JPS5847681B2 - Bisaisudarejiyoushiyakoban - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to, for example, television receivers, computer dials, oscilloscope dials, projection screens, calculator dials,
It exhibits an excellent light shielding effect against external light shining on all types of light emitting and receiving image boards, such as electronic bulletin boards and signal boards.
Relates to a fine sag-like light-shielding plate that prevents deterioration of the image of the light emitted and received image due to external light, or maintains the sharpness of the light emitted and received image due to external light, and provides a high contrast image under bright ambient light. .

First, in order to facilitate understanding of the present invention, the fine sag-like light shielding plate proposed by the present applicant will be explained using FIGS. 1 to 4.

In FIG. 1, reference numeral 1 designates a fine sag light shielding plate in which a transparent portion 2 and a colored light shading portion 3 are arranged and combined in a sag shape, and a protective transparent film 8 is adhered to the surface to prevent fine sag.

The material constituting the transparent part 2 is a transparent film (or sheet) made of a thermoplastic resin material, and a commercially available film can be used for this, but the thickness of this film depends on the distance between the transparent parts of the light shielding plate. It is necessary to select the desired one according to the purpose.

The desirable properties of this transparent film include having a certain level of transparency, being able to adhere easily, having a small variation in thickness within a certain range, and being able to easily undergo the planing process described below. Examples of materials that have both of these properties include thermoplastic resins such as vinyl chloride resin, ethyl cellulose, cellulose diacetate, cellulose acetate butyrate, acrylic resin, styrene resin, and polycarbonate resin, or blends thereof. It will be done.

The colored light-shielding portion 3 needs to be sufficiently thinner than the above-mentioned transparent film in order to ensure sufficient light-shielding properties (light absorption) and transparency of the light-shielding plate itself.

This colored light-shielding portion 3 is made by uniformly dispersing and blending an appropriate coloring agent (any color can be obtained as required using pigments or dyes) into an adhesive (hereinafter referred to as colored adhesive) to a predetermined thickness. It can be obtained by applying it to the skin.

It is desirable that the colored light-shielding portion 3 has both the function of a light-shielding layer and the function of adhering and integrating the transparent portion 2,
To this end, depending on the type of thermoplastic resin material constituting the transparent portion 2, sufficient adhesive strength is obtained and the transparent portion 2 is sufficiently cured or dried and solidified under conditions that do not adversely affect the resin material. An adhesive is selected.

Adhesives that satisfy these conditions include reaction-curing adhesives and dry-setting adhesives, such as urethane adhesives, epoxy adhesives, vinyl chloride-vinyl acetate adhesives, and rubber adhesives. .

As this adhesive, any coloring agent can be used depending on the desired light-shielding function. For example, when obtaining a light absorption layer, carbon black, triiron tetroxide, aniline black, etc.
For white light-shielding layers, titanium oxide, zinc oxide, etc. are used, and for colored light-shielding layers, Bengara (red) and benzidine yellow (yellow) are used.
A variety of inorganic or organic pigments and dyes can be used, such as cobalt blue (blue).

The thickness of the colored light-shielding part (colored adhesive) 3 after application and drying is determined by the adhesive strength of the colored light-shielding part, light-shielding ability, coating method, adhesive viscosity, etc., but in this example, the thickness is 5. It is appropriate to set the thickness to ~50μ (approximately 5 to 50?/crA), and this thickness becomes the thickness b of the light shielding portion 3 of the completed light shielding plate.

Therefore, in order to manufacture such a light shielding plate 1, first, the second
As shown in the figure, a large number of thermoplastic resin transparent films 4 coated with a colored adhesive 3 are laminated in a predetermined size, and then bonded together to form a block-shaped body 5.

This lamination and integration process is extremely important, and care must be taken to prevent air bubbles and dirt from entering the block. Uniform pressure (5~100 kg/ctyt), uniform temperature (room temperature~100℃) and sufficient time (1~100 hours) depending on the fluidity of
need to be given.

Next, as shown in FIG. 3, the flock 5 is planed on a surface perpendicular to the surface of the laminated film or a surface having a predetermined angle, so that the transparent portion and the colored light-shielding portion are parallel to each other. A sheet with a fine striped pattern arranged alternately, that is, a light-shielding stock solution 6 is obtained.

In the figure, 7 is a knife of a planing machine.

In this case, the thickness to be planed is determined based on the light-shielding angle of the resulting light-shielding plate and the difficulty of planing due to the material of the transparent portion, and is preferably about 50 to 3000 μm, for example.

Needless to say, the planar light-shielding original plate 6 has drawbacks such as not having a sufficiently smooth surface, not having sufficient strength to withstand external forces, and furthermore, its transparency being insufficient. has.

