Reflector, surveying system, and reference point surveying method

Abstract

To provide a reflector, a survey system, and a reference point survey method capable of detecting an incident direction of a light beam to the reflector regardless of the incident direction of the light beam.SOLUTION: This device is provided with a prism part 2 constituting a wide-angle prism by a plurality of prisms 4 arranged at least partially in the circumferential direction and a direction angle detector 3 arranged in a space 10 formed in the prism part. The prisms 4 are configured to reflect a part of the incident light beam 13 and transmit the remaining part, and are alternately arranged on the upper stage or the lower stage so that the height of the corner vertex is different, and the direction angle detector 3 includes a first deflection optical member that deflects the light beam transmitted through the prism on the upper stage, a first light receiving sensor, a second deflection optical member that deflects the light beam transmitted through the prism on the lower stage, and a second light receiving sensor. Output position information including a prism on which a light beam is incident and an incident angle with respect to the prism based on a light receiving position of the first light receiving sensor or the second light receiving sensor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reflector that retroreflects a light beam such as a laser beam, a surveying system, and a method for surveying reference points. [Background technology]

[0002] In laser surveying, a reflector that retroreflects the distance measurement light is used as the measurement target. The reflector is attached to a pole that indicates the measurement point, and the reflector is usually a full-circle prism that retroreflects the laser beam over a wide range.

[0003] The full-circumference prism is made up of a combination of multiple corner cube prisms, and in addition to having a complex structure, the retroreflection point (measurement reference point) may shift slightly depending on the direction of the incident light, which can cause measurement errors in distance, vertical angle, and horizontal angle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6000823 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a reflector, a surveying system, and a control point surveying method that are capable of detecting the direction of incidence of a light ray on a reflector, regardless of the direction of incidence of the light ray. [Means for solving the problem]

[0006] The present invention provides a prism section that forms a wide-angle prism using a plurality of prisms arranged at least in a portion of the circumferential direction, and a direction angle detector that is arranged in a space formed within the prism section, wherein the prisms are configured to reflect a portion of incident light rays and transmit the remainder, and the prisms are arranged alternately in upper and lower rows so that the heights of the corner vertices are different, and the direction angle detector includes a first direction detection section that includes a first deflection optical member that deflects the light rays that have passed through the prisms on the upper row side, a first imaging lens, and a first light receiving sensor, and a second deflection optical member that deflects the light rays that have passed through the prisms on the lower row side. The reflector is configured to have a second direction detection unit including an optical element, a second imaging lens, and a second light-receiving sensor, in which the light ray deflected by the first deflection optical element is incident on the first imaging lens and is imaged by the first imaging lens on the first light-receiving sensor, the light ray deflected by the second deflection optical element is incident on the second imaging lens and is imaged by the second imaging lens on the second light-receiving sensor, and to output positional information including the prism on which the light ray is incident and the angle of incidence with respect to the prism based on the light-receiving position of the first light-receiving sensor or the second light-receiving sensor.

[0007] The present invention also relates to a reflector configured so that the light rays incident on the prism are received within a specific area on the first light receiving sensor or the second light receiving sensor corresponding to each prism.

[0008] The present invention also relates to a reflector in which the first deflection optical member and the second deflection optical member are lenses that internally reflect the light beam incident from the side surface multiple times.

[0009] The present invention also relates to a reflector in which the first deflection optical member and the second deflection optical member are free-form surface mirrors each having an axisymmetric free-form reflecting surface.

[0010] The present invention also relates to a reflector in which the first deflection optical member and the second deflection optical member are each a fisheye lens with an angle of view of 180° or more.

[0011] The present invention also relates to a reflector in which the first deflection optical element and the second deflection optical element are prisms each having a reflective surface that internally reflects the light rays incident from the incident surface, and the reflective surface is an axially symmetric free-form surface.

[0012] The present invention also relates to a reflector in which the first deflection optical element and the second deflection optical element are a plurality of free-form surface mirrors arranged at predetermined angular intervals corresponding to the prisms arranged in the upper and lower stages, respectively, and the free-form surface mirrors are arranged so that the main optical axis of the direction angle detector is positioned between the corresponding prisms.

