JPS6153604A - Light transmission plate - Google Patents

Abstract

PURPOSE:To prevent a moire striped pattern and a roughness from being generated on a picture by setting a vertical diameter, a horizontal diameter, a vertical pitch and a horizontal pitch of a light transmission part, and a vertical diameter, a horizontal diameter, a vertical pitch and a horizontal pitch of a picture element for constituting a surface picture of a display element, to a numerical value of a prescribed relation, respectively. CONSTITUTION:The titled light transmitted plate is provided with a light shileding film 15 having plural light transmission parts 19 for a making a light pass through and a non-light transmission part 20 being a partition wall of this light transmission part 19. A light transmission plate 13 is provided in front of a display picture of display element 11, and an outside transparent substrate 17, and an inside transparent substrate 18 as necessary are provided as shown in the figure. Also, this light transmission plate is constituted by setting a relation of a vertical diameter dV, a horizontal diameter dH, a vertical pitch pV and a horizontal pitch pH of the light transmission plate, and a vertical diameter DV, a horizontal diameter DH, a vertical pitch PV and a horizontal pitch PH of a picture element for constituting a display picture 21 of the display element 11, as dV<DV, dH<DH, pV<PV, and pH<PH.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a light-transmitting plate that is installed and used in front of a display screen such as a television or computer display.

<Conventional technology> Conventionally, in the display screens of cathode ray tubes (CRTs), liquid crystal display devices, and other various "display elements" used in televisions and computer displays, incoming external light is regulated and the display screen is made up of external light. It is used to prevent a decrease in the contrast of the display screen, or to restrict the diffusion angle of the light emitted from the display screen to within a certain angle so that the light from the display screen is not reflected on nearby objects. "
"translucent plate" is generally known. For example, Figures 7 and 8
As shown in the figure [see JP-A-57-189439], a liquid photosensitive resin containing fine particles of silica is applied onto a transparent substrate 1, ultraviolet rays are irradiated through a negative film, and unexposed areas are removed. , a light-transmitting plate 3 that controls outside light that enters at a relatively large angle of incidence by coloring only the photosensitive resin 2 as a cured "light-shielding film" so that it becomes opaque; As shown in FIG. 51-75456, the light-shielding film 7 is obtained by planing a thermoplastic transparent resin plate 4 from a large number of laminated blocks with a light scattering layer 5 and a colored adhesive N6 interposed therebetween. There is a light-transmitting plate 8 which is sandwiched between transparent plates (not shown) to restrict the incidence of external light in the same manner as the light-transmitting plate 3 described above.

<Problems to be Solved by the Invention> However, when such a conventional transparent plate 3.8 is actually installed in front of a display screen such as a television, as described above, the contrast of the display screen due to external light is affected. Although it is possible to prevent the deterioration, the combination of the transparent plate 3.8 and the display screen may cause many so-called "moiré stripes" to appear on the display screen, or the display screen may be damaged by the transparent plate 3.8. There was a phenomenon that the area looked rough.

This invention was made by focusing on such conventional technology, and even when the display element is installed in front of the display screen, it does not cause "moiré stripes" or "roughness" on the display screen. The purpose is to provide a translucent plate that does not

Means for Solving the Problems> In order to achieve the above object, the inventor conducted various experiments and
As a result of research, we found that regarding the occurrence of the above-mentioned "moiré striped pattern" and "roughness" of the display screen, we have determined the size of the light-transmitting part in the light-shielding film that makes up the light-transmitting plate and the display screen of the display element. It was discovered that the relationship with the pixel size is closely described, and this invention was completed. That is, the present invention comprises at least a light-shielding film having a plurality of transparent parts through which light passes and non-light-transmitting parts serving as partition walls of the transparent parts, and is installed in front of a display screen of a display element. In the light-transmitting plate used as
The relationship between V, plate diameter dH1, vertical pitch pV, and horizontal pitch pH, and the vertical diameter DV, horizontal plate diameter 1, vertical pitch Pv, and horizontal pitch PH of the pixels constituting the display screen of the display element is dV<
It is assumed that DVSdH<D)l, pv<pv, and pH<PH.

<Example> This invention will be explained below based on the drawings. Note that explanations that are redundant with those of the prior art will be omitted.