In order to solve these problems, as shown in FIG. A surface protection transparent film 8 made of (cellulose, polycarbonate, glass, etc.) is adhered to both sides of the film 8 using a suitable adhesive to be integrated, and is further subjected to heat and pressure treatment if necessary.

As a result, the rough surface of the light-shielding original plate after planing becomes so smooth that it is almost imperceptible, and its transparency increases, giving it a more beautiful appearance.

In addition, the thickness of the transparent film 8 for surface protection is generally 0.
However, if the thickness of the light-shielding original plate 6 is thin or its rigidity is insufficient, it may be about 1 to 3 m.
The material of the surface protection material, which is preferably about m, is
It is preferable to use the same material as the transparent portion 2 of the light-shielding original plate 6.

The thus obtained fine sag-shaped light-shielding plate 1 can be produced by appropriately selecting the concentration of the coloring agent and its thickness in the colored light-shielding part depending on the material of the transparent part, so that light can be transmitted at the maximum light transmission angle. It is possible to increase the ratio to a maximum of 90 to 95%, and furthermore, in order to obtain the same shading angle, the depth of the shading can be reduced by optically reducing the pitch of the shading. It is possible to reduce the weight of the material itself and improve its light transmittance.

When such a light-shielding plate 1 is placed, for example, in front of a television receiver, it exhibits a light-shielding effect against external light that is irradiated onto the image-receiving screen, and prevents deterioration of the luminous image due to external light. Or to maintain the sharpness of weakly emitted images, etc.
You can enjoy high-contrast images even under bright ambient light.

However, when such a light shielding plate 1 is attached to, for example, a television receiver as described above and a television image is observed by changing the viewing angle, the television image appears as a double image when observed from a certain position.

A so-called ghost phenomenon appears.

The coast caused by the light shielding plate 1 appears particularly when a white image is projected on a screen with a black background, and conversely, if the background is brighter than a certain level, ghosts cannot be discerned.

This phenomenon of ghost generation will be further explained using FIG. 5.

In the figure, 10 is the front panel of the television receiver, 11 is the fluorescent surface formed on the inner surface, and the front panel 100
The light shielding plate 1 described above is arranged on the surface.

Now, if the bright spot A on the fluorescent surface 11 is observed at position P1, the bright spot A will be observed as the only point through the light shielding plate 1.

Next, when the observation position is shifted to P2 and bright spot A is observed from there, a bright spot is recognized at point B as well as point A.

Bright spot B is considered to be an image that appears as the light from bright spot A is reflected on the light-shielding portion 30 surface of the light-shielding plate 1, and therefore, this virtual image is an extension of the point B connecting the observation position P2 and the reflection point C on the light-shielding portion 30 surface. It appears to be at point B.

The brightness of such a ghost is naturally darker than the bright spot of the real image A, but it is thought that it varies depending on the material of the light-shielding portion 3, the state of the surface, or the viewing angle.

In order to quantitatively display such a coast phenomenon and facilitate its understanding, the amount of ghosts will be displayed in the following manner for convenience.

A dot pattern signal is displayed on a television receiver, and the peak brightness of the dots is maintained at a constant level, making it possible to vary the brightness of the background.

In this way, first, the brightness of the spot and the brightness of the background are combined and the value X at this time is read.

Next, while viewing the ghost, the background brightness level is adjusted, and the background brightness value Y when the ghost and background brightness become indistinguishable is read.

Thus, the amount of ghost G is determined as follows: δ This formula means that the larger the amount of ghost G, the less the ghost phenomenon.

Generally, in the case of a ghost image that occurs due to the directional characteristics of a television antenna, a definition has been proposed in which the detection limit is G=30 dB and the tolerance limit is 20 dB.

The results of measuring the ghost amount G on the television screen when the light shielding plate 1 is installed using the above measurement method are shown below.

The measurements were taken at positions where the screen was viewed diagonally from both left and right sides, with the position corresponding to the center of the screen as a reference, that is, L in Fig. 5.
The direction and the value from the R direction are shown.

As is clear from these measurement results, the light shielding plate 1 has a tolerable limit of 20 d regarding the amount of ghost.
Preferably below B.

In view of these points, the present invention aims to provide a fine sag-like light shielding plate which has the above-mentioned excellent light shielding effect and reduces the ghost phenomenon.

As a result of various experiments and considerations, the present inventor has developed the above-mentioned light shielding plate 1.
, the amount of ghost G is the light-shielding part, that is, the colored adhesive 3
It was confirmed that the particle size of the black substance, the coating thickness, and the degree of surface unevenness of the transparent film to which the colored adhesive is applied change.

