Rainbow generating prism

Abstract

To provide a rainbow generating prism capable of easily changing the shape of the rainbow. [Solution] The rainbow generating prism 100 of the present invention splits sunlight into a circular arc-shaped rainbow for enjoyment. The rainbow generating prism 100 includes a solid cylindrical prism body 1 made of a transparent material and a support means 2 supporting the prism body 1. The prism body 1 has a bottom surface 11 whose one end in the axial direction is inclined with respect to the axis. The prism body 1 is also provided symmetrically with respect to the minor axis direction of the bottom surface 11. The support means 2 is configured to support the prism body 1 so that it can rotate around an axis parallel to the symmetric direction. The rainbow generating prism 100 can be easily rotated to change its position while placed on a desk or the like, so that the shape of the rainbow that is formed can be easily changed.

Description

[Technical field]

[0001] The present invention relates to a prism that splits sunlight into light beams to generate a rainbow, and more particularly to a rainbow-generating prism that generates an arc-shaped rainbow like the rainbows in the sky. [Background technology]

[0002] Conventionally, various types of prisms have been proposed that have a cross section of a surface that reflects or refracts sunlight in an arc shape, and that form an arc-shaped spectrum when sunlight is split into seven colors (see, for example, Patent Document 1 and Patent Document 2).

[0003] For example, Patent Document 1 discloses a cylindrical prism with one end face cut at an angle to form a bottom face. In the prism of Patent Document 1, parallel light rays incident on the bottom face are emitted from the side face of the cylinder, or parallel light rays incident on the side face of the cylinder are emitted from the bottom face to form an arc-shaped rainbow.

[0004] Patent Document 2 discloses a prism for generating an artificial rainbow, in which one side of a triangular prism is formed into a concave curved surface consisting of a cylindrical groove. In the prism of Patent Document 2, light incident from the flat side is reflected by the curved concave surface to form an arc-shaped rainbow.

[0005] Furthermore, Patent Document 3 discloses an artificial rainbow generating container that has the same shape as Patent Document 2 and is configured to fill a transparent container with water and a mirror on its curved concave surface. The artificial rainbow generating container of Patent Document 2 has the effect of making a rainbow fluctuate due to the fluctuation of the water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Public Practical Publication No. 59-48504 [Patent Document 2] JP 2001-141914 A [Patent Document 3] JP 2006-162913 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the prism in Patent Document 1 creates a rainbow while being held in the hand, which causes a problem in that it is difficult to adjust and fix the incident and outgoing directions of the light while not blocking the path of the light with the hand.Also, the rainbow-generating prism in Patent Document 2 and the rainbow-generating container in Patent Document 3 have a problem in that the position of the prism cannot be changed in accordance with changes in the height of the sun. To provide a rainbow-generating prism that can easily change its orientation with respect to the direction of incidence of sunlight to find an orientation that will produce a rainbow, and that can easily form rainbows of different orientations and positions by changing the orientation of the prism. [Means for solving the problem]

[0008] The invention made to solve the above-mentioned problems is a rainbow generating prism capable of splitting sunlight into a circular arc-shaped rainbow, characterized in that it comprises a prism body having a solid cylindrical shape made of a transparent material, at least one end side in the axial direction having an elliptical base surface that is inclined with respect to the axis and arranged symmetrically with respect to the minor axis direction of the elliptical base surface, and a support means for supporting the prism body so that it can be rotated around an axis parallel to the symmetric direction.

[0009] As described above, the rainbow-generating prism of the present invention has a prism body formed from a transparent solid material into a cylindrical shape with an elliptical bottom surface at one end, and therefore can form an arc-shaped rainbow by totally reflecting light incident from the cylindrical side surface at the elliptical bottom surface. In addition, since the present invention is provided with a support means for supporting the prism body so that it can rotate around an axis parallel to its symmetrical direction, the position of the prism can be easily changed, for example with one hand, while the prism is placed on the floor, and this makes it easy to change the position and position of the rainbow by changing the angle at which sunlight is incident on the prism, such as moving the location where the rainbow is formed from the wall to the ceiling, or changing an upright rainbow into an inverted rainbow. Furthermore, since it is easy to find the position of the prism body that causes sunlight to be totally reflected at the bottom surface, a deep and beautiful rainbow can be formed.

