Retroreflection device

Abstract

The invention provides a retro-reflection device which eliminates offset in the retro-reflection device. A retroreflective device having a cube-corner prism, the cube-corner prism having three reflective surfaces and a light-transmitting surface, the light-transmitting surface transmitting incident light and retroreflective light reflected by the reflective surfaces of the incident light. The light-transmitting surface has a non-adjacent side and two adjacent sides. The more than eight cube-corner prisms enable adjacent edges of the light-transmitting surfaces to be in close contact with each other to form a connected ring array. Each of the cube-corner prisms is disposed so that the light-transmitting surface faces the outside of the ring, and the cube-corner prisms are disposed in a state in which the relationship between the first length and the second length is equal under a condition in which incident light in a direction perpendicular to the central axis of the ring is incident toward the cube-corner prisms. The first length is the light path length from the incident position where the incident light penetrates through the light-transmitting surface to the emergent position where the retro-reflected light penetrates through the light-transmitting surface, and the second length is the sum of the shortest distance from the incident position to the central axis and the shortest distance from the central axis to the emergent position.

Description

Technical Field

[0001] The present disclosure relates to a retroreflective device. Background Art

[0002] In a theodolite or a total station, the incident direction of the retroreflected light emitted from the installation position is measured after being retroreflected by a retroreflection device, thereby obtaining data used for measurement. In such a retroreflection device, a corner cube capable of retroreflection is sometimes used.

[0003] Regarding the retroreflective device, it is known that there is a technology that can retroreflect the entire circumference of light by combining six corner cube prisms (for example, refer to Patent Document 1). In the technology disclosed in Patent Document 1, the six corner cube prisms constituting the prism assembly are clamped by a group of a first member and a second member. The clamped state is maintained by a holding mechanism.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-204576 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the retroreflector disclosed in Patent Document 1, due to the influence of the refractive index of the corner cube, there is a deviation (offset) between the position of the virtual reflective surface of the corner cube that performs retroreflection and the position of the actual central axis in the retroreflector. Therefore, it is necessary to eliminate the deviation in the retroreflector.

[0009] The present disclosure is to eliminate the deviation of a retroreflective device capable of retroreflecting light from the entire circumference in the circumferential direction.

[0010] Means used to solve problems

[0011] In order to solve the above-mentioned problems, the retroreflective device of the present disclosure adopts the following means.

[0012] The first disclosed retroreflective device has a corner cube prism having: 3 reflecting surfaces constituting mutually orthogonal planes; and a light-transmitting surface that transmits incident light incident toward these reflecting surfaces and transmits retroreflected light reflected by the reflecting surfaces. The light-transmitting surface is a surface constituting an equilateral triangle, having: non-adjacent sides corresponding to the base of the light-transmitting surface; and 2 adjacent sides corresponding to the 2 equilateral sides excluding the base. The configuration of an even number of corner cube prisms of more than 8 has a prism assembly constructed in such a way that the adjacent sides of the light-transmitting surfaces of these corner cube prisms are in close contact with each other to form a connected ring. The corner cube prisms forming the ring array are respectively configured so that their light-transmitting surfaces are directed toward the outside of the circle of the ring array, and under the condition that the incident light in a direction perpendicular to the central axis of the circle of the ring array is incident toward the corner cube prism, the corner cube prisms are configured in a state in which a first length and a second length are equal to each other, the first length being the optical path length from the incident position where the incident light passes through the light-transmitting surface to the exit position where the retroreflected light passes through the light-transmitting surface, and the second length being the sum of the shortest distance from the incident position to the central axis observed in the direction perpendicular to the central axis and the shortest distance from the central axis to the exit position observed in the direction perpendicular to the central axis.

[0013] In addition, the "surface constituting an equilateral triangle" mentioned here includes a face whose corners are rounded and a face whose corners are chamfered and formed flat. Similarly, the "base" is a line segment connecting the vertices at the two ends of the two equal sides of the equilateral triangle.

[0014] The "incident position" here refers to the position on the light-transmitting surface where the incident light entering the reflective surface passes through the light-transmitting surface. Similarly, the "exit position" refers to the position on the light-transmitting surface where the retroreflected light reflected by the reflective surface passes through the light-transmitting surface.

[0015] According to the first disclosed retroreflection device, three reflecting surfaces are configured as mutually orthogonal planes, so that the incident light incident at the incident position of the light-transmitting surface and the retroreflected light returned at the exit position of the light-transmitting surface are in parallel relationship. In addition, in the corner cube prism of the prism assembly, the light-transmitting surface can retroreflect light in the entire circumference of the ring array. In addition, the prism assembly can adjust the deviation between the position of the imaginary reflecting surface for retroreflection of the corner cube prism and the position of the actual central axis in the retroreflection device. Thus, in the retroreflection device capable of retroreflecting light from the entire circumference, the offset of the retroreflection device can be eliminated.

[0016] The first disclosed retroreflective device may also be the second disclosed retroreflective device described later. In the second disclosed retroreflective device, there is a structure in which, in the prism assembly, the eight corner cube prisms are arranged so that the adjacent edges of their light-transmitting surfaces are in close contact with each other as a whole.

[0017] In the first disclosure, the adjacent edges of the light-transmitting surfaces of a plurality of corner cube prisms are brought into close contact with each other to form a connected ring array, thereby retroreflecting the light over the entire circumference of the ring array. Therefore, in the prism assembly, in the case where there is a non-close contact portion where the adjacent edges of the light-transmitting surfaces of the corner cube prisms are not in close contact with the adjacent edges of the adjacent light-transmitting surfaces, the retroreflection of the light over the entire circumference is not generated in the non-close contact portion. In contrast, according to the structure of the retroreflection device disclosed in the second disclosure, the non-close contact portion can be eliminated from each corner cube prism. Therefore, the situation where the retroreflection of the light over the entire circumference is not generated due to the presence of the non-close contact portion can be avoided. Thus, the effective range of the light-transmitting surface where the incident light is retroreflected can be expanded. In addition, if the prism assembly is composed of 8 corner cube prisms, the radial dimension of the central axis of the retroreflection device as a whole can be set smaller than the situation where the prism assembly is composed of an even number of corner cube prisms greater than 10.

[0018] The retroreflective device of the first or second disclosure may also be the retroreflective device of the third disclosure described later. In the retroreflective device of the third disclosure, the prism assembly has a holding mechanism that holds the corner cube prisms in a state in which they can be individually attached and detached.

[0019] According to the third disclosed retroreflective device, in the prism assembly, when a corner cube is damaged, only the damaged corner cube can be removed and an undamaged corner cube can be installed.

[0020] The third disclosed retroreflective device may also be the fourth disclosed retroreflective device described later. In the fourth disclosed retroreflective device, the holding mechanism comprises: a pair of main bodies, which clamp the corner cube prisms forming the ring from both axial sides of the central axis; a hooking protrusion, which is provided on each of the main bodies, and hooks the non-adjacent edges of the corner cube prisms in the held state from the outside; and a clamping portion, which is installed on each of the main bodies, and hooks the corners between the adjacent edges of the corner cube prisms that hook the non-adjacent edges with the hooking protrusions from the outside. By removing the clamping portion, a retreat state in which the corner cube prisms in the held state can be individually installed / removed is achieved.

[0021] According to the fourth disclosed retroreflective device, when a corner cube prism in a holding state is individually installed or removed, the corner cube prism to be hung can be prevented from falling off from the holding mechanism by the hooking protrusion provided on one side of the main body. In addition, when removing the corner cube prism in the retreat state, the corner portion of the corner cube prism can be pulled outward while the corner cube prism is hung on the hooking protrusion and the corner cube prism can be removed.

[0022] The fourth disclosed retroreflective device may also be the fifth disclosed retroreflective device described later. In the fifth disclosed retroreflective device, the holding mechanism has a through hole, and the through hole is penetrated at a position and direction corresponding to the central axis. The through hole enables the rod-shaped member to be slidably inserted through the through hole, so that the prism assembly can slide along the direction in which the rod-shaped member extends.

[0023] According to the fifth disclosed retroreflective device, the rod-shaped member slides in the through hole of the holding mechanism of the prism assembly, so that the prism assembly can slide in the direction in which the rod-shaped member extends.

[0024] The third disclosed retroreflective device may also be the sixth disclosed retroreflective device described later. In the sixth disclosed retroreflective device, the holding mechanism has recesses, the number of which corresponds to the number of the corner cube prisms arranged in the manner of forming the ring array. Each of the recesses holds each of the corner cube prisms by installing the corner portion where the three reflecting surfaces of each of the corner cube prisms are concentrated.

[0025] According to the sixth disclosed retroreflective device, each corner cube prism is mounted in each recess of the holding mechanism to form a prism assembly, thereby improving the workability of positioning each corner cube prism.

[0026] The fifth disclosed retroreflective device may also be the seventh disclosed retroreflective device described later. In the seventh disclosed retroreflective device, the retroreflective device comprises: an externally embedded member, which is externally embedded relative to the rod-shaped member; and an outer tube, which is externally embedded relative to the externally embedded member. The externally embedded member comprises: a protruding portion, which, in a state of being externally embedded relative to the rod-shaped member, protrudes toward one side radially outward of the rod-shaped member, and a locking portion, which is locked relative to any one of the paired main body portions to prevent the main body portion from rotating in the circumferential direction. When the outer tube is externally embedded in the externally embedded member, the externally embedded member is pressed against the rod-shaped member by tightening the protruding portion from the one side.

[0027] According to the seventh disclosed retroreflective device, the externally embedded component is pressed against the rod-shaped component by fastening the extended portion of the rod-shaped component from the radially outer side of the rod-shaped component using an outer cylinder. As a result, the externally embedded component is unlikely to deviate from or rotate relative to the rod-shaped component. In addition, in the externally embedded component, its locking portion is locked relative to any main body portion to prevent the main body portion from rotating in the circumferential direction. As a result, the prism assembly can be located at a predetermined position relative to the circumferential direction of the rod-shaped component.