[0013] The present invention also relates to a surveying system having a target device equipped with the above-mentioned reflector and a surveying instrument capable of measuring the reflector, wherein the target device has a communication unit for transmitting light receiving position information emitted by the first light receiving sensor or the second light receiving sensor to the surveying instrument, and the surveying instrument has in advance table data relating the incident angle to the prism and the amount of correction for the measurement result, and the surveying system is configured to detect the incident prism and the incident angle to the prism based on the position information received from the target device, and correct the measurement result of the reflector based on the incident angle.

[0014] The present invention also relates to a surveying system in which the target device further comprises a pole that is installed at the measurement point and whose axis passes through the reference point of the reflector, and a tilt detector that can detect the verticality of the pole, and the surveying instrument measures the measurement point based on the measurement result of the reflector and the known distance from the reference point to the bottom end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence with respect to the prism.

[0015] The present invention also relates to a surveying system in which the target device further comprises a pole installed at the measurement point and configured so that its axis passes through the reference point of the reflector, and a tilt detector capable of detecting two-axial tilt of the pole relative to the horizontal, and the surveying instrument measures the measurement point based on the measurement results of the reflector, the detection results of the tilt detector, and the known distance from the reference point to the bottom end of the pole, and corrects the measurement results of the measurement point based on the angle of incidence with respect to the prism.

[0016] The present invention also relates to a surveying system in which the target device further comprises a pole that is installed at the measurement point and whose axis passes through the reference point of the reflector, the direction angle detector functions as a polarized camera that can detect left-right inclination relative to the surveying instrument, the surveying instrument emits distance measuring light of a predetermined polarized light, measures the measurement point based on the measurement results of the reflector, the left-right inclination angle obtained by the polarized camera, the forward-backward inclination angle and direction angle detected based on the angle of incidence to the prism, and the known distance from the reference point to the bottom end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence to the prism.

[0017] The present invention also relates to a surveying system in which the target device is a handheld scanner capable of acquiring point cloud data of the object to be measured, and the handheld scanner further has an inclination detector capable of detecting two-axis inclination relative to the horizontal, and the surveying instrument is capable of converting the point cloud data acquired by the handheld scanner into point cloud data based on the installation position of the surveying instrument based on the measurement results of the reflector and the detection results of the inclination detector, and is configured to correct the point cloud data of the object to be measured based on the angle of incidence with respect to the prism.

[0018] Furthermore, the present invention relates to a control point surveying method using the above-mentioned reflector, in which the above-mentioned reflector is installed at at least known point 2 of known points 1 and 2, a surveying device is installed at new point 1, known points 1 and 2 are measured by the surveying device, new point 1 is made known by resection, the direction angle of new point 1 is detected with the reflector at known point 2, the surveying device is then installed at new point 2, known point 2 is measured from new point 2, the direction angle of new point 2 is detected with the reflector at known point 2, and new point 2 is made known based on the direction angles of new point 1 and new point 2 detected by the reflector and the measurement results of measuring known point 2 from new point 2. [Effects of the Invention]

[0019] According to the present invention, there is provided a prism section that forms a wide-angle prism by a plurality of prisms arranged at least in a part of the circumferential direction, and a direction angle detector that is arranged in a space formed within the prism section, wherein the prisms are configured to reflect a part of the incident light beam and transmit the rest, and the prisms are arranged alternately in upper and lower rows so that the heights of the corner vertices are different, and the direction angle detector comprises a first direction detection section that includes a first deflection optical member that deflects the light beam that has passed through the prisms on the upper row side, a first imaging lens, and a first light receiving sensor, and a second deflection optical member that deflects the light beam that has passed through the prisms on the lower row side, a second imaging lens, and a second light receiving sensor. The light ray deflected by the first deflection optical member is incident on the first imaging lens and is imaged by the first imaging lens on the first light-receiving sensor, the light ray deflected by the second deflection optical member is incident on the second imaging lens and is imaged by the second imaging lens on the second light-receiving sensor, and position information including the prism on which the light ray is incident and the angle of incidence with respect to the prism is output based on the light-receiving position of the first light-receiving sensor or the second light-receiving sensor. Therefore, regardless of the incident direction to the reflector, the prism on which the light ray is incident and the angle of inclination with respect to the prism can be detected.

