JP2011175022A - Dome screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of improving contrast of an image displayed in the center part of a dome in a dome screen, by decreasing the quantity of reflected light having a large angle, which is reflected by the periphery part of the dome and goes toward the center part of the dome. <P>SOLUTION: The dome screen 1 has hemispherical shape, and includes, on the inside surface of the dome screen 1: a reflection part 2 that reflects image light projected from a projector 10 to display the image light; and light-shielding parts 3 that are protrusively provided in stripe shape by leaving space along a horizontal direction of the dome screen on the reflection part 2 and intercept the reflected light reflected by the reflection part 2. The light-shielding part 3 is provided on the reflection part 2, for example, so as to be spiral. Also, the light-shielding part 3 is provided on the reflection part 2, for example, so as to be concentric circle shape to the circumference of the bottom part of the dome screen 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dome type screen suitably used for a large screen display such as a planetarium.

  In general, a planetarium or the like uses a reflective dome type screen that reflects and displays an image projected from one or a plurality of projectors. For example, Patent Document 1 describes a dome-shaped screen in which a plurality of divided pieces are combined to form a dome shape, and a screen paint is applied to the inner surface to form a display surface.

JP 2002-276178 A

  Here, FIG. 4 is a conceptual diagram showing a state in which light of an image projected from a projector installed inside the dome-shaped screen is reflected on the display surface of the dome-shaped screen. In FIG. 4, the light of the image directly incident on the display surface from the projector is indicated by a solid line, and the reflected light reflected by the display surface is indicated by a broken line.

  As shown in FIG. 4, for example, light of an image incident on the display surface of a dome peripheral portion (here, points A and C) of a dome type screen from a projector is reflected on the display surface to be mainly a dome shape. Although it goes to the audience seat side provided on the bottom side of the screen, a part of the reflected light is incident on the center of the dome on the display surface (in this case, point B). Further, a part of the light (reflected light) of the image projected on the center of the dome is incident on the other part of the display surface.

  As described above, the dome type screen has a wide directivity characteristic, that is, has a structure that reflects light projected from the projector to a wide range. Therefore, the larger the screen, the more easily affected by the reflected light reflected by other parts on the screen. That is, when the reflected light reflected by a certain part on the screen is incident on the other part, the part becomes so-called black floating, in other words, a phenomenon of becoming whitish is likely to occur. As described above, when the screen becomes whitish, the contrast of the screen (the difference in brightness between the bright part and the dark part) decreases, resulting in deterioration of the image quality. The contrast of a normal television receiver or the like can be obtained with a contrast of 1000 to 1 or more, whereas the contrast of a dome type screen with a contrast of 10 to 1 or less is reflected by other parts of the screen. This is largely due to the structural nature of the dome screen, which is easily affected by reflected light.

  The dome-shaped screen has a structure in which the line of sight tends to gather especially in the center of the dome when viewed from the spectator side, so when the contrast of the image displayed in the center of the dome decreases, it is viewed from the spectator side. Sometimes image quality degradation is noticeable. For this reason, in order to prevent deterioration in image quality, it is necessary to prevent a decrease in contrast of an image displayed at the center of the dome.

  However, since the technique described in Patent Document 1 does not have a structure that blocks the reflected light reflected on the screen surface, the reflected light having a large angle reflected on the periphery of the dome is incident on the center of the dome. There is a possibility that the contrast of the image displayed in the center portion is greatly reduced.

  The present invention has been made in view of the above problems, and in a dome-shaped screen, the amount of reflected light having a large angle reflected at the periphery of the dome and directed toward the center of the dome is attenuated, and is displayed at the center of the dome. It is an object of the present invention to provide a technique capable of improving the contrast of an image.

The invention according to claim 1, which has solved the problem, is a dome type screen that reflects and displays image light projected from a projector, and reflects the image light on an inner surface of the dome type screen. A reflective portion; and a light shielding portion provided in the reflective portion so as to protrude in a striped manner at intervals along the horizontal direction of the dome-shaped screen, the light shielding portion being a reflection reflected by the reflective portion It is characterized by shielding light.
Here, in the dome-shaped screen according to claim 1, the light shielding portion may be provided in a spiral shape on the reflection portion. Further, in the dome type screen according to claim 1, the light shielding part may be provided in the reflecting part concentrically with respect to a circumference of a bottom part of the dome type screen.

