening regions A facing each other across the boundary line segment L are connected to each other so as to extend in the first direction d1. Region T is assumed. In the figure, the boundary line segment L to be erased is indicated by a dotted line.

  As a result, a light shielding pattern 1P composed of the plurality of generated connecting line segments Lc is generated.

  Thus, the optical path control filter 10 is formed by forming the optical path control layer 1 including the light absorbing portion 1a and the light transmitting portion 1b so as to be the generated light shielding pattern 1P.

  According to the light-shielding pattern 1P of the present embodiment as described above, the seed pattern 2P that is the source of the light-shielding pattern 1P extends from a large number of boundary line segments L that extend between the two branch points B and define a large number of opening regions A. The average value N of the number of boundary line segments L formed from one branch point B is 3.0 ≦ N <4.0, and the number of boundary line segments L surrounding the periphery is N The area and shape of the same opening region A are not constant, and there is no direction having periodicity in the arrangement of the opening region A. As a result, even if the optical path control filter 10 including the optical path control layer 1 having the light shielding pattern 1P generated from the seed pattern 2P is superimposed on the display panel in which the pixels are regularly (periodically) arranged, the stripes It is possible to effectively prevent the occurrence of a pattern (moire, interference fringe) that can be visually recognized.

[Shape and dimensions of main cut surface of light absorbing part]
The main cut surface shape of the light absorption part 1a is arbitrary. FIG. 11 illustrates various shapes of the main cut surface shape of the light absorbing portion 1a. In the embodiment with reference to FIG. 1, the rectangular shape of FIG. In addition, there are a wedge shape such as a triangular shape shown in FIG. 11 (2) and a trapezoidal shape shown in FIG. 11 (3). Further, the main cutting plane shape may be a pentagonal shape, a hexagonal shape, or the like, or both of the triangles and trapezoids shown in FIG. 11 (4) and FIG. It may be a shaped shape (a convex shape or a concave shape toward the outside of the light absorbing portion 1a).
The height (thickness) of the light absorbing portion 1a is the same as the thickness of the light transmitting portion 1b, and the light absorbing portion 1a and the light transmitting portion 1b may be flush with each other on both sides of the optical path control layer 1, Alternatively, the height of the light absorbing portion 1a may be smaller than the thickness of the light transmitting portion 1b (for example, 80 to 99% of the thickness of the light transmitting portion 1b).
The main cut surface shape of the light absorbing portion 1a is designed according to the required external light shielding characteristics.
As an example, the dimensions of the main cut surface shape of the light absorbing portion 1a are about 50 to 200 μm in thickness (height), about 10 to 50 μm in width, and about 50 to 100 μm on average when arranged. .

[Main cut surface shape and dimensions of light transmission part]
The main cut surface shape of the light transmitting portion 1b is a complementary shape and size excluding the portion occupied by the light absorbing portion 1a in the optical path control layer 1.
The thickness of the light transmission part 1b is normally equal to the thickness of the optical path control layer 1, and is, for example, about 100 to 300 μm.

[Material of light absorption part]
The light absorbing portion 1a can be formed of a light absorbing dark material. As the dark material, either an organic material or an inorganic material may be used. As the organic material, a dark resin composition such as a paint (or ink) in which a light-absorbing color material is contained in a resin binder can be used.
As the light-absorbing color material, a dark color material having a high light-absorbing property and exhibiting a dark color, that is, a chromatic or achromatic color with low brightness can be used. A representative example of the dark color is black, and an achromatic black color is preferable because it does not affect the color of the image display and the external light absorption is large. In addition, examples of low-lightness chromatic colors include brown, amber, rosy, and dark green. As the dark color material, a known color material, for example, black pigment such as carbon black or black iron oxide, black dye such as aniline black, or the like may be used. The dark color material may be dark resin particles obtained by coloring acrylic resin particles or the like with these dark color materials in a dark color. Further, a dark color material may be an achromatic color such as black or a chromatic dark color by mixing a plurality of kinds of chromatic color materials such as blue, yellow, and red, and mixing the colors. Content of a light absorptive color material is 5-100 mass parts with respect to 100 mass parts of resin solid content, for example.
As the resin of the resin binder, for example, a thermoplastic resin or a curable resin can be used. Examples of thermoplastic resins include acrylic resins, polyester resins, vinyl chloride-vinyl acetate copolymers, and curable resins include thermosetting resins, ionizing radiation curable by electron beams, ultraviolet rays, and the like. Examples of thermosetting resins include two-component curable urethane resins, epoxy resins, and unsaturated polyester resins. Examples of ionizing radiation curable resins include acrylate-based, polyester-based, and epoxy-based resins. Resin. Among these, ionizing radiation curable resins are suitable resins because they can be cured quickly and without solvent. As the ionizing radiation, ultraviolet rays or electron beams are usually used.

