JP2013050566A - Image display panel and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display panel, which is free from generation of a moire pattern or brightness irregularity of a displayed image even when the panel is combined with an optical filter having a periodical pattern, and to provide an image display device using the display panel.SOLUTION: An image display panel 10 having a great number of pixels 3 disposed thereon includes a segmenting pattern 2P segmenting the pixels, as a partition wall 2 that partitions a space between glass substrates 1f, 1r into discharge cells 3c. The segmenting pattern is composed of a great number of boundary line segments L extending between two branch points B to define pixels, in which the average number N of the boundary line segments extending from one branch point satisfies 3.0≤N<4.0; and the pattern includes a region where no direction exists showing a repetitive period in the arrangement of pixels. The display panel optionally includes an optical filter having a periodical pattern such as an electromagnetic wave shield filter having a mesh pattern and a microlouver filter functioning as a contrast improving filter or a peep-prevention filter. The image display device includes the image display panel.

Description

  The present invention relates to an image display panel and an image display apparatus using the same, and more particularly to an image display panel and an image display apparatus that can prevent the occurrence of moire.

  Currently, various image display panels such as a liquid crystal display panel, a plasma display panel, and an electroluminescence panel are widely used. The image display panel is usually incorporated in an image display device by arranging an optical filter on the viewer side of the image. The optical filter is provided for improving the appearance of the observation image, and according to the required specifications, for example, an antireflection filter for preventing external light reflection, an electromagnetic wave shielding filter for shielding unnecessary electromagnetic waves from the plasma display panel, A contrast improving filter that suppresses the reduction of the contrast of the image due to external light mixed into the image light and increases the contrast is provided.

Some of these optical filters have a regular pattern. In terms of the above, some electromagnetic wave shielding filters and contrast enhancement filters have regular patterns.
In the electromagnetic wave shielding filter, the conductor layer having an electromagnetic wave shielding function is usually a mesh pattern having a lattice shape such as a square lattice, and this mesh pattern is a periodic pattern (Patent Document 1).
The contrast enhancement filter normally has a micro louver structure in order to prevent external light from entering the image display panel while transmitting image light, and such a filter is a kind of micro louver filter. The microlouver structure is, for example, a structure in which a large number of minute triangular prisms are arranged with their extending direction parallel to the filter surface and spaced apart from each other in the filter surface direction. Such a microlouver filter has a stripe shape when viewed from a direction perpendicular to the filter surface (Patent Document 2).

JP 61-200783 A JP 2006-313360 A

  However, an optical filter having a periodic pattern, such as a lattice shape or a stripe shape, has a periodic arrangement of pixels of the image display panel. Interference with the period of the periodic pattern of the pixel arrangement may cause moiré and reduce the quality of the display image.

  In order to prevent this moire, conventionally, in an optical filter having such a periodic pattern, the periodic direction of the periodic pattern is shifted by a predetermined angle without matching the periodic direction of the pixels of the image display panel. A so-called bias angle θ is set (Patent Document 1, Patent Document 2). The bias angle θ is usually about 3 to 45 °.

However, the moire does not depend only on the angle between the periodic direction of the periodic pattern of the optical filter and the periodic direction of the pixel arrangement of the image display panel, but the periodic pattern of the optical filter and the period of the image display panel. It occurs depending on a plurality of factors such as the ratio to the period of the pixel array, the relationship between the line width of the periodic pattern of the optical filter and the inter-pixel dimensions of the image display panel.
For this reason, the optimum bias angle θ at which moire is minimized varies depending on the design specifications of the image display panel to which the optical filter is applied. If such optical filters having different bi-eye angles θ are manufactured for each image display panel to which the optical filter is applied, there is a problem that the production of many kinds and small lots becomes complicated, the product design becomes complicated, and the productivity also decreases.

  On the other hand, there is a method of manufacturing an optical filter without determining the bias angle θ for each manufactured intermediate product. In this method, as shown in FIG. 17, as an intermediate product, an optical filter member 6w having a continuous strip shape (web shape) and a periodic direction parallel to the width direction TD or the flow direction MD is manufactured. In this method, the sheet-like optical filter 6 is cut obliquely with respect to the flow direction MD in accordance with the bias angle θ. In the same figure, the periodic pattern 6P which makes the extending direction the direction parallel to the sheet flow direction MD of the continuous belt-shaped optical filter member 6w is arranged with the sheet width direction TD of the continuous belt-shaped sheet as the periodic direction. And it becomes possible to cope with an arbitrary bias angle θ by changing the angle at the time of cutting. However, this method has a problem that there are many wasted parts 6x, as can be seen from FIG.