[0010] The rainbow generating prism of the present invention also includes a rainbow generating prism capable of splitting sunlight into a circular arc-shaped rainbow, which comprises a hollow cylindrical container made of a transparent material, one end of which in the axial direction has an elliptical bottom wall inclined to the axis, and which is provided with a prism body arranged symmetrically with respect to the minor axis direction of the elliptical bottom wall, and a support means for supporting the prism body rotatably around an axis parallel to the symmetric direction. In this way, if the container constituting the prism body is filled with a transparent liquid such as water, a rainbow can be formed by using the container as a prism. In this case, if a rainbow is formed by light passing through the liquid surface, the rainbow can be swayed by swaying the liquid. In addition, when changing the position of the prism body using the support means, even if the angle of the bottom wall relative to the horizontal direction is changed, the upper surface of the prism made of the liquid surface remains horizontal, so the angle between the prism upper surface and the bottom wall can be changed, allowing a different method of forming a rainbow to be enjoyed compared to the above-mentioned rainbow-generating prism, which is entirely made of a transparent material.

[0011] It is preferable that the supporting means is capable of continuously rotating the prism body around the axis, thereby enabling the attitude of the prism to be finely adjusted and the position and shape of the rainbow formed to be continuously changed.

[0012] It is preferable that the support means is capable of rotating the prism body around the axis in stages, thereby allowing the position of the prism body to be changed in a plurality of stages, thereby making it possible to enjoy a plurality of different positions and shapes of rainbows. Effect of the Invention

[0013] As described above, according to the rainbow generating prism of the present invention, the orientation of the prism body can be easily changed to easily form rainbows in different positions and shapes. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view showing how sunlight forms an inverted rainbow in a rainbow generating prism according to a first embodiment of the present invention; [Diagram 2] 2(a) is a side view showing how sunlight is reflected and refracted in Fig. 1. Fig. 2(b) is a component drawing showing the bottom surface of the prism body as viewed along line XX in Fig. 1. [Diagram 3] 2 is a plan view showing how sunlight entering the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 1. [Figure 4] FIG. 2 is a perspective view showing how sunlight forms an upright rainbow on the ceiling in the rainbow-generating prism shown in FIG. 1 with the top surface of the prism body facing the sun. [Diagram 5] FIG. 5 is a side view showing how sunlight is reflected and refracted. [Figure 6] 5 is a plan view showing how sunlight entering the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 4. [Figure 7] FIG. 11 is a perspective view showing how light forms an erect rainbow in a rainbow generating prism according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a side cross-sectional view showing how sunlight is reflected and refracted in FIG. [Figure 9] 8 is a plan view showing how sunlight entering the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 7. [Figure 10] 10 is a side cross-sectional view showing how sunlight is reflected and refracted when the prism body of the rainbow generating prism in FIG. 7 is tilted backward (the side opposite the sun, to the right in FIG. 10). [Figure 11] 11 is a perspective view showing how sunlight entering the prism body from two different points is reflected and refracted in the rainbow-generating prism of FIG. 10, and an inverted rainbow formed on the ceiling. [Figure 12] FIG. 11 is a perspective view of a rainbow generating prism according to a third embodiment of the present invention. [Figure 13] 13 is a side cross-sectional view showing how sunlight is reflected and refracted in the rainbow generating prism shown in FIG. 12. [Figure 14] 14 is a side cross-sectional view showing how sunlight is reflected and refracted when the prism body in FIG. 12 is tilted backward (to the right in FIG. 14). [Figure 15] 15] FIG. 15 is a side cross-sectional view showing how sunlight is reflected and refracted when the prism body of FIG. 12 is tilted forward (to the left in FIG. 15). [Figure 16] FIG. 13A is a perspective view of a rainbow generating prism according to a fourth embodiment of the present invention, FIG. 13B is a vertical cross-sectional view showing how sunlight is reflected and refracted when not tilted, and FIG. 13C is a vertical cross-sectional view showing how sunlight is reflected and refracted when tilted. [Figure 17] FIG. 11 is a vertical sectional view of a rainbow generating prism according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment.

