JPH04305638A - Reflection type screen - Google Patents

Abstract

PURPOSE:To obtain the reflection type screen of a high screen gain adequate for displaying of color images. CONSTITUTION:Reflection surfaces RF are provided in the positions at approximately mid-points near the cylindrical axis positions of the respective cylindrical convex lenses of a cylindrical convex lens array CLA and the positions at the focuses of the cylindrical convex lenses to be generated in a medium when the medium consisting of the same material as the constituting material of the cylindrical convex lens is assumed to be provided. Light is emitted from the cylindrical convex lenses as the light diverged within the plane of the direction orthogonal with the cylindrical axis of the cylindrical convex lenses by the reflection at the reflection surfaces RF. The divergent light having an approximately specified diversion direction is emitted from the cylindrical convex lenses regardless of the directions of incident light even with the reflection type screen for which the convex lens array is used.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to reflective screens.

0002

[Prior Art] A screen used for projecting a large image is one in which light containing image information is projected onto the screen from the viewer's side, and the viewer can see the image on the screen using the reflected light from the screen. a reflective screen that is used when viewing a captured image; and a reflective screen that projects light containing image information onto the screen from the side opposite to the viewer's side;
There are two types of screens: a transmissive screen, which is used when the viewer sees the image projected on the screen by the light transmitted through the screen, and a reflective screen, which is generally suitable for use in darkrooms. Furthermore, it is well known that transmission screens have been used for a long time as they are suitable for bright rooms. By the way, for example, 3 of additive color mixture
Images of each primary color are projected onto individual phosphor screens. When the light from each cathode ray tube is superimposed on the screen to project a large color image on the screen, Since the amount of light projected onto the screen from a cathode ray tube color image projector is small, a screen with high screen gain is required in order to project a high brightness image on the screen.

0003

[Problems to be Solved by the Invention] As mentioned above, even when a small amount of light is projected onto a reflective screen, such as with a cathode ray tube type color image projector, it is possible to project a high-brightness color image on the screen. To make it come out,
It is necessary to use a reflective screen with high screen gain. When a conventional reflective screen with high screen gain and directivity using beads, metal reflective surfaces, etc. is used, as in the above-mentioned cathode ray tube color image projector, different When primary color light is projected onto a reflective screen to project a color image on the reflective screen, each primary color light is emitted from the reflective screen as reflected light heading in different directions. Depending on the position of the viewer viewing the screen, the viewer may not be able to see the correct color image. The above points will be explained below with reference to the drawings. Figure 12 uses a three-tube color image projector PJ to project three primary colors of light from three different directions onto a conventional reflective screen with high screen gain using beads, metal reflective surfaces, etc. This is a diagram illustrating a case where a color image is projected on a reflective screen S. In the diagram, R, G, and B indicate cathode ray tubes that project each primary color light.

The reflection characteristics of the conventional reflective screen S with high screen gain and directivity using beads, metal reflective surfaces, etc. shown in FIG. 12 are shown in FIGS. 13 and 14.
The reflection characteristics of the reflection type screen S using beads are as shown in FIG. 13, and the reflection characteristics of the reflection type screen S using a metal reflective surface are as shown in FIG. is as illustrated in FIG. In the reflection characteristics of the conventional reflection type screen S shown in FIGS. 13 and 14, (a) in each figure shows the reflection characteristics of the reflection type screen S with respect to incident light from the normal direction of the reflection type screen S. In addition, (b) of each figure shows the reflection characteristics of the reflective screen S for incident light from a direction other than the normal direction of the reflective screen S, and (c) of each figure shows the reflection characteristics of the reflective screen S for incident light from a direction other than the normal direction of the reflective screen S. This figure shows how the reflected light of each primary color light is reflected when the light of three primary colors R, G, and B is projected onto the reflective screen S from three different directions. Therefore, as shown in Figure 12, a three-tube color image projector PJ projects three primary colors from three different directions onto a conventional reflective screen S with high screen gain using beads, metal reflective surfaces, etc. When a color image is projected on a reflective screen by projecting light of Depending on your viewing position, you may not be able to see the correct color image. Therefore, the emergence of a reflective screen with a high screen gain and without the drawbacks of conventional reflective screens has been awaited.

