JPH05142656A - Screen - Google Patents

Abstract

PURPOSE:To improve the visibility of an image projected on a screen. CONSTITUTION:Screen gains Gi (i=1, 2...n) of the screen 2 vary with the quantity of incident light and when the quantity of incident light increases to the center part of the screen 2 and the quantity of incident light decreases to the peripheral part, the screen gains Gi of the screen 2 are so distributed that G1<G2<...<Gn. Consequently, the brightness distribution of the screen can be made uniform irrelevantly to the quantity of incident light, so when the screen 2 is applied to a projection type projector, the brightness difference between the center part and peripheral part of the screen 2 becomes small, so the display image becomes bright and the image (character, etc.) at the peripheral part is clearly seen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen used for a display device (projection type projector or the like) for displaying an image, and more particularly to a screen excellent in visibility of a displayed image.

[0002]

2. Description of the Related Art In recent years, a projection type projector can project an image on, for example, a screen 1 shown in FIG. 6 to obtain a large screen, so that it can be used in a wide area such as an exhibition hall.

[0003]

By the way, the screen gain of the projection type projector screen 1 is constant over the entire surface (G (x, y) =
Constant).

Therefore, when an image is projected on the screen 1 by the projection type projector, the screen 1
The upper luminance distribution differs depending on the luminance distribution of the light source, the lens peripheral light amount ratio of the optical system, and the like. Usually, the luminance of the central portion of the screen 1 and the peripheral portion thereof are low, and the luminance becomes higher toward the central portion. There is a problem in that the visibility of the display image, especially characters and the like, is reduced in the peripheral portion of the screen 1.

The present invention has been made in view of the above problems, and an object thereof is to make the brightness of a display image on a screen substantially the same in the central portion and the peripheral portion, and to visually recognize the peripheral portion in the display image. The purpose of the present invention is to provide a screen capable of improving the property.

[0006]

In order to achieve the above object, the screen of the present invention changes the screen gain according to the amount of incident light, and the change of the screen gain depends on the screen size of the screen. The point is that they are different.

[0007]

With the above construction, in the projection type projector using the screen, the luminance distribution of the light source of the projection type projector, the lens peripheral light amount ratio of the optical system, and the like affect the luminance distribution of the screen. For example, since the brightness of the peripheral part of the screen is lower than that of the center of the screen, the gain distribution (Gi) of the screen is set so that the brightness difference between the central part and the peripheral part is minimized.

When the screen size of the screen is different, the brightness distribution of the screen is also different, but the clean gain distribution (Gi) is set in accordance with the brightness distribution as described above.

As described above, by simply setting the screen gain distribution of the screen, the brightness of the screen becomes uniform, the display image on the screen becomes brighter, and especially the characters and the like of the image in the peripheral portion can be made easy to see. It is also technically easy and inexpensive in cost.

[0010]

The screen gain of the present invention is not constant over the entire surface and is set according to the amount of incident light.

An embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, the screen gain of the screen 2 is Gi = G (x, y) (i = 1, 2, ...,
The screen gain (Gi) is smallest in the central portion of the screen 2, and the screen gain (Gi) becomes larger toward the peripheral portion.

Here, the screen gain Gi of the screen 2 is set to G1 <G2 <... <Gn-1 <Gn, but when the incident light amount distribution is a curve shown in the lower part of the figure, the light amount is small. The distribution of each of the screen gains G1, G2, ..., Gn-1, Gn depends on the incident light amount distribution so that the brightness of the peripheral portion is increased and the brightness difference between the central portion and the peripheral portion is minimized. Is set.

The screen gains G1, G2, ...
By setting the distributions of Gn-1 and Gn, ideally, the light amount distribution on the screen 2 can be a straight line shown in the lower part of the figure.

As shown in FIG. 2, when the display screen sizes of the screen 2 are different, for example, a 100-inch screen and a 6-inch screen are used.
Since the incident light amount distribution of the screen 2 is different on the 0-inch screen, the distribution of the screen gain Gi of the screen 2 is set to be different from the distribution shown in FIG.

