JP2001022283A - Filter and image device provided with filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter which has a higher opening ratio than a filter using a mesh and in which a moire pattern is hardly visible when the filter is disposed in front of an image device having square pixels. SOLUTION: In a transparent filter on which many linear conductive materials are arranged on the surface of a sheet body to be disposed in front of an image device having square pixels, the conductive materials having <=50 μm line width are arranged in two directions with a pitch P1 and a pitch P2 on the sheet body. The opening ratio of the filter is >=70%. The P1, P2 and the lengths W1 and W2 of the pixel in the image device along the vertical direction and the horizontal direction, respectively, satisfy the relation of n1 +0.35<=W1/P1<=n1+0.65 and n2+0.35<=W2/P2<=n2+0.65.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image device with a filter and a filter.

[0002]

2. Description of the Related Art Unwanted electromagnetic waves generated by electronic devices cause malfunctions of other electronic devices, and therefore, it is required to suppress them as much as possible. For example, in the housing of an electronic device, this electromagnetic wave is suppressed by a method of plating the inside with metal or the like. In addition, on the display surface of an image display device such as a CRT, a front filter is provided to suppress transmission of unnecessary electromagnetic waves. Since the front filter needs to be transparent, a laminate of a conductive mesh fabric (hereinafter, referred to as “mesh”), a transparent conductive film, and a transparent substrate has been used. Japanese Patent Application Laid-Open No. 3-221798 discloses an electromagnetic shield plate in which two transparent plates on which a large number of conductive thin wires are arranged and fixed are overlapped.

[0003] In recent years, a plasma display panel (hereinafter, referred to as "PDP"), which is an image display device utilizing plasma discharge, has been developed. However, PDP has a large amount of unnecessary electromagnetic wave radiation. There is a demand for a material that has a high effect of suppressing odor. Further, the PDP further emits light due to plasma discharge in a wavelength range of 850 to 1000 nm, which causes a malfunction of the remote controller for operating the PDP. For this reason, front filters are also required to suppress transmission of light in this wavelength range. Further, PDP is a large-screen flat display, and a large and thin glass electrode substrate of the panel body is used. Therefore, a function of preventing breakage thereof is also required for a front filter.

[0004] As a PDP front filter having such a function, a light-transmitting resin sheet having an absorption function in a near-infrared region as disclosed in Japanese Patent Application Laid-Open No. 9-247585 includes copper and copper. A laminate obtained by laminating a conductive mesh composed of polyester filaments sequentially coated with nickel is used.

[0005]

In order for a bright image to be seen even when a filter is arranged in front of the image device,
It is necessary to increase the light transmittance of the filter. However, if the wire diameter of filaments or the like constituting the mesh in the filter is set to be small and the pitch of the mesh is set wide for the purpose of increasing the light transmittance of the filter, the dispersion of the mesh interval becomes large and the appearance deteriorates. Therefore, the aperture ratio, which is the ratio of the translucent portion per unit area, is 70%.
The above mesh is difficult to manufacture, and a filter having a high light transmittance has not been obtained.

[0006] Further, moire occurs due to mutual interference between two groups of line groups, ie, a group of boundary lines between pixels and a group of lines forming a mesh. As a method of making moire less noticeable, a method of making the wire diameter smaller so as to make the moiré less noticeable can be considered. However, it is difficult to produce a mesh having a smaller wire diameter for the above-described reason. In addition, there is a method of setting the pitch of the mesh to a pitch at which moire is not noticeable. By the way, generally, the mesh is plain weave, the lines are orthogonal, and the pitch is equal in both directions. In contrast, the vertical and horizontal lengths of pixels of an imaging device are generally not equal. Therefore, when the mesh is arranged on the front side of the image device, moire due to mutual interference between the vertical boundary lines between the pixels and the vertical lines of the mesh is inconspicuous, but between the pixels. Moire may be noticeable due to mutual interference between the horizontal boundary lines and the horizontal lines of the mesh.
Conversely, moire due to mutual interference of horizontal line groups is not noticeable, but moire due to mutual interference of vertical line groups may be noticeable. In addition, in order to make moiré less noticeable, there is a method of arranging mesh lines at a certain angle such as 45 degrees with respect to a boundary between pixels. However, if this angle is 20 degrees or more, that is, the intersection angle between the boundary line between pixels and the mesh line must be 20 degrees or more, it is necessary to cut and remove a large amount of the end of the mesh when manufacturing the filter. Therefore, there is a problem that the filter manufacturing cost is increased. Also, Japanese Unexamined Patent Application Publication No.
No. 798 does not describe or suggest any technique relating to moiré prevention.