[0005]

[Means for Solving the Problems] The present invention provides a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, and in which the cylindrical convex lens A reflective screen in which a reflective surface is formed at a position approximately at the midpoint of the focal point of the cylindrical convex lens that occurs in the medium when a medium made of the same material as the constituent material is provided. and each cylindrical convex lens in a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, and a reflective screen configured with a reflective surface exhibiting diffusivity in the cylindrical axis direction as the above-mentioned reflective screen. and the position of the focal point of the cylindrical convex lens that occurs in the medium when a medium made of the same material as the constituent material of the cylindrical convex lens is provided continuously to the cylindrical convex lens. A reflective screen formed by arranging in series a cylindrical convex lens array having a reflective surface at approximately the midpoint position and having a cylindrical axis perpendicular to the cylindrical axis of the cylindrical convex lens array described above, and a plurality of minute convex lenses. A medium made of the same material as the constituent material of the convex lenses is provided near the center position of the curvature of the surface of the convex lenses in a convex lens array configured by two-dimensionally arranging them in a predetermined arrangement manner, and continuously to the convex lenses described above. A reflective screen is provided in which a reflective surface is formed at a position approximately at the midpoint of the focal point of the convex lens that occurs in the medium when

[0006]

[Operation] In a cylindrical convex lens array in which cylindrical convex lenses of minute width are closely arranged in parallel, a medium made of the same material as the constituent material of the cylindrical convex lenses is formed near the cylindrical axis position of each cylindrical convex lens and continuously to the cylindrical convex lenses described above. is provided, the light generated in the medium described above is reflected by a reflecting surface provided at approximately the midpoint of the focal point position of the cylindrical convex lens, that is, the light incident from the cylindrical convex lens described above. The reflected light is
Since light exits from the cylindrical convex lens as light that diverges in a plane perpendicular to the cylindrical axis of the cylindrical convex lens, reflected light with an approximately constant divergence direction is obtained regardless of the direction of incidence of the incident light, and each primary color Even when light of different primary colors is projected from different directions onto the reflective screen Sr using a projector that projects light from different directions, the viewer will hardly feel that the color balance is disrupted due to the difference in viewing position. Further, by the configuration of the reflecting surface described above, it is possible to emit light from the cylindrical convex lens that is also diverging in the extension direction of the cylindrical axis of the cylindrical convex lens. In a convex lens array constructed by two-dimensionally arranging a plurality of minute convex lenses in a predetermined arrangement manner, the area near the center of the curvature of the surface of the convex lens and continuously from the convex lens described above are made of the same material as the constituent material of the convex lens. If a medium is provided, light generated in the medium and reflected by a reflective surface at a position approximately at the midpoint of the focal point of the convex lens;
That is, the reflected light of the light incident from the above-mentioned convex lens exits from the convex lens as diverging light having a substantially constant divergence direction regardless of the direction of the incident light. If a light absorption layer is provided between each cylindrical convex lens in a cylindrical convex lens array or a light absorption layer is provided between each convex lens in a convex lens array, reflected external light can be removed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the specific structure of the reflective screen of the present invention will be explained in detail with reference to the accompanying drawings. Figure 1
2 to 4 and 6 to 8 are perspective views of the reflective screen of the present invention, and FIG. , FIG. 11 is a perspective view of a part of the reflective screen of the present invention, FIGS. 5 and 9 are diagrams for explaining the operation of the reflective screen of the present invention, and FIG. 15 is a curve for explaining the reflection characteristics of the reflective screen. It is a diagram. First, FIG. 1 shows a reflective screen Sr of the present invention (for example, as illustrated in FIG. The reflective screen Sr of the present invention is configured with a planar cross-sectional shape of a reflective screen Sr (see the reflective screen Sr shown in FIG. The cylindrical convex lens array C
Reflective screen Sr of the present invention showing a cross section of each cylindrical convex lens in LA on a plane perpendicular to the cylindrical axis
FIG. 2 is a plan cross-sectional view of FIG.
) indicates that the portion with the drawing code is used to commonly represent both the planar cross-sectional shape of the convex lens array FEL and the planar cross-sectional shape of the cylindrical convex lens array CLA as described above. This is the drawing code.

