JP5843228B2 - Split projection method of starry sky in planetarium - Google Patents

Description

  The present invention relates to a planetarium, and more particularly to a division projection method in which division projection images from a plurality of projectors are connected to project the entire starry sky on a dome screen.

  In the planetarium, the entire starry sky is projected on a dome screen by combining divided projection images from multiple projectors. That is, as shown in FIG. 9, the whole sky A is divided into a plurality of surfaces, and the divided projection images B are projected onto the respective divided surfaces by a plurality of projectors in which a projection original plate is arranged on the projection optical system, and these are connected. The starry sky is reproduced together. In this case, the shape of the divided projected image is usually a regular polyhedron or a truncated polyhedron, and the shape of the divided projected image is a convex polygon in which each internal angle of the figure does not exceed 180 degrees (Patent Document). 1).

  It is a matter of course that the completion of one image by joining divided projection images from a plurality of projectors is not a technique specific to a planetarium, but is a technique commonly used in general image projection technology (for example, Patent Document 2).

  In the above-mentioned jointing in the planetarium, in principle, the jointed portions of the projected images are designed to be continuous without any overlap or gaps. In actual planetarium production, joining is performed as designed. As mentioned above, the latest attention was paid so as not to cause an error in the arrangement of the projectors and an error in the projection magnification.

  On the other hand, in general projection technology, by arranging adjacent parts of each projected image so as to overlap each other, even if the placement of each projector and the accuracy of the projection magnification are somewhat less accurate, In the past, a method for smooth connection without causing gaps has been proposed (for example, Patent Document 3).

  In this case, in addition to a method (for example, Patent Document 4) in which the same image is superimposed and projected from each projector at an overlapping portion, a method for distributing and projecting an image to each projector (for example, Patent Document) 5) has been proposed, and in the latter case, an effect of preventing image shift was obtained.

  On the other hand, in the planetarium field, when the number of stars projected increases, as in the case of projecting stars that are darker than the 6th magnitude stars that cannot be recognized as point images by the naked eye for the purpose of natural reproduction of the Milky Way, The problem that the dividing boundary line becomes conspicuous if it is not connected as designed. Therefore, the above-mentioned general projection technology that distributes and projects images to each projector at the overlapping locations is applied, and adjacent portions of each projection image are arranged so as to overlap each other and should be projected to the overlapping locations. A method has been proposed in which a star cluster is distributed to each projector and projected (Patent Document 6). Specifically, in this method, both projection masters are provided with overlapping parts, and the projection ratio of the stars in that part is distributed to each projection master according to the overlapping position, thereby adjusting the number of stars on each projection master. ing. In Patent Document 6, a convex figure having no corners is shown in the embodiment disclosed with respect to the divided projected image.

Also, Patent Document 7 discloses a method for determining an original plate to be drawn according to the star grade provided with overlapping portions on adjacent star original plates. For divided projection images, FIGS. It is shown to be a convex figure. In this document, FIGS. 11 and 12 are graphs showing the limit grade of the stellar for each overlapping portion in order to show how to assign the stellar at the portion where the original plates overlap each other.
Japanese Patent Laid-Open No. 9-218641 Japanese Patent Laid-Open No. 5-19347 JP 58-125986 A Japanese Patent Laid-Open No. 3-58082 Japanese Unexamined Patent Publication No. 64-27374 JP 2001-134172 A JP 2003-122247 A

  In order to reproduce a natural starry sky, the method described in Patent Document 6 is very effective in a planetarium that projects a large number of stars. According to this method, even when the installation error of the projector is large or when the installation position of the planetarium projector is not correct, it is possible to reproduce a starry sky in which the division boundary line is not noticeable to some extent.

  However, when projecting using the method as described above, the starry sky with inconspicuous divisional boundaries is reproduced without accurate assembly, adjustment, and installation work, so appropriate assembly adjustment work or installation work It has become difficult to visually determine whether or not Therefore, accurate assembly, adjustment, and installation work become difficult, and a problem arises that the positions of the stars in the starry sky reproduced on the dome are not always accurate.