According to such a configuration, the reflection reflected by the reflection portion between the light shielding portions is formed on the reflection portion of the dome type screen by the light shielding portions protruding in stripes at intervals along the horizontal direction of the dome type screen. Light can be blocked.
In other words, a portion of the reflected light that is reflected at the dome periphery of the dome-shaped screen and directed toward the center of the dome can be shielded by the light shielding portion provided at the periphery of the dome. The amount can be effectively attenuated. Therefore, the contrast and image quality of the image displayed at the center of the dome can be improved. Further, it is possible to prevent the image quality displayed in the other part from being deteriorated by the reflected light that is reflected from the central part of the dome and directed to the other part of the screen.

  According to a fourth aspect of the present invention, in the dome-type screen according to any one of the first to third aspects, the light-shielding portion has an installation interval at a dome central portion of the dome-shaped screen. It is larger than the installation interval in the peripheral part.

Here, if the reflected light reflected from the dome periphery of the dome-shaped screen is directly incident on the dome center, the contrast of the dome center is reduced, so it is necessary to effectively shield the reflected light. Become. On the other hand, the reflected light reflected at the dome central portion of the dome screen hardly enters the dome central portion due to the structure of the dome screen.
Therefore, in order to effectively attenuate the reflected light from the periphery of the dome that affects the contrast of the image displayed in the center of the dome, the interval between the light shielding portions is reduced in the periphery of the dome, In the center of the dome, the interval between the light shielding parts is increased.

  As a result, it is possible to effectively shield the reflected light having a large angle reflected at the dome periphery and toward the center of the dome, and to simplify the configuration of the dome type screen. Furthermore, although the installation interval is large, since the light shielding part is also provided at the center of the dome, the reflected light that is reflected at the center of the dome and directed toward the other part of the screen can be shielded to some extent. For this reason, the improvement of the contrast of the image displayed on other parts other than the dome center part can still be expected.

According to the present invention, the following excellent effects can be obtained.
According to the invention described in claims 1 to 3, since the light shielding portion that protrudes in a stripe shape along the horizontal direction of the dome-shaped screen is provided on the reflection portion provided on the inner surface of the dome-shaped screen. Reflected light reflected from the dome periphery of the dome type screen and directed toward the center of the dome can be effectively blocked. As a result, the contrast of the image displayed at the center of the dome can be improved, and as a result, a high-contrast and high-quality image can be displayed on the entire dome-shaped screen.
According to the invention described in claim 4, in addition to the effects of the invention described in claims 1 to 3, the configuration of the dome type screen can be simplified, so that the dome type screen becomes inexpensive.

It is the figure which shows the whole structure of the dome shape screen which concerns on embodiment of this invention, and the figure which expanded a part. (A) shows the base material which comprises the dome shape screen shown in FIG. 1, (b) is the figure which expanded further the base material of (a), (c) is (b) from A direction. FIG. It is a conceptual diagram for demonstrating a mode that reflected light is light-shielded by the light-shielding part. It is a conceptual diagram which shows a mode that the image light projected from the projector in the conventional dome shape screen reflects in a screen surface.

Hereinafter, a dome type screen 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the dome-shaped screen 1 has a hemispherical shape, and reflects the image light projected from the projector 10 on the inner surface thereof. The dome-shaped screen is configured to include a light shielding portion 3 that is projected in a striped manner with a space along the horizontal direction and shields the reflected light reflected by the reflecting portion 2. Here, the case where the two projectors 10 respectively project images corresponding to different areas of the reflecting portion 2 of the dome-shaped screen 1 is illustrated, but the number of the projectors 10 is not particularly limited. . In the enlarged view of FIG. 1, for convenience of explanation, the light-shielding portion 3 is highlighted and enlarged, and the interval is widened.

  As shown in FIG. 2 (a), the dome-shaped screen 1 has a dome-shaped frame (not shown) so that the base 1a, which is a small piece of a metal screen such as aluminum, becomes a dome shape. And a plurality of the base materials 1a are fixed to a frame (not shown) with bolts, rivets or the like. In FIGS. 2B and 2C, the base material 1a is shown as a rectangular shape for convenience. However, in actual production, in order to correspond to the dome shape, the base material 1a may be trapezoidal or the like. Of course.

  The base material 1a may be formed of, for example, a flexible plastic film made of acrylic, polyester, or the like. If the base material 1a is formed of a flexible material, it can be easily attached to a curved portion of a frame (not shown). The thickness of the substrate 1a can be appropriately set in consideration of the strength as a screen. Hereinafter, the configuration of the dome-shaped screen 1 will be described using the substrate 1a with reference to FIGS. 2 (a) to 2 (c) as appropriate.