1 to 6 are diagrams showing an embodiment of the present invention. A transparent plate 13 is installed at an interval of 5 fl in front of a display screen 12 of a cathode ray tube 11 as a "display element 1" of a small automobile television 10 installed in the center of an automobile instrument panel 9. . The small automobile television 10 is oriented 20 degrees upward so that the display screen 12 faces the passenger 14 and can be easily seen, and a transparent plate 13 installed in front of the display screen 12 prevents light from entering the display screen 12. This is to prevent the contrast of the display screen 12 from decreasing by regulating the incident angle θ of the external light L1. Specifically, this transparent plate 13 is made of fine silica powder (-average particle size 7μ).
A light-shielding film made of a photosensitive resin composition containing 5 wt% of
0.3 mm thick) 15, double-sided adhesive tape 1
It has a structure in which an outer transparent substrate 17 made of an achromatic polycarbonate plate (0.5+n thickness) and an inner transparent substrate 18 made of a colorless transparent polycarbonate plate (0.5 mm) are sandwiched and bonded via 6.

The purpose of mixing fine silica powder into the light-shielding film 15 (photosensitive resin composition) is to prevent characters and other displays on the display screen 12 from blurring. 20μ and the content is preferably about 3 to 51%. In addition, the light shielding film 15 is connected to an outer transparent substrate 17 and an inner transparent substrate vi,
The reason why the light-shielding film 15 was sandwiched between 18 and 18 was because a special liquid and hydrophilic photosensitive resin composition was used to make it easy to remove the uncured resin and easily dissolve in an alkaline cleaning solution. This is done to prevent the light-shielding film 15 from absorbing moisture in the air and swelling later, and also to prevent dust and dirt from accumulating on the light-shielding film 15 by using the transparent substrates 17 and 18 as protective covers. It is for the purpose of The shape of this light shielding film 15 is 1. For example, as shown in FIG. 1, a regular hexagonal transparent part 19 that passes light
Even if the non-transparent part 20 acts as a partition wall between the transparent part 19,
Some have a honeycomb structure, but there are other shapes as well. The light-transmitting portion 19 has an optimum diffusion angle θ that does not reflect the light from the display screen 12 to external objects, that is, an optimum diffusion angle 24' that was previously proposed by the applicant.
In order to satisfy e<54', the aperture of the transparent part 19 or the transparent part 1
The ratio of the diameter d of the inscribed circle of 9 and the depth h of the transparent part 19 is 0.
23 < d / h < 0°5, and transparent part 1
The ratio of the width 2 of the non-transparent part 20 between 9 and the diameter d is 1.2<
d//! <25 and so. This time, we will discuss the vertical diameter dV, plate diameter dH, and vertical pitch pV of the transparent portion 19 of the transparent plate 13.
, by variously changing the horizontal pitch PHO size and the shape of the transparent part 19, the display screen 12 of the small automobile television 10 was
We investigated the occurrence of the moire striped pattern above and the roughness of the display screen 12. Note that the vertical pitch pV represents the vertical pitch between two vertically adjacent transparent parts 19, and the horizontal pitch pH represents the horizontal pitch between two horizontally adjacent transparent parts 19. And 21 is a pixel, located on the surface of the display screen 12,
Three phosphors 22 of three primary colors, red (R), green (G), and blue (B), are arranged inside. And DV
, DH, PV, and PH indicate the vertical diameter, plate diameter, vertical pinch, and horizontal pitch of the pixel 21, respectively.

Furthermore, in this way, the vertical diameter dV of the transparent part 19, the plate diameter d11
, vertical pitch pV, horizontal pitch pH, and the shape of the light-transmitting portion 19. At the same time, the bonding surface 17a of the outer transparent substrate 17 and the inner transparent substrate 18 opposite to the light-shielding film 15 was tested.
, 18a [hereinafter simply referred to as anti-bonding surfaces 17a and 18a]
We also conducted an experiment in which the surface was made into a finely uneven surface.

The experiment was conducted in a dark room, with a light transmitting plate 1 at a brightness of 5006x.
3 and examined how the display screen 12 looked. 1st above
The table shows the experimental results obtained.

Experiments were conducted with the shapes of the transparent portion 19 being a regular hexagon, a vertically elongated hexagon, a rectangle, and a circle. In addition, for each shape, the vertical diameter dV of the transparent part 19, the plate diameter dH,
Examples 1 to 5 are those in which the vertical pitch pV and the horizontal pitch pH are smaller than the vertical diameter DV, the horizontal plate diameter, the vertical pitch pv, and the horizontal pitch P)I of the pixel 21, respectively. At least one of the vertical diameter dV, plate diameter dH, vertical pitch pV, and horizontal pinch pH of the pixel 21 is defined as the vertical diameter DV, the horizontal plate diameter, the vertical pitch pv, and the horizontal pitch PH (in the example of
V=0.500. DI (=0.380゜PV=0.5
50, PH=0.420) were designated as Reference Examples 1 to 3.