1 and 2, the distribution of the screen gain Gi spreads in a circular shape, but if the incident light on the screen 2 has an elliptical shape, the distribution of the screen gain Gi has the elliptical shape. It will spread in a shape.
When the brightness distribution of the screen 2 is lower toward the center, the screen gain distribution of the screen 2 is opposite to that in the above embodiment.

Here, for example, in the case of a projection type projector, the display brightness of the screen 2 is determined by the amount of light incident on the screen 2 and the screen gain, so that the brightness distribution on the screen 2 is incident. It depends on the light intensity and screen gain distribution.

Since the incident light quantity distribution is determined by the luminance distribution of the light source of the projection type projector, the peripheral light quantity ratio of the optical system (various lenses) of the projection type projector, the light source and the optical system are improved, Although it is possible to make the brightness distribution on the screen uniform, there are drawbacks such that it adversely affects the entire optical system and causes a cost increase due to a major design revision.

On the other hand, in the present invention, as already described, it is only necessary to change the screen gain distribution of the screen 2 used in the projection type projector in accordance with the display screen size of the screen 2, thus technically. Is also easy, and is extremely advantageous in terms of cost.

Thus, the screen gain distribution of the screen 2 is changed according to the amount of incident light,
Since the brightness difference between the central part and the peripheral part of the screen 2 is minimized and the brightness of the entire screen 2 is maximized, the brightness distribution on the screen 2 becomes uniform and The displayed image can be brightened, and the visibility of the image can be improved.

Further, with the above screen gain distribution, the screen gain increases as the distance from the center of the screen 2 increases, but the directivity increases accordingly.

Therefore, the viewing angle of the screen 2 becomes narrow, and the display image may deteriorate depending on how the screen 2 is viewed from a predetermined angle (oblique direction) with respect to the front of the screen 2. The brightness of the display image is uniform within the corner, and the display image is bright, and for example, the peripheral partial image (such as characters) can be clearly seen.

As a method of changing the screen gain distribution, for example, glass powder on the surface of the screen 2,
Alternatively, it is conceivable to apply aluminum powders having different reflectances or change the shape, density and number of the grooves formed on the surface thereof, but other methods may be used.

As a method of installing the screen 2, as shown in FIG. 3, the screen 2 can be easily attached to the metal plate 4 by providing a magnet sheet 3 on the back surface of the screen 2. Reference numeral 5 is a projection type projector that projects an image on the screen 2.

Further, as shown in FIGS. 4 and 5, a ring 6 is attached to the screen 2 and a hook 7 for hooking is attached to the ring 6, so that the screen 2 can be easily attached to the rod 8 by the hook 7. It can be hung.

In this case, if the bar 9 at the bottom of the screen 2, for example, the bar 9 used when the screen 2 is wound around, is used as a weight, the screen 2 can be pulled evenly and loosened. It can be lost.

[0026]

As described above, according to the screen of the present invention, since the screen gain of the screen is changed according to the incident light amount, the incident light amount distribution of the screen is constant when used in the projection type projector. Without
Since the brightness of the central part and the peripheral part of the screen becomes small, the display image of the screen becomes brighter, and the peripheral part of the image, such as characters, can be seen well, that is, the visibility of the image is improved. Can be planned.

[Brief description of drawings]

FIG. 1 is a schematic front view illustrating a screen according to an embodiment of the present invention.

FIG. 2 is a schematic front view illustrating a screen showing a modified example of the present invention.

FIG. 3 is a schematic side view illustrating an example of a mounted state of the screen shown in FIGS. 1 and 2.

FIG. 4 is a schematic side view illustrating another example of a mounted state of the screen shown in FIGS. 1 and 2.

5 is a schematic front view illustrating another example of a mounted state of the screen illustrated in FIGS. 1 and 2. FIG.

FIG. 6 is a schematic front view illustrating a conventional screen.

[Explanation of symbols]

 1, 2 screen 3 magnet sheet 4 metal plate 5 projection type projector 6 ring 7 hook 8, 9 bar

Claims (3)

[Claims] 1. A screen, wherein the screen gain is changed according to the amount of incident light. 2. The screen according to claim 1, wherein the change in the screen gain varies depending on the screen size of the screen. 3. The screen according to claim 1, wherein the screen gain is smaller in the center where the amount of incident light is larger and is larger in the periphery where the amount of projected light is smaller.