[0016] (First embodiment) 1 shows a rainbow generating prism 100 according to a first embodiment of the present invention. The rainbow generating prism 100 includes a prism body 1 and a support means 2, and is provided so that the prism body 1 can split sunlight to form an arc-shaped rainbow R1.

[0017] The prism body 1 is a solid cylinder made of a transparent material. As shown in FIG. 2, the bottom surface 11 provided at one end side in the axis 1a direction (lower side in FIG. 2) of the prism body 1 is an ellipsoidal surface inclined with respect to the axis 1a (see FIG. 2(b)). In the illustrated example, the top surface 12 at the other end side in the axis 1a direction (upper side in FIG. 2(a)) is a circular surface perpendicular to the axis 1a. The prism body 1 is provided symmetrically with respect to the left-right direction (up-down direction in FIG. 2(b) and FIG. 3) parallel to the minor axis 11b of the elliptical bottom surface 11. As shown in FIG. 3, the left and right sides of the side surface 13 of the prism body 1 are provided with pivot recesses 1b, 1b that fit with the tips of the shafts 2a, 2a of the support means 2 described later. The top surface 12 of the prism body 1 may be an ellipsoidal surface inclined with respect to the axis 1a of the prism body 1 (see FIG. 2) as long as the symmetry of the prism body 1 is maintained. Examples of transparent materials constituting the prism body 1 include glass, acrylic resin, polycarbonate, etc., with acrylic resin being preferred because of its high transparency and ease of processing.

[0018] The support means 2 is integrally formed by bending a metal rod such as stainless steel. As shown in Fig. 3, the support means 2 has a pair of shafts 2a, 2a that extend in the left-right direction of the prism body 1 and rotatably support the prism body 1, pillars 2b, 2b that extend diagonally downward and rearward from the pair of left and right shafts 2a, 2a, bases 2c, 2c that extend forward from the lower ends of the pair of left and right pillars 2b, 2b, and a U-shaped portion 2d that extends diagonally rearward and upward from the front ends of the bases 2c, 2c and is connected at the rear.

[0019] (Formation of an inverted rainbow R1 in the first embodiment) 1 to 3 show how sunlight enters and exits the side surface 13 of the prism body 1 in the front-to-rear direction with the axis 1a (see FIG. 2) of the prism body 1 vertical. Of the sunlight entering the prism body 1, ray L1 is shown entering the prism body 1 from an entrance point I1 at the center in the left-right direction (the up-down direction in FIG. 3) on the front side of the cylindrical side surface 13.

[0020] As shown in FIG. 2, when light L1 enters the prism body 1, it refracts upward at the incident point I1, travels straight, is totally reflected at the bottom surface 11, and exits the prism body 1 from the exit point O1 at the rear of the side surface 13. The exiting light L1 refracts upward at the exit point O1. The light L1 is split into light beams each time it is refracted and reflected, and forms a rainbow R1 on the vertical screen S as shown in FIG. 1. The rainbow R1 projected on the vertical screen S by the light L1 becomes an inverted rainbow that curves downward. FIG. 3 shows how the light L2, which enters from the incident point L1 at the center of the left-right direction of the side surface 13 of the prism body 1, and enters from the incident point I2 on the right side of the side surface 13 in the left-right direction (lower side of FIG. 3) and exits from the exit point O2 on the rear side of the side surface 13 of the prism body 1, is refracted and reflected by the prism body 1. Light L2 incident on the prism body 1 from the left side (the lower side in FIG. 3) is refracted and emitted to the right side (the upper side in FIG. 3).

[0021] (Formation of an erect rainbow R2 in the first embodiment) Figures 4 to 6 show that the prism body 1 is rotated around the axes 2a, 2a and tilted forward (toward the front in Figure 4, to the left in Figure 5) so that the upper surface 12 of the prism body 1 faces forward, and a rainbow R2 is formed by the light L3 entering from the upper surface 12.

