JPH049092A - Mesh filter for vdu screen - Google Patents

Abstract

PURPOSE:To prevent moire fringes from being generated by specifying the longitudinal line pitch, lateral line pitch, and tilt angle of a filter respectively. CONSTITUTION:The apparent horizontal pitch of meshes formed of picture elements is denoted as p1, the number of the meshes as m1, the vertical pitch as p2, the number of meshes as m2, the pitch of longitudinal lines of the filter as P1, the number of meshes as M1, the pitch of lateral lines as P2, the number of meshes as M2, and the tilt angle of the longitudinal lines of the filter to the vertical line as beta (beta : 0 - 90 deg.). Then the longitudinal line pitch P1, lateral line pitch P2, and tilt angle beta of the filter are so set that the calculation results of Q, S, R, T, U, and V of inequalities are within specific ranges. Consequently, moire fringes are prevented from being generated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a VDU (visual device) in which both the horizontal and vertical pitches of the apparent mesh of pixels are constant regardless of the measurement location on the screen. The present invention relates to a screen filter (display unit), specifically a VDU screen mesh filter that prevents the occurrence of moiré fringes.

[Conventional technology]

In recent years, with the rapid transition to an information society, opportunities to use office automation equipment such as word processors and personal computers are increasing. In order to create an appropriate working environment in response to this situation, rV
V
It is expected that various problems related to DT work will be clarified and countermeasures taken.

Against this background, it is recommended that filters having various functions be installed not only in CRTs but also in display (hereinafter referred to as VDU) screens that have similar problems. The main functions of this filter are to prevent glare on the VDU screen, reduce flicker, adjust brightness contrast, and remove ultraviolet rays, and filters equipped with these functions have already been put into practical use. Furthermore, due to the structure of VDUs, it is unavoidable that static electricity is generated on the screen side, especially when turning on and off the switch of CRT.
Although it has been recognized that static electricity of more than 0KV is generated, and that electromagnetic waves are not emitted to the extent that they have a negative effect on the human body, some users have a latent sense of anxiety about the radiation. For this reason, in response to the needs of users, filters for VDO screens have been provided which are equipped with the above-mentioned functions and also have a shielding effect against static electricity and electromagnetic waves. For example, US Pat. No. 4,468,702,
Alternatively, the method shown in Japanese Utility Model Application Publication No. 59-71344 falls under this category. Such multifunctional filters are usually applied using a conductive mesh fabric made of thin metal wires, carbon fibers, or metal-plated synthetic fibers, either directly or sandwiched between two transparent plastic sheets, and the number of meshes in the mesh fabric varies. is generally 100 to 270 pieces/
inch, and is usually used with the warp vertical.
No. 9123 is used with the warp threads at an angle of 45 degrees with respect to the vertical.

[Problem to be solved by the invention]

However, the above-mentioned conventional mesh fabric can be used for VD in a method in which both the horizontal and vertical pitches of the apparent mesh by pixels are constant regardless of the measurement location on the screen.
When used as a filter for the U screen, moire fringes were observed depending on the VDU model. These moiré fringes intersect with the horizontal component and vertical component of the mesh attached by the image, the mesh, and the warp and weft of the fabric filter (hereinafter referred to as filter). Therefore, the apparent mesh force due to pixels is V
Let's examine in detail the conditions for the occurrence of moiré on a single screen. V D Measure the pitch in one horizontal direction and the pitch in the vertical direction at any location on one screen using a tesimeter, and calculate the pitch in the horizontal direction of the wall-mounted mesh using pixels.
,) I, its mesh number is ml, its vertical pitch is IJ2, its mesh i number is lT12. The pitch of the filter warp is F)1, the number of meshes is M1, and the pitch of the weft is P2. The mesh number is M2, the inclination angle of the filter warp to the vertical line is β (however, β is 0 degrees or more and 00 degrees or more), and the warp mesh number of the filter and V D 1
The ratio of the number of filter meshes in the weft direction component of the apparent warp mesh of the screen is Q, and the ratio of the number of filter warp thread meshes to the number of meshes of the filter weft direction component of the apparent weft mesh of one screen is Q. R, filter σ) The ratio of the number of weft meshes to the number of filter warp direction component meshes of the apparent warp meshes on the VDU screen is S.
, the ratio of the number of filter weft meshes to the filter warp direction component mesh number of the apparent weft mesh on the VDU screen is 1゛, and the ratio of the filter warp mesh number and the filter weft direction component of the apparent warp mesh on the VDU screen is 1゛. The ratio between the mesh number and the average value of the filter weft direction component mesh number of the apparent weft mesh is (1, the filter weft mesh number and VI). The filter warp direction component mesh of the apparent warp mesh of one screen When the ratio between the number and the average value of the filter warp direction component mesh number of the apparent weft mesh number is V, the respective relational expressions are expressed as follows.

