Prism for rainbow generation

Abstract

The present invention provides a prism for rainbow generation that makes it possible to easily change the shape of a rainbow.　This prism 100 for rainbow generation disperses sunlight to form an arc-shaped rainbow for enjoyment. The prism 100 for rainbow generation comprises a solid cylindrical prism body 1 which comprises a transparent material and a support means 2 which supports the prism body 1. One end side of the prism body 1 in the axial direction comprises a bottom surface 11 which is inclined with respect to the axis. The prism body 1 is provided symmetrically with respect to the minor diameter 11a direction of the bottom surface 11. The support means 2 is configured to support the prism body 1 in a manner enabling rotation thereof about an axis parallel to the direction of symmetry of the prism body 1. When the prism 100 for rainbow generation is on a desk or the like, the prism body 1 can easily be rotated to change the orientation thereof, and thus it is possible to easily change the shape of a rainbow that is formed.

Description

Rainbow generating prism

[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.

[0002] Various types of prisms have been proposed in the past that have arc-shaped cross sections on the surfaces that reflect or refract sunlight, and that split sunlight into seven colors to form arc-shaped spectra (see, for example, Patent Documents 1 and 2).

[0003] For example, Patent Document 1 discloses a cylindrical prism with one end face formed as a beveled bottom face, in which 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, thereby forming an arc-shaped rainbow.

[0004] Furthermore, 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, thereby forming 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 the curved concave surface. The artificial rainbow generating container of Patent Document 2 has the effect of making a rainbow fluctuate with the fluctuation of the water.

[0006] Published Unexamined Patent Application No. 59-48504 JP 2001-141914 JP 2006-162913

[0007] However, the prism of Patent Document 1 has the problem that, because it forms a rainbow while being held in the hand, it is difficult to adjust and fix the direction of incidence and emission of light without blocking the path of the light with the hand. Furthermore, the rainbow-generating prism of Patent Document 2 and the rainbow-generating container of Patent Document 3 have the problem that the position of the prism cannot be changed to match changes in the height of the sun. The present invention has been made in consideration of these problems, and aims to provide a rainbow-generating prism that can be easily changed in position relative to the direction of incidence of sunlight to find a position that will produce a rainbow, and that can easily form rainbows of different positions and positions by changing the position of the prism.

[0008] The invention made to solve the above problem is a rainbow generating prism that can disperse sunlight to form an arc-shaped rainbow, characterized in that it comprises a prism body that is a solid cylinder made of a transparent material, at least one end side of which in the axial direction has an elliptical base that is inclined with respect to the axis and is arranged symmetrically with respect to the minor axis direction of the elliptical base, and a support means that supports the prism body so that it can rotate around an axis parallel to the symmetric direction.

[0009] The rainbow-generating prism of the present invention has a prism body formed from a transparent solid material in a cylindrical shape with an elliptical base at one end, thereby forming an arc-shaped rainbow by total reflection of light incident from the cylindrical side at the elliptical base. Furthermore, the present invention includes a support means for rotatably supporting the prism body around an axis parallel to its symmetry direction. Therefore, the orientation of the prism can be easily changed, for example, with one hand, while the prism is still placed on the floor. This allows for easy adjustment of the orientation and position of the rainbow, such as by changing the angle at which sunlight enters the prism and shifting the location of the rainbow from a wall to a ceiling, or by changing an upright rainbow to an inverted rainbow. Furthermore, since it is easy to find the orientation of the prism body that causes total reflection of sunlight at the base, a rich and beautiful rainbow can be formed.

[0010] The rainbow-generating prism of the present invention is capable of splitting sunlight into a circular arc-shaped rainbow. It includes a hollow cylindrical container made of a transparent material, a prism body arranged symmetrically about the minor axis of the elliptical bottom wall, and a support means for supporting the prism body so that it can rotate about an axis parallel to the symmetry direction. By filling the container constituting the prism body with a transparent liquid such as water, the container can be used as a prism to form a rainbow. If a rainbow is formed by light passing through the liquid surface, the rainbow can be swayed by shaking the liquid. Furthermore, when the orientation of the prism body is changed by the support means, even if the angle of the bottom wall relative to the horizontal is changed, the top surface of the prism, which is made of the liquid surface, remains horizontal. This allows the angle between the top surface of the prism and the bottom wall to be changed, allowing for different rainbow formation methods compared to the rainbow-generating prism described above, which is made entirely of a transparent material.