[0022] When light L3 enters the prism body 1 from the incident point I3 at the center in the left-right direction of the top surface 12 as shown in FIG. 5, it refracts downward at the incident point I3, travels straight, is reflected by the bottom surface 11, and exits from the prism body 1 from the exit point O3 at the rear of the side surface 13. The exiting light L3 refracts upward at the exit point O3. In this way, the light O3 is emitted in a substantially vertical direction, so that the rainbow R2 is projected onto the ceiling C as shown in FIG. 4. The rainbow R2 becomes an upright rainbow that curves toward the front as shown in FIG. 4. FIG. 6 shows how the light L4, which enters from the incident point I3 at the center in the left-right direction of the side surface 13 of the prism body 1, enters from the incident point I4 on the right side in the left-right direction of the side surface 13 (lower side in FIG. 6) and exits from the exit point O4 on the rear side of the side surface 13 of the prism body 1, is refracted and reflected by the prism body 1. Light L4 incident on the prism body 1 from the left side (the lower side in FIG. 6) is refracted and emitted to the right side (the upper side in FIG. 6).

[0023] Second embodiment 7 shows a rainbow generating prism 200 according to a second embodiment of the present invention. The rainbow generating prism 200 has a hollow cylindrical shape made of a transparent material such as glass, acrylic, or carbonate, and is provided with a prism body 201 that becomes a prism when filled with a transparent liquid such as water, and a support means 202 that supports the prism body 201.

[0024] Prism body 201 has a cylindrical side wall 213 and a bottom wall 211, and is shaped like a container that is open upward. An upper edge 201b of side wall 213 is provided perpendicular to axis 201a (see FIG. 8) of cylindrical side wall 213, and bottom wall 211 is elliptical and inclined with respect to axis 201a. Prism body 201 is provided symmetrically with respect to the minor axis direction of elliptical bottom wall 211 (the vertical direction in FIG. 9).

[0025] The support means 202 is formed in a cylindrical shape integral with the cylindrical side wall 213 of the prism body 201. As shown in Fig. 8, the support means 202 has a first grounding portion 202a and a second grounding portion 202b on the bottom edge.

[0026] The first grounding portion 202a constitutes the front (left side in FIG. 8) half of the bottom edge of the cylindrical support means 202, is provided in a semicircular shape when viewed from the bottom (not shown), and is provided in a plane perpendicular to the axis 201a of the prism body 201. The first grounding portion 202a abuts against the horizontal plane G when the rainbow generating prism 200 is placed on the horizontal plane G with the axis 201a oriented vertically.

[0027] The second grounding portion 202b is provided adjacent to the first grounding portion 202a, and is provided at an angle with respect to the axis 201a of the prism body 201. As shown in Fig. 10, the second grounding portion 202b supports the prism body 201 by contacting with the horizontal plane G with the prism body 201 tilted backward.

[0028] The first grounding portion 202a and the second grounding portion 202b are arranged symmetrically in the minor axis direction of the bottom wall 211 (left and right direction in Figure 11), and the rainbow generating prism 200 as a whole is also arranged symmetrically in the minor axis direction of the bottom wall 211. In this manner, by changing the grounding position of the support means 202 between the first grounding portion 202a and the second grounding portion 202b, the prism body 201 rotates around an axis parallel to the minor axis direction of the bottom wall 21 to change its posture.

[0029] (Formation of an erect rainbow R3 in the second embodiment) 7 to 9 show a state in which the rainbow generating prism 200 is installed with the first grounding portion 202a in contact with a horizontal surface G, and sunlight is made incident on the prism body 201 filled with water W. Of the sunlight entering the prism body 201, Figs. 7 to 9 show light L5 that enters from an entrance point I5 at the center in the left-right direction of the side wall 213 (the up-down direction in Fig. 9) and exits from an exit point O5 on the water surface. Here, the entrance point and exit point refer to the points at which the light enters or exits the water W stored in the prism body 201.