In FIG. 1, O, O... are convex lens arrays F.
It shows the center position O of the curvature of the surface of each convex lens in EL, or the cylindrical axis position O, O... of each cylindrical convex lens in a cylindrical convex lens array,
In addition, FF in the figure is a medium made of the same material (same refractive index n) as the convex lens constituent material of the convex lens array FEL.
When a medium having a cylindrical convex lens is continuous, a surface indicating the position of the focus f, f... of the convex lens occurring in the medium, or a cylindrical convex lens in the cylindrical convex lens array CLA is made of the same material as the constituent material of the cylindrical convex lens. (medium with the same refractive index n) is continuous, it shows a plane showing the positions of the focal points f, f, etc. of the cylindrical convex lens that occur in the medium, and furthermore, r indicates the radius of curvature of the curved surface.

In FIG. 1, RF is a reflective surface, and in the reflective screen Sr of the present invention, the reflective surface RF is the center position O of the curvature of each convex lens in the convex lens array (or each of the cylindrical convex lens arrays). Cylindrical axis position of cylindrical convex lens O, O...)
The focal point f, f of the convex lens that occurs in the vicinity and in the medium...
(or the positions of the focal points f, f, . . . of the cylindrical convex lenses occurring in the medium). By providing the reflective surface RF at the position described above, the reflective screen S of the present invention
r is the parallel incident light A, as illustrated in FIG.
B, C, D, E, F are reflected lights Ar, Br in the state of divergent light.
, Cr, Dr, Er, Fr. Incident lights A, B, and C in FIG. 1 are examples of incident lights parallel to the optical axis of each convex lens in a convex lens array (or the optical axis of each cylindrical convex lens in a cylindrical convex lens array). 1
The incident lights D, E, and F are parallel lights that are incident obliquely to the optical axis of each convex lens in a convex lens array (or the optical axis of each cylindrical convex lens in a cylindrical convex lens array).

In the reflective screen Sr of the present invention,
Incident lights A, B, and C parallel to the optical axis of each convex lens in the convex lens array FEL (or the optical axis of each cylindrical convex lens in the cylindrical convex lens array CLA)
is incident, the reflecting surface RF arranged at the related position as described above, that is, the convex lens array FEL
near the center position O of the curvature of the surface of each convex lens (or the cylindrical axis position O, O... of each cylindrical convex lens in the cylindrical convex lens array CLA) and the position of the focal point f, f... of the convex lens occurring in the medium (or The reflected lights Ar, Br, and Cr reflected by the reflecting surface RF, which is located approximately at the midpoint of the focal points f, f, etc. of the cylindrical convex lens, generated in the medium are O which is mirror symmetrical to the position
The convex lens array FEL passes through the position (f” position)
The light is emitted from each convex lens (or each cylindrical convex lens in the cylindrical convex lens array CLA) as diverging light in a limited range that is symmetrical about the optical axis.

Further, in the reflective screen Sr of the present invention, parallel lights D and E are incident obliquely to the optical axis of each convex lens in the convex lens array FEL (or the optical axis of each cylindrical convex lens in the cylindrical convex lens array CLA). . cylindrical axis position O, O...) and the position of the focus f, f... of the convex lens occurring in the medium (or the position of the focus f, f... of the cylindrical convex lens occurring in the medium) The reflected lights Dr, Er, and Fr reflected by the reflecting surface RF located at the midpoint position are mirror-symmetrical with respect to the original focal point f' of the incident lights D, E, and F. The light passes through point f'' and exits from each convex lens in the convex lens array FEL (or each cylindrical convex lens in the cylindrical convex lens array CLA) as a diverging light.