Further, the achromatic polycarbonate plate employed as the outer transparent substrate 17 has substantially uniform transmission and reflection characteristics over the entire visible light region of 400 to 700 nm so as not to impair the color tone of the display screen 12. In addition, when we investigated the relationship between the total light transmittance ratio (%) and the contrast ratio of the achromatic transparent plate, we found that the contrast ratio (%) was 70%, as shown in Figure 6. Since it was found that the maximum value was shown when the total light transmittance ratio (%) was around 70%, the achromatic polycarbonate board used this time also
．． 7% was adopted. The inner transparent substrate 18 is made of a colorless and transparent material with high light transmittance so as not to reduce the light transmittance of the entire light transmitting plate 13. If the total light transmittance ratio (%) of the outer transparent substrate 17 is 85% or more, the display screen 12 will be dazzling and difficult to see, and if it is less than 50%, the overall brightness will be insufficient, so it should be 50 to 85%. It doesn't matter if it's something in between.

Furthermore, in this experiment, between the outer transparent substrate 17 and the inner transparent substrate 18, the bonding surface 17a of the outer transparent substrate 17 was made into a finely uneven surface. This finely uneven surface has a 60 degree specular gloss (G1) of 62.2% (Jl l□5K5
400-1979 6.7), glossiness of untreated smooth surface (
128.1%) relative gloss (G2) of 48.6
%, center line average roughness Ra) is 0.38μ (JISB0
601-1982). In addition, the specular gloss G1 of the finely uneven surface is measured using the Suga Test Instruments Color Computer (S
M-2 type).

Regarding moiré fringes (waves), each of the vertical diameter dV, plate diameter dH, vertical pitch pV, and horizontal pitch pH of the light-transmitting part 19 is determined by the vertical diameter DV of the element 21, the horizontal plate diameter,
Even when comparing Examples 1 to 5, which are smaller in size than the vertical pitch Pv and horizontal pinch Pl+, with Reference Examples 1 to 3, which are not smaller in size, the reference example has color moiré where multicolored stripes can be seen. In addition, in Reference Example 3, where the size of the transparent part 19 was set to the widest size, there was no moiré stripe pattern, and the transparent part 19 itself was clearly visible. Therefore, visibility of the display screen 12 was significantly obstructed.

In Examples 1 to 5, each size of the transparent portion 19 is reduced, so that the shape of Examples 1 to 5 is hexagonal.
Although it was possible to limit the occurrence of only some black moire, no improvement was seen to the extent that the occurrence of moire stripes was completely eliminated. However, if the pressure bonding surface 17a of the outer transparent substrate 17 is provided with a finely uneven surface, the -cut moiré striped pattern will not occur, and the driver's seat,
It was found that the display screen 12 was not glare-free when viewed from either the passenger seat or the rear seat, and the external scenery was not reflected on the pressure joint surface 17a, so that the display screen could be viewed clearly.

On the other hand, as shown in Table 1, "roughness" on the display screen 12 is almost completely prevented by making the size of the transparent part 19 smaller than the pixel 21.・I was able to improve. In particular, when the shape of the transparent portion 19 is a regular hexagon, a vertically elongated hexagon, or a hexagon, roughness of the display screen 12 can be prevented by reducing the size. Even in the case of rectangles and circles, it was confirmed that there was an improvement, with only slight black lines remaining on the display screen 12. From this, it can be seen that a hexagonal shape is more effective than a rectangular or circular shape in preventing roughness of the display screen 12. Also, as before, due to the presence of the finely uneven surface, external scenery was not reflected on the anti-bonding surface 17a.

In addition, in the above experiment, an example was shown in which a certain finely uneven surface having a certain specular gloss etc. was provided on the opposite contact surface 17a of the outer transparent substrate 17, but additional experiments regarding this finely uneven surface were conducted. However, the opposite surface 18a of the inner transparent substrate 18
or on the opposite bonding surface 17a of the outer transparent substrate 17.
It has been found that moire striped patterns and roughness can be prevented even if it is provided on both the anti-bonding surface 18a of the inner transparent group Fi18.