[0011] The support means is preferably capable of continuously rotating the prism body around the axis, thereby enabling the orientation of the prism to be finely adjusted, thereby continuously changing the position and shape of the rainbow that is formed.

[0012] The support means is preferably capable of rotating the prism body around the axis in stages, thereby allowing the position of the prism body to be changed in multiple stages, allowing the viewer to enjoy multiple different positions and shapes of rainbows.

[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.

[0014] 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. (a) is a side view showing how sunlight is reflected and refracted in FIG. 1 . (b) is a component diagram showing the bottom surface of the prism body as viewed from the X-X line in FIG. 1 . (c) is a plan view showing how sunlight incident on the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 1 . (d) is a perspective view showing how sunlight forms an erect rainbow on the ceiling in the rainbow generating prism shown in FIG. 1 , with the top surface of the prism body facing the sun. (e) is a side view showing how sunlight is reflected and refracted in FIG. 4 . (f) is a plan view showing how sunlight incident on the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 4 . (g) 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. (h) is a side cross-sectional view showing how sunlight is reflected and refracted in FIG. 7 . 10 is a plan view showing how sunlight incident on the prism body from two different points is reflected and refracted in the rainbow generating prism of FIG. 7; FIG. 11 is a side cross-sectional view showing how sunlight is reflected and refracted when the prism body of the rainbow generating prism of FIG. 7 is tilted backward (away from the sun, to the right in FIG. 10); FIG. 12 is a perspective view showing how sunlight incident on 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; FIG. 13 is a side cross-sectional view showing how sunlight is reflected and refracted in the rainbow generating prism of FIG. 12; FIG. 14 is a side cross-sectional view showing how sunlight is reflected and refracted when the prism body of FIG. 12 is tilted backward (to the right in FIG. 14); 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). 10A is a perspective view of a rainbow generating prism according to a fourth embodiment of the present invention, FIG. 10B is a longitudinal cross-sectional view of a rainbow generating prism according to a fourth embodiment of the present invention, FIG. 10C is a longitudinal cross-sectional view of a rainbow generating prism according to a fifth embodiment of the present invention, and FIG. 10D is a longitudinal cross-sectional view of a rainbow generating prism according to a fifth embodiment of the present invention.

[0015] Hereinafter, embodiments 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 embodiments.

[0016] 1 shows a rainbow generating prism 100 according to a first embodiment of the present invention. The rainbow generating prism 100 comprises a prism body 1 and a support means 2, and is configured so that the prism body 1 can split sunlight into light components to form an arc-shaped rainbow R1.

[0017] The prism body 1 is a solid cylindrical member made of a transparent material. As shown in FIG. 2, the bottom surface 11 at one end (lower side in FIG. 2) of the prism body 1 in the direction of its axis 1a 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 (upper side in FIG. 2(a)) in the direction of the axis 1a is a circular surface perpendicular to the axis 1a. The prism body 1 is symmetrical with respect to the left-right direction (up-down direction in FIGS. 2(b) and 3) parallel to the minor axis 11b of the elliptical bottom surface 11. As shown in FIG. 3, pivot recesses 1b, 1b are provided on both the left and right sides of the side surface 13 of the prism body 1 to fit onto the tips of the shafts 2a, 2a of the support means 2 (described later). Furthermore, the top surface 12 of the prism body 1 may be an ellipsoidal surface inclined with respect to the axis 1a (see FIG. 2) of the prism body 1, as long as the symmetry of the prism body 1 is maintained. Examples of transparent materials that can be used to form the prism body 1 include glass, acrylic resin, and polycarbonate, but acrylic resin is preferred because it is highly transparent and easy to process.

[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 extending in the left-right direction of the prism body 1 and rotatably supporting the prism body 1, pillars 2b, 2b extending diagonally downward and rearward from the pair of left and right shafts 2a, bases 2c, 2c extending forward from the lower ends of the pair of left and right pillars 2b, and a U-shaped portion 2d extending diagonally upward and rearward from the front ends of the bases 2c, 2c and connected at the rear.

