JPH0862726A - Screen for projector - Google Patents

Abstract

PURPOSE: To widen the angle of view, to improve luminance and to provide high-contrast images, even under indoor illumination by forming an irregularly wavy surface by providing continuous rugged parallel ridges for a numerous high-density lines on the surface of a screen, made of a metal plate material, and simultaneously recessing/bending the surface of the screen in vertical direction. CONSTITUTION: Numerous high-density continuous rugged parallel ridges 11 are provided on the surface of a screen 1 made of the metal plate, the irregularly wavy surface of the screen 1 is formed from these ridges and at the same time, the surface of the screen 1 is recessed and bent vertically. The respective ridges 11 are made mutually parallel and bent while meandering, and the size of gap between both the adjacent ridges 11 is made nonuniform but less than 5μm. Besides, it is more preferable to perform flat processing through alkali washing to the surface, while forming it from an aluminium plate material and to form the formation and cover of transparent film layer of alumina (Al2 O3 ) through anode processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen, and more particularly, to increasing a gain and a wide viewing angle.
The present invention relates to a projector screen that retains a wing cone and still obtains a high contrast image under general illumination.

[0002]

2. Description of the Related Art At present, there are two types of reflective screens used for projection of general movies and televisions. For example, a diffusive reflective screen such as a cambric screen (gain of about 1) and, for example, metal plating. There are directional reflective screens, such as curtains (gains of 3 or more), and both types of screens have different advantages and disadvantages.

That is, the diffuse reflection screen has a wide viewing angle, but has a low reflection brightness and a low gain, so that the screen image on the screen cannot be clearly viewed under ordinary electric lighting, and the dark room or It is barely visible in a dark room. The directional reflection screen has a relatively high reflection brightness and can obtain a high-contrast image even under dim lighting, but the viewing angle of the screen is narrow and the viewing angle of the viewer is limited, resulting in a narrow viewing angle. If it deviates from this, the brightness will drop sharply and the images will be indistinguishable.

Since the gain of the screen is inversely proportional to the viewing angle, in order to keep the viewing angle at an appropriate level,
The screen gain cannot be increased unnecessarily, and if an attempt is made to increase the screen gain, the viewing angle is always limited. Since the conventional screen adopts a uniform reflecting surface, the reflection method belongs to the same regardless of the vertical direction or the horizontal direction.For example, if the vertical direction is diffuse reflection, the horizontal direction is also diffuse reflection, Similarly,
If the vertical direction is directional reflection, the horizontal direction also belongs to directional reflection in most cases. Therefore,
Conventional reflective screens, whether diffuse or directional, cannot simultaneously increase brightness (or gain) as the viewing angle is widened.

[0005]

SUMMARY OF THE INVENTION In view of the problems in the conventional projector screen as described above, the present invention widens the viewing angle and at the same time enhances the brightness (gain), and produces a high-contrast image even under room lighting. It is an object of the present invention to provide a projector screen that is obtained and can effectively eliminate the interference of extraneous light.

[0006]

In order to achieve the above-mentioned object, the present invention provides a screen surface made of a metal plate material with a large number of high-density parallel ridges having continuous uneven undulations. It is configured to form an irregular wave-like surface on the screen by a dense ridge, and at the same time, make the screen surface concave and curved in the vertical direction.

The ridges are formed so as to be slightly meandering in parallel with each other, and the size of the gap between adjacent ridges of each ridge is nonuniform, but is formed to be approximately 5 μm or less; If the screen is made of an aluminum plate material, the surface of the screen is delustered by the erosive action in alkaline washing, and the transparent film layer of alumina (Al ₂ O ₃ ) is formed by anodization. It becomes more preferable.

[0008]

According to the present invention having the above-described structure, a light beam projected from a vertical direction is formed by a large number of parallel ridges with high density and continuous unevenness provided on the screen surface made of the metal plate material. Is directionally reflected and the light rays projected from the horizontal direction are diffusely reflected to widen the horizontal viewing angle and somewhat narrow the vertical viewing angle, but the overall gain can be increased. Further, since the screen is concavely curved in the vertical direction, the gain is further improved, the luminance distribution is made more uniform, and the interference of extraneous light rays can be effectively eliminated.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural view of the present invention. As shown in the drawing, the present invention mainly uses a metal plate as a screen 1.
Of the present invention (the present invention uses an aluminum plate as a screen substrate), and the screen 1 is subjected to a number of mechanical processes such as rolling and polishing, and is continuously and parallelly formed on its surface in a number of lines. To form a ridge 11 which is uneven.
Then, in the screen 1, a part of the outer peripheral surface of the horizontal cylindrical body is a concave surface cut out along the vertical surface so as to form a circular bracket shape in the vertical cross section, that is, the ridge 11 is the axis M of the peripheral wall of the cylindrical body. It is provided so as to form an arc shape in a direction orthogonal to each other and to be in parallel. As can be seen by also referring to FIG. 2 which is an enlarged photograph of the screen before the matting treatment of the present invention taken with a microscope of 5 hundred magnification, the surface of the screen 1 has a high-density linear shape after the rolling treatment. The ridges 11 arranged in parallel are clearly seen, and the adjacent intervals of these ridges 11 that do not intersect with each other are non-uniform, but almost 5 μm or less. This type of uneven ridges with non-uniform spacing is mainly intended to prevent interference between the projected figure and the Moire pattern due to the screen line shape.