  The reflection unit 2 reflects and displays the image light projected from the projector 10. The reflection part 2 can be formed by coating one surface of the base material 1a with, for example, white paint (for example, white ink).

  The light-shielding part 3 shields the reflected light reflected by the reflecting part 2, and is spaced from the reflecting part 2 along the horizontal direction of the dome-shaped screen 1, as shown in FIGS. Projected in a striped pattern. That is, the light-shielding part 3 extends and projects in a horizontal streak shape when the reflection part 2 is viewed from the front side. Here, as shown in FIG. 2B, the light shielding portions 3 are arranged so that the reflection portions 2 and the light shielding portions 3 are alternately arranged when the dome type screen 1 is viewed from the front side. For example, the light shielding unit 3 may be provided on the reflection unit 2 concentrically with the circumference of the bottom of the dome-shaped screen 1 or may be provided on the reflection unit 2 in a spiral shape.

  The light-shielding part 3 is arranged by arranging a plurality of cables whose surfaces are coated with black dye or the like (for example, black ink or black powder) on the reflection part 2 in a striped manner at intervals in the horizontal direction of the dome-shaped screen 1. And it can comprise by fixing this cable to the reflection part 2 with an adhesive agent etc., respectively. In addition, in the example shown in FIG.2 (c), although the top part of the light-shielding part 3 is made into the flat shape, it is not restricted to this, It may be pointed and may be circular arc shape. Moreover, although the cross-sectional shape of the light-shielding part 3 is made into the rectangular shape, it is not restricted to this, It can change suitably. The material of the light-shielding part 3 can be appropriately selected from known materials. However, when the light-shielding part 3 is attached to the frame with the light-shielding part 3 attached to the base 1a, the base material It is necessary to consider the balance with the base material 1a so that 1a does not bend and deform due to the weight of the light shielding portion 3.

Next, it is necessary to make the installation interval p ₁ of the light shielding portions 3 in the vertical direction of the dome-shaped screen 1 small enough that the audience does not feel disturbed when viewing the image on the screen. For example, the distance between the zenith portion of the dome-shaped screen 1 having a diameter of 40 m and the spectator seated in the spectator seat provided at the center of the bottom portion of the dome-shaped screen 1 is approximately 10 m. The distance between the zenith portion of the dome-shaped screen 1 and the spectator seated in the spectator seat provided at the bottom corner of the dome-shaped screen 1 is about 5 m at the shortest. Becomes 10 m or more. The zenith portion is the top portion of the dome-shaped screen 1 and refers to the position of the North Pole when the dome-shaped screen 1 is regarded as the northern hemisphere of the earth.

  Here, for example, on the basis of a person with a visual acuity of 1.0, it is felt that if there are 60 lines per angle of 1 degree for viewing a portion on the screen from the eye, that is, it is fine and hardly visible. If there are 8 lines per degree of visual perception, it is felt that there is a clear line. And in order to make the line almost invisible when looking at the zenith of the dome-shaped screen 1 from the spectator seat, when viewed from a distance of 10 m, the condition of 60 lines per degree is 3 mm. Become.

In view of this, in consideration of people with other visual acuity, it is preferable to provide the installation interval p1 of the light-shielding part 3 to be ₂ to 5 mm. Installation interval p ₁ and a 2mm smaller than the light shielding portion 3, becomes finer than necessary, making the dome type screen 1 in addition to be difficult, the screen feels dark when viewed from the audience fear There is. On the other hand, the installation interval p ₁ and a 5mm smaller than the light shielding portion 3, spacing becomes too large, the light shielding portion 3 will increasingly likely to be felt disturbing visible to the audience.

Also, for example, if a Super Hi-Vision 8K image (7680 pixels horizontally) is displayed on half of the dome-shaped screen 1 having a diameter of 20 m (30 m because the circumference is approximately 60 m), the size of one pixel is 4 mm. since, it is desirable that the installation interval p ₁ of the light shielding portion 3 and 2mm or less is half. In this way, when an 8K image is displayed on the dome-shaped screen 1, the possibility of generating moire or the like is reduced, and deterioration in image quality can be prevented.

  In any of the above cases, it is desirable that the height H of the light-shielding portion 3 is about 1 mm. If the height H of the light-shielding part 3 is too large, the entire screen becomes dark, which is not preferable. On the other hand, if it is too small, reflected light having a large angle passes through the light-shielding part 3 and is incident on the center of the dome. This is because the amount of light may not be effectively attenuated.