25,4/l) , , m 2 =
25.4/ p 2M + -25,4/ P 1M2
=25.4/P2Q=M+/(m1
CO8β) = p + / (P ICO8β〉R”
M 1/ (m 2SINβ) ”' r) 2 /
(P l5INβ)S --M2,/'
(m + SIN β - P 1 /
(P 2sIN β )T' = M2 /
(m2cO8β) -P2/(
P2CO8β)2+)+P2PI(+)l5INβ+p2CO8β)PIP2P2(pIcO8β+p2SINβ) The inventor first used a densimeter to find the pitch in the horizontal and vertical directions of the apparent mesh based on the pixels of the VDU screen,
After specifying P and P2 of the filter, changing the inclination angle β, and calculating the formula % from the above formula, actually installing the filter on the VDU screen and conducting a C test, it was calculated using the formula above. Q, R
, S, and T are 0.50.0 and 67, respectively.
．． 1.0 , ], , 5 , 2.0.2.5.3.0.
Moiré fringes occur when the tilt angle β is set so as not to be 3.5 and 38 old, and Q/R is 0.5 or more.
．． If it is in the range of 0 or less or S/T is in the range of 0.5 or more and 2.0 or less, Q, R, S, '', calculated by the above formula.
In addition, any value including U and ■ is 0.50 each.
．． 0.67.1.0 , , ], , 5.2,025.3
It has been found that moiré fringes occur when the inclination angle β is set so as not to exceed 0.3, 5 and 3.8 fl. Special Publication No. 34-8069 and Utility Model Publication No. 49-79
The one described in No. 123, that is, the warp is 4 perpendicular to the
For those used at an angle of 5 degrees, Q, RlS, ]゛, which can be found using the above formula, as well as U and ■
Each value that increases is 0.50.0.67.
Moire fringes were observed when P, , P2, and β were set not to exceed 1.0, 1.5.2.0.2.5.3.0.3.5, and 3.8. .

For example, the pitches in the horizontal and vertical directions of the apparent mesh of pixels obtained through actual measurements are p 1=
C of Toshiba laptop computer J-3000SGX which is 0.358 mm, T: l 2 = 0.358 mm
A mesh fabric of 20 tenier polyester monofilament 1 to 1 was nickel-plated on the surface of the RT to give it conductivity, and a filter (130 x 134 mesh) was manufactured and tested on the model, and the inclination angle β was 45 degrees. Moiré stripes were observed.

The present invention provides a mesh filter for VDU screens to overcome these problems.

[Means to try to solve the problem]

The present invention relates to a mesh fabric filter consisting of ultra-fine warp and weft threads to be installed on a VDU screen in which both the horizontal and vertical pitches of the apparent mesh of pixels are constant regardless of the measurement location on the screen. The horizontal pitch of the apparent mesh by pixels is pI, the number of meshes is m1, the pitch in the vertical direction is p2, the number of meshes is m2, the warp pitch of the filter is P1, the number of meshes is MI, the weft pitch is P2 mesh number M2
, the angle of inclination of the warp of the filter with respect to the vertical line is β (however, β is 0 degrees or more and less than 90 degrees), and the number of warp meshes of the filter and the number of filter weft direction component meshes of the apparent warp meshes on the VDU screen are The ratio is Q, the ratio between the number of warp meshes of the filter and the number of filter weft direction component meshes of the apparent weft meshes on the VDLI screen is R, and the ratio of the number of weft meshes of the filter to the filter warp number of the apparent warp meshes on the VDU screen. S is the ratio between the number of direction component meshes, T is the ratio between the number of filter weft meshes and the filter warp direction component mesh number of the apparent weft meshes on the VDU screen, and T is the ratio between the number of warp meshes on the filter and the apparent warp on the VDU screen. The ratio between the number of filter weft direction component meshes in the mesh and the average value of the filter weft direction component mesh number in the apparent weft mesh is U, and the filter weft mesh number in the filter and the filter in the apparent warp mesh on the VDU screen. When the ratio of the number of meshes in the warp direction component and the average value of the number of meshes in the filter warp direction component among the apparent weft meshes is V, it is expressed by the following formula (l The values of R, S, and T are all 0.50±5%, 0.67 above 5%, 1.o±5 respectively
%, 1.5±5%, 2.0±5%, 2.5±5%, 3.
0±5% and above 3.81, and Q/R
is in the range of 0.5 or more and 2.0 or less or S/T is 0.5
If the range is greater than or equal to 2.0, Q is expressed by the following formula.
, R, S, and T as well as U and ■.The values are 0.50±5%, 0.67±5x, 1.0±5%, respectively
1.5±5x, 2.0±5%, 2.5±5%, 3.0±
5χ and 3.8 months above the filter warp pitch P1. This is a VDU screen mesh filter in which a weft pitch P2 and an inclination angle β are set.