  Therefore, the present inventors have randomized the pixel array that is the basis of the periodicity on the image display panel side, not on the optical filter side, so that the optical filter has a periodic pattern. However, as a result of diligent efforts to prevent moiré, the following was found. That is, when the pixel arrangement is completely messed up, bright and dark unevenness occurs in the display image. On the other hand, if the pixel arrangement is left messed up with periodicity, moire will remain. Therefore, it has been impossible to eliminate moire while suppressing the occurrence of uneven brightness.

  That is, an object of the present invention is to provide an image display panel that does not cause moiré and does not cause unevenness in the display image even when combined with an optical filter having a periodic pattern. Moreover, it is providing the image display apparatus using this image display panel.

Therefore, in the present invention, an image display panel and an image display device having the following configuration are provided.
(1) In an image display panel in which a large number of pixels are arranged,
The partition pattern that partitions the pixels is composed of a number of boundary line segments that extend between two branch points to define the pixels,
A pattern including an area where the average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0, and there is no direction having a repetition period in the pixel arrangement. An image display panel.
(2) The image display panel according to (1), further including an optical filter on the viewer side of the image, the optical filter having a periodic pattern.
(3) The image display panel according to (1) or (2), which is any one of a liquid crystal display panel, a plasma display panel, and an electroluminescence panel.
(4) An image display device comprising the image display panel according to any one of (1) to (3) above.

(1) According to the image display panel of the present invention, since the pixel arrangement itself includes a region where there is no direction having a repetition period, the optical filter has a periodic pattern when combined with the optical filter. Even if this is the case, the periodic pattern and the arrangement of the pixels do not interfere with each other, and moire does not occur. In addition, there is no occurrence of uneven brightness in the image.
Even when an image display panel having an optical filter is used, it is not necessary to provide a bias angle because the optical filter can be selected without worrying about the occurrence of moire due to its periodic pattern. For this reason, the optical filter does not need to cope with a large variety of low-volume products in which the bias angle is optimized for each design specification of the image display panel, and a common general-purpose specification is possible, and the cost can be reduced.
Such an image display panel can be a liquid crystal display panel, a plasma display panel, or an electroluminescent panel.
(2) According to the image display device of the present invention, the effect of the above-described image display panel can be obtained, and the device can be used in which neither moiré nor brightness unevenness occurs, and the cost can be reduced.

1 is an exploded perspective view illustrating an embodiment of an image display panel according to the present invention. The top view which shows an example of the relationship between the shape and arrangement | positioning of the pixel defined by the division pattern, and an address electrode. The top view which shows an example of a division pattern. The top view explaining that a repeating period does not exist in a division pattern. The figure which shows the method of determining a generating point in the method of designing a division pattern. The figure which shows the method of determining a generating point in the method of designing a division pattern. The figure which shows the method of determining a generating point in the method of designing a division 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 division pattern. The top view which shows an example by which the division pattern was repeated as a unit pattern area | region of the magnitude | size of 1/3 or more of the dimension of the display area of an image display panel. The top view which shows the division pattern which the image display panel of this invention has. The top view which shows the periodic pattern of an optical filter. The top view which shows the state which accumulated FIG. 11A and FIG. 11B. The top view which shows the image display panel which pixel arrangement arranged periodically. The top view which shows the periodic pattern of an optical filter. The top view which shows the state which accumulated FIG. 12A and FIG. 12B. Sectional drawing which illustrates another one Embodiment of the image display panel by this invention. The perspective view which shows an example (electromagnetic wave shielding filter) of the grid | lattice pattern corresponding to the periodic pattern of an optical filter. The perspective view which shows an example (micro louver filter) of the micro louver structure applicable to the periodic pattern of an optical filter. 1 is a cross-sectional view illustrating 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 it has a periodic pattern.

    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] Image display panel:
First, an image display panel according to the present invention will be described with reference to an embodiment shown in an exploded perspective view of FIG.

  The image display panel 10 of the present invention illustrated in FIG. 1 is an example of a plasma display panel. In the image display panel 10 illustrated in FIG. 1, a space between a pair of glass substrates including a front glass substrate 1 f and a rear glass substrate 1 r disposed opposite to the front glass substrate 1 f is sealed one by one by a partition wall 2. Each pixel 3 is composed of discharge cells 3c partitioned as a space. Here, a plane parallel to the front glass substrate 1f and the back glass substrate 1r is defined as an XY plane in the XYZ orthogonal coordinate system.

The plasma display panel according to the present embodiment is an image display panel 10 that is monochromatic display and DC-driven.
The front glass substrate 1f includes a plurality of horizontal address electrodes 4h parallel to the Y axis on the surface facing the back glass substrate 1r. The back glass substrate 1r includes a vertical address electrode 4v parallel to the X axis on the surface facing the front glass substrate 1f.
Accordingly, the discharge cell 3c is partitioned by the partition wall 2 in the space between the front glass substrate 1f provided with the horizontal address electrode 4h and the rear glass substrate 1r provided with the vertical address electrode 4v. Corresponding to one horizontal address electrode 4h and one vertical address electrode 4v, one discharge cell 3c for discharging between these address electrodes is located.
Neon gas is filled in the space of the discharge cell 3c as a gas for discharge light emission.