An object of the present invention is to provide a filter having a higher aperture ratio than when a conventional conductive mesh made of polyester filaments coated with copper and nickel sequentially is used. Another object of the present invention is to provide a high-quality image device in which moire is inconspicuous by disposing the filter in front of an image device having square pixels.

[0008]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a transparent device in which a large number of linear conductors are arranged on the surface of a planar object to be disposed on the front surface of an image device having rectangular pixels. In the filter, conductive materials having a line width of 50 μm or less are arranged in two directions at a pitch P1 and a pitch P2, respectively, and the filter has an aperture ratio of 70% or more and a vertical direction of pixels of an image device. The length of Y and the length of horizontal X are each W
1 and W2, P1, P2, W1 and W2 are represented by the following equations (1) and (2), equations (3) and (4),
A filter characterized by satisfying any one of the equations (5) and (6) or the equations (7) and (8).

[0009] n1 + 0.35≤W1 / P1≤n1 + 0.65 (1) n2 + 0.35≤W2 / P2≤n2 + 0.65 (2) n1 + 0.35≤P1 / W1≤n1 + 0.65 (3) n2 + 0.35≤P2 /W2≦n2+0.65 (4) n1 + 0.35 ≦ W1 / P2 ≦ n1 + 0.65 (5) n2 + 0.35 ≦ W2 / P1 ≦ n2 + 0.65 (6) n1 + 0.35 ≦ P1 / W2 ≦ n1 + 0.65 (7) N2 + 0.35 ≦ P2 / W1 ≦ n2 + 0.65 (8) (n1 and n2 are each an integer of 1 to 5) The average light transmittance of the planar material is 30% or less in the wavelength range of 850 to 1000 nm, and the wavelength is 400. 4 in the range of ~ 650 nm
It is preferably 0% or more.

The gist of the present invention is that the smaller angle θ1 or θ2 between the longitudinal direction of the linear conductor of the filter and the vertical direction Y and the horizontal direction X of the image device is 3 to 3 respectively. An image device with a filter arranged within a range of 18 degrees.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the planar material constituting the filter of the present invention include a transparent plate-like material and a film-like material. They can also be laminated to form a sheet.
The plate-like object may be processed into an arch shape.

[0012] Examples of the plate-like material and the film-like material include those made of resin or glass. Examples of the resin for the plate-like material include an acrylic resin, a polycarbonate resin, a polyolefin resin, and a polystyrene resin. As the resin for the film-like material, a polyester resin, a urethane resin, an acrylic resin, a polyolefin resin,
Triacetate and the like can be mentioned.

The average light transmittance of the planar material is 850-100.
It is preferably 30% or less in the range of 0 nm and 40% or more in the range of wavelengths of 400 to 650 nm. When a plurality of planar objects are stacked, the average light transmittance of at least one planar object is 30 in a wavelength range of 850 to 1000 nm.
% Or less, and preferably 40% or more in the wavelength range of 400 to 650 nm. If the average light transmittance in the wavelength range of 850 to 1000 nm is too high, the near-infrared cut function becomes insufficient, which causes a malfunction of the remote control for operating the PDP, which is not preferable. The average light transmittance in the wavelength range of 850 to 1000 nm is more preferably 20% or less.

The method for controlling the light transmittance includes a method using a light absorbing agent and a method using a near-infrared reflective film.

As a method of controlling the light transmittance with a light absorber, there is a method of including a dye or pigment having an absorption in a predetermined wavelength range in the above-mentioned planar material. As a method of containing the dye and pigment, a method of mixing the resin and the dye and pigment, extrusion molding, or a method of dissolving the resin and the dye and pigment in a solvent and casting and forming a sheet or film into a predetermined wavelength range A method of dispersing a metal ion having an absorption in a polymerizable monomer and then polymerizing to form a sheet is exemplified.

Examples of dyes and pigments include metal complex dyes such as dithiol / nickel complex dyes, diimmonium dyes, aminium dyes, and phthalocyanine dyes.

As a method of controlling the light transmittance by the near-infrared reflecting film, a method of forming a metal film, a metal oxide film, or a laminated film thereof on a surface of a planar object to reflect light in a near-infrared wavelength region. Is mentioned. Examples of the metal constituting the metal film include gold and silver. Examples of the metal oxide forming the metal oxide film include titanium oxide, zinc oxide, and ITO.

Examples of the large number of linear conductors arranged on the surface of the planar object include conductive ink and various metals.
Examples of the arrangement method include a method of printing a pattern with conductive ink, a method of forming a metal film on the surface of a planar object and etching the metal, and a method of arranging metal wires on the planar object at a constant pitch. No. Examples of the metal for etching include copper, an alloy containing copper as a main component, nickel, and the like. Metal wires include tungsten, stainless steel, copper,
Alloys mainly composed of copper, aluminum alloys, and the like can be given.