As mentioned above, when the convex lens array FEL is continuously provided with a medium made of the same material as that of the convex lenses, the focal point f of the convex lenses (or the cylindrical convex lens When a medium made of the same material as the constituent material of the cylindrical convex lens is provided continuously, the focal point f) of the cylindrical convex lens that occurs in the medium is:
Since it is a point that is a mirror image of the center of curvature of each convex lens in the convex lens array FEL (or the cylindrical axis of each cylindrical convex lens in the cylindrical convex lens array CLA) O by the reflecting surface RF, each of the points in the convex lens array FEL of the above-mentioned incident light The center of curvature of a convex lens (
Or, the reflected light Er of the incident ray E that has passed through the cylindrical axis (cylindrical axis) O of each cylindrical convex lens in the cylindrical convex lens array CLA behaves as if it were light emitted from the focal point f mentioned above, and is transmitted through the convex lens as light Er parallel to the optical axis. The light is emitted from the convex lens of the array FEL (or the cylindrical convex lens of the cylindrical convex lens array CAL). The above-mentioned ray E is transmitted through the convex lens array FEL.
Since the rays are approximately at the center of the parallel rays D, E, and F that are incident on the convex lens in (or the cylindrical convex lens in the cylindrical convex lens array CLA), the reflected rays Dr, Fr, etc. due to the incident rays D and F are on the optical axis. Even if the light is incident obliquely to the optical axis, or parallel to the optical axis, the diffusion range remains almost the same. As reflected light, a convex lens in a convex lens array FEL (or a cylindrical convex lens array CLA
The light is emitted from the cylindrical convex lens). In this way, the reflective screen Sr of the present invention shown in FIG. 1 has a high screen gain because the reflected light is diffused only in a limited range, and the direction of diffusion of the reflected light does not change regardless of the incident direction. Even when light of different primary colors is projected onto the reflective screen Sr from different directions, the viewer will hardly feel that the color balance is disrupted due to the difference in viewing position.

In the reflective screen Sr of the present invention, the lights A to F incident thereon diverge in the direction of the curve of the curved surface of the convex lens array FEL or the curved surface of the cylindrical convex lens array CLA, as shown in FIG. Since the reflected light Ar to Fr in such a state is emitted, the reflective screen Sr is connected to the convex lens array F.
In the case of an embodiment configured with an EL (for example, FIG.
(Refer to the reflective screen Sr exemplified in ),
When a beam of light with a circular cross section is incident thereon, a diverging beam of light in the shape of a quadrangular pyramid with the point f" as its apex is emitted as reflected light from the reflective screen Sr. Therefore, for example, cathode rays of each primary color are emitted. Even when light of different primary colors is projected onto the reflective screen Sr from multiple different directions, as in the case of a color image projector with It is now possible to view color images.

Further, in the case of an embodiment in which the reflective screen Sr includes a cylindrical convex lens array CLA (for example, see the reflective screen Sr illustrated in FIG. 2), from the reflective screen Sr,
Due to the reflected light from the reflecting surface RF configured in such a manner that no diverging light is generated, reflected light of a diverging light beam that appears to be diverging only in a plane perpendicular to the direction of the cylindrical axis of the cylindrical convex lens is emitted. . Therefore, if, for example, cathode ray tubes that project images of each of the three additive primary colors on separate phosphor screens are arranged in a direction perpendicular to the direction of the cylindrical axis of the cylindrical convex lens, The divergence of each primary color light on the reflective screen Sr allows the viewer to perceive the image as a natural color image. However, it is desirable that the reflected light from the reflective screen Sr configured with the cylindrical convex lens array CLA be made into a diverging light beam that is somewhat divergent in the direction of the cylindrical axis of the cylindrical convex lens. . In other words, it is a multi-tube type in which light from images displayed on multiple cathode ray tubes is projected onto the same display screen from different directions and superimposed on the display screen to form one complete image. The arrangement of cathode ray tubes generally employed in projectors is to arrange them horizontally.