(Light transmission part)
The light transmission portion 1b is an optical element that transmits image light.
The light transmitting portion 1b has a thickness that is greater than or equal to the thickness of the light absorbing portion 1a in the thickness direction, and supports the light absorbing portion 1a from at least the side surface by filling the space between the light absorbing portions 1a (see the light in FIG. 1). This is an optical element that reinforces the mechanical strength and transmits image light when the thickness of the absorbing portion 1a and the light transmitting portion 1b is the same. The light transmission part 1b can be formed as a transparent resin layer.

[material]
The resin constituting the light transmitting portion 1b is not particularly limited as long as it is transparent, and for example, a thermoplastic resin or a curable resin can be used. Examples of the thermoplastic resin include acrylic resins, polyester resins, olefin resins, and polycarbonate resins. Examples of the curable resins include thermosetting resins and ionizing radiation curable resins that are cured by electron beams or ultraviolet rays. Yes, examples of thermosetting resins include two-component curable urethane resins, epoxy resins, unsaturated polyester resins, etc., and examples of ionizing radiation curable resins include acrylate resins, polyester resins, and epoxy resins. Can be mentioned. Among these, ionizing radiation curable resins are suitable resins because they can be cured quickly and without solvent. As the ionizing radiation, ultraviolet rays or electron beams are usually used.

[Method of forming optical path control layer]
The optical path control layer 1 is formed by, for example, a so-called photopolymer method (also called 2P method) formed by irradiating an ionizing radiation curable resin with ionizing radiation and polymerizing it. In the photopolymer method, if a cylindrical mold is used, the transparent base material 3 can be continuously molded while being supplied as a continuous sheet, and is a molding method with excellent productivity.
For example, first, a mold having an uneven shape corresponding to the light absorbing portion 1a on the surface of the coating film formed by coating an uncured and liquid ionizing radiation curable resin on the transparent substrate 3 is prepared. The ionizing radiation curable resin is irradiated with ionizing radiation such as ultraviolet rays in the contacted state, cured, and then released to form a light transmitting portion 1b having a light absorbing portion 1a and a concave portion having a concave and convex shape on the surface. Form. Next, only the inside of the concave portion is filled with dark ink of a dark color material by a wiping method and solidified to form a light absorbing portion 1a, whereby the optical path control layer 1 is obtained.

(Transparent substrate)
In the present invention, as illustrated in FIG. 2, the optical path control filter 10 may have the transparent substrate 3 laminated on the optical path control layer 1. The transparent substrate 3 is provided for the case where the optical path control layer 1 itself has insufficient mechanical strength, the case where the optical path control layer 1 is easily formed, or the like.
As the transparent substrate 3, an inorganic plate such as a resin sheet made of polyester resin, acrylic resin, polyolefin resin, polyvinyl chloride, glass, ceramics, or the like is used.

[Other layers]
In the present invention, although not shown, the optical path control filter 10 may be laminated with other layers other than those described above. For example, a functional layer. As a functional layer, conventionally well-known things can be suitably employ | adopted in various optical sheets. For example, the optical functional layer responsible for the optical function includes an antireflection layer, an antiglare layer, an ultraviolet absorbing layer, an infrared absorbing layer, a neon light absorbing layer, a colored layer, and the like. Examples of the layer include an electromagnetic wave shielding layer, an antistatic layer, an antifouling layer, an impact resistant layer, a hard coat layer, an adhesive layer, and an adhesive layer. The contents of each functional layer can be conventionally known.
The optical path control filter 10 can have one or a plurality of functions by these functional layers. When a plurality of functions are provided, one layer may be provided for each function, or a plurality of functions may be provided in one layer.
The position of the functional layer with respect to the optical path control layer 1 is arbitrary. However, in some cases, the position of the antireflection layer is naturally determined by the functional layer, for example, as an outermost layer.

[Deformation]
The optical path control filter 10 of the present invention can take other forms other than the above-described forms. Some of these will be described below.

[Shape of opening area]
The shape of the opening region A preferably includes at least a pentagon and a hexagon. By including at least a pentagon and a hexagon in the opening region A, moire can be made inconspicuous, and light and dark unevenness due to the density of the original seed pattern 2P can also be made inconspicuous. More preferably, the shape of the opening region A includes a pentagon, a hexagon, and a heptagon.
For example, when the seed pattern 2P shown in FIG. 4 is measured for a total of 4631 open areas A (polygons),
Triangle 0
79 squares
1141 pentagons
2382 hexagons
927 heptagons
94 octagons
Eight 9-sided
There were 0 decagons or more.
With respect to this mesh pattern, the average number of boundary line segments L coming from the branch point B was measured and found to be 3.07.