[0028] The retroreflective device disclosed in the seventh disclosure may be the retroreflective device disclosed in the eighth disclosure described later. In the retroreflective device disclosed in the eighth disclosure, a level detector is mounted on at least one of the pair of main bodies.

[0029] According to the eighth disclosed retroreflective device, the horizontal detector can detect the inclination of the prism assembly relative to the horizontal direction. Thus, the leveling accuracy of the prism assembly along the extending direction of the sliding rod-shaped member is improved, and the accuracy of measurement using the retroreflective device can be improved.

[0030] The third disclosed retroreflective device may also be the ninth disclosed retroreflective device described later. In the ninth disclosed retroreflective device, the holding mechanism has an insertion hole, which is opened at a position and in a direction corresponding to the central axis. A support body is inserted into the insertion hole to support an external force applied to the holding mechanism.

[0031] According to the ninth disclosed retroreflective device, the support body does not block light and can reinforce the prism assembly in the direction along the central axis of the ring of the corner cube prism array.

[0032] The ninth disclosed retroreflective device may also be the tenth disclosed retroreflective device described later. The tenth disclosed retroreflective device includes a mounting portion, which is supported by the support and capable of mounting a target of a positioning system.

[0033] According to the retroreflective device of the tenth disclosure, by attaching the target of the positioning system to the support column of the holding mechanism, the position of the retroreflective device can be measured by the total station and the positioning system.

[0034] Effects of the Invention

[0035] The present disclosure has the above-mentioned structure, and can eliminate the deviation in the retroreflective device that can retroreflect the light from the entire circumference in the circumferential direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is an explanatory diagram showing a usage state of the retroreflective device 100 according to the first embodiment.

[0037] Figure 2It is a perspective view of the retroreflective device 100 according to the first embodiment.

[0038] Figure 3 It is a front view of the retroreflective device 100 according to the first embodiment.

[0039] Figure 4 1 is a plan view of the retroreflective device 100 according to the first embodiment.

[0040] Figure 5 yes Figure 3 VV line section view.

[0041] Figure 6 yes Figure 3 The VI-VI line section view.

[0042] Figure 7 yes Figure 3 The VII-VII line section view.

[0043] Figure 8 It is an exploded perspective view of the retroreflective device 100 according to the first embodiment.

[0044] Fig. 9 yes Figure 3 This is an explanatory diagram when the middle holding mechanism 150 is released and the engaging portion 210 is removed.

[0045] Fig.10 It is a front view of a retroreflective device 600 according to the second embodiment.

[0046] Fig.11 yes Fig.10 The XI-XI line section view.

[0047] Description of Reference Numerals

[0048] 60 rod-shaped member, 70 eccentric positioning pin, 71 extension portion, 72 gripping portion, 73A one end side inclined surface, 73B the other end side inclined surface, 74 locking portion, 81 screw, 81A shaft, 81B head, 100 retroreflective device, 103 through hole, 110 main body, 130 prism assembly, 131 corner pyramid, 132 reflecting surface, 132A corner portion, 133 light-transmitting surface, 134 corner portion, 136A non-adjacent side, 136B adjacent side, 137 ring, 140 shaft portion, 141 frame, 141A recess, 142 barrel portion, 142A threaded hole, 142B convergence portion, 142C flat surface, 142D inclined surface, 143 shaft through hole, 150 holding mechanism, 201A flat head screw, 201B head, 201C shaft , 210 engaging portion, 211A hollow cylinder, 211B countersunk hole, 211C flat head countersunk hole, 211D lower hole, 211F contact portion, 211G inclined surface, 211H cut surface, 220 hook protrusion, 221 hook piece, 221A protrusion, 221B claw, 230 inner cylinder, 231 external threaded portion, 233 guide surface, 234 locking groove, 240 support portion, 241 internal threaded portion, 243 guide surface, 244 sliding hole, 320 level detector, 320A mounting plate, 320B mounting hole, 320C insertion hole, 320D bubble tube, 560 rod-shaped member, 565 pillar body, 565A threaded hole, 581 screw, 581A shaft, 581B head, 592 screw, 592B head, 592F seat surface, 600 retroreflective device, 603 through hole, 610 main body, 630 prism assembly, 631 corner pyramid, 632A corner portion, 633 light-transmitting surface, 634 corner, 636A non-adjacent edge, 636B adjacent edge, 640 shaft, 641 frame, 641A recess, 642 barrel, 642A threaded hole, 643 shaft through hole, 650 holding mechanism, 701A flat head screw, 710 engaging portion, 720 hanging protrusion, 721 hanging piece, 721A protrusion, 900 total station, 910 laser light source, 920 target, A110 main body at one end, A111 facing portion, A112 non-facing portion, A112A threaded hole, A113 through hole at one end, A117 embedding hole, A118 sinking hole hole, A118A lower hole, A610 one end side main body, A611 facing part, A612 non-facing part, A613 one end side through hole, A617 embedded hole, A618 countersunk hole, A618A lower hole, A820 one end side base, A820A one end side base, A820B insertion hole, A820C countersunk hole, A820D threaded joint, A820E external thread, A820F bottom hole, B110 other end side main body, B111 facing part, B111A engagement hole, B111B threaded hole, B111C countersunk hole, B111F insertion hole, B112 non-facing part, B113 other end side through hole, B117 embedded hole, B118 countersunk hole, B118A lower hole, B610 other end side main body,B611 facing part, B611A engaging hole, B611B threaded hole, B611C countersunk hole, B612 non-facing part, B613 through hole on the other end side, B617 embedded hole, B820 other end side base, B820A other end side base, B820B insertion hole, B820C countersunk hole, B820D gasket, B820E mounting hole, B820G bottom, C10 center axis, C60 center axis, C70 center axis, C80 center axis, ER effective range, ERC area, GR earth, IP incident position, L11 length, L12 length, L13 length, L21 shortest incident distance, L22 shortest exit distance, L31 support interval, L32 reinforced interval, LR laser, OP exit position, RP1 first reflection position, RP2 second reflection position, S10 accommodation space, S20 gap, S30 slit. , DETAILED DESCRIPTION

[0049] <First embodiment>

[0050] like Figure 1 As shown, the retroreflection device 100 of the first embodiment of the present disclosure is installed and fixed at a measurement location to be measured. The retroreflection device 100 is used to retroreflect the laser light LR emitted by the total station 900 during the measurement operation using the total station 900.

[0051] <Structure of Retroreflective Device According to First Embodiment>

[0052] like Figure 8 As shown, the retroreflective device 100 has a prism assembly 130 (see Figure 2 ), the prism assembly 130 has an even number of 8 or more (8 in this embodiment) corner cube prisms 131. Figure 2 As shown in FIG. 1 , the prism assembly 130 is configured such that the corner cube prisms 131 have adjacent sides 136B of their light-transmitting surfaces 133 in close contact with each other to form a continuous ring array 137. Each corner cube prism 131 is configured such that its light-transmitting surface 133 faces the outside of the ring array 137. In addition, the prism assembly 130 has a holding mechanism 150, which holds the corner cube prisms 131 in a state where they can be individually attached / detached. In addition, as shown in FIG. Figure 5 as well as Figure 6 As shown, the incident light here is the total station 900 (refer to Figure 1 ) releases the laser light LR and enters the light-transmitting surface 133.

[0053] <Structure of Corner Cube Prism>

[0054] like Figure 8As shown, the corner cube prism 131 has a right-angled triangular pyramid shape having three reflecting surfaces 132 respectively constituting mutually orthogonal planes and one light-transmitting surface 133. In the right-angled triangular pyramid shape, the right angles of the three reflecting surfaces 132 are concentrated at one point to form an angle portion 132A.

[0055] The three reflecting surfaces 132 are respectively surfaces in the form of right-angled isosceles triangles. In addition, the light-transmitting surface 133 is a surface in the form of an equilateral triangle. The concept of the above-mentioned "surface in the form of a right-angled isosceles triangle" includes surfaces in which each corner is rounded or chamfered in a right-angled isosceles triangle. In addition, the concept of the above-mentioned "surface in the form of an equilateral triangle" includes surfaces in which each corner is rounded or chamfered in an equilateral triangle. In the present embodiment, the corner cone prism 131 is a prism in which chamfering is performed on all the ridges in the above-mentioned right-angled triangular pyramid shape and all the corner portions (including the corner portion 132A). The chamfering process is, for example, a light chamfering process to form a surface with a width smaller than the beam diameter of the laser LR.

[0056] The light-transmitting surface 133 has a non-adjacent side 136A corresponding to the base of the equilateral triangle and two adjacent sides 136B corresponding to the two equilateral sides excluding the base. Similarly, the light-transmitting surface 133 has a corner 134 between each adjacent side 136B. That is, in the light-transmitting surface 133, the opposite side of the corner 134 becomes a non-adjacent side 136A.

[0057] Reflective materials that reflect incident light are provided on the three reflecting surfaces 132. In addition, the light-transmitting surface 133 transmits incident light incident on the three reflecting surfaces 132 and retroreflected light reflected by the three reflecting surfaces 132. Retroreflected light is light that is parallel to the incident light and propagates in the opposite direction to the incident light.

[0058] <Structure of prism unit>

[0059] like Figure 8 As shown in FIG. 1 , the prism assembly 130 is a structure in which eight corner cube prisms 131 are arranged. That is, the prism assembly 130 is a structure in which the eight corner cube prisms 131 are arranged so that the adjacent sides 136B of their light-transmitting surfaces 133 are in close contact with each other. In other words, the corner cube prisms 131 constituting the prism assembly 130 are in a relationship in which both ends of the adjacent sides 136B of the light-transmitting surfaces 133 are adjacent to both ends of the adjacent sides 136B of the adjacent light-transmitting surfaces 133.

[0060] In addition, if Figure 2 As shown, the corner cubes 131 of the prism assembly 130 are arranged so that the light-transmitting surfaces 133 thereof face different directions from each other. In other words, the eight light-transmitting surfaces 133 of the prism assembly 130 are arranged so as to have the same shape as the side surfaces of a regular square prism.

[0061] The corner cube prism 131 is arranged in a state where a first length and a second length, which will be described later, are equal to each other.