  The structure and materials constituting each element, the driving method, and the like are the same as those of a conventionally known single-color display and DC-driven plasma display panel.

In the image display panel 10 of the present invention, unlike the conventional image display panel, the planar view shape of the partition walls 2 partitioning the individual discharge cells 3c constituting each pixel 3, and the shape and arrangement of each pixel 3 are random ( The pixel arrangement is an arrangement including a region where there is no direction having a repeating cycle.
The shape in plan view is a shape when the partition wall 2 is viewed from the Z-axis direction perpendicular to the XY plane parallel to the surfaces of the pair of glass substrates.

  In order to apply a voltage to each discharge cell 3c constituting the pixel 3 having such a random shape and arrangement, the horizontal address electrode 4h and the vertical address electrode 4v for selecting the pixel 3 are separated in units of the pixel 3 by the partition wall 2. The discharge cells 3c are crossed at right angles with the discharge cell 3c interposed therebetween.

  At this time, as shown in the plan view of FIG. 2, for each discharge cell 3c corresponding to each pixel 3, a discharge cell 3c and a vertical address electrode 4v that are energized from a horizontal address electrode 4h to which a voltage is applied. The horizontal address electrode 4h, the vertical address electrode 4v, and the pattern of each pixel 3 are designed so that one discharge cell 3c that is energized from 1 corresponds to one cell.

For this reason, in the image display panel 10 of the present invention, the discharge cell 3c corresponding to the intersecting portion 5 to which the voltage is applied as the potential difference between the horizontal address electrode 4h and the vertical address electrode 4v is selected as in the conventional plasma display panel. The pixel 3 is turned on (light emitting state) by light emission of neon atoms excited by plasma discharge.
In this way, for example, the vertical address electrode is used as a scan electrode and the horizontal address electrode is used as a data electrode, and the degree of discharge of the discharge cell 3c at a predetermined position is controlled in accordance with an image signal while sequentially scanning the intersection 5 within the screen. Thus, an image composed of a plurality of pixels 3 can be displayed.
In the present embodiment, the plasma display panel is a panel for monochromatic display and direct current drive, but may be applied to other types of panels such as color display and alternating current drive, and is not limited to this. Absent.

[Division pattern and pixels defined by this]
FIG. 3 is a plan view for explaining in more detail the partition pattern 2P which is a planar view shape of the partition wall 2 that partitions the large number of pixels 3 one by one.

In the image display panel 10 as a plasma display panel in the present embodiment, a large number of pixels 3 are defined by partition walls 2 each having a partition pattern 2P.
As shown in FIG. 3, the partition pattern 2 </ b> P is formed from a large number of boundary line segments L that extend between two branch points B to define the pixels 3 one by one, and extend from one branch point B. Arrangement of the pixels 3 defined by the boundary line segment L when the average value N of the numbers of L is 3.0 ≦ N <4.0, that is, 3.0 or more and less than 4.0 The pattern includes a region where there is no direction having a repetition period.

Further, regarding the partition pattern 2P, a plan view shape when the partition pattern 2P is observed from the normal direction (Z-axis direction in FIG. 1 ) of the display surface of the image display panel 10 while mainly referring to FIGS. Then, I will explain.

  In these drawings, the partition pattern 2P is drawn exaggerated in black so that the pattern can be easily understood, but the actual partition wall 2 can also be made black.

  As shown in FIGS. 3 and 9, the line portion Lt of the partition pattern 2P includes a large number of branch points B. The line portion Lt of the partition 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 partition pattern 2P is composed of a number of boundary line segments L extending between the two branch points B. At the branch point B, the boundary line segment L is connected, so that the discharge cell 3c corresponding to the pixel 3 is defined. In other words, a discharge cell 3c as one closed region corresponding to one pixel 3 is defined by being surrounded and partitioned by the boundary line segment L.

  On the other hand, in order to prevent the occurrence of moire, in the partition pattern 2P of the image display panel 10 according to the present embodiment, the entire region does not have a direction in which the arrangement of the pixels 3 has a repeating cycle. In order to surely eliminate moiré, it is preferable that the entire area of the partition pattern 2P is composed of only such areas. The present embodiment has such a configuration. As a result of intensive research, the inventors have not made the pattern of the partition pattern 2P simply irregular, but repeated the arrangement of the pixels 3 partitioned by the partition pattern 2P with a certain regularity. By defining the pattern of the partition pattern 2P so that there is no direction arranged in a period, moire that can occur when combined with an optical filter having a periodic pattern can be made extremely inconspicuous. It turned out.