Now, in a multi-tube projector having three cathode ray tubes in which an image of each of the three primary colors is projected on a separate phosphor screen, the arrangement of the three cathode ray tubes described above is as follows. In the case where the arrangement follows the general arrangement of cathode ray tubes described above, that is, three cathode ray tubes are arranged in the horizontal direction, a reflective type configured with a cylindrical convex lens array CLA is used. Screen S
The cylindrical convex lens array CLA at r is connected to a reflective screen S with its cylindrical axis in the vertical direction.
Since the direction of divergence of the light emitted from the reflective screen Sr is set in a horizontal plane, the viewer who is observing the image projected by the light emitted from the reflective screen Sr must use a multi-tube projector. A good image can be observed in the horizontal plane where the three cathode ray tubes are arranged, but if the position of the observer's eyes deviates up or down from the horizontal plane, the observer cannot see the image. You will not be able to do so. Therefore, in order to enable the viewer to observe the image even if the position of the viewer's eyes is shifted vertically from the horizontal plane, it is necessary to The emitted light, which is also diverging in the direction of the cylindrical axis of the convex lens array CLA, passes through the reflective screen Sr.
It is hoped that this will be done in such a way that it arises from the

As described above, the cylindrical convex lens array CL in the reflective screen Sr is configured with the cylindrical convex lens array CLA.
As a means for making the emitted light diverged in the direction of the cylindrical axis of A from the reflective screen Sr, for example, as illustrated in FIG. The purpose can be sufficiently achieved by applying a simple light divergence means to the reflecting surface RF, such as making the reflecting surface uneven by making scratches in orthogonal directions. In other words, since the multiple cathode ray tubes for projecting the light of multiple images to be superimposed on the reflective screen are arranged horizontally as described above, the state of divergence of each color light in the vertical direction is This is because the reflection surface R
No special configuration is required as a means for diffusing light at F. FIG. 3 illustrates a reflective screen Sr having a configuration in which a reflective surface RF is provided with unevenness for diffusing reflected light in the direction of the cylindrical axis of a cylindrical convex lens.

As an example of the configuration of a reflective screen Sr that is configured with a cylindrical convex lens array CLA, for example, scratches in the direction perpendicular to the cylindrical axis of the cylindrical convex lenses are formed on the above-mentioned reflective surface RF on the flat side of the cylindrical convex lens array CLA. Then, by applying a vapor deposition method, a reflective surface (mirror surface) RF is formed by a thin aluminum film. In addition, if the scratches formed on the reflective surface RF described above are in the form of frosted glass,
The state of divergence of the reflected light from the reflective surface RF is non-directional, and the reflected light from the screen Sr is not only directed in the direction of the cylindrical axis of the cylindrical convex lens, but also in a direction perpendicular to the direction of the cylindrical axis of the cylindrical convex lens. Although the light is diverging, the degree of divergence of the reflected light in this case is extremely small, so there is no problem in practical use.

FIG. 3 shows a cylindrical convex lens array CL.
3 is a perspective view showing an example of the configuration of a reflective screen Sr configured with A. The reflective screen Sr illustrated in FIG. 3 is also required in the direction of the cylindrical axis of the cylindrical convex lens. In the case of the reflective screen Sr, which is configured so that the amount of light diverged is the same, uneven brightness (shading) does not occur in the direction of the cylindrical axis of the cylindrical convex lens. In the case of a reflective screen Sr (high-gain reflective screen Sr) with a configuration in which light divergence is small in the direction, a configuration in which a reflective surface RF is provided on a cylindrical convex lens array CLA in which the cylindrical axis of the cylindrical convex lens is curved. It is desirable that the reflective screen Sr is a reflective screen Sr having a cylindrical surface as illustrated in FIG. In addition, FIG. 5 shows that image light is projected from a projector PJ onto a reflective screen Sr having a curved surface as illustrated in FIG. This is an example of a viewing area that can be observed. Note that the outer shape of the reflective screen Sr may be configured as a part of a spherical surface.