[0062] The first length is the optical path length from the incident position IP where the incident light passes through the light-transmitting surface 133 to the exit position OP where the retroreflected light passes through the light-transmitting surface 133, under the condition that the incident light in the direction perpendicular to the central axis C10 of the ring array 137 is incident toward the corner cube prism 131. Among them, the "optical path length" is a value defined when light propagates in a certain substance, and has the dimension of length. When the refractive index of the substance is independent of the part and can be regarded as homogeneous, the optical path length is given by the product of the sum of the lengths of the propagation paths of the light in the substance and the refractive index of the substance.

[0063] In this embodiment, the refractive index (hereinafter also referred to as "n") of the corner cube prism 131 is modulated to be uniform regardless of the location. Figure 5 As shown, in the corner cube prism 131, the incident light incident to the position IP first reaches the first reflection position RP1 and is reflected there. The reflected light reaches the second reflection position RP2 from the first reflection position RP1 and becomes a retroreflected light. The retroreflected light reaches the exit position OP and exits there. Therefore, the first length is given in the form of (L11+L12+L13)×n. Among them, L11 is the length from the incident position IP to the first reflection position RP1. In addition, L12 is the length from the first reflection position RP1 to the second reflection position RP2. In addition, L13 is the length from the second reflection position RP2 to the exit position OP.

[0064] like Figure 6 As shown, the second length is the sum of the shortest distance from the incident position IP to the central axis C10 under the above conditions, that is, the shortest incident distance L21 and the shortest distance from the central axis C10 to the exit position OP, that is, the shortest exit distance L22.

[0065] The “incident position IP” mentioned here is the position on the transparent surface 133 where the incident light incident on the reflective surface 132 passes through the transparent surface 133. Similarly, the “exit position OP” is the position on the transparent surface 133 where the retroreflected light reflected by the reflective surface 132 passes through the transparent surface 133.

[0066] <Structure of the maintenance mechanism>

[0067] like Figure 2 As shown, the holding mechanism 150 holds each corner cube prism 131 constituting the ring array 137 in a state where the light-transmitting surface 133 faces the outside of the ring array 137. Figure 8As shown, the holding mechanism 150 has a pair of main body parts 110, a shaft part 140, a latching projection 220, an engaging part 210, and a through hole 103. The pair of main body parts 110 sandwich eight corner prisms 13 forming the ring array 137 from both axial sides of the central axis C10 to be in a clamping state. Through the shaft part 140, the corner prism 131 is aligned at a specified position. The latching projection 220 latches a non-adjacent side 136A of the corner prism 131 from the outside of the circle of the ring array 137. The engaging part 210 engages the corner part 134 of the corner prism 131 latched by the latching projection 220 from the outside of the circle of the ring array 137. By slidably inserting a rod-shaped member 60 (refer to Figure 5 ) into the through hole 103, the prism assembly 130 can be slid along the extending direction of the rod-shaped member 60. The main body part 110, the shaft part 140, the latching projection 220, the engaging part 210, and the through hole 103 will be described below.

[0068] <Structure of the main body part>

[0069] The pair of main body parts 110 has a pair of one-end-side main body part A110 and the other-end-side main body part B110. The one-end-side main body part A110 has an opposing part A111 which is the part opposing the other-end-side main body part B110. The other-end-side main body part B110 has an opposing part B111 which is the part opposing the one-end-side main body part A110. In the present embodiment, the opposing part A111 and the opposing part B111 each have a shape imitating the appearance of a "four-cornered star pattern shape (bulging thread winding)" (a shape in which the four sides of a rounded square are bent inward respectively). Each side of the opposing parts A111 and B111 is positioned along the arrangement of each non-adjacent side 136A in each corner prism 131 constituting the prism assembly 130.

[0070] As Figure 8 shown, in the pair of main body parts 110, the opposing part A111 of the one-end-side main body part A110 and the opposing part A111 of the other-end-side main body part B110 have the same shape. Therefore, hereinafter, regarding the respective structures of the opposing parts A111 and B111, the detailed description will be represented by the description of the shape of the opposing part B111. Regarding the structure of the opposing part A111, the respective reference numerals of the structures in the opposing part B111, that is, the initial letter "B", are replaced with the initial letter "A" to make them correspond, and the detailed description thereof is omitted.

[0071] Two insertion holes B111F are provided on each of the four inwardly curved sides of the facing portion B111. In the present embodiment, the insertion hole B111F is a long hole of a size into which a hanging piece 221 (described later) can be inserted, and is formed so that a protrusion 221A (described later) protrudes from the facing portion B11 by inserting the hanging piece 221. The insertion hole B111F is arranged along the non-adjacent side 136A of the corner cube prism 131 clamped by a pair of main bodies 110 in the clamped state. The orientation of the long hole of the insertion hole B111F is arranged so that its length direction is parallel to the non-adjacent side 136A in the clamped state. The two insertion holes B111F are arranged to be separated from each other and away from the corner 134.

[0072] like Figure 4 As shown, each of the four rounded corners in the facing portion B111 has a snap-in hole B111A. Fig. 9 As shown, in the present embodiment, the engaging hole B111A is a countersunk hole having a threaded hole B111B and a countersunk hole B111C with the opening edge of the threaded hole B111B as a cylindrical groove surface. Among them, the countersunk hole B111C is a recessed portion that allows the engaging portion 210 (described later) to be installed and engaged with a "clearance fit" fit. The threaded hole B111B is a hole opened perpendicularly to the bottom surface at the center of the bottom surface of the countersunk hole B111C. The hole is designed to be deeper than the extension length of the axis of the flat head screw 201A extending from the engaging portion 210 when the engaging portion 210 is installed in the engaging hole B111A. The engaging hole B111A is configured to contact the corner 134 of the corner cube prism 131 clamped by a pair of main bodies 110 in the above-mentioned clamping state.

[0073] like Figure 8 As shown, the facing portion B111 has an embedding hole B117 that is engaged with the axial end of the shaft portion 140 by "clearance fit". The lower hole B118A of the countersunk hole B118 passes through the bottom of the embedding hole B117. The countersunk hole B118 is a threaded hole for screwing the shaft portion 140 in an embedded state (described later) by means of a screw 81. The countersunk hole of the countersunk hole B118 completely accommodates the head 81B of the screw 81, and the depth of the lower hole B118A is designed to be shorter than the shaft 81A of the screw 81. In addition, the depth of the threaded hole 142A (described later) of the shaft portion 140 is designed to be longer than the shaft 81A of the screw 81. That is, the support portion 240 (described later) is attached in a manner that does not interfere with the head 81B of the screw 81 in the other end side main body portion B110.

[0074] The counterbore A118 of the main body A110 on one end side (see Figure 5 ) is also configured similarly to the counterbore B118. A level detector 320 (described later) is provided so as not to interfere with the head 81B of the screw 81 of the one end side main body A110.

[0075] The one end side body portion A110 has a non-facing portion A112 on the side opposite to the facing portion A111. The non-facing portion A112 has a surface perpendicular to the central axis C10 of the ring array 137. Three threaded holes A112A are provided at positions of the non-facing portion A112 that do not interfere with the counterbore A118.

[0076] like Figure 5 As shown, the other end side main body B110 has a non-facing portion B112 on the side opposite to the facing portion B111. In the non-facing portion B112, the inner cylinder portion 230 of the cylinder forming the external thread is provided to protrude toward the other end side. That is, the inner cylinder portion 230 is provided in the non-facing portion B112, and when the rod-shaped member 60 can be slidably inserted into the other end side through hole B113 (described later), the inner cylinder portion 230 forms a tube wall extending outward in a manner along the outer circumference of the rod-shaped member 60.

[0077] The inner cylinder 230 has an external threaded portion 231, a guide surface 233 and a retaining groove 234. The external threaded portion 231 is a threaded surface in a screwed state with the internal threaded portion 241 of the support portion 240 (described later). The guide surface 233 is an inclined surface formed by C-chamfering the inner peripheral edge of the cylinder of the inner cylinder 230. The guide surface 233 is a surface that slides the inclined surface 73A (described later) of one end of the eccentric positioning pin 70 when the eccentric positioning pin 70 (described later) is externally embedded relative to the rod-shaped member 60. The retaining groove 234 is a groove (notch) formed by cutting a rectangular cutout at the end of the cylinder of the inner cylinder 230 in the axial direction. The size of the retaining groove 234 can retain the retaining portion 74 of the eccentric positioning pin 70 in the externally embedded state.

[0078] <Shaft structure>

[0079] The shaft portion 140 is a cylindrical component having a shaft through hole 143 (described later). The two axial ends of the tube are in an embedded state in the embedding holes A117 and B117 in a prescribed arrangement direction. In addition, threaded holes 142A connected to the countersunk holes A118 or the countersunk holes B118 are provided at both ends of the shaft portion 140. The screws 81 inserted into the countersunk holes A118 or the countersunk holes B118 are screwed into these threaded holes 142A. Thus, the shaft portion 140 is fixed to a pair of main body portions 110. That is, the pair of main body portions 110 are fixed in an embedded state by the shaft portion 140 (refer to Figure 5 ). The shaft portion 140 is formed by integrally forming a frame 141 and a barrel portion 142 by metal insert molding. The frame 141 is a fixture for aligning the eight corner cube prisms 131 to the positions constituting the prism assembly 130. In addition, the barrel portion 142 is a barrel having a shaft portion through hole 143 and the above-mentioned threaded hole 142A. The frame 141 and the barrel portion 142 are described below.

[0080] <Frame structure>

[0081] The frame 141 of the shaft portion 140 has eight recesses 141A corresponding to the eight corner cube prisms 131 arranged to form the ring array 137. The eight recesses 141A are substantially triangular pyramid-shaped recesses arranged at substantially equal intervals in the circumferential direction of the shaft portion 140. Each recess 141A holds each corner cube prism 131 by installing each corner portion 132A of the eight corner cube prisms 131. At this time, each recess 141A engages with each reflection surface 132 in each corner cube prism 131 from the inner side of the ring array 137. In addition, each corner portion 132A of each corner cube prism 131 installed in each recess 141A is located in a state of being separated from each other in the circumferential direction of the ring array 137.

