Prism for rainbow generation

Abstract

To provide a prism for rainbow generation which can easily change the shape of a rainbow.SOLUTION: A prism 100 for rainbow generation is used to enjoy forming a circular arc rainbow by spectrally separating sunlight. The prism 100 for rainbow generation comprises a solid columnar prism body 1 which is composed of a transparent material, and support means 2 for supporting it. The prism body 1 includes a bottom face 11 one axial end side of which is inclined with respect to the axis. The prism body 1 is constructed symmetrical with respect to the minor axis direction of the bottom face 11. The support means 2 is constituted to support the prism body 1 so as to be pivotable around an axis parallel to the direction of symmetry. The prism 100 for rainbow generation is constructed so that the prism body 1 can be easily pivoted to change its attitude while being placed on a desktop, and the shape of a formed rainbow can, therefore, be easily changed.SELECTED DRAWING: Figure 1

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] Various types of prisms have been proposed in the past that have arc-shaped cross sections on the surface that reflects or refracts sunlight, and that form arc-shaped spectra resulting from the splitting of sunlight into seven colors (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 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, 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 causing a rainbow to fluctuate due to the pulsation of the water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Publicly-available Practical Publication No. 59-48504 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-141914 [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 makes it difficult to adjust and fix the direction of light incidence and emission without blocking the path of the light with the hand.Furthermore, the rainbow-generating prism in Patent Document 2 and the rainbow-generating container in 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 view of the above problem, and aims to provide a rainbow-generating prism that can easily change its attitude relative to the incident direction of sunlight to find an attitude that will produce a rainbow, and that can easily form rainbows with different attitudes and positions by changing the attitude of the prism. [Means for solving the problem]

[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 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. Furthermore, 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 symmetry direction, the position of the prism can be easily changed, for example with one hand, while the prism is left on the floor. This allows the angle at which sunlight is incident on the prism to be changed, making it easy to change the position and orientation of the rainbow, such as moving the location where the rainbow is formed from the wall to the ceiling or changing an upright rainbow to an inverted rainbow. Furthermore, since it is easy to find the position of the prism body so that sunlight is totally reflected at the bottom, a rich and beautiful rainbow can be formed.

[0010] The rainbow generating prism of the present invention is a rainbow generating prism that can disperse sunlight into a circular arc-shaped rainbow, and includes a hollow cylindrical container made of a transparent material, with one end in the axial direction having an elliptical bottom wall inclined to the axis, and 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 so that it can rotate 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, the container can be used as a prism to form a rainbow. In this case, if a rainbow is formed by light passing through the liquid surface, the rainbow can be made to sway by shaking the liquid. Furthermore, when changing the position of the prism body using 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. Therefore, the angle between the top surface of the prism and the bottom wall can be changed, allowing for a different method of forming a rainbow compared to the above-mentioned rainbow-generating prism, 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. [Effects 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 explanation 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. FIG. [Figure 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. [Figure 3] 2 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. FIG. [Figure 4] FIG. 2 is a perspective view showing the rainbow-generating prism shown in FIG. 1, with the top surface of the prism body facing the sun, and sunlight forming an erect rainbow on the ceiling. [Figure 5] FIG. 5 is a side view showing how sunlight is reflected and refracted in FIG. [Figure 6] 5 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. FIG. [Figure 7] FIG. 10 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 cross-sectional side view showing how sunlight is reflected and refracted in FIG. 7. [Figure 9] 8 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. [Figure 10] 10 is a cross-sectional side view showing how sunlight is reflected and refracted when the prism body of the rainbow-generating prism in FIG. 7 is tilted backward (away from the sun, to the right in FIG. 10). [Figure 11] 11 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. [Figure 12] FIG. 10 is a perspective view of a rainbow generating prism according to a third embodiment of the present invention. [Figure 13] 13 is a cross-sectional side view showing how sunlight is reflected and refracted in the rainbow-generating prism shown in FIG. 12. FIG. [Figure 14] 14 is a cross-sectional side view showing how sunlight is reflected and refracted when the prism body of FIG. 12 is tilted backward (to the right in FIG. 14). [Figure 15] 15 is a cross-sectional side 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. 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 showing how sunlight is reflected and refracted when the prism is not tilted; and FIG. 10C is a longitudinal cross-sectional view showing how sunlight is reflected and refracted when the prism is tilted. [Figure 17] FIG. 10 is a vertical cross-sectional view of a rainbow generating prism according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE 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] (First embodiment) 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 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 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] (Formation of 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-back direction when the axis 1a (see FIG. 2) of the prism body 1 is vertical. 1 to 3 show light L1 of the sunlight entering the prism body 1, which enters the prism body 1 from an incident point I1 at the center in the left-to-right direction (the 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 is refracted upward at the incident point I1, then 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 different 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 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), with the top surface 12 of the prism body 1 facing forward, and a rainbow R2 is formed by light L3 incident from the top surface 12.