FIG. 6 shows a cylindrical convex lens array CL.
The shape of the reflective surface RF of the reflective screen Sr configured with A is a cylindrical convex lens array CLA.
6 shows a reflective screen Sr having a configuration in which the cylindrical convex lens array has a cylindrical axis that is orthogonal to the cylindrical axis of the cylindrical convex lens. In the reflective screen Sr having the configuration shown in FIG. It is possible to generate reflected light that diverges in both the vertical and vertical directions. In addition, FIG. 7 shows the convex lens array FE.
7 shows a configuration example of a reflective screen Sr configured with a convex lens array FEL as shown in FIG. It is possible to generate reflected light that diverges in both directions. Figure 8 (a), (
b) is a cylindrical convex lens array CLA with a reflective surface R.
On the front surface of the reflective screen Sr configured by providing a cylindrical lens F, cylindrical lenses are arranged in such a manner that the direction of the cylindrical axis is orthogonal to the cylindrical axis direction of the cylindrical convex lens of the cylindrical convex lens array CLA in the reflective screen Sr. This is an example of a reflective screen SrA having a configuration in which a convex lens array CLAf is provided, and the reflective screen SrA shown in FIGS. It is possible to generate reflected light that diverges in the direction.

Convex lens array FEL (or cylindrical convex lens array C) in reflective screen Sr
The light incident on the convex lens array FEL (or the cylindrical convex lens array CLA) is reflected by the reflective surface RF, and the reflected light generated by the reflective surface RF is emitted from the front surface of the reflective screen Sr again. By the way, when the reflective screen Sr is used in the presence of external light, it is not desirable for the reflective screen Sr to give the observer light reflected from the external light. In actual use of the reflective screen Sr, external light may enter the reflective screen Sr from the side windows of the reflective screen Sr, or light from a ceiling light above and in front of the reflective screen Sr may enter the reflective screen Sr. It is not uncommon for a reflective screen Sr to be used in a state where the external light is incident on the reflective screen Sr, and as mentioned above, when external light is incident on the reflective screen Sr, It is used in undesirable situations where external light is perceptible to the observer.

Since the direction of incidence of external light on the reflective screen Sr is different from the direction of incidence of the image light from the projector PJ on the reflective screen Sr, the above-mentioned external light from the reflective surface RF of the reflective screen Sr is different from the direction of incidence of the image light from the projector PJ on the reflective screen Sr. By providing a light absorption layer in the optical path of the reflected light, the reflected light from the external light is absorbed, and the reflected light from the external light is prevented from emitting from the reflective screen Sr. Allows the light to be invisible to the observer. FIG. 9 shows a light absorption layer 2 on at least a part of the boundary between each convex lens in a reflective screen Sr configured by providing a reflective surface RF on a convex lens array FEL.
and a reflective screen Sr configured by providing a reflective surface RF on a cylindrical convex lens array CLA, and a reflective screen Sr configured by providing a light absorption layer 2 at the boundary between each cylindrical convex lens. 9 is a diagram showing a planar cross-sectional shape in common with the screen Sr. In FIG. 9, 1 is an antireflection film and 2 is a light absorption layer, and the reflective screen having the configuration shown in FIG. According to Sr, it is possible to prevent the observer from receiving the light reflected from the reflective screen Sr due to the external light Pi as described above. In FIG. 9, a convex lens array FE used in the configuration of the reflective screen Sr
L or the light Pi incident on the cylindrical convex lens used to configure the cylindrical convex lens array CLA
When the focal point f' of is at an angle that deviates from the horizontal line drawn at the base of arrow 3, the reflection surface R of the incident light Pi
The reflected light from F is absorbed by the light absorption layer 2. Figure 1
0 and FIG. 11 show a reflective screen Sr as described with reference to FIG. 9, which absorbs external light and has a configuration in which light reflected from the reflective screen Sr by external light is not given to the observer. Convex lens array FEL used in the configuration of
, or a perspective view showing a configuration example of a cylindrical convex lens array CLA, and is a perspective view showing a configuration example of a cylindrical convex lens array CLA, and FIG.
10 is an example of the configuration of a convex lens array FEL used in the configuration of the reflective screen Sr, and FIG. 10(b) is an example of the configuration of a cylindrical convex lens array CLA. It is an absorbent layer.