[0082] like Fig. 9 As shown, in this embodiment, each recess 141A is formed to have a gap S20 with respect to the corner portion 132A of the corner cube 131 to be mounted. The size of the gap S20 is set to be able to absorb the corner portion 134 of the corner cube 131 when it is pulled outward of the ring array 137 (see Fig. 9 The shaking of the corner portion 132A of the imaginary line).

[0083] <Cylinder structure>

[0084] The barrel 142 fixes a pair of main bodies 110 and strengthens the frame 141. The barrel 142 has a convergence portion 142B between the two ends in the axial direction. In the present embodiment, the convergence portion 142B is in the shape of an hourglass formed by connecting the axial sides of a truncated cone and a cylinder. A threaded hole 142A is provided at one end side of the barrel of the barrel 142 in the axial direction. The threaded hole 142A corresponds to the lower hole A118A of the countersunk hole A118 in the main body A110 on one end side in the embedded state. Similarly, a threaded hole 142A is provided at the other end side of the barrel of the barrel 142 in the axial direction. The threaded hole 142A corresponds to the lower hole B118A of the countersunk hole B118 in the main body B110 on the other end side in the embedded state. When screw hole 142A is connected to lower holes A118A and B118A in a pair of body parts 110, non-adjacent side 136A of corner cube 131 mounted in recess 141A is engaged with engaging protrusion 220. Screw hole 142A is set to have a depth greater than shaft 81A of screw 81.

[0085] <Combination of hooking protrusion and engaging portion>

[0086] The hooking protrusion 220 and the engaging portion 210 are provided at the facing portion B111 of the holding mechanism 150. The hooking protrusion 220 and the engaging portion 210 will be described below.

[0087] <Structure of the hook protrusion>

[0088] like Figure 2 As shown, two hooking protrusions 220 are provided on each of the four inwardly curved sides of the facing portion A111 and the facing portion B111. The hooking protrusions 220 hook the non-adjacent sides 136A of the corner cube prism 131 from the outside of the ring array 137. In this way, the hooking protrusions 220 suppress the positional deviation of the corner cube prism 131.

[0089] like Figure 8 As shown, each hooking protrusion 220 is configured so that the hooking piece 221 is inserted into the insertion hole (not shown) of the facing portion A111 or the insertion hole B111F of the facing portion B111. The insertion structure of the hooking piece 221 inserted into the insertion hole of the facing portion A111 is the same as the insertion structure of the hooking piece 221 inserted into the insertion hole B111F. Therefore, the following will describe the insertion structure of the hooking piece 221 inserted into the insertion hole B111F as a representative description of the insertion structure of the hooking piece 221 inserted into the insertion hole of the facing portion A111 or the insertion hole B111F.

[0090] The hook piece 221 has two widened claws 221B on the side inserted into the insertion hole B111F, and the claws 221B are engaged with the side surface of the insertion hole B111F by a force to open them. Thus, the hook piece 221 is fixed in a state of being inserted into the insertion hole B111F.

[0091] like Fig. 9 As shown, the hook protrusion 220 is inserted into the insertion hole B111F (see Figure 8 ) state, with claw 221B (refer to Figure 8 ) protrusion 221A on the opposite side protrudes from the facing portion B111. The protrusion 221A hooks each non-adjacent edge 136A. Among the two hooking protrusions 220 provided on each edge of the facing portion B111, two protrusions 221A are arranged along the non-adjacent edge 136A of the corner cube 131 sandwiched by the pair of main body portions 110 in the clamped state.

[0092] <Structure of the engagement part>

[0093] like Figure 8 As shown, the engaging portion 210 is installed at the four rounded corners of the four-pointed star pattern in the facing portion A111 and the facing portion B111 (refer to Figure 4 ). The engaging portion 210 is in a state of being locked from the outside of the ring array 137 (refer to Fig. 9 ) is engaged with each corner portion 134 of each corner cube prism 131. Thus, the engaging portion 210 suppresses positional deviation of the corner cube prism 131. The engaging portion 210 is attached to the engaging hole B111A via a flat head screw 201A.

[0094] Fig. 9As shown, the engaging portion 210 has a hollow cylinder 211A that is fitted with the counterbore B111C of the engaging hole B111A to form a "clearance fit" and a bottom surface extending from the end portion in the length direction thereof. Fig. 9 The hollow cylinder 211A has a contact portion 211F protruding from one end side. The hollow cylinder 211A has an outer diameter substantially the same as that of the countersink B111C. A countersink 211B is provided on the hollow cylinder 211A so as to be concentric with the countersink B111C when a "clearance fit" is formed with respect to the countersink B111C. The flat head countersink 211C of the countersink 211B is of a size that allows a "clearance fit" to be formed with respect to the head 201B of the flat head screw 201A. In addition, the lower hole 211D of the countersink 211B is designed to have a length shorter than the length of the shaft 201C of the flat head screw 201A. The contact portion 211F is a supporting portion that faces the side of the corner portion 134 of the corner pyramid 131 and is in surface contact with the countersink B111C when the hollow cylinder 211A has a "clearance fit" with respect to the countersink B111C. The contact portion 211F has one side ( Fig. 9 A flat inclined surface 211G extending outwardly (to the left) and a flat cut surface 211H having an elliptical cross-section cut inwardly in the diameter direction of the hollow cylinder 211A.

[0095] like Fig. 9 As shown, the engaging portion 210 switches between the above-mentioned engaging state and the retreat state described later by attaching and detaching the flat head screw 201A. In the retreat state, the engaging portion 210 and the flat head screw 201A are separated from the main body 110. Thus, the engaging portion 210 and the flat head screw 201A retreat in a manner that does not contact the corner portion 134 of the corner cube prism 131 in which the corner portion 132A is installed in the recess 141A.

[0096] like Figure 3 As shown, the engaging portion 210 has a portion extending from the facing portion B111 toward the facing portion A111 ( Figure 3 The contact portion 211F protrudes from the facing portion B111 to a substantially same extent as the protrusion 221A of the hanging piece 221 protrudes from the facing portion B111.

[0097] <Through hole structure>

[0098] like Figure 5As shown, the through hole 103 is composed of a through hole A113 on one end side, a through hole B113 on the other end side, and a shaft through hole 143. The main body portion A110 on one end side has a through hole A113 on one end side that is penetrated at a position corresponding to the central axis C10 of the main body portion 110. The main body portion B110 on the other end side has a through hole B113 on the other end side that is penetrated at a position corresponding to the central axis C10 of the main body portion 110. In addition, the barrel 142 of the shaft portion 140 has a shaft through hole 143 that is penetrated at a position corresponding to the central axis C10 of the main body portion 110. The through hole A113 on one end side, the through hole B113 on the other end side, and the shaft through hole 143 are concentric and form a cylindrical shape with the same diameter. The rod-shaped member 60 (refer to Figure 1 ) can be slidably inserted through the one end side through hole A113, the other end side through hole B113 and the shaft portion through hole 143. According to such a structure, the prism assembly 130 can be slid along the direction in which the rod-shaped member 60 extends.

[0099] The through hole A113 at one end is connected to the rod-shaped member 60 (see Figure 1 ) is a circular hole having an outer diameter substantially the same as that of the rod-shaped member 60, and is provided to vertically penetrate the bottom surface at the center of the bottom of the embedding hole A117. The other end side through hole B113 is a circular hole having an outer diameter substantially the same as that of the rod-shaped member 60, and is provided to vertically penetrate the bottom surface at the center of the bottom of the embedding hole B117.

[0100] The shaft through hole 143 is connected to the rod-shaped member 60 (see Figure 1 ) is provided so as to penetrate in the axial direction at the center of the end surface of the cylinder portion 142 in the axial direction.

[0101] <Attached structure>

[0102] like Figure 8 As shown, the retroreflective device 100 includes an eccentric positioning pin 70, a support portion 240, and a level detector 320. These will be described below.

[0103] <Structure of eccentric positioning pin>

[0104] like Figure 7 As shown, the eccentric positioning pin 70 is a member that is fitted onto the outer peripheral surface of the rod-shaped member 60 and has an extension portion 71, a pair of gripping portions 72, and an inclined surface 73A on one end side (see Figure 5 ), the other end side inclined surface 73B (refer to Figure 5 ) and a locking portion 74. The eccentric positioning pin 70 is equivalent to the "externally embedded member" in the present disclosure. In addition, in the description of this embodiment, the state in which the eccentric positioning pin 70 is externally embedded relative to the outer peripheral surface of the rod-shaped member 60 is also referred to as the "externally embedded state". In this embodiment, the eccentric positioning pin 70 is formed with a portion in the axial direction ( Figure 7The slit S30 is a cylindrical shape extending in the direction perpendicular to the paper surface (in the figure). The slit S30 is a space clamped by the respective ends of a pair of holding parts 72 in the circumferential direction of the cylinder.

[0105] <Structure of the extension part>

[0106] like Figure 7 As shown, the extension portion 71 is in the externally fitted state toward the rod-shaped member 60 (see Figure 1 In the present embodiment, the extension portion 71 is a portion in which a portion of the cylinder of the eccentric positioning pin 70 on the side opposite to the slit S30 is partially thickened.

[0107] <Grip Structure>

[0108] The gripping portion 72 is a portion constituting the cylindrical side surface of the eccentric positioning pin 70. The gripping portion 72 extends from both ends of the extending portion 71 so as to cover the rod-shaped member 60 in the circumferential direction.