Examples of a method of integrating the metal wire and the planar object include a bonding method using an adhesive and a bonding method using an ultraviolet curable resin. When the sheet is a thermoplastic resin, a method of embedding a metal wire in the sheet by pressing or the like can be used.

In the filter according to the present invention, a large number of linear conductors are provided on the surface of a planar object in two directions at pitches P1 and P2, respectively.
The conductive material and the planar material are integrated. The configuration of the filter may be such that a large number of linear conductors are arranged in one direction on one surface of a sheet as shown in FIG. 1 and integrated, and as shown in FIG. And a large number of linear conductors may be arranged in each case. Further, a planar material in which a large number of linear conductors are arranged and integrated in one direction and another planar material in which a large number of linear conductors are arranged and integrated in one direction may be laminated. . The laminated configuration in this case is
As shown in FIG. 3, the conductive material may be stacked such that it is on the inner surface side, or as shown in FIG. 4, the conductive material may be stacked such that one conductive material is arranged on the front surface side. In addition, in FIGS. 1 to 4, the member indicated by 1 represents a conductive material, and the member indicated by 3 represents a planar material.

A large number of linear conductors may be arranged in three or more directions. In that case, the pitches in any two directions among the multiple directions are P1 and P2.

The line width of the conductor is 50 μm or less. From the viewpoint of electromagnetic wave shielding properties, it is preferable that the line width is large.
If the thickness is larger than μm, the line is easily viewed, which is not preferable.

The aperture ratio of the filter is 70% or more. The aperture ratio is a ratio of a portion through which light is transmitted when viewed from a surface direction of the filter, and means a ratio of a light transmitting portion per unit area. If the aperture ratio is less than 70%, the amount of transmitted light is small, and the performance as a filter is undesirably reduced. More preferably, the aperture ratio is 75% or more.

[0024] A filter in which a large number of linear conductors are arranged and integrated on a transparent sheet-like material, such as a mesh even if the line width and pitch of the conductors are set so that the aperture ratio is 70% or more. This is preferable because there is no disturbance in the arrangement of the metal wires.

It is preferable that the surface of the conductive material is blackened, since the reflection of light is suppressed and the glare is eliminated.

When printing a pattern with a conductive ink, there are a method of printing the pattern printed with the conductive ink with a black ink, and a method of printing the pattern with the black conductive ink.

In the case of an etching method in which a metal film of copper or the like is formed on a substrate, a resist layer is formed thereon in a pattern, and the metal film in a portion without the resist layer is removed with an etching solution, a black resist is used. The method used is mentioned.

When the surface of the metal wire is to be blackened, a method of coating a black polymer at the time of manufacturing the metal wire, a method of applying a conductive black paint in which carbon particles are dispersed to the metal wire, a chemical treatment of the metal wire surface, or the like. And a method of partially oxidizing and blackening. Further, a method using a black metal wire such as tungsten may be used.

FIG. 5 shows a front view of an image device having square pixels.
It is an example of the top view in which the filter of the present invention was arranged. Image devices having square pixels include PDPs, liquid crystal panels,
And a cathode ray tube. In FIG. 5, 1
The line indicated by 2 represents a conductor, and the line indicated by 2 represents a boundary line between pixels of the image device.

When the lengths of the pixels of the image device in the vertical direction Y and the horizontal direction X are W1 and W2, respectively, P1, P2,
W1 and W2 represent any one of the expressions (1) and (2), the expressions (3) and (4), the expressions (5) and (6), or the expressions (7) and (8). Fulfill. Here, Expressions (1) and (2), and Expressions (3) and (4) indicate that the longitudinal direction of a large number of linear conductors arranged at the pitch P1 is perpendicular to the image device. Closer to horizontal X than Y, pitch P
2 is a formula relating to a case where the longitudinal direction of a large number of conductors arranged in 2 is closer to the vertical direction Y than the horizontal direction X. On the other hand, Expressions (5) and (6), and Expressions (7) and (8) indicate that the longitudinal direction of a large number of linear conductors arranged at the pitch P1 is horizontal with respect to the image device. This is an equation relating to a case where the longitudinal direction of a large number of conductors arranged at a pitch P2 is closer to the horizontal direction X than to the vertical direction Y than X.