[No repeat cycle]
FIG. 4 is a plan view in a plane parallel to the XY plane for explaining that there are no repetition periods in the large number of pixels 3 defined by the partition pattern 2P. In this plane, one virtual straight line di is selected at an arbitrary position facing an arbitrary direction.
This one straight line di intersects the boundary line segment L 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 the dimension t1 of the certain pixel 3 on the straight line di. Next, the dimension t2 on the straight line di is similarly determined for another pixel 3 adjacent to the pixel 3 on the straight line di. Then, with respect to a straight line di at an arbitrary position in an arbitrary direction and a boundary line segment L intersecting with the straight line di, a number of pixels 3 that encounter the straight line di at an arbitrary position in an arbitrary direction are defined as t1 on the straight line di. , T2, t3,..., T8 are determined. And the sequence of numerical values of t1, t2, t3,..., T8 has no periodicity.
In FIG. 4, these t1, t2, t3,..., T8 are drawn separately from the partition pattern 2P together with the straight line di in the lower part of the drawing for easy understanding.

When the straight line di is rotated at an arbitrary angle from the position shown in FIG. 4 to obtain the dimensions t1, t2,... Of each pixel 3 in another direction, the straight line di is also obtained as in FIG. There is no periodicity in the direction.
That is, there is no direction having a repetition period in the arrangement of the pixels 3 defined by the boundary line segment L as in the arrangement of numerical values of t1, t2, t3,.
In other words, the arrangement of the pixels 3 is a sequence of numbers of pixel widths ti on an imaginary line segment di in an arbitrary direction passing through an arbitrary position. That is, there is no M that satisfies t (i) = t (i + M) (i and M are independent positive integers).

  Furthermore, in the partition pattern 2P in the image display panel 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. . 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 arrangement pattern of the partition pattern 2P is shown in FIG. 12A. It is possible to make the pattern greatly different from the square lattice pattern (N = 4.0). 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, the average value N of the number of boundary line segments L extending from one branch point B is set to 3.0 ≦ N <4.0, and the arrangement of the pixels 3 is made irregular to obtain the arrangement of the pixels 3. It was confirmed that the directions arranged with the repetition period can be prevented from being stably present, and as a result, it is possible to make the moire extremely inconspicuous.

  The average value N of the number of boundary line segments L extending from one branch point B is strictly determined by examining the number of boundary line segments L extending for all branch points B included in the partition pattern 2P. The average value is calculated. In practice, however, the overall tendency of the number of boundary line segments L extending from one branch point B in consideration of the size of one pixel 3 defined by the line portion Lt, etc. Boundary extending about a branch point B included in one section having an area expected to reflect (for example, a section of 10 mm × 10 mm in the section pattern 2P in which the pixel 3 is formed in the dimension example described later) The number of line segments L is examined 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 partition pattern 2P. Good.

  Actually, in the partition pattern 2P constituting the partition wall 2 in the image display panel 10 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 division pattern 2P in 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 branch points. 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.

[Presence or absence of moire when combined with periodic pattern of optical filter]
In FIG. 11C, the partition pattern 2P in the image display panel 10 shown in FIGS. 3 and 11A is overlaid with the square lattice-shaped periodic pattern in the optical filter 6 shown in FIG. 11B. The state is shown.

Here, the periodic pattern 6P of the optical filter 6 shown in FIG. 11B is a typical pattern in the electromagnetic wave shielding filter.
As can be understood from FIG. 11C, when the partition pattern 2P shown in FIGS. 3 and 11A is combined with an optical filter 6 having a periodic pattern of a square lattice shape, a striped pattern that can be visually recognized, That is, moire (interference fringes) did not occur.
In these drawings, the partition pattern 2P is drawn exaggerated in black so that the pattern can be easily understood, but the actual partition wall 2 can also be made black.

  On the other hand, FIGS. 12A to 12C exemplify the occurrence of moiré when the pixel 3 defined by the partition pattern 52P has a certain repetition period. In these drawings, the partition pattern 52P is drawn in black so that the pattern can be easily understood. Here, the partition pattern 52P explicitly indicates that it has a constant repetition cycle, and hereinafter, the partition pattern 52P is also referred to as a repetition cycle pattern 52P.

The image display panel shown in FIG. 12A is an image display panel including a partition wall 52 that exhibits a repeating periodic pattern 52P having a predetermined repeating period in the vertical and horizontal directions in a square lattice pattern, and is different from the image display panel 10 of the present invention. Is.
FIG. 12C shows a periodic pattern 52P having the repetition period shown in FIG. 12A as a periodic pattern in the optical filter 6 shown in FIG. 12B (the same as that shown in FIG. 11B). The superimposed state is shown. As can be understood from FIGS. 12A, 12B, and 12C, when the image display panel having the partition 52 of the repeating periodic pattern 52P is arranged so as to overlap the optical filter 6 having the periodic pattern, the partition 52 is formed. Light and dark streaks (in the example shown in FIG. 12C, light and dark streaks extending from the upper left to the lower right and light and dark streaks extending from the upper right to the lower left) are visually recognized due to the interference with the repeating periodic pattern 52P. Will come to be.