[0109] <Structure of the inclined surface on one end and the inclined surface on the other end>

[0110] like Figure 5 As shown, the one-end side inclined surface 73A is an inclined surface provided on one end side of the holding portion 72, and in the externally fitted state, is inclined inwardly in the radial direction of the rod-shaped member 60. The one-end side inclined surface 73A is a surface facing a portion of the guide surface 233 of the inner cylinder portion 230. If the one-end side inclined surface 73A slides on the guide surface 233, the holding portion 72 (see Figure 7 ) follows the sliding and pressing rod-shaped member 60. Similarly, the other end side inclined surface 73B is an inclined surface provided on the other end side of the holding portion 72, and is inclined radially inward of the rod-shaped member 60 in the externally embedded state. The other end side inclined surface 73B is a surface facing a portion of the guide surface 243 of the support portion 240. If the other end side inclined surface 73B slides on the guide surface 243 of the support portion 240, the holding portion 72 follows the sliding and pressing rod-shaped member 60. In the present embodiment, the one end side inclined surface 73A is a structure in which the outer edge of the end on the other end side main body portion B110 side in the tube of the eccentric positioning pin 70 is C-chamfered. Similarly, the other end side inclined surface 73B is a structure in which the outer edge of the end on the side opposite to the one end side inclined surface 73A in the tube of the eccentric positioning pin 70 is C-chamfered.

[0111] <Structure of the locking part>

[0112] The locking portion 74 is formed in the state of being fitted externally and extending toward the protruding portion 71 (see Figure 7). When the inclined surface 73A on the one end side faces a part of the guide surface 233 of the inner cylinder portion 230, the locking portion 74 extends in a manner of engaging with the locking groove 234. The locking portion 74 is locked with the locking groove 234 of the other end side main body portion B110 to prevent the rotation of the other end side main body portion B110. In the present embodiment, the locking portion 74 is a portion formed by extending the cylinder wall on the side opposite to the slit S30 in the cylinder of the eccentric positioning pin 70 toward the other end side main body portion B110. Specifically, the locking portion 74 is in the shape of a rectangular parallelepiped.

[0113] <Structure of the support section>

[0114] The support portion 240 is a tube (a sleeve with a set screw in this embodiment) that externally embeds the eccentric positioning pin 70 in an externally embedded state from the radially outer side of the rod-shaped member 60. The support portion 240 is equivalent to the "outer tube" in the present disclosure. The support portion 240 has an internal thread portion 241, a guide surface 243, a sliding hole 244, and a storage space S10. The internal thread portion 241 is a thread surface in a screwed state with the external thread portion 231 of the inner tube portion 230. The guide surface 243 is an inclined surface that extends radially outwardly of the rod-shaped member 60. The guide surface 243 is a surface on which the other end side inclined surface 73B of the eccentric positioning pin 70 slides when the eccentric positioning pin 70 is externally embedded relative to the rod-shaped member 60. The sliding hole 244 is a hole that is "clearance-fitted" with the rod-shaped member 60. The sliding hole 244 is provided on the side opposite to the internal thread portion 241 in the tube of the support portion 240. The accommodation space S10 is located between the internal thread portion 241 and the sliding hole 244 in the cylinder of the support portion 240. The accommodation space S10 accommodates the eccentric positioning pin 70 by a "clearance fit" in a screwed state.

[0115] <Structure of the level detector>

[0116] The level detector 320 has a mounting plate 320A, three mounting holes 320B, an insertion hole 320C, and a bubble tube 320D. The mounting plate 320A is a rounded square plate, and its area is designed to be smaller than the area of ​​the non-opposing portion A112. The mounting hole 320B is a hole provided in the mounting plate 320A. By inserting the screw 81 into the mounting hole 320B, the mounting plate 320A can be installed in the non-opposing portion A112. The insertion hole 320C is a hole that forms a "clearance fit" with the rod-shaped member 60, and is provided on the mounting plate 320A. The bubble tube 320D is a structure in which liquid and bubbles are sealed in a transparent disk with scale lines (not shown), and is provided in a state of being embedded in a hole opened on the mounting plate 320A.

[0117] <Structure of rod-shaped member>

[0118] like Figure 1As shown, the rod-shaped member 60 is a column having the prism assembly 130 mounted on its periphery and supporting the prism assembly 130. In this embodiment, the rod-shaped member 60 is Figure 1 The rod-shaped member 60 is divided into a red and white cylinder (in the vertical direction), and a cap (not shown) is installed at the lower end to contact the ground GR at the measurement location. The rod-shaped member 60 extends in the direction of contact with the corner cube prism 131 (refer to Figure 2 ) constitutes a ring array 137 (refer to Figure 2 ) are arranged so that the central axis C10 of the circle overlaps.

[0119] <Assembly Procedure of Retroreflective Device According to First Embodiment>

[0120] The assembly procedure of the retroreflective device 100 of the first embodiment will be described. When assembling the retroreflective device 100, an operator (not shown) first mounts the engaging portion 210 on each of the one-side body A110 and the other-side body B110.

[0121] Next, the operator performs an integration operation of sandwiching the shaft portion 140 from both sides in the axial direction through the one-end side body portion A110 and the other-end side body portion B110 and integrating them. In this integration operation, the operator puts the one-end side body portion A110 and the shaft portion 140 in the above-mentioned embedded state and screws them together with the screw 81. In addition, the operator puts the other-end side body portion B110 and the shaft portion 140 in the above-mentioned embedded state and screws them together with the screw 81.

[0122] Next, the operator performs the installation operation of installing the corner cube 131 in the recess 141A in the shaft portion 140. This operation is hereinafter also referred to as the "first installation operation". In the first installation operation, the operator engages one side (the side to be regarded as the non-adjacent side 136A) of the equilateral triangle light-transmitting surface 133 with the inner side of the engaging protrusion 220 to achieve an engaged state, while the corner portion 132A of the corner cube 131 is facing the recess 141A side. Next, the operator pushes the corner portion (the corner portion to be regarded as the corner portion 134) that becomes the vertex angle when the above-mentioned one side is used as the base of the light-transmitting surface 133 of the corner cube 131 in the above-mentioned engaged state toward the shaft portion 140. Thus, the operator engages each of the reflective surfaces 132 of the corner cube 131 in the above-mentioned engaged state with the recess 141A. Then, the operator engages the engaging portion 210 with the corner portion pushed toward the shaft portion 140 , and screws the engaging portion 210 to the facing portion B111 with the flat head screw 201A.

[0123] Next, the operator selects one recess 141A in the shaft portion 140 that is adjacent to the recess 141A in which the corner cube prism 131 has been installed, from among the recesses 141A in which the corner cube prism 131 has not been installed. Then, the operator performs an operation of installing one corner cube prism 131 in the selected recess 141A. This operation is also referred to as the "second installation operation" below. The operator repeats the second installation operation until the number of recesses 141A in which the corner cube prism 131 has not been installed reaches 2 (i.e., it is repeated only 5 times). The installation steps of the corner cube prism 131 in the second installation operation are the same as the installation steps of the corner cube prism 131 in the first installation operation, and therefore a detailed description thereof is omitted.

[0124] Next, the operator performs an installation operation of installing the corner cube prisms 131 one by one in each of the two recesses 141A in the shaft portion 140 where the corner cube prisms 131 have not been installed. This operation is also referred to as the "third installation operation" below. Except for the fact that the two corner cube prisms 131 are installed at the same time, the installation steps of the corner cube prisms 131 in the third installation operation are the same as the installation steps of the corner cube prisms 131 in the first installation operation, and therefore a detailed description thereof is omitted.

[0125] Next, the operator performs an attachment operation of attaching the level detector 320 to the non-facing portion A112 of the one end side body portion A110. In this attachment operation, the operator screws the mounting plate 320A of the level detector 320 to the non-facing portion A112 with screws 81.

[0126] Next, the operator performs the installation operation of installing the eccentric positioning pin 70 and the support portion 240 to the other end side main body portion B110. Through this installation operation, the assembly of the retroreflective device 100 is completed. During the installation operation, the operator causes the locking portion 74 of the eccentric positioning pin 70 to lock with the locking groove 234 of the other end side main body portion B110. In addition, the operator causes the eccentric positioning pin 70 to be accommodated in the accommodation space S10 of the support portion 240. Then, the operator causes the internal thread portion 241 of the support portion 240 to be screwed with the external thread portion 231 of the other end side main body portion B110.

[0127] <Steps for removing the corner cube>

[0128] use Fig. 9 A procedure for removing the corner cube 131 in the retroreflective device 100 according to the first embodiment will be described.

[0129] First, when removing the corner cube prism 131 in the holding state, the operator removes the engaging portion 210 in the engaging state with the corner portion 134 of the corner cube prism 131 from the main body 110 to put it in the retreat state. At this time, when observed from the axial direction of the central axis C10, the rounded corners of the plates imitating the appearance of the "four-pointed star pattern shape" of the facing parts of the pair of main bodies 110 to which the engaging portion 210 is attached are exposed to the outside and are not covered or blocked by the facing part of the other party.

[0130] Next, when removing the corner cube 131 in the retracted state, the operator moves the corner portion 134 of the corner cube 131 toward the ring array 137 (see FIG. 1 ) while maintaining the hooked state. Figure 2 ) and pull it out from the outside of the circle.

[0131] Furthermore, when removing the corner cube prism 131 in the retracted state, the operator may also release the countersunk holes A118 and B118 (see Figure 8 ) screw 81.

[0132] <Installation procedure of retroreflective device>

[0133] The installation procedure of the retroreflective device 100 according to the first embodiment will be described.

[0134] First, a measurer (not shown) attaches the retroreflection device 100 to the rod-shaped member 60 and places the rod-shaped member 60 against the ground GR (refer to FIG. Figure 1 ) abut and secure.

[0135] Next, the measurer adjusts the inclination so that the rod-shaped member 60 faces the vertical direction while checking the horizontal detector 320. As a result, the central axis C10 of the prism assembly 130 faces the vertical direction.

[0136] Then, if Figure 5 as well as Figure 6 As shown, the measurer slides the prism assembly 130 along the extending direction of the rod-shaped member 60 to adjust the height of the prism assembly 130. At this time, the measurer temporarily loosens the screwing state between the support portion 240 and the inner cylinder portion 230 to slide the prism assembly 130.