[0020] According to the present invention, there is also provided a surveying system having a target device provided with the above-mentioned reflector and a surveying instrument capable of measuring the reflector, wherein the target device has a communication unit for transmitting light receiving position information emitted by the light receiving sensor to the surveying instrument, and the surveying instrument has in advance table data correlating the incident angle to the prism with the amount of correction for the measurement result, and is configured to detect the incident prism and the incident angle to the prism based on the position information received from the target device, and correct the measurement result of the reflector based on the incident angle, so that measurement results from which errors have been removed can be obtained regardless of the incident direction to the reflector, thereby providing the excellent effect of improving measurement accuracy. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a cross-sectional view showing an optical system of a reflector according to the first embodiment. [Figure 2] (A) is a perspective view of a reflector according to the first embodiment, (B) is a cross-sectional view of a prism portion, (C) is an explanatory diagram illustrating a light receiving area formed on a first light receiving sensor, and (D) is an explanatory diagram illustrating a light receiving area formed on a second light receiving sensor. [Figure 3] FIG. 2 is a configuration diagram showing an optical system of a direction angle detector according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing a first surveying method using the reflector. [Figure 5] 10 is a graph showing the relationship between the angle of incidence of the reflector on the prism and the distance correction value. [Figure 6] FIG. 10 is an explanatory diagram showing a second surveying method using the reflector. [Figure 7] FIG. 10(A) is an explanatory diagram showing a third surveying method using the reflector, and FIG. 10(B) is an explanatory diagram explaining a polarized camera. [Figure 8] FIG. 10 is an explanatory diagram showing a fourth surveying method using the reflector. [Figure 9] (A) and (B) are explanatory diagrams of the conventional resection method for measuring new points. [Figure 10] 10(A) and 10(B) are explanatory diagrams showing a fifth surveying method for measuring new points using the reflector. [Figure 11] FIG. 10 is a configuration diagram showing an optical system of a direction angle detector according to a second embodiment. [Figure 12] FIG. 10 is a configuration diagram showing an optical system of a direction angle detector according to a third embodiment. [Figure 13] FIG. 10 is a configuration diagram showing an optical system of a direction angle detector according to a fourth embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing an optical system of a reflector according to a fifth embodiment. [Figure 15] FIG. 1A is a perspective view showing a modified example of a prism portion according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view of the prism portion. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] A reflector 1 according to a first embodiment of the present invention will be described with reference to FIGS.

[0024] The reflector 1 is composed of a prism portion 2 made up of a plurality of prisms, and a direction angle detector 3 for detecting the incident direction of light onto the reflector 1 .

[0025] The prism portion 2 is a full-circumference prism serving as a retroreflector. As shown in FIG. 2(A), it is composed of a plurality of prisms 4, e.g., six prisms 4a-4f, arranged at least circumferentially as corner cubes. Each prism 4 has a truncated triangular pyramid shape, e.g., a regular triangular pyramid with the apex removed. In the following description, the light incident surface of the prism 4 is referred to as the lower base surface, and the surface through which light passes that lower base surface is referred to as the upper base surface. The upper and lower base surfaces are parallel. It is sufficient that only a portion of the light passing through the lower base surface passes through the upper base surface. Therefore, to maximize the efficiency of the transmitted light, the upper base surface is coated with, for example, an AR coating. Alternatively, the upper base surface may be uncoated to reduce costs.