Further, referring to FIG. 3 which is an enlarged photograph of the screen after the matting treatment of the present invention taken with a microscope of a magnification of 500, as can be seen from the photograph, the ridge originally had a straight line. 11 is a ridge shape that slightly meanders. The reason for this is that when the surface of the screen 1 is washed with alkali, the surface of the screen 1 is eroded to form an irregular surface with unevenness, and a slight meandering curve from irregular reflection of light rays. It is seen as a shape, and since the reflection of the light of the serpentine curved ridge diffuses partly regardless of the vertical or horizontal direction, it has the effect of reducing the reflective glare (glare) of the screen and has a matte effect. Play the role of. Further, as described above, the screen of the present invention uses an aluminum plate as a base material, so that the surface of the aluminum plate having a high hardness (Al ₂ O 3) is anodized.
By forming the transparent coating layer of ₃ ), the screen is provided with abrasion resistance and corrosion resistance.

FIG. 4 is a reflection relationship diagram when the projected light is parallel to the ridge in the present invention. Referring also to FIG. 1, the light projected by the projector on the screen 1 is projected light α. Then, when the projection light α is parallel to the ridge 11 of the screen 1, that is, when the projection light α is projected from above and below the screen 1, most of the light rays are smooth parts of the surface of the screen 1. Since it is projected along and reflected, the reflected light α'belongs to directional reflection, and this kind of reflected brightness is relatively concentrated and less diffused.

FIG. 5 is a reflection relationship diagram when the projected light is orthogonal to the ridge in the present invention. When the projected light β is orthogonal to the ridge 11 of the screen 1, that is, the projected light β is in the right and left direction of the screen 1. When projected from above, the ridge 11 on the surface of the screen 1 exposes the wave-like portion with high and low undulations to the projected light β, so that the reflected light β ′ belongs to the diffuse reflection but is completely diffused. Rather, its degree of diffusion is directly proportional to the density of the ridges 11. As can be seen from the above description, the reason why the reflection screen of the present invention has different reflection methods for different projection directions of light rays is due to the interference action of the ridges 11 on the surface of the screen 1 with light.

Subsequently, as shown in FIG. 6 which is a view showing a dependency curve between the viewing angle and the gain of the flat screen, 1/10 of the maximum gain in this figure is the effective gain range, and the left and right angles correspond to the screen. The viewing angle range is 1. Most of the canbrick curtains are completely diffused, so when the gain is set to 1, the horizontal viewing angle obtained by the test is about 102 degrees and the vertical viewing angle is about 10 degrees when the screen 1 is a plane and is not the concave surface of the side wall of the columnar body. It has a gain of 60 degrees and a gain of 2.9 (obviously higher than the conventional cambric curtain). Further, referring to FIG. 7, which is a view showing the dependency curve between the viewing angle and the gain on the concave screen of the lateral columnar wall (according to the test inspection report of Taiwan Industrial Technology Research Institute, Photoelectric Industry Research Institute), the lateral columnar wall The inwardly concave curved surface (curvature radius: 3.5 m) of the screen 1 has a horizontal viewing angle of 102 degrees, a vertical viewing angle of 32 degrees, and a gain of 5.5, which are obtained by testing. As can be seen from such test values, when the flat screen is inwardly concavely curved in the shape of the lateral wall of the columnar body, the horizontal viewing angle does not change but the vertical viewing angle becomes small, and the gain also becomes relatively high. Calculating the rate of change from the numerical values displayed in FIG. 7; As can be seen from the above calculation, the gain of an inwardly concave curved screen is 1.9 times higher (nearly 2 times) higher than that of a flat screen, and the vertical viewing angle is relatively reduced to nearly half, but the gain is Since the height is increased, the brightness of the screen is improved, and even if the vertical viewing angle is reduced to 32 degrees, the viewing angle of the human with respect to the screen is not affected. For example, when the height of a person is 1.75 m and is 3 m or more away from the screen, the viewing angle when standing and sitting is within 15 degrees. Therefore, the 32 degree vertical viewing angle is by no means narrow.

FIG. 8 is a three-dimensional display diagram when the screen is curved in the shape of an upright column peripheral wall. In the curved screen 8 as shown in the drawing, the ridge 81 and the centerline N along the axis of the upright column peripheral wall are parallel to each other and are perpendicular to the ground. As a result of performing a test similar to the above with respect to the screen 8 of this kind, its characteristic curve becomes similar to that of FIG. 6, and the gain, horizontal viewing angle and vertical viewing angle do not show different changes. In other words, the characteristic when the screen 8 is curved in the shape of the peripheral wall of the upright column is the same as that of the flat screen, and there is no improvement effect on the gain and the viewing angle. Therefore, it is meaningless to form the present invention into a concave lens-shaped curved screen (which is concavely curved in both the vertical and horizontal directions), and it only unnecessarily increases manufacturing complexity.