[0137] Then, if Figure 5As shown, the measurer makes the support part 240 and the inner cylinder part 230 of the other end side main body part B110 be in a screwed state. In this way, the inclined surface 73A on one end side of the eccentric positioning pin 70 slides along the guide surface 233, and the inclined surface 73B on the other end side slides along the guide surface 243. The eccentric positioning pin 70 is externally embedded through the support part 240, the extension part 71 is embedded from one side, and the holding part 72 strongly presses the rod-shaped member 60. In addition, the locking groove 234 of the inner cylinder part 230 is locked by the locking part 74 of the eccentric positioning pin 70, thereby suppressing the position deviation or rotation of the prism assembly 130 relative to the rod-shaped member 60.

[0138] <Function and Effect>

[0139] According to the above-mentioned retroreflection device 100, the three reflection surfaces 132 are respectively configured as mutually orthogonal planes, so that the incident light incident at the incident position IP of the light-transmitting surface 133 is parallel to the retroreflected light returned at the emission position OP of the light-transmitting surface 133. In addition, in the corner cube 131 of the prism assembly 130, the light-transmitting surface 133 can retroreflect light over the entire circumference of the ring array 137. Moreover, the prism assembly 130 can adjust the deviation between the position of the imaginary reflection surface 132 for retroreflection of the corner cube 131 and the position of the actual central axis C10 in the retroreflection device 100. Therefore, in the retroreflection device 100 that can retroreflect light from the entire circumference, the deviation of the retroreflection device 100 can be eliminated.

[0140] According to the above-mentioned retroreflective device 100, when viewed from one end side of the central axis C10, each rounded corner of the facing portion B111 (see Figure 4 ) is not covered and blocked by the opposite end side main body A110. Therefore, the pair of main bodies 110 can set each corner cube prism 131 so that the light-transmitting surface 133 faces in different directions. Moreover, the operator can easily remove the flat head screw 201A for mounting the engaging portion 210 from each fillet.

[0141] According to the above-mentioned retroreflection device 100, each adjacent edge 136B of each light-transmitting surface 133 of a plurality of corner cube prisms 131 is brought into close contact with each other to form a connected ring array 137. Therefore, light can be retroreflected over the entire circumference of the ring array 137. In the prism assembly, when there is a non-close contact portion (not shown) where the adjacent edges of the light-transmitting surface of the corner cube prism are not in close contact with the adjacent edges of the adjacent light-transmitting surface, the above-mentioned retroreflection of light over the entire circumference will not occur in the non-close contact portion. However, according to the retroreflection device 100 disclosed in the present invention, the non-close contact portion of each corner cube prism 131 can be eliminated. Therefore, the situation where retroreflection of light is not generated over the entire circumference of the ring array 137 can be avoided. As a result, the effective range ER of the light-transmitting surface 133 of the incident light retroreflection can be expanded. Furthermore, when the prism assembly 130 is composed of eight corner cube prisms 131 , the radial dimension of the central axis C10 of the entire retroreflective device can be set smaller than when the prism assembly is composed of an even number of 10 or more corner cube prisms 131 .

[0142] According to the above-mentioned retroreflective device 100, the hooking protrusions 220 provided in the facing portion B111 can hook each non-adjacent side 136A of each corner cube prism 131 in the held state from the outside of the circle of the ring array 137 in the clamped state. That is, the eight protrusions 221A in the clamped state can hook each non-adjacent side 136A of each corner cube prism 131 in the held state from the outside of the circle of the ring array 137.

[0143] According to the above retroreflective device 100, four engaging portions 210 in the clamped state engage corners 134 of corner cubes 131 from outside the circle of annular array 137. That is, engaging portions 210 can engage corners 134 of corner cubes 131 at contact portions 211F.

[0144] According to the above-described retroreflective device 100 , when the corner cube 131 in the prism assembly 130 is damaged, only the damaged corner cube 131 can be removed and an undamaged corner cube 131 can be installed instead.

[0145] According to the above-mentioned retroreflective device 100, when the corner cube 131 in the held state is individually mounted / removed, the corner cube 131 being caught can be prevented from falling off from the holding mechanism 150 by the hooking protrusion 220 provided on one side of the main body 110. In addition, when the corner cube 131 in the retreated state is removed, the corner portion 134 can be pulled outward of the ring array 137 while the hooking protrusion 220 is hooking the corner cube 131, and the corner cube 131 can be removed.

[0146] According to the above-described retroreflective device 100 , when removing the corner cube 131 in the held state, the light-transmitting surface 133 is brought into contact with the surface of the protrusion 221A, so that the corner cube 131 can be lifted up.

[0147] According to the above-mentioned retroreflective device 100, the prism assembly 130 can slide along the extending direction of the rod-shaped member 60 by sliding the rod-shaped member 60 in the one end side through hole A113, the other end side through hole B113 and the shaft through hole 143 of the holding mechanism 150 of the prism assembly 130. That is, the prism assembly 130 can slide along the extending direction of the rod-shaped member 60 by slidably inserting the one end side through hole A113, the other end side through hole B113 and the shaft through hole 143.

[0148] According to the above-described retroreflective device 100 , each corner cube 131 is mounted in the recess 141A of the holding mechanism 150 to form the prism assembly 130 , so that the workability of positioning the corner cube 131 can be improved.

[0149] According to the above-described retroreflective device 100, the presence of the gap S20 where the corner absorbing portion 132A is able to facilitate removal of the corner cube 131 in the retracted state while maintaining the corner cube 131 being hooked.

[0150] According to the above-mentioned retroreflection device 100, the extension portion 71 is fastened by the support portion 240 from one side of the radially outer side of the rod-shaped member 60, thereby the eccentric positioning pin 70 is pressed on the rod-shaped member 60. Therefore, it is difficult to cause the eccentric positioning pin 70 to deviate from or rotate relative to the rod-shaped member 60. In addition, the eccentric positioning pin 70 prevents the other end side body B110 from rotating in the circumferential direction by the locking portion 74 and the other end side body B110. Thus, the prism assembly 130 can be arranged at a predetermined position in the circumferential direction of the rod-shaped member 60.

[0151] According to the retroreflective device 100 , the extension portion 71 is fastened by the support portion 240 from the one side and is close to the axis of the rod-shaped member 60 .

[0152] According to the above-mentioned retroreflective device 100, the eccentric positioning pin 70 is sandwiched between the inner cylinder 230 and the support part 240 in a screwed state. Therefore, the one end side inclined surface 73A and the other end side inclined surface 73B respectively move radially inward of the rod-shaped member 60, and the holding part 72 strongly presses the rod-shaped member 60. Therefore, when the support part 240 is externally embedded in the eccentric positioning pin 70, the eccentric positioning pin 70 can be pressed on the rod-shaped member 60 by tightening the extension part 71 from one side. That is, the eccentric positioning pin 70 in the externally embedded state is sandwiched between the inner cylinder 230 and the support part 240, and the one end side inclined surface 73A and the other end side inclined surface 73B respectively move radially inward of the rod-shaped member 60. As a result, the holding part 72 can press the rod-shaped member 60 following the movement of the one end side inclined surface 73A and the other end side inclined surface 73B.

[0153] According to the above-mentioned retroreflective device 100, in the eccentric positioning pin 70 in the externally-fitted state, when the extension portion 71 is not fastened by the support portion 240, the grip portion 72 presses the rod-shaped member 60. In addition, in the eccentric positioning pin 70 in the externally-fitted state, the extension portion 71 is fastened by the support portion 240 from the above-mentioned one side, and the grip portion 72 presses the rod-shaped member 60 with a force greater than the force pressing the rod-shaped member 60. Therefore, the force pressing the rod-shaped member 60 of the eccentric positioning pin 70 in the externally-fitted state becomes stronger due to the fastening of the support portion 240. Therefore, it is difficult for the position deviation or rotation of the eccentric positioning pin 70 relative to the rod-shaped member 60 to occur.

[0154] According to the retroreflection device 100, the level detector 320 can detect the inclination of the prism assembly 130 relative to the horizontal direction. This improves the leveling accuracy of the prism assembly 130 in the direction in which the sliding rod-shaped member 60 extends, and the measurement accuracy using the retroreflection device 100 can be improved.

[0155] <Second embodiment>

[0156] use Figure 1 , Fig.10 as well as Fig.11 The structure of the retroreflective device 600 of the second embodiment of the present disclosure is described. The retroreflective device 600 of the second embodiment is a modified embodiment of the retroreflective device 100 of the first embodiment. Therefore, with respect to the structures common to the various structures of the retroreflective device 100 of the first embodiment, the numerals of the reference numerals of the various structures of the retroreflective device 100 of the first embodiment are marked with the reference numerals after "500" and made to correspond, and the detailed description thereof is omitted.

[0157] <Structure of Retroreflective Device According to Second Embodiment>

[0158] like Figure 1As shown, the retroreflection device 600 of the second embodiment of the present disclosure is installed and fixed at a measurement location to be measured, so as to be able to measure the distance from the measurement location to the total station 900. In addition, a target 920 (see FIG. 1 ) of a positioning system (not shown) is installed in the retroreflection device 600. Fig.10 ). The target 920 is attached to the holding mechanism 650 of the prism assembly 630 in the retroreflection device 600. The target 920 and the holding mechanism 650 are described below.

[0159] <Structure of the maintenance mechanism>

[0160] like Fig.10 As shown, the holding mechanism 650 holds each corner cube prism 631 forming a ring (not shown) with its light-transmitting surface 633 facing the outside of the ring. The holding mechanism 650 includes a pair of main body parts 610, a shaft part 640 (see Fig.11 ), the hooking protrusion 720, the engaging portion 710, the through hole 603 (refer to Fig.11 )、One end side base A820、pillar body 565 (refer to Fig.11 ) and the other end side base B820. A pair of main body parts 610 are axially extending from the central axis C60 (refer to Fig.11 ) are clamped by clamping eight corner cube prisms 631 forming a ring array on both sides. The corner cube prisms 631 are aligned with the specified position through the shaft portion 640. The hooking protrusions 720 hook the non-adjacent sides 636A of the corner cube prisms 631 from the outside of the ring array. The engaging portion 710 engages the corner 634 of the corner cube prism 631 hooked by the hooking protrusions 720 from the outside of the ring array. The support body 565 is accommodated in the through hole 603 in a manner that forms a chimeric fit. The support body 565 supports the external force applied to the pair of main body portions 610. The base A820 on one end side supports the target 920 of the positioning system (not shown), and the weight of the target 920 is applied to the support body 565. The support body 565 applies the external force applied to the base A820 on one end side to the base B820 on the other end side. The other end side base B820 applies the external force applied to the support body 565 to the rod-shaped member 560. Hereinafter, the pair of main body parts 610, the through hole 603, the one end side base A820, the support body 565, and the other end side base B820 will be described.