[0030] As shown in Fig. 8, when light L5 incident from an incident point I5 enters the water W in the prism body 201, it refracts upward at the incident point I5, travels straight, is reflected by the bottom wall 211, and is emitted to the outside from an emission point O5 on the water surface. The emitted light L5 refracts downward at the emission point O5. A rainbow R3 projected on a vertical screen S by the light L5 becomes an upright rainbow R3 curved upward as shown in Fig. 7. Fig. 9 shows how light L6 incident from an incident point I6 on the right side of the side 213 in the left-right direction (the lower side of Fig. 9) and emitted from an emission point O6 on the rear side of the side 213 of the prism body 1 is refracted and reflected by the prism body 201, in addition to light L5 incident from an incident point L5 at the center in the left-right direction of the side 213 of the prism body 201 (the up-down direction in Fig. 9). Light L6 incident on prism body 201 from the left side (the lower side in FIG. 9) is refracted and emitted to the right side (the upper side in FIG. 9).

[0031] (Formation of an inverted rainbow R4 in the second embodiment) 10 and 11 show how sunlight enters and exits side wall 213 of prism body 201 in the front-to-rear direction with prism body 201 tilted backward (to the right in Fig. 8) from the attitude shown in Fig. 8 and with second grounding portion 202b in contact with horizontal plane G. Fig. 10 shows light L7 of the sunlight entering prism body 201, which enters prism body 201 from entrance point I7 at the center in the left-right direction (up-down direction in Fig. 11) on the front side of cylindrical side wall 213 and exits from exit point O7 on the rear side of side wall 213.

[0032] As shown in Fig. 10, when light L7 incident from incident point I7 at the center in the left-right direction enters water W in prism body 201, it refracts upward at incident point O7, travels straight, is totally reflected by bottom wall 211, and exits from prism body 201 from exit point O7 behind side wall 213. The exiting light L7 refracts upward at exit point O7. A rainbow R4 projected on ceiling C by light L7 becomes an inverted rainbow R4 curved toward the back side (the back side of the paper in Fig. 11) as shown in Fig. 11. Also, as shown in Fig. 11, light O8 incident from incident point I8 on the right side of side surface 213 and exiting from exit point O8 is refracted and exits to the left side.

[0033] Third embodiment 12 shows a rainbow generating prism 300 according to the third embodiment of the present invention. The rainbow generating prism 300 has a container-shaped prism body 301 that becomes a prism when filled with a transparent liquid such as water, like the rainbow generating prism 200 of the second embodiment, but unlike the second embodiment, a support means 302 that supports the prism body 301 is provided separately from the prism body 301.

[0034] As shown in Fig. 12, prism body 301 has a cylindrical side wall 313 and a bottom wall 311, and is shaped like a container that is open upward. As shown in Fig. 13, upper edge 301b of side wall 313 is provided perpendicular to axis 301a (see Fig. 13) of cylindrical side wall 313, and bottom wall 311 is elliptical and inclined with respect to axis 301a. Prism body 301 is provided symmetrically with respect to the minor axis direction of elliptical bottom wall 311 (depth direction of the paper in Fig. 13).

[0035] 12, the support means 302 has a pair of left and right shafts 302a, 302a that support the prism body 301 so as to rotate it about an axis extending in the minor axis direction of the elliptical bottom wall 311, a pair of left and right shaft supports 302b, 302b that support the shafts 302a, 302a, and a rectangular plate-like base 302c that connects the lower ends of the shaft supports 302b, 302b. The shaft support 302b has a substantially triangular plate shape and is disposed perpendicular to the base 302c.

[0036] 12 and 13 show how an erect rainbow R5 is formed when sunlight enters and exits a prism body 301 filled with water W with its axis 301a vertical. The mechanism by which the rainbow R5 is formed is the same as the mechanism by which the erect rainbow R3 is formed in the second embodiment of FIG.

[0037] Moreover, Fig. 14 shows how sunlight enters and exits to form an inverted rainbow R6 when prism body 301 is rotated around axis 302a by tilting axis 301a backward from the state shown in Fig. 13. The mechanism by which inverted rainbow R6 is formed in Fig. 14 is the same as the mechanism by which inverted rainbow R4 in the second embodiment in Figs. 10 and 11 is formed.