FIG. 15 is a diagram used to explain the directional characteristics of reflected light (emitted light) from the reflective screen Sr of the present invention described above, and FIG. FIG. 15(b) shows the directional characteristics of reflected light when incident light Pi from the normal direction is incident on the reflective screen Sr of the present invention. This figure shows the directional characteristics of reflected light when incident light Pi enters from a direction other than the normal direction of the reflective screen of the present invention. Sr has a directional pattern of reflected light (emitted light) that is almost unrelated to the direction of incident light. So, for example, as illustrated in FIG. 15(c),
When different primary color lights R, G, and B are incident on the reflective screen Sr of the present invention from three different directions,
Since the reflected light from the reflective screen Sr due to the three primary color lights incident from different directions described above exhibits similar directional characteristics, the viewer feels that the color balance is disrupted due to the difference in viewing position. There are almost no such things. Furthermore, the reflection characteristics of the reflective screen Sr of the present invention shown in FIGS. 15(a) to (c),
For reference, when compared with the reflection characteristics of a reflective screen with a screen gain of 1 that reflects perfectly diffused white omnidirectionally, as shown in FIG. 15(d), the reflective screen of the present invention limits the incident light. It is easy to understand that the screen gain is high because the reflected light is diffused only within a certain range.

[0023]

Effects of the Invention As is clear from the above detailed explanation, the reflective screen of the present invention has a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, and the cylindrical axis position of each cylindrical convex lens is fixed. approximately in the middle of the focal point of the cylindrical convex lens that occurs in the medium when a medium made of the same material as the constituent material of the cylindrical convex lens is provided continuously to the cylindrical convex lens. The light reflected by the reflective surface provided at the point position, that is, the reflected light of the light incident from the cylindrical convex lens mentioned above, is the light that diverges from the cylindrical convex lens in a plane perpendicular to the cylindrical axis of the cylindrical convex lens. Since the light is emitted from a cylindrical convex lens, reflected light having a substantially constant divergence direction is obtained regardless of the direction of incidence of the incident light.
Even when light of different primary colors is projected from different directions, the viewer will hardly notice any loss of color balance due to the difference in viewing position, and due to the configuration of the reflective surface described above, the cylindrical axis of the cylindrical convex lens It is possible to emit light that is diverging also in the extension direction of the cylindrical convex lens, and also to emit light that is diverging in the direction of extension of the convex lens in a convex lens array constructed by two-dimensionally arranging a plurality of minute convex lenses in a predetermined arrangement manner. Abbreviation of the position near the center of the curvature of the surface and the focal point of the convex lens that occurs in the medium when the convex lens is continuously provided with a medium made of the same material as the constituent material of the convex lens. The light reflected by the reflective surface at the midpoint position, that is,
The reflected light of the light incident on the convex lens described above exits from the convex lens as diverging light having a substantially constant divergence direction regardless of the direction of the incident light. By providing a light absorption layer between each cylindrical convex lens in a cylindrical convex lens array or providing a light absorption layer between each convex lens in a convex lens array, reflected external light can be removed. The screen gain is high because the reflected light is diffused only within the specified range, and the reflected light (outgoing light) has a directional pattern that is almost unrelated to the direction of the incident light. Even when light is projected from different directions, the viewer will hardly feel any disruption in color balance due to the difference in viewing position, and the present invention can satisfactorily solve the above-mentioned conventional problems.

[Brief explanation of drawings]

FIG. 1 is a plan cross-sectional view of a reflective screen for explaining the principle of construction and operation of the reflective screen of the present invention.

FIG. 2 is a perspective view of a reflective screen of the present invention.

FIG. 4 is a perspective view of a reflective screen of the present invention.

FIG. 5 is a diagram for explaining the operation of the reflective screen of the present invention.

FIG. 6 is a perspective view of a reflective screen of the present invention.