[0022] As shown in FIG. 5, light L3 incident from incident point I3 at the center of the top surface 12 in the horizontal direction enters the prism body 1. After refracting downward at incident point I3, it travels straight ahead and is reflected by the bottom surface 11. The emitted light L3 is then refracted upward at exit point O3. Since light O3 is emitted in a generally vertical direction, a rainbow R2 is projected onto the ceiling C, as shown in FIG. 4. As shown in FIG. 4, the rainbow R2 becomes an erect rainbow that curves toward the viewer. FIG. 6 shows how light L3 incident from incident point I3 at the center of the side surface 13 of the prism body 1, as well as light L4 incident from 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 exit point O4 on the rear side of the side surface 13 of the prism body 1, are refracted and reflected by the prism body 1. Light L4 that enters 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. Rainbow generating prism 200 is a hollow cylinder made of a transparent material such as glass, acrylic, or carbonate, and includes prism body 201 that becomes a prism when filled with a transparent liquid such as water, and support means 202 that supports 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 disposed perpendicular to axis 201a (see FIG. 8) of cylindrical side wall 213, and bottom wall 211 is elliptical and tilted relative to axis 201a. Prism body 201 is disposed 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 integrally 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 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 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 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 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 21 and changes 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 so that the first grounding portion 202a is in contact with a horizontal surface G, and sunlight is incident on the prism body 201 filled with water W. Of the sunlight incident on 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 light enters or exits the water W stored in the prism body 201.

[0030] As shown in FIG. 8, when light L5 enters water W inside prism body 201, it refracts upward at incident point I5, travels straight ahead, is reflected by bottom wall 211, and exits from exit point O5 on the water surface. The exiting light L5 is refracted downward at exit point O5. A rainbow R3 projected onto vertical screen S by light L5 becomes an erect rainbow R3 that curves upward, as shown in FIG. 7. FIG. 9 shows how light L6, which enters from incident point L5 at the center of side surface 213 of prism body 201 in the left-right direction (the up-down direction in FIG. 9), and light L6, which enters from incident point I6 on the right side of side surface 213 in the left-right direction (the lower side in FIG. 9) and exits from exit point O6 on the rear side of side surface 213 of prism body 1, are refracted and reflected by 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] (Formation of 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 when prism body 201 is tilted backward (to the right in FIG. 8) from the attitude shown in FIG. 8 and second grounding portion 202b is in contact with horizontal plane G. Fig. 10 shows ray L7 of 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 enters water W inside prism body 201, it is refracted upward at incident point O7, travels straight ahead, 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 paper in Fig. 11), as shown in Fig. 11. Furthermore, as shown in Fig. 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] (Third embodiment) 12 shows a rainbow generating prism 300 according to the third embodiment of the present invention. Similar to the rainbow generating prism 200 of the second embodiment, the rainbow generating prism 300 comprises 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, 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 disposed 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 disposed symmetrically with respect to the minor axis direction of 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 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] 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 shown 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 shown 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, and thereby rainbows of different shapes 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 ellipsoidal surface 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. 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] (Fifth embodiment) 17 shows a rainbow generating prism 500 according to the fifth embodiment of the present invention. Rainbow generating prism 500 comprises a solid cylindrical prism body 501 and cylindrical support means 502, with the bottom edge of support means 502 provided with a first ground contact portion 502a that is perpendicular to the axis 501a of prism body 501, and second and third ground contact portions 502b, 502c that are inclined at different angles relative 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-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. [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 arc-shaped rainbow, a prism body made of a transparent material and having a solid cylindrical shape, with at least one end in an axial direction having an elliptical base inclined with respect to the axis, and arranged symmetrically with respect to the minor axis direction of the elliptical base; a support means for supporting the prism body so that the prism body can rotate about an axis parallel to the symmetry direction of the prism body; A rainbow generating prism comprising:

2. A rainbow generating prism capable of splitting sunlight into a circular arc-shaped rainbow, a container made of a transparent material and having a hollow cylindrical shape, with one end 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 that the prism body can rotate about an axis parallel to the symmetry direction of the prism body; A rainbow generating prism comprising:

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

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

Images