In the example shown in FIGS. 12B and 12C, the square lattice shape of the periodic pattern 6P of the optical filter 6 is inclined by several degrees with respect to the repeating periodic pattern 52P of the pixel array shown in FIG. 12A. Yes. This inclination angle is generally called a bias angle (degree). Such an inclination is a technique that is widely used in general to make moire inconspicuous. However, as can be understood from the fact that the striped pattern is visually recognized in FIG. 12C, the degree of occurrence of moire is not determined solely by the bias angle. In addition, the repeating cycle pattern 52P of the image display panel and the optical pattern It also depends on factors such as the relative repetition period ratio with respect to the periodic pattern of the filter, the line width of each of the repetition period pattern 52P of the image display element and the periodic pattern of the optical filter. If the moire is to be eliminated only by the bias angle between the repeating pattern 52P on the image display panel side and the periodic pattern on the optical filter side, optical filters having different bias angles are prepared according to the design specifications of the image display panel. It becomes necessary to do.

[Pattern pattern creation method]
Here, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, and the pixels 3 are arranged in a repeating cycle having a certain regularity. An example of a method for producing a pattern of the partition pattern 2P in which no direction exists 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 demarcate each boundary line segment L to determine a pattern of the partition 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 partition pattern 2P is to be formed. When the mother point cannot be arranged in the region where the partition pattern 2P is to be formed, the step of creating the mother point is completed. By the processing so far, the group of irregularly arranged points on the two-dimensional plane (XY plane) is uniformly dispersed in the region where the partition 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 R between any two adjacent mother points constituting the mother point group is 0 to infinity, but from the origin o. This means that the distance is distributed within a finite range from R _AVG −ΔR to R _AVG + ΔR (a donut-shaped region from radius R _MIN to R _MAX ).

As described above, by setting the distance between each generating point, the Voronoi area XA obtained from the generating point group by the method described below, and the circumscribed circle diameter (or The distribution of the area of the pixels 3 is not uniform (completely random) but distributed within a finite range.
By configuring in this way, the brightness unevenness of the image displayed by the pixels defined by the partition pattern 2P is more effectively eliminated. In order to make the light and dark unevenness of the image substantially invisible and compatible with the moire prevention due to the non-periodicity of the pixel arrangement, the maximum value of the circumscribed circle diameter D (the size of the pixel 3) of the pixel 3 is set to D _MAX , where the minimum value is D _MIN , the distribution range ΔD = D _MAX −D _MIN of the circumscribed circle diameter D is the average value D _AVG of the circumscribed circle diameter D,
0.1 ≦ ΔD / D _AVG ≦ 0.6
More preferably,
0.2 ≦ ΔD / D _AVG ≦ 0.4
And

  Note that, in the step of determining the generating point, the size of each pixel 3 can be adjusted by changing the size of the distance r. Specifically, the size of each pixel 3 can be reduced by reducing the size of the distance r, and conversely, the size of each pixel 3 can be reduced by increasing the size of the distance r. 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 partition 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.

As described above, the pattern of the partition pattern 2P can be determined.
Here, a specific example of the dimensions will be described. Regarding the dimensions of the discharge cells 3c corresponding to the respective pixels 3, the average value D _AVG of the circumscribed circle diameter D is 300 μm, and the distribution range ΔD of the circumscribed circle diameter D is 100 μm (275-275). 325 μm range). Therefore, ΔD / D _AVG = 0.33.
The line width of the partition pattern 2P, that is, the width of the partition wall 2 is 35 μm, and the height of the partition wall 2 is 30 μm.

  According to the present embodiment as described above, the partition pattern 2P that partitions each pixel 3 of the image display panel 10 extends between the two branch points B to define the pixel 3. The average value N of the number of boundary line segments L formed from the line segment L and extending from one branch point B is 3.0 ≦ N <4.0, and the arrangement of the pixels 3 is repeated. There is no direction with a period. As a result, it is possible to effectively prevent the optical filter 6 having a periodic pattern from being generated to such an extent that a striped pattern (moire, interference fringe) can be visually recognized even when the image display panel 10 is overlapped. Can do.

[Repeat as unit pattern area]
In the embodiment described above, in the entire area of the display surface having the plurality of pixels 3 of the image display panel 10, there is no direction having a repetition period in the arrangement of the pixels 3 defined by the partition pattern 2P. An example of a form has been described. However, as shown in FIG. 10, the entire area of the partition pattern 2P is configured such that the entire area of the partition pattern 2P is configured by collecting a plurality of unit pattern areas S, and each unit pattern area S Inside, a plurality of pixels 3 may be arranged in a region arranged in a pattern having no predetermined repetition period.