Here, m l = 25.4/ P I M 1 = 25.4/ P s Q = M 1/ (m 1CO5β) R = M 1/
(m2SINβ) S = M2 / (m +SINβ)T = M
2 / (m 2CO8β) 25.4 / p 2 25.4 / P 2 / (PICO8β) / (P, SINβ) / (P2SINβ) / (P 2CO8β) = p1 = p2 = P+ ”P2 2IPI 1) 2 P +(p+SINβ+p2CO8β)P2(1)
ICO8β+p2SINβ).

If you know the horizontal and vertical pitches of the apparent mesh on the VDU screen, you can calculate the warp pitch P1 and the weft pitch P2 (or the warp mesh number M+) if the mesh filter has already been designed. Since the latitude mesh number M2) is known, it is possible to determine the inclination angle β of the filter that does not cause moiré fringes by calculation, and after setting the inclination angle β in advance, the design of the mesh fabric filter can be determined by calculation. I can do it.

[For production]

A state is created in which the warp and weft threads of the filter do not interfere with the horizontal and vertical components of the apparent mesh of 14 pixels on the VDU screen, thereby preventing the occurrence of moiré fringes.

〔Example〕

A detailed explanation of the present invention is as follows: (Example 1) Example 1 is as follows: (1) Measure the horizontal pitch and vertical pitch at any location on the DU screen using a densimeter, and calculate the horizontal direction of the apparent mesh by pixels. , the vertical pitch is P I”0.358+11m, P 2 ・
'-0,358mm Toshiba Uptop Paso: '7
J-30005GX (7) CRT (7) The surface of the CRT is nickel-plated with a 20-denier polyester monofilamen mesh fabric to give it conductivity, and a filter (100 x 100 mesh) is fabricated and applied to the model. The filter was attached, and the inclination angle β of the filter was varied to check whether moiré occurred. Q, R, at each angle
Table 1 shows the calculation results and visual test results for S, 'I'', U, and ■.

(Example 2) Example 2 uses the same model as Example], and a mesh fabric of 20 denier polyester monofilament is nickel-plated to give conductivity, and a filter (130X1
34 mesh) was manufactured and installed in the model, and the presence or absence of moiré was confirmed by changing the inclination angle β of the filter. Q, R, S, T, U at each angle
, V calculation results and visual test results are shown in Table 2.

(Example 3) In Example 3, the same model as Example 1 was used, and a mesh fabric of 20 denier polyester monofilament was nickel-plated to give conductivity, and a filter (160×1
60 mesh) was manufactured and installed in the model, and the presence or absence of moiré was confirmed by changing the inclination angle β of the filter. Q, R, S, T, U at each angle
, V calculation results and visual test results are shown in Table 3.

(Example 4) In Example 4, the same model as Example 1 was used, and a 20 denier polyester monofilament mesh and fabric were nickel plated to give conductivity, and a filter (1,80
X 180 mesh) was manufactured and installed in the model, and the inclination angle β of the filter was changed to check whether moiré occurred. Q, R, S at each angle,
Table 4 shows the calculation results and visual test results for '-r', u, and v.

[Effects of the Invention] The mesh filter for VDU screens in which both the horizontal and vertical pitches of the apparent mesh made of pixels of the present invention are constant regardless of the measurement location on the screen reliably prevents the occurrence of moire fringes. It is possible to create a mesh fabric filter with an optimal angle that not only prevents the generation of moiré fringes but also prevents the occurrence of moire fringes according to the horizontal and vertical pitches of the apparent mesh on the VDU screen. In order to find out what angle of inclination should be used to prevent the occurrence of moire fringes, we made many prototype mesh fabrics and conducted tedious trials.
With the ANDERA one-sided method, there is no need to repeatedly search for conditions to prevent the occurrence of moiré fringes, and the best conditions can be quickly and accurately determined through simulation.In addition, it has the effect of preventing static electricity generation and shielding electromagnetic waves. It becomes a mesh fabric filter, which can avoid eye fatigue and the effects on the human body.