  If the accuracy of assembly and adjustment is poor, the relative position of the stars for each projector will be incorrect, and if the installation position is poor, the relative position with the dome screen will be higher than the actual starry sky. A starry sky that is projected after being enlarged and a starry sky that is projected when it is reduced will be mixed. In the method described in Patent Document 7, the same problem arises although there is a difference depending on what grade distribution is used.

  Even in the conventional planetarium where the number of stars is as small as tens of thousands, the position of the stars has been required to be as accurate as possible except in special cases. In the above-mentioned method proposed as a countermeasure when the number of stars becomes very large, it is impossible to determine whether assembly adjustment or installation has been performed with the same accuracy as before unless measurement is separately performed. Caused a problem.

  The starry sky division projection method in the planetarium of the present invention was created in view of the above problems of the prior art, and even if the number of projected stars is very large, assembly adjustment work and installation adjustment work It is possible to easily realize this by visually observing the projected image, to ensure the same reproducibility of the star position as before, and to reproduce the starry sky in which the dividing boundary line is not conspicuous.

In order to achieve the above object, according to the starlit sky division projection method of the present invention, the whole sky is divided into a plurality of planes, and a plurality of projectors each having a projection master plate arranged on a projection optical system are divided into projection planes. When projecting images and connecting them together to reproduce the starry sky, when projecting the entire sky on the dome screen by combining the divided projection images from multiple projectors, the divided projection images do not overlap each other The divided projection images projected onto the dome screen are formed into a figure surrounded by a waveform or a sawtooth line .

In other words, in the present invention, the divided projected image projected on the dome screen is not provided with a design overlapping portion in the divided projected area, and the projected figure (which connects two arbitrary points in the figure) that has been used in the past. It is assumed that the line segment is a figure surrounded by a wavy or saw-toothed line rather than a figure that is all included in the figure.

  The slight error that occurs in the production of the planetarium is basically an error in the projection magnification and an error in the arrangement of the projectors. Among these, the mutual arrangement error can be minimized by adjustment, but it is very difficult to adjust the projection magnification error.

  Since this error appears as a difference in the size of the projected image, if the projection range of each original plate is a convex figure, the radial direction from the center of the projection unit as a gap or overlap of the amount that directly reflects the magnification error Appear in

However, in the case of a figure surrounded by a wavy or sawtooth line , the actual gap or overlap is the same as the tangential direction of the drawing area, even if the value is the same amount in the radial direction from the center of the projection unit. Since the components are orthogonal to each other, the smaller the angle formed with the radial direction, the smaller the angle, and the dividing boundary line of the original plate becomes less noticeable.

  On the other hand, if the error of the center position exceeds the allowable amount, the deviation direction becomes brighter than the surrounding area, becomes darker in the opposite direction, and becomes a bright and dark pattern that repeats in the orthogonal direction. As a result, the direction to be adjusted can be easily determined.

  As described above, according to the divided projection method according to the present invention, even when the number of projection stars is remarkably increased, the division boundary line is not conspicuous while maintaining the same star position accuracy as before, and it is natural. It is possible to reproduce an accurate starry sky. On the other hand, when the position accuracy exceeds the allowable range, it is possible to easily determine and adjust the direction to be adjusted visually.

The conceptual diagram which shows the division | segmentation projection image by the projection method of this invention. The conceptual diagram which shows the division | segmentation projection image by the projection method of this invention. The conceptual diagram which shows the effect | action of the projection method of this invention, and the projection method of a prior art. The conceptual diagram which shows the effect | action of the projection method of this invention. The conceptual diagram which shows the effect | action of the projection method of this invention, and the projection method of a prior art. The conceptual diagram which shows the effect | action of the projection method of this invention, and the projection method of a prior art. The conceptual diagram which shows the effect | action of the projection method of this invention, and the projection method of a prior art. The conceptual diagram which shows the effect | action of the projection method of this invention, and the projection method of a prior art. The block diagram of the projection method of a prior art.

FIG. 1 shows a part of a divided projected image 1 composed of a figure surrounded by a waveform or a sawtooth line as an example. The shape of the divided projected image 1 is composed of a curve (sin curve), and has a wave shape as shown in the figure. FIG. 2 is a diagram showing a state in which the divided projected images 1 are accurately connected so as not to overlap each other.