[Repeat as unit pattern area]
In the above-described embodiment, in the entire region of the optical path control layer 1 in the optical path control filter 10, the seed pattern 2P that is the basis of the light shielding pattern 1P included in the optical path control layer 1 is an aperture defined by the seed pattern 2P. An example in which the area and shape of the opening area A having the same number of boundary line segments L surrounding the area A are not constant, and there is no periodic direction in the arrangement of the opening area A Explained. However, as shown in FIG. 12, the entire region of the seed pattern 2P included in the optical path control layer 1 in the interior is configured such that the entire region of the seed pattern 2P is configured by collecting a plurality of unit pattern regions S. In each unit pattern region S, a plurality of opening regions A may be formed of regions arranged in a pattern having no predetermined repetition period.
That is, in this embodiment, two or more unit pattern regions S in which opening region groups are arranged in the same pattern are included in the entire region of the seed pattern 2P when viewed locally. In this case, the connection between the unit pattern regions S is substantially inconspicuous and can be ignored unless there are four or more repetitions in a certain period in a specific direction. Of course, no moire occurs in the unit pattern region S. In this example, the pattern of the seed pattern 2P in one unit pattern region S can be created in the same manner as the pattern creation method described with reference to FIGS.

  In particular, the display panel has recently been increased in size, and for such a large-screen display panel, the seed pattern 2P that is the basis of the light shielding pattern 1P that the optical path control layer 1 has has a plurality of unit pattern regions. It is preferable that the unit pattern area S includes a plurality of unit pattern areas S that are configured by the arrangement of the S and the opening areas A are arranged in the same pattern in each unit pattern area S. It is preferable in that the pattern creation of the seed pattern 2P can be greatly facilitated.

  In particular, in the example in which one type of unit pattern region S is arranged in a plurality of vertical and horizontal directions as shown in FIG. 12, there is a repetition as the unit pattern region S in a specific direction (two directions in the drawing vertical direction and horizontal direction). . In the embodiment of FIG. 12, the unit pattern region S is repeated with a repetition period SP2 in the horizontal direction and a repetition period SP1 in the vertical direction. Under this condition, when the dimension of the unit pattern area S in a specific direction is Ls, and the unit pattern area S has M opening areas A in the dimension Ls on an arbitrary straight line dj extending in the specific direction, When attention is paid to a certain opening area A on dj, there is a regularity that there is always an opening area A having exactly the same size tj and shape at a position where the number of the opening areas A is separated by M on the straight line dj. Have. That is, regarding the dimension tj on the straight line dj of the opening region A, the kth dimension tj (k) counted in order on the straight line dj, and the Mth (k + M) th dimension tj (k + M) from there. Is the same, and the relationship of tj (k) = tj (k + M) is established (k and M are independent positive integers).

  However, this regularity is based on the repetition cycle as the unit pattern region S (the dimension Ls corresponds to the repetition cycle in the above description), and is not the periodicity as the opening region A but each unit. In the pattern region S, the opening region A does not have periodicity in the arrangement in the specific direction. In addition, the repetition cycle as the unit pattern region S is not close to the dimensional relationship in which moire is generated because the size is different from the arrangement cycle of the pixel arrangement of the display panel by, for example, 1000 times or more. This relationship is the same in the light shielding pattern 1P generated from the seed pattern 2P.

  In the example shown in FIG. 12, the optical path control filter 10 is divided into six unit pattern areas S having the same shape, and in each unit pattern area S, the light shielding pattern 1P included in each optical path control layer 1 is formed. The original seed pattern 2P is configured identically. In the six unit pattern regions S, three regions are arranged in the vertical direction (vertical direction in the drawing) in FIG. 12 at a repetition cycle SP1, and two regions are arranged in the horizontal direction in FIG. 12 at a repetition cycle SP2. Are arranged as follows.

[C] Image display device:
The image display apparatus according to the present invention is an image display apparatus 100 including at least the optical path control filter 10 as described above and the display panel 20 as in the embodiment illustrated in FIG. In addition to the display panel 20, the image display device 100 may be a publicly known device such as a tuner or the like in the case of a television receiver, depending on the application of the image display device, in addition to a housing (cabinet) and input / output components. It is equipped with various parts. These other components are not particularly limited, and depend on the application.
The display panel 20 is a display panel capable of displaying a planar image such as a plasma display panel, a liquid crystal panel, and an EL (electroluminescence) panel. Further, a CRT with a flat display surface may be used. The display panel 20 may include various circuits such as a display drive circuit, wiring between the drive circuit and the display panel main body, a chassis, a frame, and the like that integrate them. Accordingly, the display panel 20 can also be called a “display module” or a “panel module”.

  The arrangement of the optical path control filter 10 with respect to the display panel 20 may be on the front side (screen side) on the viewer V side for observing the image of the display panel 20 as shown in FIG. Although not shown, the back side of the display panel 20 may be used, or both the front side and the back side may be used. In addition, when arrange | positioning on the back side, it becomes a member for receiving the light from the light source which illuminates the display panel 20 from a back surface, and illuminating the display panel 20. Moreover, when arrange | positioning at the back side, the condensing function of the light source light from a light source, etc. are expressed instead of an image contrast improvement function and a viewing angle control function.