  In the example shown in FIG. 10, the image display panel 10 is divided into six unit pattern regions S having the same shape, and a plurality of pixels 3 are partitioned one by one in each unit pattern region S. The 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. 10 with a repetition cycle SP1, and two regions are arranged in the horizontal direction in FIG. 10 with a repetition cycle SP2. Are arranged as follows.

  That is, in this embodiment, two or more unit pattern regions S in which a plurality of pixels 3 are arranged in the same partition pattern 2P when viewed locally are included in the entire region of the partition pattern 2P. It becomes like this. 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, neither moiré nor brightness unevenness occurs in the unit pattern area S. In this example, the pattern of the partition 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 image display panel 10 has recently been increased in size, and for such a large-screen image display panel 10, a partition pattern 2P that partitions the pixels 3 one by one has a plurality of unit pattern regions. It is configured by including a plurality of unit pattern regions S that are configured by an arrangement of S and in which each pixel pattern 3 is arranged in the same pattern in each unit pattern region S. It is preferable in that the pattern creation of the partition pattern 2P can be greatly facilitated.

  In particular, in an example in which a single type of unit pattern region S is arranged in a plurality of vertical and horizontal directions as shown in FIG. . In the embodiment of FIG. 10, 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 pixels 3 in the dimension Ls on an arbitrary straight line dj extending in the specific direction, the straight line dj When attention is paid to a certain pixel 3 above, there is a regularity that there is always a pixel 3 of exactly the same size tj and shape at a position where the number of pixels 3 is separated by M on the straight line dj. That is, for the dimension tj of the pixel 3 on the straight line dj, the kth dimension tj (k) counted in order on the straight line dj is the same as the Mth (k + M) th dimension tj (k + M). The relationship tj (k) = tj (k + M) holds (k and M are independent positive integers).

  However, this regularity is based on the repetition period (the dimension Ls corresponds to the repetition period as described above) as the unit pattern region S, not the repetition period as the arrangement of the pixels 3. In each unit pattern region S, the arrangement of the pixels 3 does not have a repetition period in the specific direction. In addition, when the optical filter 6 has the periodic pattern 6P, the repetition period as the unit pattern region S is different from the general periodic pattern 6P in size by, for example, 1000 times, so that moire occurs. There is no similar dimensional relationship.

[Optical filter]
The image display panel 10 of the present invention can include an optical filter.

The image display panel 10 of the embodiment illustrated in the cross-sectional view of FIG. 13 includes the optical filter 6 on the light exit surface 11 a side of the image display panel main body 11.
Various optical filters 6 can be used, but the optical filter 6 in the present embodiment is an optical filter 6 having a periodic pattern 6P that can particularly enjoy the moire prevention effect of the present invention.
The image display panel main body 11 is the remaining components excluding the optical filter 6. For example, the image display panel 10 as the plasma display panel illustrated in FIG. 1 corresponds to the image display panel main body 11 in the embodiment of FIG. Alternatively, a liquid crystal display panel, an electroluminescent panel, or the like may be used.

  The optical filter 6 in the present embodiment transmits image light emitted from the light exit surface 11a of the image display panel body 11 to the viewer V side after performing an appropriate filter function. At this time, even if the optical filter 6 has the periodic pattern 6P, the predetermined partition pattern 23P that defines the arrangement of the pixels 3 included in the image display panel main body 11 constituting the image display panel 10 has a repetition cycle. Therefore, moire does not occur. At the same time, light and dark unevenness does not occur.

[Periodic pattern of optical filter]
The periodic pattern 6P of the optical filter 6 is such that light passing through the optical filter 6 as a single unit before being combined with the image display panel main body 11 (not image light from the image display panel main body 11) is this periodic pattern. There is no particular limitation as long as it is a pattern that is modulated by 6P to produce a bright and dark pattern. Since this light and dark pattern is a single optical filter 6, it does not mean a light and dark pattern caused by interference with the regular arrangement of the pixels 3 constituting the image display panel.

In the present invention, the optical filter 6 having the periodic pattern 6P does not need to have the bias angle θ. That is, the bias angle θ may be 0 degrees. Here, the bias angle θ is not an angle with respect to the predetermined arrangement direction but with respect to the long side or the short side of the image display panel 10 because there is no predetermined arrangement direction in the arrangement of the pixels 3 included in the image display panel 10. This means the angle in the periodic direction of the periodic pattern 6P of the optical filter 6.
Of course, the optical filter 6 may be given a bias angle θ, but no moire occurs at any bias angle θ. In other words, the bias angle θ may or may not be added.

  If the specific example of the said optical filter 6 is shown, the electromagnetic wave shielding filter shown in FIG. 14 and the micro louver filter shown in FIG. 15 can be mentioned. In the optical filter 6 having such a periodic pattern 6P, moire and light / dark unevenness are not visually observed.