[0019] 1 to 3 show how sunlight enters and exits the side surface 13 of the prism body 1 in the front-to-rear direction when the axis 1a (see FIG. 2) of the prism body 1 is vertical. 1 to 3 show light L1 of sunlight entering the prism body 1 from an entrance point I1 at the center in the left-to-right direction (up-to-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 ahead, is totally reflected by 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 is refracted upward at the exit point O1. As the light L1 is refracted and reflected, it is split into light beams, forming a rainbow R1 on the vertical screen S, as shown in FIG. 1. The rainbow R1 projected onto the vertical screen S by the light L1 is an inverted rainbow that curves downward. FIG. 3 shows how the prism body 1 refracts and reflects light L1, which enters from the incident point L1 at the center of the side surface 13 of the prism body 1 in the horizontal direction, and light L2, which enters from the incident point I2 on the right side of the side surface 13 in the horizontal direction (the lower side of FIG. 3) and exits from the exit point O2 at the rear of the side surface 13 of 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 upright 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), with the top surface 12 of the prism body 1 facing forward, and rainbow R2 is formed by light L3 incident from the top surface 12.

[0022] As shown in FIG. 5 , light L3 incident from an incident point I3 at the center of the top surface 12 in the horizontal direction enters the prism body 1. The light L3 is refracted downward at the incident point I3, then travels straight ahead, is reflected by the bottom surface 11, and exits the prism body 1 from an exit point O3 at the rear of the side surface 13. The exiting light L3 is refracted upward at the exit point O3. Thus, since the light O3 is emitted in a generally vertical direction, a rainbow R2 is projected onto the ceiling C as shown in FIG. 4 . The rainbow R2 becomes an upright rainbow that curves toward the viewer, as shown in FIG. 4 . FIG. 6 shows how light L3 incident from the incident point I3 at the center of the side surface 13 of the prism body 1 in the horizontal direction, as well as light L4 incident from an incident point I4 on the right side of the side surface 13 in the horizontal direction (the lower side of FIG. 6 ) and exiting from an exit point O4 at the rear of the side surface 13 of the prism body 1, are 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] 7 shows a rainbow generating prism 200 according to a second embodiment of the present invention. The rainbow generating prism 200 is a hollow cylindrical prism body 201 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 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 opens upward. An upper edge 201b of side wall 213 is perpendicular to an axis 201a (see FIG. 8) of cylindrical side wall 213, and bottom wall 211 has an elliptical shape that is tilted with respect to axis 201a. Prism body 201 is symmetrical 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 at its bottom edge.

[0026] The first grounding portion 202a constitutes the front half (left side in FIG. 8) of the bottom edge of the cylindrical support means 202, is semicircular 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 surface G when the rainbow generating prism 200 is placed on the horizontal surface 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 is in contact with the horizontal plane G with the prism body 201 tilted backward, thereby supporting the prism body 201.

[0028] The first grounding portion 202a and the second grounding portion 202b are provided symmetrically in the minor axis direction of the bottom wall 211 (the left-right direction in FIG. 11 ), and the rainbow generating prism 200 as a whole is also provided symmetrically in the minor axis direction of the bottom wall 211. In this way, 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 211 to change its posture.

[0029] 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 incident on the prism body 201 filled with water W. Figures 7 to 9 show light L5 of sunlight incident on the prism body 201, which enters at an incident point I5 at the center in the left-right direction of the side wall 213 (the up-down direction in Figure 9) and exits from an exit point O5 on the water surface. Here, the incident point and exit point refer to the points at which light enters or exits the water W stored in the prism body 201.

[0030] As shown in FIG. 8 , when light L5 enters the water W inside the prism body 201, it refracts upward at the incident point I5, travels straight, is reflected by the bottom wall 211, and exits from the exit point O5 on the water surface. The exiting light L5 refracts downward at the exit point O5. The rainbow R3 projected onto the vertical screen S by the light L5 becomes an upright rainbow R3 that curves upward, as shown in FIG. 7 . FIG. 9 shows how light L6, which enters from the incident point L5 at the center of the left-right direction of the side surface 213 of the prism body 201 (the up-down direction in FIG. 9 ), and light L6, which enters from the incident point I6 on the right side of the side surface 213 in the left-right direction (the lower side in FIG. 9 ) and exits from the exit point O6 on the rear side of the side surface 213 of the prism body 1, are refracted and reflected by the prism body 201. Light L6 incident on the 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] 10 and 11 show how sunlight enters and exits the side wall 213 of the prism body 201 in the front-to-rear direction when the prism body 201 is tilted backward (to the right in FIG. 8 ) from the attitude shown in FIG. 8 and the second grounding portion 202b is in contact with the horizontal plane G. Figure 10 shows ray L7 of sunlight entering the prism body 201, which enters the prism body 201 from an entrance point I7 at the center in the left-right direction (the up-and-down direction in FIG. 11 ) on the front side of the cylindrical side wall 213 and exits from an exit point O7 on the rear side of the side wall 213.