Next, the influence of the installation interval p ₁ and the height H of the light shielding part 3 on the dome type screen 1 on the light shielding performance will be described.
Here, the angle seen from the surface of the center of the dome when the light of the image projected on the center of the dome (here, point B in FIG. 1) reaches the spectator seat is approximately ± on the structure of the dome type screen 1. The range is 30 degrees. On the other hand, the incident angle seen from the surface of the dome center when the light of the image projected on the dome periphery (here, point A or point C in FIG. 1) is incident on the center of the dome is The structure is approximately 45 degrees.

  Here, the dome peripheral portion refers to a wall portion that enters the field of view when sitting in a natural posture on the auditorium. Here, an area between the equator and 35 degrees north latitude when the dome-shaped screen 1 is regarded as the northern hemisphere of the earth is referred to as a dome periphery. The center of the dome is the ceiling that enters the field of view for the first time when the back of the audience seat is tilted backwards. Here, when the dome-shaped screen 1 is regarded as the northern hemisphere of the earth, the region from 35 degrees north latitude to the north pole is called the dome center.

Here, when the light shielding part 3 is not provided, the light amount reflected in the direction of the reflection angle θ is 1, and when the light shielding part 3 is provided, the light amount reflected in the direction of the reflection angle θ is R _θ. The relationship represented by the following expression (101) is established between the installation interval p ₁ of the light shielding portion 3 and the height H. Similarly, when the light-shielding portion 3 is provided, the following formula (between the light amount R ₃₀ reflected in the direction of the reflection angle of 30 degrees and the installation interval p ₁ of the light-shielding portion 3 and the height H is given by 102) is established, and when the light-shielding portion 3 is provided, between the light amount R ₄₅ reflected in the direction of the reflection angle of 45 degrees, the installation interval p ₁ of the light-shielding portion 3 and the height H, The relationship represented by the following formula (103) is established.

According to this equation (103), the light shielding portion 3 of height H / _{p 1,} for example 0.5 indicating the ratio of the installation interval _{p 1} for H, that is, the height H of the light shielding portion 3 to installation interval _{p 1} When the ratio is 1: 2, the amount of light reflected in the direction of the reflection angle of 45 degrees when the light shielding unit 3 is provided is attenuated by 50% compared to the case where the light shielding unit 3 is not provided. That is, the amount of reflected light from the periphery of the dome toward the center of the dome is attenuated by 50% by the light shielding portion 3. On the other hand, according to the equation (102), the amount of light reflected in the direction of the reflection angle of 30 degrees when the light shielding unit 3 is provided is attenuated by only 30% compared to when the light shielding unit 3 is not provided. That is, 70% of the luminance at the center of the dome is secured around the spectator seat.

Further, according to the equation (101), when H / P ₁ is 0.5, the reflected light toward the center of the dome at a reflection angle of 63 degrees or more is completely blocked by the light blocking unit 3 and enters the center of the dome. Not. More specifically, in equation (101), tan θ is 2 when H / P ₁ is 0.5 and R _θ = 0. R _θ = 0 means that the reflected light is completely blocked by the light blocking unit 3. The reflection angle corresponding to tan θ = 2 is approximately 63 degrees.

  Thus, the reflected light reflected in the region within 54 degrees (180 degrees -63 degrees -63 degrees) from the zenith portion of the dome-shaped screen 1, that is, the angle viewed from the surface of the dome central portion is within 54 degrees. Since the reflected light reflected by the region is completely blocked by the light blocking unit 3 and is not incident on the center of the dome, the contrast of the image displayed at the center of the dome can be maintained in a high state.

  According to such a dome type screen 1, since a part of the reflected light having a large angle reflected at the periphery of the dome and going toward the center of the dome can be shielded by the light shielding unit 3, the reflection incident on the center of the dome. The amount of light can be attenuated, thereby preventing a decrease in contrast and image quality at the center of the dome. As a result, a high-contrast and high-quality image can be displayed on the entire screen. Further, it is only necessary to attach the light shielding part 3 to the reflecting part 2, and the light shielding part 3 can be made of an inexpensive and simple material such as a black cable, so that the dome type screen 1 is inexpensive.

  Although not shown, the dome type screen 1 may have a plurality of small holes for absorbing sound over the entire surface. If the base material 1a is made of hard aluminum or the like, it is easy to reflect sound. Therefore, for example, when a commentary sound is played through a speaker in conjunction with an image like a planetarium, it is difficult for the audience to hear the sound. However, according to this, since a part of the sound toward the reflecting portion 2 passes through the small hole to the back, the reflection of the sound can be reduced.

  The dome type screen of the present invention described above is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.