However, if anything, the anti-bonding surface 18 of the inner transparent substrate 18
It is more effective to prevent moire stripes and roughness when provided on the anti-bonding surface 18a of the outer transparent substrate 17 than on the surface 18a of the outer transparent substrate 17, so it is especially effective to prevent moire stripes and roughness on the display screen 12 and to provide a clear display screen. 12 is required, it is desirable to provide a finely textured surface at least on the anti-bonding surface 17a of the outer transparent substrate 17.

Regarding the degree of the finely uneven surface, the relative gloss (G1) is greater than 73%, and the center line average roughness (Ra) is 0.2.
If the image is less than 45%, there is almost no effect of eliminating moiré stripes, and the reflection of external scenery on the display screen 12 is thick (and the relative gloss (G1) is less than 45%, and the center line average If the roughness (Ra) is larger than 0.5 μ, it will become unclear as if viewed through ground glass, so the relative gloss (G1) is 45 to 73%, and the center line average roughness (Ra) is It was found that a value of 0.2 to 0.5 is appropriate.

Effects> Since the transparent plate according to the present invention has the content as described above, when it is installed in front of a display screen such as a television or computer display, it will not cause the occurrence of "moiré stripes" or display on the display screen. This has the effect of preventing "roughness" on the screen. Furthermore, according to the embodiment of the present invention, the anti-bonding surface of the transparent substrate that is bonded to the light-shielding film has a finely uneven surface, which further reliably prevents "moiré striped patterns" and "roughness" of the display screen. This also has the effect of preventing external scenery from being reflected on the surface of the transparent plate. Furthermore, since it can fully demonstrate its original function of regulating the incident angle of external light incident on the display screen and regulating the diffusion angle of light from the display screen within a certain range, it is suitable for use in automobiles. When used in small TVs, it is necessary to provide a hood-like protrusion on the TV to prevent the contrast of the display screen from decreasing due to incident external light, and to block external light and prevent reflections on the outside. It also has the added benefit of being cheap because there is no

[Brief explanation of the drawing]

FIG. 1 is an enlarged plan view showing each size of the light-shielding film and display screen of a light-transmitting plate according to an embodiment of the present invention, and FIG. 2 is an enlarged plan view of an automobile equipped with a light-transmitting plate according to an embodiment of the present invention. A plan view of the vehicle interior showing the installation position of a small TV, Figure 3 is an enlarged sectional view of the transparent plate taken along the arrow line m-m in Figure 2, and Figure 4 shows a finely uneven surface provided on the opposite surface. Fig. 5 is an enlarged sectional view corresponding to Fig. 3, Fig. 5 is an enlarged sectional view showing the part indicated by the arrow ■ in Fig. 3, and Fig. 6 is a graph showing the relationship between the total light transmittance ratio and contrast ratio of an achromatic transparent substrate. , Fig. 7 is a plan view showing a conventional example of a transparent plate, Fig. 8 is a cross-sectional view taken along the line indicated by the arrow ■-■ in Fig. 7, and Fig. 9 shows another conventional example of a transparent plate. FIG. 8 is a sectional view corresponding to FIG. 8; 3.8.13 - Light transmitting plate 7.15 - Light shielding film 11 - Braun tube (display element) 12 - Display screen 19 - Light transmitting section 20 - Non-light transmitting section 21 - Pixel dV -... Vertical diameter dH of the transparent part - Plate diameter pV of the transparent part - Vertical pitch pH of the transparent part - Horizontal pitch DV of the transparent part - Vertical diameter D)l of the pixel - Horizontal diameter pv of the pixel・・・ Vertical pinch of pixel PH〜・〜 Horizontal pitch of pixel LI ・−・・External light L2− Light e from display screen −・Incidence angle, diffusion angle d −・−Aperture or inner diameter of transparent part Diameter of tangent circle h - Depth of transparent part l - Width of non-transparent part G1 - Specular gloss 02 - Relative gloss Ra - Center line average roughness B - I DH 6 Figure 1 7 items t μ skin p 4 Basic knowledge 6
)70 Figure 8 Figure 9

Claims (1)

[Scope of Claims] At least a light-shielding film having a plurality of light-transmitting parts through which light passes and non-light-transmitting parts serving as partition walls of the light-transmitting parts,
In a light-transmitting plate used by being installed in front of a display screen of a display element, the vertical diameter dV, the horizontal diameter dH, the vertical pitch pV, and the horizontal pitch pH of the light-transmitting part and the pixels constituting the display screen of the display element are The relationships between vertical diameter DV, horizontal diameter DH, vertical pitch PV, and horizontal pitch PH are dV<DV, dH<DH, pV<PV, and p
A transparent plate characterized in that H<PH.