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

[0033] 12 shows a rainbow generating prism 300 according to a third embodiment of the present invention. Similar to the rainbow generating prism 200 of the second embodiment, 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, but unlike the second embodiment, the support means 302 that supports the prism body 301 is provided separately from the prism body 301.

[0034] As shown in Fig. 12, the 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, an upper edge 301b of the side wall 313 is disposed perpendicular to an axis 301a (see Fig. 13) of the cylindrical side wall 313, and the bottom wall 311 is elliptical and tilted relative to the axis 301a. The prism body 301 is disposed symmetrically with respect to the minor axis direction of the elliptical bottom wall 311 (the 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 around 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 the prism body 301, which has its axis 301a vertical and is filled with water W. 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] 14 shows how sunlight enters and exits the prism body 301, forming an inverted rainbow R6, when the prism body 301 is rotated around the axis 302a by tilting the axis 301a backward from the state shown in FIG. 13. The mechanism by which the inverted rainbow R6 is formed in FIG. 14 is the same as the mechanism by which the inverted rainbow R4 in the second embodiment shown in FIGS. 10 and 11 is formed.

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

[0039] 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] The prism body 401 has a bottom surface 411 formed of an ellipsoidal surface inclined to the axis 401 a of the prism body 401 , and a top surface 412 formed of a circular surface perpendicular to the axis 401 a of the 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. In the rainbow generating prism 400 of the fourth embodiment, as shown in Figures 16(b) and 16(c), by changing the position, it is possible to form and enjoy rainbows R8 and R9 of different positions.

[0042] 17 shows a rainbow generating prism 500 according to the fifth embodiment of the present invention. The rainbow generating prism 500 comprises a solid cylindrical prism body 501 and a cylindrical support means 502. The bottom edge of the support means 502 is provided with a first ground contact portion 502a that is perpendicular to the axis 501a of the prism body 501, and second and third ground contact portions 502b, 502c that are inclined at different angles relative to the axis 501a, so that the angle of the 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-described embodiments. For example, it may be a solid prism body with both ends inclined to the axis of the prism body as an elliptical surface. Furthermore, in any of the embodiments in which the prism body and the support means are integrally formed, the prism body and the support means may be provided separately. A container-shaped prism may be provided with a lid. The liquid filled in the container-shaped prism body is not limited to water, as long as it is transparent.

[0044] L1, L2, L3, L4, L5, L6, L7, L8 Sunlight (light) R1, R2, R3, R4, R5, R6, R7, R8, R9 Rainbow 100, 200, 300, 400, 500 Rainbow generating prism 1a, 201a, 301a, 401a, 501a Axis 11,411,511 Bottom surface 211,311 Bottom wall (bottom surface) 11b Short diameter 1,201,301,401,501 Prism body 2,201,302,402,502 Supporting means

Claims

1. A rainbow-generating prism capable of splitting sunlight into a circular arc-shaped rainbow, comprising: a prism body made of a transparent material and having a solid cylindrical shape, with at least one end in the axial direction having an elliptical base that is inclined relative to the axis and is arranged symmetrically with respect to the minor axis of the elliptical base; and support means for supporting the prism body so that it can rotate around an axis parallel to the symmetrical direction.

2. A rainbow generating prism capable of splitting sunlight into a circular arc-shaped rainbow, comprising: a hollow cylindrical container made of a transparent material, one end of which in the axial direction has an elliptical bottom wall tilted toward said axis, and a prism body arranged symmetrically with respect to the minor axis direction of said elliptical bottom wall; and support means for supporting said prism body so that it can rotate around an axis parallel to the symmetrical direction.

3. A rainbow generating prism according to claim 1 or claim 2, wherein said support means is capable of continuously rotating said prism body around said axis.

4. A rainbow generating prism according to claim 1 or claim 2, wherein said support means is capable of rotating said prism body in stages around said axis.

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