In one experimental example, by roughening the surface of a transparent film by sanding, the ghost amount G was 25 to 30.
dB, and the sonocoast phenomenon was reduced by % to % compared to the one without sanding.

From this, it has become clear that the ghost phenomenon can be reduced by reducing the specular reflection component of the light on the plane of the light shielding portion 3 of the light shielding plate 1 and scattering it.

The present invention is based on the results of such experiments and considerations.
As shown in the figure, the light-scattering layer 12 is provided at the interface between the transparent portion 2 and the light-shielding portion 3 in the above-mentioned fine sag-like light-shielding plate.

The particle size of the light scattering substance constituting the light scattering layer 12 is 1μ.
The following fine particles can be used, for example, silica (S102), titanium oxide (TiO2), etc. can be used.

Next, an example of the light scattering layer 12 will be described, but this example does not limit the present invention.

A paint having the above composition is applied to the surface of the transparent film 20 to a predetermined thickness in a process prior to applying the colored adhesive 3 to form a light scattering layer 12.
form.

Next, colored adhesive 3 is applied onto this light scattering layer 12.

A large number of transparent films 2 coated with the light scattering layer 12 and the colored adhesive 3 are laminated and combined as shown in FIG. 6 to form a flock-like body.

Then, if this block-shaped body is planed on a plane perpendicular to the plane of the laminated film or a plane having a predetermined angle as shown in FIG. A light-shielding original plate 13 having a light-scattering layer 12 formed at the interface between the transparent part and the colored light-shielding part is obtained, a transparent film 8 for surface protection is adhesively laminated on both sides of this light-shielding original plate 130, and heat-pressure treatment is performed as necessary. give

In this way, the desired light-shielding plate 14 in the form of fine sag can be obtained as shown in FIG.

Here, it is recognized that the coating thickness of the light scattering layer 12 has a correlation with the ghost amount G.

That is, if the coating thickness is too thin, the effect of improving ghosting will be small, that is, the ghost amount G will be less than 20 dB, and if it is too thick, the light shielding portion 3 will become whitish and the effect as a light shielding plate will be reduced.

As a product, the ghost amount G must be at least 20 dB or more, and there is no problem if it is 30 dB or more.

According to experiments, the practical thickness of the light scattering layer 12 is in the range of 0.3 .mu.m to 3 .mu.m.

Note that the measurement results of the ghost amount G by the light shielding plate 14 of the present invention obtained in the above example are shown in relation to the coating thickness t of the light scattering layer 12.

Furthermore, in the examples of FIGS. 6 and 7, the transparent film 2
Although the light scattering layer 12 is provided on both sides of the transparent film, for example, if the direction in which the image is viewed is constant, the light scattering layer 12 may be provided on only one side of the transparent film.

As described above, according to the invention, it is possible to obtain a fine sag-like light-shielding plate that prevents the occurrence of a ghost phenomenon due to reflection at the light-shielding portion without degrading the excellent light-shielding effect.

Furthermore, since external light is also scattered by the light scattering layer 12, even external light having a small incident angle has a superior light shielding effect, and an image with high contrast can be obtained.

Therefore, it is suitable for being attached to the surface of any light-emitting or light-receiving image display such as a television receiver.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a partially enlarged perspective view of a light-shielding plate provided for explaining the present invention, Fig. 2 is an explanatory drawing of the state in which transparent materials coated with colored adhesive are laminated, and Fig. 3 is An explanatory diagram of the state of planing,
FIG. 4 is an explanatory diagram of a state in which a surface protection material is laminated to the original light shielding plate, FIG. 5 is an explanatory diagram of a state in which a ghost phenomenon occurs to explain the present invention, and FIG. 6 is an explanatory diagram of a state in which a ghost phenomenon occurs to explain the present invention. FIG. 7 is an explanatory view of a state in which transparent materials coated with a light scattering layer and a colored adhesive are laminated, and FIG. 7 is a partially enlarged sectional view of a light shielding plate according to the present invention. 1 is a light-shielding plate, 2 is a transparent portion, 3 is a colored light-shielding portion, 8 is a surface protection transparent film, and 12 is a light-scattering layer.

Claims (1)

[Claims] 1 Consisting of transparent parts and colored parts arranged alternately in parallel, and arranged in front of a light-emitting or light-receiving screen so that the interface between the transparent part and the colored part forms a predetermined angle with respect to the screen. In the fine sag-shaped light shielding plate for shielding external light used, at least one of the interfaces of the transparent portion is provided with a light scattering layer that scatters external light and light emitted from the screen reflected at the interface. A fine sag-like light-shielding plate is installed.