  Hereinafter, an electromagnetic wave shielding filter and a microlouver filter will be further described as examples of the optical filter 6 having the periodic pattern 6P.

(Electromagnetic wave shielding filter)
The periodic pattern 6P in the electromagnetic wave shielding filter is obtained by, for example, laminating a conductive metal foil such as copper or aluminum on a transparent resin film such as polyethylene terephthalate, and then chemically etching it into a pattern such as a mesh shape. Can be formed. Alternatively, a conductive ink in which conductive particles such as silver and copper are dispersed in a binder resin can be printed on the transparent resin film as described above in a pattern shape such as a mesh shape.
As a specific example, the transparent resin film has a thickness of 100 μm, and a square lattice mesh pattern as shown in FIG. 11B, that is, the periodic pattern 6P has a line width of 10 μm and a period of 300 μm. The thickness is 10 μm.

  Various other patterns are known as the periodic pattern 6P in the electromagnetic wave shielding filter. For example, a triangular lattice or a hexagonal lattice (honeycomb shape) may be used. A pattern that is random in one direction but has periodicity in the other direction that intersects with this is also the periodic pattern 6P (see, for example, JP-A-11-121974).

(Micro louver filter)
The micro louver filter is an optical filter 6 having a micro louver structure as a periodic pattern 6P. The micro louver filter is used as a viewing angle control filter, a contrast enhancement filter, and the like. As the micro louver structure, for example, a structure described in JP 2007-272161 A can be adopted.

  The perspective view of FIG. 15 is an example of the optical filter 6 having the microlouver structure 7 as the periodic pattern 6P. In the microlouver structure 7, a plurality of light absorbing portions 7a are parallel to the extending direction (X direction) and spaced from each other in the filter surface direction (XY plane direction), and are orthogonal to the extending direction. It has a structure arranged in the (Y direction) at regular intervals. A portion other than the light absorbing portion 7a is a light transmitting portion 7b, and the light absorbing portion 7a and the light transmitting portion 7b constitute a microlouver structure.

The light absorbing portion 7a can be formed from a dark color material in which a dark colorant such as carbon black is contained in an ionizing radiation curable resin. As the ionizing radiation curable resin, for example, a known resin such as an acrylate type can be used.
The light absorbing portion 7a is a 2P method using an ionizing radiation curable resin, for example, a light transmitting portion 7b in which a groove-like recess having a concave and convex shape opposite to the light absorbing portion 7a is formed on a transparent resin film such as polyethylene terephthalate ( It is formed by first forming by a molding method such as a photopolymer method) and then filling only the inside of the groove-shaped recess with a dark color material by a known wiping method and curing.

  If the specific example of the dimension of a microlouver structure is shown, the thickness of the light absorption part 7a will be about 70 to 100% normally with respect to the thickness of the light transmission part 7b. In the case of a columnar body having a trapezoidal cross section, the dimensions of the light absorbing portion 7a are 3 μm in the upper base, 10 μm in the lower base larger than the upper base, 95 μm in height, and 95 μm in the arrangement period (interval between the lower bases In other words, the thickness (height) of the light transmission portion 7b is 100 μm.

[Position of optical filter]
In the embodiment shown in FIG. 13, the position of the optical filter 6 is on the image viewer V side of the image light output surface 11 a of the image display panel body 11. However, the image display panel main body 11 may be of a transmissive type that uses a back light source for image light as in the liquid crystal display method, and when configured in this transmissive type, the back light source and the image display panel main body 11 It is also possible to adopt a mode of between. Even if the illumination light that illuminates the image display panel main body 11 has periodicity due to the periodic pattern 6P, it is possible to prevent both the occurrence of moire and the occurrence of uneven brightness.
As the optical filter 6 having the periodic pattern 6P used in such a positional relationship, for example, a linear prism array in which a large number of triangular prisms are arranged with their ridge directions parallel to each other, A lenticular lens in which a large number of semi-cylindrical or semi-ellipsoidal unit lenses are arranged in parallel with each other in the ridge line direction, or a semispherical or spheroid semi-circular unit lens in two directions in the plane (for example, the front- There are eyelid lenses etc. arranged in large numbers in the left-right direction).

  In FIG. 13, the optical filter 6 is separated from the image display panel main body 11 and is disposed with an air layer interposed therebetween, but may be laminated and integrated with an adhesive layer of a transparent resin in between. The total thickness can be reduced by integration.

The optical filter 6 may be any of a film shape, a sheet shape, and a plate shape.
As used herein, the terms “sheet”, “film”, and “plate” are not distinguished from each other based solely on the difference in designation.

[Filter elements with no periodic pattern]
The optical filter 6 having the periodic pattern 6P may further include a filter element that does not have the periodic pattern 6P.
As the filter element not having such a periodic pattern 6P, a conventionally known optical filter can be appropriately employed. For example, there are an antireflection function, a color correction function, particularly a near infrared absorption function effective for a plasma display panel.

