JPS58140732A - Distinctly visible screen and its arranging method - Google Patents

Abstract

PURPOSE:To eliminate disturbance light, and to prevent a drop of contrast, by utilizing a directional pattern of a distinctly visible screen having a specified directional pattern, and specifying its arrangement. CONSTITUTION:An irregular reflected light distribution in the longitudinal direction of a distinctly visible screen is sharp and ''0'' degree <=¦alpha-alpha'¦<=5.5 degrees. alpha and alpha' shown scattering angles at which a reflected light quantity Q in alpha is 2/3 of a mean reflected light quantity P in 0-alpha, and alpha' shows an angle at which a reflected light quantity R in its angle is 1/3 of the reflected light quantity Q in alpha. When the screen 1 is placed so as to be inclined by alpha'/2 in the depression angle direction, external light irradiated to the screen is generally turned toward the horizontal direction or in the diagonally lower direction from the upper direction than said direction, therefore, its distubance light can be eliminated so that it does not go into eyes 2 of a viewer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bright vision screen with directional characteristics and a method for arranging the same.

Scattering reflective screens have been used for a long time to project images. If the light incident on the screen is scattered and reflected in all directions, the intensity of the reflected light in the desired direction will be weakened, so screens that scatter and reflect only in a specific limited range are now being used. It has become to. This screen is called a clear vision screen. That is, the bright vision screen has a large number of small irregularities formed on the reflective surface, so that the incident light is scattered and reflected only in nine areas. Generally, in a clear vision screen, similarly to the case where there is a reflection line for an incident ray on a steel surface, the reflected light in the direction centered around the reflection line is the strongest, and the intensity is gradually weakened and reflected in a scattered manner in all directions.

Further, the scattering angle range of the scattered reflected light is generally approximately 90 degrees in the horizontal direction at the available light intensity, and is generally smaller than this in the vertical direction.

In conventional bright vision screens, the distribution of scattered reflected light generally changes gradually and is not sharp, so the reflected light is concentrated in a relatively small reflection angle range and exceeds the normally required scattered reflection angle. Scattered light is distributed. Therefore, the scattered reflected light (
This (hereinafter referred to as disturbance light) also has the drawback that the screen surface is easily affected by the disturbance light over a wide range, resulting in a reduction in the contrast of the image.

An object of the present invention is to provide a clear vision screen in which the intensity of light incident on the screen and scattered and reflected within a specific angle range is averaged as much as possible, and there is almost no scattered reflected light outside the specific angle range; How to Arrange the Screen Normally indoors is much darker than outdoors, so the strongest outside light that hits the screen is the light that comes from the window on the back. When the outside light from this mask hits the screen and the disturbance light that is generated enters the eyes of the observer (audience), this disturbance light lowers the contrast of the screen surface and makes the image unclear, as described above. In order to eliminate this reduction in contrast due to ambient light, it is necessary to take measures to prevent the ambient light from entering the eyes of the audience.

As a means to achieve this, the directional characteristics of the screen in the vertical direction are sharpened so that the amount of reflected light decreases rapidly when a predetermined scattering/reflection angle range is exceeded, and the screen is set at a specific angle with respect to external light. It is conceivable that the external light may be placed in the area to exclude external light from the eyes of the audience.

However, the directional characteristics of many conventional screens in the vertical direction are generally not sharp, as shown in FIG. 1, so that it is substantially necessary to rotate the screens to eliminate the ambient light. In Figure 1, β is the scattering angle at which the intensity θ of the scattered reflected light corresponds to % of the average intensity P of the scattered reflected light within the range (0 to β) of the scattering angle β. , β' is the scattering angle whose intensity R of the scattered light is -the intensity Q of the scattered light at β. In this case, Q is usually selected as the range in which the image on the screen can be seen almost brightly and clearly, and R is selected empirically as the limit point of reflected light for the screen, and in the range below this, means that the intensity of reflected light becomes very weak.

With conventional screens, the distribution of scattered reflected light is not sharp, so the 1β-1 angle is 7 to 8 degrees or more! is inevitably a large angle. Therefore, it is substantially difficult to select the arrangement angle of the screen to eliminate the disturbance light as much as possible.

The reason for this is that in order to avoid disturbing light from the viewer's eyes, it is necessary to make the screen tilt extremely large, and if the screen tilt angle becomes large, it will not function properly for the original image. Because it will be.

On the other hand, the distribution of scattered reflected light in the vertical direction of the clear vision screen of the present invention is sharp as shown in the 21st example, and has an average distribution within the scattering angle range of /15 rM. , when the value is exceeded, the amount of reflected light decreases rapidly. α and α′ in FIG. 2 correspond to β+7” in FIG. The amount of reflected light Q when the amount of reflected light R is α
Indicates the angle that is A.