[0161] <Main body structure>

[0162] A pair of main body parts 610 includes a main body part A610 on one end side and a main body part B610 on the other end side as a pair. Among them, the main body part A610 on one end side has a facing portion A611 as a portion facing the main body part B610 on the other end side. The main body part B610 on the other end side has a facing portion B611 as a portion facing the main body part A610 on one end side. In the present embodiment, the facing portion A611 and the facing portion B611 both have a shape imitating the appearance of a "four-pointed star pattern shape". The sides of the facing portions A611 and B611 are arranged in a manner along the arrangement of the non-adjacent sides 636A of the corner cube prisms 631 forming the prism assembly 630.

[0163] In the pair of main body parts 610, the one-end side main body part A610 is an embodiment obtained by deforming the one-end side main body part A110 of the first embodiment. Therefore, with respect to the structures common to the structures of the one-end side main body part A610 of the first embodiment, the numerals of the reference numerals marked with the structures of the one-end side main body part A110 of the first embodiment are marked with the reference numerals after "500" and made to correspond, and the detailed description thereof is omitted.

[0164] In the facing portion B611, two insertion holes (not shown) are respectively provided corresponding to each of the four sides that are bent inward. In the present embodiment, the insertion hole is a long hole of a size that the card hanging piece 721 can be inserted, and is formed so that the protrusion 721A protrudes from the facing portion B611 by inserting the card hanging piece 721. The insertion hole is positioned along the non-adjacent side 636A of the corner cube prism 631 clamped by a pair of main body parts 610 in the above-mentioned clamping state. The orientation of the long hole of the insertion hole is arranged so that the length direction of the long hole is parallel to the non-adjacent side 636A in the clamping state. The two insertion holes are arranged to be separated from each other and away from the corner 634.

[0165] like Fig.11 As shown, each of the four fillets of the facing portion B611 has a locking hole B611A. In the present embodiment, the locking hole B611A is a countersunk hole having a threaded hole B611B and a countersunk hole B611C. The countersunk hole B611C is formed by forming the opening edge of the threaded hole B611B into a cylindrical groove surface. The countersunk hole B611C is a shape that enables the locking portion 710 to be installed and locked with a "clearance fit". The threaded hole B611B is a hole opened perpendicularly to the bottom surface in the center of the bottom surface of the countersunk hole B611C. The threaded hole B611B is designed to be deeper than the protruding length of the shaft of the flat head screw 701A from the locking portion 710 when the locking portion 710 is installed in the locking hole B611A. The engagement hole B611A is arranged so as to contact the corner portion 634 of the corner cube 631 sandwiched between the pair of main body portions 610 in the above-mentioned sandwiched state.

[0166] The facing portion B611 has an embedding hole B617 that is fitted with a "clearance fit" with the axial end of the shaft portion 640. The lower hole (not shown) of the countersunk hole (not shown) passes through the bottom of the embedding hole B617. The countersunk hole is a threaded hole used to screw the shaft portion 640 with the screw 581 when the shaft portion 640 is embedded in the embedding hole B617 in a specified arrangement direction. The countersunk hole of the countersunk hole completely accommodates the head 581B of the screw 581, and the depth of the lower hole is designed to be shorter than the shaft 581A of the screw 581. In addition, the depth of the threaded hole 642A of the shaft portion 640 is designed to be longer than the shaft 581A of the screw 581. That is, at the other end side main body portion B610, the other end side base B820 is arranged in a manner that does not interfere with the head 581B of the screw 581.

[0167] The structure of the countersunk hole A618 of the one-end side main body portion A610 is also the same as the above-mentioned countersunk hole, and the one-end side base A820 is configured so as not to interfere with the head 581B of the screw 581.

[0168] The other end side body part B610 has a non-facing part B612 on the side opposite to the facing part B611. The non-facing part B612 has a flat surface that contacts with the other end side base B820.

[0169] <Through hole structure>

[0170] The through hole 603 is composed of a through hole A613 on one end side, a through hole B613 on the other end side, and a shaft through hole 643. The main body portion A610 on one end side has a through hole A613 on one end side that is penetrated at a position and direction corresponding to the central axis C60 in a pair of main bodies 610 in a clamped state. The main body portion B610 on the other end side has a through hole B613 on the other end side that is penetrated at a position and direction corresponding to the central axis C60 in a pair of main bodies 610 in a clamped state. The barrel 642 of the shaft portion 640 has a shaft through hole 643 that is penetrated at a position and direction corresponding to the central axis C60 in a pair of main bodies 610 in a clamped state. The through hole A613 on one end side, the through hole B613 on the other end side, and the shaft through hole 643 are concentric and have cylindrical shapes with the same diameter. The support body 565 (refer to Fig.11 ) is inserted through the through hole 603 with a gap. The support column 565 is positioned along the central axis C60 of the ring array (not shown) of the corner cube prism 631.

[0171] The through hole A613 on one end is a circular hole having substantially the same outer diameter as the support body 565, and is provided to vertically penetrate the bottom surface at the center of the bottom of the embedding hole A617. Similarly, the through hole B613 on the other end is a circular hole having substantially the same outer diameter as the support body 565, and is provided to vertically penetrate the bottom surface at the center of the bottom of the embedding hole B617.

[0172] The shaft through hole 643 is a circular hole having substantially the same outer diameter as the support body 565 , and is provided so as to penetrate in the axial direction at the center of the end surface of the cylinder portion 642 in the axial direction.

[0173] <Structure of one end base>

[0174] The one-end side base A820 has an one-end side base A820A, an insertion hole A820B, a counterbore A820C and a threaded joint A820D.

[0175] The one end side base A820A has a cylindrical shape, and its outer diameter is smaller than the distance between two opposing sides of the four inwardly curved sides of the facing portion A611. In the present embodiment, the cylinder is a metal tube painted black and has strength capable of supporting the target 920.

[0176] The insertion hole A820B is a hole that can be fitted with the support body 565 to form a "clearance fit" and is opened at a position and direction corresponding to the central axis C70 of the tube of the one-end side base A820A. Therefore, in a state where the support body 565 is inserted into the insertion hole A820B (hereinafter also referred to as the "one-end side insertion state"), the direction in which the support body 565 extends coincides with the central axis C60. That is, the insertion hole A820B is opened at a position and direction corresponding to the central axis C60.

[0177] The counterbore A820C is a hole formed on the one-end side base A820A in a manner concentric with the insertion hole A820B. By connecting the counterbore A820C with the insertion hole A820B, the support body 565 can be screwed and fastened by the screw 592 when the support body 565 is in the one-end side inserted state. In this embodiment, the counterbore portion of the counterbore A820C and the head of the screw 592 form a "clearance fit" fit, and the lower hole portion and the shaft portion of the screw 592 form a "clearance fit" fit.

[0178] In the one-end side base A820A, a threaded joint A820D is extended from the opening edge of the countersunk portion in the countersunk hole A820C and protrudes to the side opposite to the insertion hole A820B. The inner peripheral surface of the threaded joint A820D is flush with the inner side surface of the countersunk portion of the countersunk hole A820C. An external thread A820E that is screwed into a sleeve (described later, not shown) of the target 920 is provided on the outer side surface of the threaded joint A820D. In addition, the threaded joint mentioned here is equivalent to the "mounting portion" in the present disclosure.

[0179] <Structure of the pillar>

[0180] The support body 565 is a round rod that supports the external force applied to the holding mechanism 650 when it is in the state of insertion on one end side and the state of insertion on the other end side (described later). The support body 565 is a round rod that passes through the through hole A613 on one end side, the through hole B613 on the other end side, and the through hole 643 on the shaft portion in the holding mechanism 650 in the clamping state, and threaded holes 565A that can be screwed with the screw 592 are provided at both ends. The support body 565 is designed so that when it is in the state of insertion on one end side and the state of insertion on the other end side, in the direction in which it extends, the support interval L31 is larger than the reinforced interval L32. The support interval L31 is the interval between the hole bottom A820F of the insertion hole A820B in the state of insertion on one end side and the seat surface 592F of the head 592B of the screw 592 in the base B820 on the other end side. The reinforced interval L32 is the interval between the hole bottom A820F of the insertion hole A820B in the inserted state on the one end side and the bottom B820G of the countersunk hole B820C in the base B820 on the other end side.

[0181] <Structure of the other end base>

[0182] The other end side base B820 has the other end side base B820A, the insertion hole B820B, the counterbore B820C and the mounting hole B820E.

[0183] The other end side base B820A is formed into a cylinder, and its outer diameter is smaller than the interval between two opposing sides among the four sides of the opposing portion B611 that are curved inwardly.

[0184] The insertion hole B820B is a hole that can be fitted with the support body 565 to form a "clearance fit" and is opened at a position and direction corresponding to the central axis C80 of the tube of the other end side base B820A. Therefore, in a state where the support body 565 is inserted into the insertion hole B820B (hereinafter also referred to as the "other end side insertion state"), the direction in which the support body 565 extends coincides with the central axis C60. That is, the insertion hole B820B is opened at a position and direction corresponding to the central axis C60.

[0185] The countersunk hole B820C is a hole formed in the other end side base B820A in a manner concentric with the insertion hole B820B. The countersunk hole B820C is connected to the insertion hole B820B, and when the support body 565 is in the other end side insertion state, the support body 565 can be screwed by the screw 592. In the present embodiment, the countersunk hole B820C is formed so that its countersunk portion and the head of the screw 592 form a "clearance fit" fit, and similarly, the lower hole portion and the shaft of the screw 592 form a "clearance fit" fit. In addition, the countersunk hole B820C in the present embodiment is formed by forming a countersunk hole on the inner periphery of the gasket B820D integrally formed with the other end side base B820A.