  The image display device 100 may further include a functional layer 30 as shown in the exemplary embodiment of FIG. The functional layer 30 is the above-described functional layer described as a layer belonging to the optical path control filter 10, for example. An optical member having such a functional layer 30 is disposed. Therefore, the functional layer 30 is, for example, an optical filter having an electromagnetic wave shielding layer. The position at which the functional layer 30 is disposed is a position corresponding to the use for the function. FIG. 13B shows a form in which the optical path control filter 10 is disposed on the viewer V side of the display panel 20. FIG. 13B shows a form in which the functional layer 30 is disposed between the display panel 20 and the optical path control filter 10 disposed on the viewer V side of the display panel 20. In addition, although illustration is omitted, a mode in which the functional layer 30 is further arranged on the observer V side with respect to the optical path control filter 10 arranged on the observer V side of the display panel 20, and the observer V of the display panel 20 The optical path control filter 10 may be disposed on the side, and the functional layer 30 may be disposed on the back side of the display panel 20.

  In the drawing, each of the optical path control filter 10, the display panel 20, and the functional layer 30 is configured to be separated and independent from each other with an air layer interposed therebetween, with a transparent resin adhesive layer interposed therebetween. Stacking may be integrated, and the total thickness can be reduced by integration.

  As described above, the image display device 100 using the optical path control filter 10 eliminates the occurrence of moire caused by the periodic arrangement of the light absorbing portions 1a of the optical path control layer 1, and also provides a light and shade due to the density of the arrangement. Unevenness is also eliminated, and an image display device in which these are compatible can be obtained.

[D] Application:
The optical path control filter 10 according to the present invention is preferably used on the front side (screen) side of the viewer side of various display panels or the back side of the opposite side. The image display device 100 including the optical path control filter 10 is an image of a television receiver, measuring device or instrument, office device, medical device, computer device, telephone, electronic signboard, game device, digital photo frame, or the like. It is suitable as a display device.
In addition, the optical path control filter 10 according to the present invention is attached to a window, a transparent door, a transparent wall or a partition of a house, store, school, office, hospital or clinic, etc. It can also be used for applications that provide functions such as shielding.

DESCRIPTION OF SYMBOLS 1 Optical path control layer 1a Light absorption part 1b Light transmission part 1P Light shielding pattern 2P Seed pattern 3 Transparent base material 10 Optical path control filter 20 Display panel 40 Conventional optical path control filter 41 (Conventional) light absorption part 42 Waste part 100 Image display apparatus A opening area B branch point BP generating point d1 first direction d2 second direction L boundary line segment Lc, Lc1, Lc2,... Connecting line segment Lt line part (set of boundary line segment)
Pe, Pe1, Pe2, ... End point Ps, Ps1, Ps2, ... Start point S Unit pattern area T Transmission area W Generation area W2a One end W2b The other end

Claims (3)

An optical path control filter including an optical path control layer having a plurality of columnar light absorption portions arranged in stripes at intervals along the filter surface and a light transmission portion between the light absorption portions. And
A light-shielding pattern having a planar view shape when the light absorbing portion is viewed from the normal direction of the filter surface and having the light transmitting portion as a transmission region is generated from a seed pattern,
This kind of pattern
An average value N of the number of boundary lines extending from one branch point is formed from a number of boundary lines extending between two branch points and defining an opening region that is the base of the transmission region as a closed region. 3.0 ≦ N <4.0, and a pattern including a region where the area and shape of the opening region having the same number of boundary line segments surrounding the periphery are not constant,
The shading pattern is
For the seed pattern, a parallelogram whose opposing opposite sides are parallel to each other is defined as a generation region for generating the light-shielding pattern, and a first direction parallel to any side of the parallelogram with respect to the generation region And a second direction parallel to the side intersecting with the arbitrary side,
A light shielding pattern extending globally in the first direction,
In order from one end to the other end of the generation region in the second direction, the boundary line segment starts from an intersection with one of two sides parallel to the second direction of the generation region. And set the intersection with the other side as the end point,
In order from the one end to the other end in the second direction, a boundary line segment connecting the start point and the end point with the shortest distance is selected as a connection line segment, and the boundary line deviated from the connection line segment By erasing the minutes and connecting the opening regions facing each other across the boundary line segment to form the transmission region extending in the first direction,
It is generated as a light-shielding pattern consisting of connecting line segments corresponding to the light absorption part,
Optical path control filter.   The optical path control filter according to claim 1, wherein a transparent base material is laminated on the optical path control layer. An image display device comprising a display panel and the optical path control filter according to claim 1.

Images