In the screen of the present invention, when such α' is determined, it is a good condition that θ°≦1α−α′1≦5.5°. The distribution of scattered reflected light changes sharply as 1α-α'I becomes smaller, but although it is possible to make 1α-α/1 close to 06, it is difficult to make it 00 in terms of practical screen manufacturing. Normally, even if the scattering/reflection angle is strictly controlled, it is about 1° to 3°. 1α−α
If '1 exceeds 5.5 degrees, it will be difficult to exclude the disturbance light from the clear vision screen from the eyes of the audience, as will be described later.

Next, a method of arranging the clear vision screen of the present invention will be described. FIG. 3 shows the difference in scattered reflection between the conventional screen and the screen according to the present invention when external light is irradiated onto the screen 1 from the horizontal direction. The scattering reflection range α' of the horizontal external light of the screen according to the present invention is shown by a solid line, and β' of the conventional screen is shown by a dotted line. When screen 1 is placed vertically against external light coming from the horizontal direction, the ambient light from both screens enters the eyes of the audience 2 located in the same direction as this external light, causing trouble in viewing the image. .

However, as shown in Fig. 4, if this screen 1 is placed at an angle of α', for example, tilted by 2 in the direction of depression, in the case of the screen according to the present invention, the disturbance light that had hit the audience's eyes 2 will be diverted from their line of sight. while being excluded further downwards,
Since the conventional screen has a wide distribution range of disturbance light, it still reduces the contrast of the image that enters the audience's eyes. In order to exclude the disturbance light of conventional screens from the eyes of station passengers 2, if the screen illumination is tilted too much, the screen's original function for images will be impaired. Therefore, when arranging the screen of the present invention,
Preferably, the slope is slightly greater than the angle. Even with this degree of inclination, the external light that is illuminated on the screen is generally directed horizontally or diagonally downward rather than above, so that external light can be eliminated so as not to enter the audience's eyes. It is from.

Although FIG. 4 shows the case where the screen 1 is tilted in the direction of the angle of depression, the same is true when the screen 1 is tilted in the direction of the angle of elevation. In this case, the disturbance light from the screen 1 is reflected upward from the horizontal line of sight of the audience and does not enter the eyes 2, contrary to the case where the screen 1 is tilted at an angle of depression. When arranging the screen, whether to set it at an angle of depression or elevation should be selected appropriately, taking into consideration the direction of projection onto the screen 1 and the direction of external light. However, in the case of a projection TV screen, it is generally placed diagonally downward. Since the image is projected from the ground, the screen is often arranged at an angle in the direction of the depression angle, as shown in Figure 4.

As described above, the clear vision screen according to the present invention has sharp directional characteristics, so compared to conventional screens, it is possible to uniformly increase the amount of scattered light within a predetermined scattering and reflection angle, resulting in a bright image. It will be done. In addition, by specifying the placement of the screen using the directional characteristics of the screen, it is possible to exclude external light from entering the audience's eyes, thereby preventing a decrease in the contrast of the screen due to such external light. You can see clear images.

[Brief explanation of drawings]

FIG. 1 is a distribution diagram of scattered reflected light in the vertical direction of a conventional screen, FIG. 2 is a distribution diagram of scattered reflected light of a screen according to an embodiment of the present invention, and FIG. 3 is a diagram of the distribution of scattered reflected light of a screen according to the present invention and a conventional screen. A comparative explanatory diagram of scattered reflected light, and FIG. 4 is a side view of the screen arrangement method according to the present invention.

Claims (1)

[Claims] 1. In the scattering reflection distribution in the vertical direction of a clear vision screen having directional characteristics, the intensity of the scattered reflection light at a point where the scattering reflection angle is α is equal to the intensity of the reflected light within this scattering reflection angle range. and the intensity of the scattered reflected light is 1/3 of the intensity of the scattered reflected light at this angle α.
A clear vision screen where 0°≦1α−α′1≦5.5° when the angle α′ is calculated. 2. In the vertical scattered reflection distribution of a clear vision screen with directional characteristics, the intensity of the scattered reflected light at the point where the scattered reflection angle is α is % of the average intensity of the reflected light within this scattered reflection angle range. When calculating the angle α' where the intensity of the scattered reflected light is 3 times the intensity of the scattered reflected light at this angle α, 0°≦lα−α′≦5.5. ° clear vision screen,
A method of arranging a clear vision screen, characterized in that the screen is arranged at an angle of 0 so that the average direction of normal lines in the vertical direction is 906〉θ〉ge with respect to a horizontal plane.