  FIG. 3 is a diagram showing the difference in operation between the projection method of the present invention and the projection method of the prior art. In the figure, reference numeral (3-1) is a divided projected image 1 by the projection method of the present invention, and (3-2) is a divided projected image 10 by the projection method of the prior art. Here, there is a gap between the divided projected images. The state is illustrated.

  The above (3-1) and (3-2) show examples in which the same amount of gaps are generated, but the gap S10 between the divided projected images 10 composed of the convex figures of the prior art is a straight line. Although the gap between the divided projected images 1 of the present invention is a sin curve, the same gap S1 is generated at the top / bottom of the curve as in the case of a straight line, but the gap S2 on the slope of the other curves is small. Become. That is, as shown in FIG. 4, the interval BB of the gap S2 on the slope is narrower than the interval AA of the gap S1 at the top / bottom of the curve.

  Since the planetarium is a machine installed at the center of the dome, the biggest cause of the incorrect position of the projected star is the largest when there is an error in the projection magnification. In the projection method of the present invention, an error in this direction (from the projection center to the radiation direction) becomes inconspicuous by using a sin curve.

FIG. 5 is a diagram showing the projection method of the present invention and the projection method of the prior art. In the figure, reference numeral (5-1) denotes a divided projected image 1 by the projection method of the present invention, and (5-2) represents a divided projected image 10 by the projection method of the prior art. Here, the waveform or sawtooth by the projection method of the present invention is shown. As a divided projection image 1 composed of figures surrounded by a line, a saw blade-shaped one composed of straight lines is shown.

  FIG. 6 is a diagram showing a state in which a positional deviation has occurred between the divided projection images of the projection method of the present invention shown in FIG. 5 and between the divided projection images of the projection method of the prior art due to an error in the arrangement of the projectors. is there. In this case, an overlapping portion S11 and a gap S10 are generated between the divided projected images 10 of the conventional projection method (6-2), and the overlapping portion is clearly seen as a bright line and the gap is clearly seen as a dark line.

On the other hand, the overlapping portions and gaps between the divided projected images 1 according to the projection method of the present invention are narrow and not easily noticeable. In this case, if a figure surrounded by a waveform or a sawtooth line is formed by a curve, the overlapping portion and the density of the gap change and become less noticeable.

On the other hand, in the projection method of the present invention, when the deviation exceeds the allowable range and the overlapping portion or the gap is clearly noticeable, the combined portion of the top or bottom of the divided projection image shows the accuracy in the radial direction from the projection center, and the slope Indicates the accuracy in the direction orthogonal to it, and if the figure surrounded by the waveform or sawtooth line is rotationally symmetric as in the divided projection image in this figure, it is obvious at which direction it is greatly shifted. The visual adjustment can be easily performed.

  FIG. 7 is a diagram showing a state in which a gap is generated between the divided projection images of the projection method of the present invention shown in FIG. 5 and the divided projection images of the projection method of the prior art due to the projection magnification error between the projectors. is there. In this case, the gap between the divided projected images 1 according to the projection method of the present invention of (7-1) is not conspicuous as described above, but between the divided projected images 10 of the conventional projection method of (7-2). In this case, an annular gap S10 is generated around the divided projected image 10A having a small projection magnification, so that it can be clearly seen as a dark line.

  FIG. 8 is a diagram showing a state where overlapping portions are generated between the divided projection images of the projection method of the present invention shown in FIG. 5 and the divided projection images of the projection method of the prior art due to the projection magnification error between the projectors. It is. In this case, the overlapping portion of the divided projection images 1 by the projection method of the present invention of (8-1) is not conspicuous as described above, but the divided projection images 10 of the conventional projection method of (8-2) In this case, an annular overlapping portion S11 is generated around the divided projected image 10A having a large projection magnification, and is clearly visible as a bright line.

Claims (1)

Divide the whole sky into multiple planes, project multiple projected images on each divided plane using multiple projectors with a projection master plate on the projection optical system, and connect them to reproduce the starry sky. When projecting the entire starry sky on the dome screen by synthesizing the divided projection images from other projectors, the divided projection images are projected together so as not to overlap each other, and the divided projections projected on the dome screen are projected. A method for dividing the starry sky in a planetarium, characterized in that the shape of the image is a waveform or a figure surrounded by a sawtooth line.

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