When P1, P2, W1, and W2 satisfy the above relationship, the boundary between the pixels, that is, the vertical direction Y or the horizontal direction X of the image device, and the longitudinal direction of the linear conductive material When this filter is arranged on the front surface of the image device such that the filter is parallel, the moire observed when the filter is extremely small. When P1, P2, W1, and W2 do not satisfy the above relationship, moire is conspicuous when the boundary between pixels and the longitudinal direction of the linear conductor are parallel, which is not desirable. A filter in which P1 and P2 have different lengths is preferable, and a filter in which P1 / P2 is 1.05 or more, or a filter in which P1 / P2 is 0.95 or less is more preferable. Conductors having different values of the pitch P1 and the pitch P2 in this way have many types of applicable image devices as compared to conductors having the same value for both pitches. That is,
A conductor designed for one image device is rotated 90 degrees clockwise or counterclockwise with respect to the design standard, and is applied to another image device having a pixel size different from that of the image device. May be possible.

The filter is set so that the narrower angle between the longitudinal direction of the linear conductive material arranged in the filter and the vertical direction Y and the horizontal direction X of the image device is within a range of 0 to 18 degrees. Preferably, it is located on the front of the imaging device. Also,
This angle is more preferably 3 degrees or more. on the other hand,
This angle is more preferably 15 degrees or less.

FIG. 5 shows a vertical direction Y and a horizontal direction X of the image device.
2 shows an example in which the longitudinal direction of the linear conductor forms angles θ1 and θ2 in the counterclockwise direction, respectively. θ
1 and θ2 are either clockwise angles,
The other may be counterclockwise. When the filter is arranged at the above-mentioned angle, moiré becomes less noticeable, which is more preferable.

The filter of the present invention is suitable as a filter for a front panel of a PDP. When this filter is used as a front panel of a PDP, if necessary, an anti-reflection film or a non-glare film is attached to the filter surface facing the observer when attached to the PDP to reduce reflection of external light. can do. Further, by attaching a similar film to the filter surface on the back surface side as viewed from the observer side, it is possible to suppress the occurrence of Newton rings generated between the glass electrode substrate and the filter.

[0035]

The present invention will be specifically described below with reference to examples.

As the metal wire, a tungsten wire manufactured by Nippon Tungsten Co., Ltd. or a SUS wire manufactured by Nippon Seisen Co., Ltd. was used. As a transparent film, a non-carrier adhesive film “LS 131B” manufactured by Lintec Co., Ltd. (thickness: 3)
0 μm) was used.

A non-carrier film having a diameter of 400 mm and a width of 1
The film was wound around a side peripheral surface of a 300 mm drum, and a metal wire was further wound around the film at a predetermined pitch to integrate the metal wire and the film. Using a roll laminator, two films obtained by arranging a number of metal wires thus obtained are laminated between a colorless and transparent acrylic resin plate (300 × 300 mm) having a thickness of 1.5 mm and a thickness of 0.2 mm. And a filter was manufactured.

The filter was arranged at a distance of 3 mm from the PDP (manufactured by Fujitsu General) and in front of the filter, and the occurrence of moire was observed from all angles. The length W1 in the vertical direction Y of the pixel of the PDP is 1080 μm, and the length W2 in the horizontal direction X is
Was 360 μm. The smaller angle between the metal wires arranged at the pitch P1 and the horizontal direction X is θ2, the pitch P2
The smaller one of the angles formed by the metal wires arranged in the vertical direction and the vertical direction Y was defined as θ1.

[Example 1] A tungsten wire having a thickness of 30 µm was used as a metal wire.

The pitch P1 is 234 μm, and the pitch P2 is 256
A filter having a thickness of 7 μm and an aperture ratio of 77.0% was manufactured. Moiré was not visible. Table 1 shows the relationship between W1 / P1, W2 / P2, θ1, θ2 and moire.

[Examples 2 to 4] Filters were manufactured and arranged in the same manner as in Example 1 except for the conditions described in Table 1. In both cases, moire was not visually recognized.

Example 5 The conditions other than those described in Table 1 were the same as in Example 1.
A filter was manufactured and arranged in the same manner as described above. Moiré was not visible.

Note that light reflection by the metal wire was observed as compared with Example 1.

Example 6 The length and width of the acrylic resin plate were set to PD
It was the same size as the front of P. Further, on an acrylic resin plate having a thickness of 1.5 mm, 0.21 g / m ^{2 of} IRG022 manufactured by Nippon Kayaku Co., Ltd. as a diimmonium-based dye, and SI manufactured by Sankyo Chemical Co., Ltd. as a dithiol-nickel complex-based dye.
R159 was added at 0.22 g / m ² to impart near infrared absorption properties. The average light transmittance of this plate is 400 wavelength.
50% or more in the range of 650 to 650 nm, wavelength 850 to 100
It was 15% or less in the range of 0 nm. Using these acrylic resin plates, a filter was manufactured and arranged in the same manner as in Example 1 except for the conditions described in Table 1. Moiré was not visible. Also, the remote control of the PDP worked normally.