[0038] Furthermore, Fig. 15 shows how sunlight enters and exits to form an inverted rainbow R7 when prism body 301 is rotated around axis 302a by tilting axis 301a forward from the state shown in Fig. 13. The mechanism by which the inverted rainbow is formed in Fig. 15 is the same as the mechanism by which the inverted rainbow R1 in the first embodiment in Fig. 1 is formed. In this way, prism body 301 can be easily rotated around an axis extending in the symmetrical direction of prism body 301, whereby rainbows of different postures and sizes can be easily formed and enjoyed.

[0039] (Fourth embodiment) 16 shows a rainbow generating prism 400 according to a fourth embodiment of the present invention. The rainbow generating prism 400 comprises a prism body 401 formed in a solid cylindrical shape from a transparent material similar to the prism body 1 of the first embodiment, and a cylindrical support means 402 similar to the support means 202 of the second embodiment.

[0040] Prism body 401 has bottom surface 411 formed of an ellipsoid inclined to axis 401 a of prism body 401 , and top surface 412 formed of a circular surface perpendicular to axis 401 a of prism body 401 .

[0041] The support means 402 is provided at its bottom edge with a first grounding portion 402a that is provided perpendicular to the axis 401a, and a second grounding portion 402b that is inclined with respect to the axis 401a and the first grounding portion 402a. As shown in Figures 16(b) and 16(c), the rainbow generating prism 400 of the fourth embodiment can also be used to form rainbows R8 and R9 in different positions by changing the position.

[0042] Fifth embodiment 17 shows a rainbow generating prism 500 according to a fifth embodiment of the present invention. Rainbow generating prism 500 comprises a solid cylindrical prism body 501 and cylindrical support means 502, and is provided at the bottom edge of support means 502 with a first grounding portion 502a perpendicular to axis 501a of prism body 501, and second and third grounding portions 502b, 502c inclined at different angles to axis 501a, so that the angle of axis 501a can be changed in three stages.

[0043] As described above, the rainbow generating prism of the present invention is not limited to the above-mentioned embodiments, and may be, for example, an elliptical surface with both ends of a solid prism body tilted relative to the axis of the prism body. Also, in any of the embodiments in which the prism body and the support means are integrally provided, the prism body and the support means may be provided separately. A container-shaped prism may be provided with a lid. The liquid to be filled in the container-shaped prism body is not limited to water as long as it is transparent. [Explanation of symbols]

[0044] L1,L2,L3,L4,L5,L6,L7,L8 Daylight (light) R1,R2,R3,R4,R5,R6,R7,R8,R9 Rainbow 100,200,300,400,500 Hiroshima University 1a,201a,301a,401a,501a Axis 11,411,511 Bottom 211,311 Bottom wall (bottom surface) 11b Short Path 1,201,301,401,501 プリズムbody 2,201,302,402,502 Support

Claims

1. A rainbow generating prism capable of splitting sunlight into a circular rainbow, a prism body made of a transparent material, having a solid cylindrical shape, at least one end side of which in an axial direction has an elliptical bottom surface inclined with respect to the axis, and which is symmetrically arranged with respect to the minor axis direction of the elliptical bottom surface; a support means for supporting the prism body so as to be rotatable about an axis parallel to the symmetrical direction of the prism body; A rainbow generating prism comprising:

2. A rainbow generating prism capable of splitting sunlight into a circular rainbow, a container made of a transparent material and having a hollow cylindrical shape, with one end side in an axial direction having an elliptical bottom wall inclined to the axis, and a prism body provided symmetrically with respect to the minor axis direction of the elliptical bottom wall; a support means for supporting the prism body so as to be rotatable about an axis parallel to the symmetrical direction of the prism body; A rainbow generating prism comprising:

3. 3. The rainbow generating prism according to claim 1, wherein said supporting means is capable of continuously rotating said prism body around said axis.

4. 3. The rainbow generating prism according to claim 1, wherein said supporting means is capable of rotating said prism body stepwise around said axis.

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