  In the above-described embodiment, the light-shielding portions 3 are provided on the entire reflection portion 2 of the dome type screen 1 at substantially equal intervals. However, the present invention is not limited to this, and the installation interval may be changed depending on the location. . For example, the installation interval of the light shielding unit 3 at the center of the dome may be made larger than the installation interval of other portions, that is, the light shielding unit 3 at the periphery of the dome.

  If the reflected light reflected from the dome periphery of the dome-type screen 1 is directly incident on the dome central portion, the contrast of the dome central portion is lowered, so that it is necessary to effectively shield the reflected light. On the other hand, the reflected light reflected at the center of the dome of the dome type screen 1 hardly enters the center of the dome because of the structure of the dome type screen 1.

  Therefore, in order to effectively attenuate the reflected light from the periphery of the dome that affects the contrast of the image displayed at the center of the dome, the installation interval of the light shielding portions 3 is reduced in the periphery of the dome. On the other hand, the reflected light from the central part of the dome has little influence on the image contrast displayed in the central part of the dome, so that the installation interval of the light shielding parts 3 is increased in the central part of the dome.

  Thereby, the contrast of the image displayed at the center of the dome can be improved, and the configuration of the dome type screen 1 can be simplified, so that the dome type screen 1 is inexpensive. Furthermore, although the installation interval is large, since the light shielding part 3 is provided to some extent at the center of the dome, the reflected light that is reflected at the center of the dome and directed to other parts of the screen can be shielded to some extent. For this reason, the improvement of the contrast of the image displayed on other parts other than the dome center part can also be expected.

  In the above-described embodiment, as shown in FIG. 2B, the light shielding portion 3 is provided on the reflecting portion 2 so as to be linearly continuous along the horizontal direction of the dome-shaped screen 1, but this is not limited thereto. For example, the light-shielding part may be configured as a dot-like protrusion, and may be provided discontinuously on the reflecting part 2 along the horizontal direction of the dome-shaped screen 1.

  Note that the point-like protrusions refer to, for example, cylindrical, conical, prismatic, and spherical protrusions, but the shape is not particularly limited. When the light-shielding part is a dot-like protrusion, the dot-like protrusion may be directly attached to the reflecting part 2, but for example, on the surface of the string or cable with a white coating on the surface, the surface A black projection is attached to the reflective portion 2 with an adhesive or the like, and a plurality of these strings or cables are arranged in a stripe shape along the horizontal direction of the dome-shaped screen 1 on the reflective portion 2 to the reflective portion 2 with an adhesive or the like. It may be attached. At this time, the interval between the light shielding portions adjacent to each other on the same line can be appropriately set within a range in which reflected light having a large angle does not pass between the light shielding portions. Further, the height of the light shielding part and the installation interval in the vertical direction of the dome-shaped screen can be set in the same manner as the light shielding part 3 described above.

  Furthermore, in the above-described embodiment, as an example of the light shielding part 3, an example in which a cable whose surface is painted in black is fixed to the reflecting part 2 with an adhesive or the like is shown, but the present invention is not limited to this. A groove is provided on one surface of the substrate 1a with a gap along one direction (here, the longitudinal direction), and a plate coated with black dye or the like is fitted and fixed in this groove. Can also be configured. In this case, the height of the plate is made larger than the depth of the groove so that the top of the plate protrudes from the opening of the groove when the plate material is fitted and fixed in the groove. If it does in this way, since the light shielding part 3 can be comprised only by fitting a plate in the groove | channel provided previously, positioning becomes easy, and it can attach to the reflection part 2 without using an adhesive agent etc. Therefore, the attachment process is simplified.

DESCRIPTION OF SYMBOLS 1 Dome type screen 1a Base material 2 Reflection part 3 Light-shielding part 10 Projector

Claims (4)

A dome-shaped screen that reflects and displays image light projected from a projector,
On the inner surface of the dome-shaped screen,
A reflection part for reflecting the image light;
A light-shielding portion provided in a striped pattern at intervals along the horizontal direction of the dome-shaped screen,
The dome-shaped screen, wherein the light shielding part shields reflected light reflected by the reflecting part. The shading part is
The dome-shaped screen according to claim 1, wherein the reflecting portion is provided in a spiral shape. The shading part is
The dome-shaped screen according to claim 1, wherein the reflecting portion is provided concentrically with respect to a circumference of a bottom portion of the dome-shaped screen. The shading part is
The dome type screen according to any one of claims 1 to 3, wherein an installation interval at the center of the dome is larger than an installation interval at the periphery of the dome.

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