  The image display panel 10 of the present invention may include an optical filter or an optical film that does not have the periodic pattern 6P. For example, an optical filter having a filter element that does not have the periodic pattern 6P described above, an optical film having an antistatic function, a surface protection function, and the like.

[Panel module]
The image display panel 10 according to the present invention includes, as components other than those described above, various circuits such as a drive circuit for image display, wiring between the drive circuit and the image display panel main body 11, a chassis and frame for integrating them. In addition, a touch panel or the like may be included. Therefore, the image display panel 10 can also be referred to as “panel module”, “display module}, and the like.

[Display method]
In the embodiment described above, the display method of the image display panel 10 is the plasma display panel illustrated in FIG. 1, but the display method of the image display panel 10 in the present invention is arbitrary, and other than this. In addition, for example, a liquid crystal display panel, an electroluminescent panel, and the like can be given. In addition to monochrome display, color display may be used.

  The display method and the position of the optical filter are naturally related. That is, since the plasma display panel and the electroluminescence panel are self-luminous type, the optical filter 6 having the periodic pattern 6P is limited to a form arranged on the viewer V side with respect to the image display panel main body 11. Since the liquid crystal display panel can perform transmissive display in addition to the reflective display, the optical filter 6 may be arranged on the back side of the image display panel main body 11.

[B] Image display device:
The image display device according to the present invention is an image display device including at least the image display panel 10 according to the above-described specific present invention having a pixel arrangement characteristic as an image display panel.
An image display apparatus 100 according to an embodiment illustrated in FIG. 16 is an example in which a transmissive panel is used as the image display panel 10. For this reason, in this embodiment, the light source 20 is provided on the back side of the image display panel 10 as a back light source. Image light from the light exit surface 10 a of the image display panel 10 reaches the observer V.

The light source 20 is a surface light source having a flat light exit surface 20a, and a known light source can be adopted as the light source 20 of the surface light source.
For example, if a planar light-emitting electroluminescent light source (EL light source) is used as the light source, the light source 20 can be used as it is. Further, when using a cold cathode tube of a linear light emitter or a light emitting diode (LED) of a point light emitter as a light source, the light exit surface 20a is appropriately combined with a light guide plate, a light diffusion plate, a light reflection plate, or the like. The light source 20 is configured as an edge light (side light) type or a direct type so as to be planar. In other words, in this case, the light source 20 can also be said to be a light source module.
The light exit surface 20a may be a virtual surface. For example, there is a case where a space is provided in a portion from the light emitter to the optical member 10 with a direct type surface light source.

In addition to the surface light source 20 and the image display panel 10, the image display device 100 is used for an image display device in addition to an optical film, a casing (cabinet), an input / output component, etc. that are not integrated with the image display panel 10. Correspondingly, for example, in the case of a television receiver, various known components in the image display device such as a tuner are provided. These other components are not particularly limited, and depend on the application.
The optical film is, for example, a brightness enhancement film such as a polarized light separation film, a polarizing film, a retardation film, a light diffusion sheet, or a light collecting sheet.

  Since the above-described image display panel 10 is used for the image display device 100 having such a configuration, when the image display device 100 is viewed from the viewer V side of the image, It becomes an apparatus capable of displaying an image in which moiré does not occur and light and dark unevenness does not occur.

[C] Application:
An image display panel 10 according to the present invention and an image display apparatus 100 including the same are a television receiver, a measuring device, an instrument, office equipment, a medical device, a computing device, a telephone, an electronic signboard, an amusement device, a digital photo frame. It can be suitably used for image display applications such as.

1f Front side glass substrate 1r Back side glass substrate 2 Partition 2P Partition pattern 3 Pixel 3c Discharge cell 4h Horizontal address electrode 4v Vertical address electrode 5 Intersection 6 Optical filter 6P Periodic pattern 6w Continuous band-shaped optical filter member 6x Waste part 7 Micro Louver structure 7a Light absorbing portion 7b Light transmitting portion 10 Image display panel 11 Image display panel body 20 Light source 100 Image display device B Branch point BP Generating point L Boundary line segment Lt Line part (set of boundary line segment)
S Unit pattern area V Observer

Claims (4)

In an image display panel in which a large number of pixels are arranged,
The partition pattern that partitions the pixels is composed of a number of boundary line segments that extend between two branch points to define the pixels,
A pattern including an area where the average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0, and there is no direction having a repetition period in the pixel arrangement. An image display panel.   The image display panel according to claim 1, further comprising an optical filter on an observer side of the image, wherein the optical filter has a periodic pattern.   The image display panel according to claim 1, wherein the image display panel is a liquid crystal display panel, a plasma display panel, or an electroluminescence panel. An image display apparatus comprising the image display panel according to claim 1.

Images