[0186] The mounting hole B820E is provided at the end portion of the other end side base B820A on the opposite side to the insertion hole B820B, and is engaged with the rod-shaped member 560 by a “clearance fit”.

[0187] <Structure of the target>

[0188] Target 920 has a communication module (not shown) corresponding to the service of the global navigation satellite system (hereinafter also referred to as "GNSS"). Among them, the infrastructure (not shown) for providing the GNSS service has a satellite segment including at least 4 artificial satellites and a control segment for controlling these artificial satellites. In addition, as target 920, a conventionally known target can be used. The shape of the target can be appropriately selected. Target 920 of this embodiment has a sleeve (not shown) that can be screwed with the external thread A820E.

[0189] <Assembly Procedure of Retroreflective Device of Second Embodiment>

[0190] The assembly procedure of the retroreflective device 600 of the second embodiment is described below. When assembling the retroreflective device 600, an operator (not shown) first performs an installation operation of installing the engaging portion 710 on each of the one-side body portion A610 and the other-side body portion B610.

[0191] Next, the operator performs an integration operation of sandwiching the shaft portion 640 from both axial sides through the one end side body portion A610 and the other end side body portion B610 and integrating them. The specific steps of the integration operation are the same as the specific steps of the integration operation described in the description of the first embodiment, so the detailed description thereof is omitted.

[0192] Next, the operator performs the installation operation of installing each corner cube prism 631 in the eight recesses 641A of the shaft portion 640. This installation operation is an operation in which the same operations as the "first installation operation", "second installation operation" and "third installation operation" described in the description of the first embodiment are performed in this order. Therefore, the detailed description of the specific steps of the above operation is omitted.

[0193] Next, the operator performs a screw tightening operation to screw the one-end side base A820 and the other-end side base B820. Through this screw tightening operation, the assembly of the retroreflective device 600 is completed. In the screw tightening operation, the operator inserts the support body 565 through the shaft through hole 643, and then screws the one-end side base A820 and the other-end side base B820 to the threaded holes 565A provided at both ends of the support body 565.

[0194] <Installation procedure of retroreflective device>

[0195] The installation procedure of the retroreflective device 600 of the second embodiment described above will be described. When installing the retroreflective device 600 , a measurer (not shown) first installs the rod-shaped member 560 in the installation hole B820E of the retroreflective device 600 .

[0196] Next, the surveyor brings the rod-shaped member 560 into contact with the ground GR at the measurement location and fixes it.

[0197] Next, the measurer adjusts the rod-shaped member 560 so as to be inclined in the vertical direction. When the target 920 is attached to the threaded joint A820D of the retroreflective device 600 , the measurer can check the information from the communication module (not shown) of the target 920 .

[0198] <Function and Effect>

[0199] According to the above-mentioned retroreflective device 600, when the counterbore B820C of the other end side base B820 is engaged with the head 592B of the screw 592, since the one end side body A610 moves along with the other end side, the force applied to the one end side base A820 is difficult to be applied to the non-opposing portion A612. Thus, the support body 565 can reinforce the prism assembly 630 in the direction along the central axis C60 of the ring array (not shown) of the corner cube prism 631.

[0200] According to the above-described retroreflective device 600 , the support pillars 565 do not block light, and the prism assembly 630 can be reinforced in a direction along the central axis C60 of the ring array (not shown) of the corner cube prisms 631 .

[0201] According to the retroreflector 600, the position information (not shown) of the retroreflector 600 can be confirmed from the positioning information obtained by the target 920. Thus, the position information (not shown) of the position of the measurement point obtained by the target 920 and the distance information from the position where the total station 900 is placed to the retroreflector 600 can be compared.

[0202] According to the above-described retroreflective device 600 , by attaching a target 920 of a positioning system (not shown) to the support column 565 of the holding mechanism 650 , the position of the retroreflective device 600 can be measured by the total station 900 and the positioning system.

[0203] The present disclosure can eliminate the deviation of a retroreflective device that retroreflects light from the entire circumference in the circumferential direction.

[0204] <Other embodiments>

[0205] Above, the above-mentioned embodiments illustrate the methods for implementing the present invention. However, it is obvious to those skilled in the art that various substitutions, modifications, and changes can be made without departing from the purpose of the present invention. That is, the methods for implementing the purpose of the present invention may include all substitutions, modifications, and changes that do not depart from the spirit and purpose of the scope of the claims attached to this specification. For example, the following various methods can be implemented as methods for implementing the present invention.

[0206] In the retroreflective device disclosed herein, adjacent sides of each corner cube prism may also be butted and fixed by a detachable hook and loop fastener. In this case, a prism assembly can be formed by a plurality of corner cube prisms without using a holding mechanism.

[0207] In the retroreflective device disclosed herein, the number of the corner cube prisms constituting the prism assembly is not limited to 8. For example, the prism assembly can be formed by 10 corner cube prisms. In this case, when viewed from the horizontal direction, the prism assembly is in the shape of a regular pentagonal anti-prism consisting of equilateral triangles of ten faces and regular pentagons of two faces. Thus, in the prism assembly, the inclination angle of the light-transmitting surface relative to the central axis of the ring array can be set to be smaller.

[0208] In the retroreflective device disclosed herein, the protrusion of the hook piece in the hook protrusion may be a smooth curved surface that makes the surface of the corner cube prism convex toward the corner cube prism side. In this case, when removing the corner cube prism in the hooked state, the corner cube prism can be smoothly removed by rotating the corner cube prism while making the light-transmitting surface contact the curved surface of the protrusion.

[0209] In the retroreflective device of the first embodiment of the present disclosure, an elastic body can be arranged in the storage space of the support portion. The elastic body can accommodate the eccentric positioning pin in the external embedded state in the natural state, and deform radially inward of the rod-shaped member by being sandwiched between the support portion and the inner cylinder portion to become a compressed state. In the support portion, the eccentric positioning pin in the external embedded state can also be externally embedded by the elastic body in the compressed state. In addition, the elastic body can use, for example, a cylindrical rubber.

Claims

1. A retroreflective device, characterized in that: A corner cube prism is provided, wherein the corner cube prism has: 3 reflecting surfaces, forming mutually orthogonal planes, and a light-transmitting surface for transmitting incident light incident toward the reflecting surfaces and transmitting retroreflected light reflected by the reflecting surfaces; The light-transmitting surface is a surface forming an equilateral triangle, having: The non-adjacent edges are edges corresponding to the bottom edge of the light-transmitting surface, and 2 adjacent sides are sides corresponding to the two equal sides excluding the base; An even number of corner cube prisms, which are more than 8, have adjacent sides of their respective light-transmitting surfaces in close contact with each other to form a prism assembly that is connected in a ring. Each of the corner cube prisms is configured so that the light-transmitting surface faces the outside of the ring of the annular array, and under the condition that the incident light in a direction perpendicular to the central axis of the ring of the annular array is incident on the corner cube prism, the corner cube prism is configured in a state in which a first length and a second length are equal to each other. The first length is the optical path length from the incident position of the incident light through the light-transmitting surface to the exit position of the retroreflected light through the light-transmitting surface. The second length is the sum of the shortest distance from the incident position to the central axis observed in a direction perpendicular to the central axis and the shortest distance from the central axis to the exit position observed in a direction perpendicular to the central axis.

2. The retroreflective device according to claim 1, characterized in that: In the prism assembly, the eight corner cube prisms are arranged so that the adjacent sides of the light-transmitting surfaces thereof are in close contact with each other as a whole.

3. The retroreflective device according to claim 1 or 2, characterized in that: The prism assembly includes a holding mechanism that holds the corner cube prism in a state in which the corner cube prism can be individually attached and detached.

4. The retroreflective device according to claim 3, characterized in that: The holding mechanism comprises: A pair of main bodies, sandwiching the corner cube prisms forming the ring array from both axial sides of the central axis; The main body has: a hooking protrusion for hooking the non-adjacent edges of the corner cube prism in the holding state from the outside, and A clamping portion, clamping the corners between the adjacent sides of the corner cube prism with the clamping protrusions clamping the non-adjacent sides from the outer side; By removing the engaging portion, a retracted state is achieved in which the corner cube prism in the held state can be individually attached and detached.

5. The retroreflective device according to claim 4, characterized in that: The holding mechanism has a through hole, and the through hole is penetrated at a position and direction corresponding to the central axis. The through hole allows the rod-shaped member to be slidably inserted therethrough, thereby allowing the prism assembly to slide along a direction in which the rod-shaped member extends.

6. The retroreflective device according to claim 3, characterized in that: The holding mechanism has recesses, the number of which corresponds to the number of the corner cube prisms arranged in the ring array. Each of the recesses holds each of the corner cube prisms by seating a corner portion where the three reflection surfaces of each of the corner cube prisms are concentrated.

7. The retroreflective device according to claim 5, characterized in that: have: an externally embedded member, which is externally embedded relative to the rod-shaped member, and An outer cylinder, externally embedded relative to the externally embedded component; The external embedded component has: The extension portion extends radially outward from the rod-shaped member in a state where the extension portion is externally fitted to the rod-shaped member, and A locking portion is locked relative to any one of the pair of main body portions and prevents the main body portion from rotating in the circumferential direction; When the outer cylinder is externally fitted on the external fitting member, the external fitting member is pressed against the rod-shaped member by tightening the protruding portion from the one side.

8. The retroreflective device according to claim 7, characterized in that: A level detector is mounted on at least one of the pair of main body parts.

9. The retroreflective device according to claim 3, characterized in that: The holding mechanism has an insertion hole, and the insertion hole is opened at a position and direction corresponding to the central axis. A support column body that supports external force applied to the holding mechanism is inserted into the insertion hole.

10. The retroreflective device according to claim 9, characterized in that A mounting portion is provided, the mounting portion being supported by the support column and capable of mounting a target of a positioning system.

Images