FIG. 7 is a perspective view of a reflective screen of the present invention.

FIG. 8 is a perspective view of a reflective screen of the present invention.

FIG. 9 is a diagram for explaining the operation of the reflective screen of the present invention.

FIG. 10 is a perspective view of a portion of the reflective screen of the present invention.

FIG. 11 is a perspective view of a portion of the reflective screen of the present invention.

FIG. 12 is a plan view showing an image being projected onto a reflective screen from a three-tube projector.

FIG. 13 is a plan view showing the reflective characteristics of a bead screen as one of conventional reflective screens.

FIG. 14 is a plan view showing the reflection characteristics of a metal reflective screen, which is one of conventional reflective screens.

FIG. 15 is a plan view showing the reflective characteristics of a reflective screen for explaining the reflective characteristics of the reflective screen of the present invention.

[Explanation of symbols]

FEL...Convex lens array, CLA...Cylindrical convex lens array, RF...Reflection surface, O...Convex lens array FEL
The center position of the curvature of the surface of each convex lens in , or the cylindrical axis position of each cylindrical convex lens in a cylindrical convex lens array, FF...The convex lens of the convex lens array FEL is provided with a medium made of the same material as the constituent material of the convex lens (
When the medium (having the same refractive index n) is continuous, the surface indicating the position of the focal point of the convex lens that occurs in the medium, or the same material as the constituent material of the cylindrical convex lens in the cylindrical convex lens in the cylindrical convex lens array CLA (Medium having the same refractive index n) A surface indicating the focal point position of the cylindrical convex lens that occurs in the medium when the medium is continuous, S, Sr... Reflective screen, 1... Light reflecting film , 2...light absorption layer,

Claims (8)

[Claims] Claim 1: In a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, a portion near the cylindrical axis position of each cylindrical convex lens and continuously to the cylindrical convex lens is made of the same material as the constituent material of the cylindrical convex lens. A reflective screen comprising a reflective surface located approximately at the midpoint of the focal point of the cylindrical convex lens that would occur in the medium if the medium was provided. 2. In a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, the vicinity of the cylindrical axis position of each cylindrical convex lens and continuously from the cylindrical convex lens are made of the same material as the constituent material of the cylindrical convex lens. If a medium is provided, a reflecting surface exhibiting diffusivity in the cylindrical axis direction is constructed at a position approximately midway between the focal point of the cylindrical convex lens that occurs in the medium. A reflective screen. 3. The reflective screen according to claim 2, wherein the diffusing properties of the reflective surface are obtained by scratches in a specific direction on the reflective surface. 4. A reflective screen according to claim 2, wherein a second cylindrical convex lens surface having a cylindrical axis perpendicular to the cylindrical axis of the cylindrical convex lens is formed, and the second cylindrical convex lens surface is a reflective surface. 5. In a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel, the area near the cylindrical axis position of each cylindrical convex lens and continuously from the cylindrical convex lens is made of the same material as the constituent material of the cylindrical convex lens. If a medium is provided, a reflective surface is formed at a position approximately at the midpoint of the focal point of the cylindrical convex lens that occurs in the medium, and is orthogonal to the cylindrical axis of the cylindrical convex lens array. A reflective screen consisting of a cylindrical convex lens array with a cylindrical axis arranged in series. 6. The reflective screen according to claim 1, wherein a light absorbing layer is provided at the boundary between each cylindrical convex lens in a cylindrical convex lens array in which cylindrical convex lenses with minute widths are closely arranged in parallel. 7. In a convex lens array configured by two-dimensionally arranging a plurality of minute convex lenses in a predetermined arrangement manner, a convex lens structure is formed near the center position of the curvature of the surface of the convex lens and continuously from the convex lens described above. A reflective screen comprising a reflective surface located approximately at the midpoint of the focal point of the convex lens that would occur in the medium if a medium made of the same material as the material is provided. 8. The reflective screen according to claim 7, wherein a light absorption layer is provided at least in part of the boundary between each convex lens in the convex lens array.