FIG. 9 is a diagram showing the photosensitive area of the present invention. There are two types of light rays that can be reflected by the screen 1, one of which is an electric light ray of interference and its wall reflection light, which is called an extraneous light ray, and the other of which is an effective projector light ray, which is called a projection light ray. The higher the contrast of the reflected brightness of the projected ray and the extraneous ray on the screen, the better the definition of the image. When the projected ray is constant, the reflection contrast can be improved by reducing the intensity of the extraneous ray. it can. Further, the ratio of the reflected photosensitivity of the screen to the external light rays is calculated from the numerical values shown in FIG. Therefore, it can be understood that the screen is sensitive to the irradiation of 10% of the external light rays, and the interference of the relative 90% of the external light rays can be eliminated. That is, when the interference range of the screen with respect to the external light is low, the reflection contrast of the screen becomes high and the image becomes clearer.

The image on the screen of a conventional general projector is a real image, but when the gain of the screen is improved, the screen can be regarded as a mirror having a relatively poor reflection effect. Therefore, what is seen on the screen includes not only the projected real image but also a virtual image with a blurred projection light ray. This kind of virtual image becomes more and more clear as the gain is increased, and generally when the gain is 4 or more, the so-called glare zone is obtained. Occurs. As can be seen from the explanatory view for forming the glare zone of the flat screen shown in FIG. 10, when the light rays of the light source 3 are projected on the flat screen 2, the ridges on the surface of the screen 2 are vertically perpendicular to each other. A virtual image is formed on the bed, and the horizontal bright virtual image area 3 is formed by the accumulation of a large number of ridges.
1 is formed, and this virtual image area 31 forms a glare zone in the flat screen 2.

Next, as shown in FIG. 11 which is an explanatory view in which the screen curved in the shape of a lateral wall of the peripheral wall can eliminate the glare zone, the present invention is a screen 1 curved in the vertical direction. Half of the radius of curvature of the screen 1 corresponds to the focus F. It is most ideal to position the projection light source of the projector at the focus F. When the light ray of the light source 4 is projected on the screen 1, the reflected light rays are parallel and have no intersections, so that a virtual image of the light ray 4 is not formed and the glare zone of the virtual image is formed. Disappears. That is, the screen 1 which is concavely curved in the vertical direction of the present invention has an advantage that a glare zone of a virtual image is not generated, and it seems that the brightness of the projected real image on the screen is more uniform, and the curved surface is The gain can be further improved by the condensing and reflecting action.

[0019]

Since the present invention is configured as described above, it is possible to increase the horizontal viewing angle and at the same time increase the reflection brightness (that is, gain) of the screen. In addition to solving the drawback that cannot be increased, it is possible to eliminate the interference of extraneous rays, and it is possible to maintain a clear image contrast under ordinary lighting.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of the present invention.

FIG. 2 50 before the screen of the present invention is matt treated
It is an enlarged photograph figure taken with a 0 magnification microscope.

FIG. 3 50 after the screen of the present invention is matt treated
It is an enlarged photograph figure taken with a 0 magnification microscope.

FIG. 4 is a reflection-related display diagram when a projection light beam is incident on a screen of the present invention in parallel with a ridge.

FIG. 5 is a reflection-related display diagram when a projection light ray is incident perpendicularly to a ridge on the screen of the present invention.

FIG. 6 is a dependence curve diagram of a viewing angle and a gain of a flat screen.

FIG. 7 is a dependence curve diagram of a viewing angle and a gain of a screen which is concavely curved in the vertical direction.

FIG. 8 is a perspective view of a screen that is concavely curved in the horizontal direction.

FIG. 9 is a light-sensitive range display diagram of the present invention.

FIG. 10 is an illustration of a flat screen forming a glare zone.

FIG. 11 is an explanatory diagram showing that the reflective screen of the present invention can erase a glare zone.

[Explanation of symbols]

 1 ... Screen 2 ... Flat screen 4 ... Light source 11 ... Ridge 31 ... Glare zone α, β ... Projected light α ', β' ... Reflected light F ... Focus

Claims (4)

[Claims] 1. A screen (1) made of a metal plate material is provided with a large number of high-density and parallel ridges (11) having continuous unevenness, and the high-density ridge (11).
The screen for projectors is configured such that an irregular wave-like surface is formed on the screen (1) and the surface of the screen (1) is concavely curved in the vertical direction. 2. The ridges (11) are slightly meandered in parallel with each other, and the adjacent ridges (11) of the ridges (11) have non-uniform spacing sizes. The projector screen according to claim 1, wherein the screen has a thickness of about 5 μm or less. 3. The projector screen according to claim 1, wherein the screen (1) is formed of an aluminum plate material. 4. The screen (1) surface is delustered by an erosive action in alkaline washing, and anodized to form and coat a transparent film layer of alumina (Al ₂ O ₃ ). Projector screen.