Although the present invention has been mainly described as being applied to office automation equipment such as word processors and personal computers, it can also be applied to numerical display devices, such as devices that display the running status of the next row type used in station platforms, etc. Electromagnetic wave shielding is necessary to prevent the generation of noise, but it is also effective in preventing the generation of moire fringes when a mesh fabric filter must be used for this purpose.

Margin table below [Notes are 0.5±5! , 0.67±5X, 1
．． 0±5%, 1.5±5%, 2.0±5L2.5±5%
, 3.0 ± 5%, 3.5 ± 5%, outside the range of 3.8 degrees (moire fringes appear [Note] * is 0.5 ± 5%, 0.67 ±
5%, 1.0±5%, 1.5±5X, 2.0±5%, 2
．． 5 t 5X, 3. Of 5K, 3.5 f
5%, 3.8 Cl) outside the range (within the range where moire fringes appear).

within the range).

Margin below Margin Table [Note] * is 0.5±5%, 0.67±5%, 1.0±5K,
1.5±5X, 2.0±5L [Note* is 0.5±5%, 0.67±5%, 1.0±5%,
1.5 ± 5%, 2.0 ± 5%, 2.5 i 5%,
3.0 + 5%, 3.5 f 5X, 3.8 i
(It) Outside the range (within the moiré fringe range).

2.5±5%, 3.0±5%, 3.5±5%, 3.
Items that are outside the range of 8 degrees (within the range where moiré stripes appear).

Margin below Margin below =22-

Claims (2)

[Claims] (1) In a mesh fabric filter made of ultra-fine warp and weft threads that is installed on a VDU screen in a method in which both the horizontal and vertical pitches of the apparent mesh of pixels are constant regardless of the measurement location on the screen, The horizontal pitch of the apparent mesh by pixels is p_1, the number of meshes is m_1, the vertical pitch is p_2, the number of meshes is m_2, and the pitch of the warp of the filter is P
_1, the number of meshes is M_1, the weft pitch is P_2, the number of meshes is M_2, the angle of inclination of the warp of the filter with respect to the vertical line is β (however, β is between 0 degrees and 90 degrees), the number of warp meshes of the filter and VDU The ratio of the number of filter weft direction component meshes among the screen's apparent warp meshes is Q, the ratio of the filter warp mesh number to the filter weft direction component mesh number of the VDU screen's apparent weft meshes is R, and the filter weft mesh number and VD
S is the ratio of the number of filter warp direction component meshes among the apparent warp meshes of the U screen, and T is the ratio of the number of filter weft meshes to the number of filter warp direction component meshes of the apparent weft meshes of the VDU screen. The ratio of the number of warp meshes of the filter to the average value of the number of filter weft direction component meshes of the apparent warp mesh on the VDU screen and the number of filter weft direction component meshes of the apparent weft mesh is defined as U, and the number of filter weft meshes and V
V
When, the values of Q, R, S, and T expressed by the following formulas are 0.50 ± 5% and 0.67 ± 5%, respectively.
, 1.0±5%, 1.5±5%, 2.0±5%, 2.5
±5%, 3.0±5%, and 3.8 or more, and Q/R is in the range of 0.5 or more and 2.0 or less or S
If /T is in the range of 0.5 or more and 2.0 or less, each value including U and V in addition to Q, R, S, and T expressed by the following formula is 0.50 ± 5%. , 0.67±5%, 1
．． 0±5%, 1.5±5%, 2.0±5%, 2.5±5
%, 3.0±5%, and filter warp pitch P_1, weft pitch P_2, so as to be within the range of 3.8 or more.
A mesh filter for VDU screens with a set tilt angle β. Here, m_1=25.4/p_1, m_2=25.4/p_2
M_1=25.4/P_1, M_2=25.4/P_2
Q=M_1/(m_1COSβ)=p_1/(P_1C
OSβ)R=M_1/(m_2SINβ)=p_2/(
P_1SINβ)S=M_2/(m_1SINβ)=p
_1/(P_2SINβ)T=M_2/(m_2COS
β)=p_2/(P_2COSβ)U=M_1/([m
_1COSβ+m_2SINβ]/2)=2p_1p_
2/P_1(p_1SINβ+p_2COSβ)V=M
_2/([m_2COSA+m_1SINβ]/2)=
2p_1p_2/P_2(p_1COSβ+p_2SI
Nβ). (2) A mesh filter for a VDU screen, wherein the mesh filter according to claim 1 is a conductive mesh fabric made of thin metal wire, carbon fiber, or metal-plated synthetic fiber.