[Comparative Example 1] Conditions other than those described in Table 1 were the same as in Example 1.
A filter was manufactured and arranged in the same manner as described above. Moiré was spotted. Further, the image was dark because the aperture ratio was lower than that in Example 1. Further, the metal wire was easily visible.

Comparative Examples 2 to 5 Filters were manufactured and arranged in the same manner as in Example 1 except for the conditions described in Table 1. In each case, moire was visually recognized.

[0047]

[Table 1]

[0048]

According to the filter of the present invention, the aperture ratio can be made higher than in the case where a conventional conductive mesh made of polyester filaments coated with copper and nickel sequentially is used, and the visible light transmittance is increased. can do. Further, by disposing this filter in front of an image device having square pixels, it is possible to provide a high-quality image device in which moire is inconspicuous. When this filter is arranged on the front surface of the image device, the smaller angles θ1 and θ2 between the longitudinal direction of the linear conductor of the filter and the vertical direction Y and the horizontal direction X of the image device are smaller than those in the conventional art. They can be arranged within a small angle range of 18 degrees or less, instead of a large angle such as 45 degrees.

[Brief description of the drawings]

FIG. 1 is an example of a cross-sectional view of a filter of the present invention.

FIG. 2 is another example of a cross-sectional view of the filter of the present invention.

FIG. 3 is another example of a cross-sectional view of the filter of the present invention.

FIG. 4 is another example of a cross-sectional view of the filter of the present invention.

FIG. 5 is a plan view showing an example in which the filter of the present invention is attached to an image device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Linear conductor 2 Boundary between pixels of an imaging device 3 Transparent planar object P1 Pitch of a linear conductor P2 Pitch of a linear conductor W1 Length of pixel Y of an imaging device in the vertical direction Y W2 Horizontal X length of pixel of image device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H05K 9/00 H05K 9/00 V

Claims (10)

[Claims] 1. A transparent filter in which a large number of linear conductors are arranged on the surface of a planar object to be disposed on the front surface of an image device having rectangular pixels. Is 50 μm or less in each of the pitches P1 in two directions.
And a pitch P2. When the aperture ratio of the filter is 70% or more and the lengths of the pixels of the image device in the vertical direction Y and the horizontal direction X are W1 and W2, respectively, P1,
P2, W1 and W2 are any of the following formulas (1) and (2), formulas (3) and (4), formulas (5) and (6), or formulas (7) and (8) A filter that satisfies the relationship n1 + 0.35≤W1 / P1≤n1 + 0.65 (1) n2 + 0.35≤W2 / P2≤n2 + 0.65 (2) n1 + 0.35≤P1 / W1≤n1 + 0.65 (3) n2 + 0.35≤P2 / W2≤ n2 + 0.65 (4) n1 + 0.35 ≦ W1 / P2 ≦ n1 + 0.65 (5) n2 + 0.35 ≦ W2 / P1 ≦ n2 + 0.65 (6) n1 + 0.35 ≦ P1 / W2 ≦ n1 + 0.65 (7) n2 + 0. 35 ≦ P2 / W1 ≦ n2 + 0.65 (8) (n1 and n2 are each an integer of 1 to 5) 2. The filter according to claim 1, wherein P1 and P2 have different lengths. 3. P1 / P2 is 1.05 or more, or P1
/ P2 is 0.95 or less.
The filter according to. 4. The filter according to claim 1, wherein the linear conductor is a metal wire. 5. The filter according to claim 1, wherein the surface of the conductive material is blackened. 6. An average light transmittance of the planar material is 850 to 850.
30% or less in the range of 1000 nm, wavelength of 400 to 650
The filter according to any one of claims 1 to 5, wherein the ratio is 40% or more in a range of nm. 7. The filter according to claim 1, wherein the filter has an average light transmittance of 850 to 1000 n.
A laminated filter formed by laminating 30% or less in the range of m and 40% or more in the range of the wavelength of 400 to 650 nm. 8. The smaller angle θ1 between the longitudinal direction of the linear conductor of the filter according to claim 1 and the vertical direction Y and the horizontal direction X of the image device. An image device with a filter in which θ2 is arranged within a range of 0 to 18 degrees. 9. The image apparatus according to claim 8, wherein the angles θ1 and θ2 are both within a range of 3 to 18 degrees. 10. The apparatus according to claim 8, wherein the imaging device is a plasma display panel.