[0026] The prisms 4a to 4f are arranged alternately in the circumferential direction with their lower bases inverted upside down. That is, the prism unit 2 allows light from all around the 360° horizontal direction to be incident on any of the six prisms 4a to 4f and retroreflect it. Therefore, when the main optical axis O of the direction angle detector 3 (described later) is vertical, the prism unit 2 can retroreflect light from all around the 360° horizontal direction and from about ±70° excluding the zenith direction and downward.

[0027] Furthermore, by arranging the prisms 4a to 4f as described above, a space 10 corresponding to the removed vertex portion is formed in the center of the prism portion 2, and the direction angle detector 3 is provided within this space 10.

[0028] As shown in Figure 2(B), of the six prisms 4a to 4f arranged in the circumferential direction, the adjacent prisms 4a and 4b have different heights above and below the apex of the triangular pyramid, i.e., the corner apex, before cutting, and the prism 4b is located below the prism 4a.

[0029] Regarding the positional relationship of the other adjacent prisms 4, the corner apex of prism 4c is located higher than the corner apex of prism 4b, the corner apex of prism 4d is located lower than the corner apex of prism 4c, the corner apex of prism 4e is located higher than the corner apex of prism 4d, the corner apex of prism 4f is located lower than the corner apex of prism 4e, and the corner apex of prism 4a is located higher than the corner apex of prism 4f. At this time, the heights of the corner apexes of prisms 4a, 4c, and 4e are the same, and the heights of the corner apexes of prisms 4b, 4d, and 4f are the same.

[0030] Therefore, if a prism 4 whose corner apex is located above its neighboring prism 4 is defined as the prism 4 arranged in the upper tier, and a prism 4 whose corner apex is located below its neighboring prism 4 is defined as the prism 4 arranged in the lower tier, then prisms 4a, 4c, and 4e are the prisms 4 arranged in the upper tier, and prisms 4b, 4d, and 4f are the prisms 4 arranged in the lower tier. That is, the corner apexes of prisms 4a to 4f are alternately arranged in the upper or lower tier to align the heights of their optical centers in the horizontal direction. Here, the optical center refers to the measurement reference point located inside each corner cube prism.

[0031] As described above, adjacent prisms 4 are arranged so that their bottom surfaces are upside down and their inclination directions relative to the horizontal are also opposite. As a result, the refraction direction of light incident on the prisms 4 is also opposite, and the horizontal heights of the optical centers A of the prisms 4a, 4c, and 4e on the upper side and the optical centers B of the prisms 4b, 4d, and 4f on the lower side can be aligned. In this case, the center of a circle passing through each optical center, or the center of a circle approximating each optical center, serves as the reference point 1a of the reflector 1.

[0032] In this embodiment, the positions of the corner apexes of adjacent prisms 4, for example, prisms 4a and 4b, are shifted vertically so that the vertical heights of the retroreflected light match, particularly near the horizontal where the reflector 1 is frequently used. Therefore, the reflector 1 is configured so that there is no error in the measured vertical angle near the horizontal, regardless of which of the prisms 4a to 4f the light is incident on.

[0033] Next, the direction angle detector 3 will be described in detail with reference to Fig. 3. In Fig. 3, the upper side of the paper is referred to as "up", the lower side of the paper is referred to as "down", the right side of the paper is referred to as "right", and the left side of the paper is referred to as "left".

[0034] The direction angle detector 3 has a main optical axis O, and has a first direction detector 5 and a second direction detector 6 provided on the main optical axis O. The first direction detector 5 and the second direction detector 6 have the same configuration and are arranged upside down.

[0035] The first direction detection unit 5 has a first front group lens 7 as a first deflection optical element, a first diaphragm plate 8, a first rear group lens 9 as a first imaging lens consisting of a group of convex lenses, a first external light cut filter 11, and a first light receiving sensor 12, which are arranged in sequence downward on the main optical axis O.

[0036] The first front lens group 7 is, for example, a single concave lens, and has a side surface 7a onto which light rays 13 having a predetermined wavelength that have passed through the lower prisms 4b, 4d, and 4f are incident, an upper surface 7b, and a lower surface 7c on which a recess is formed. The first front lens group 7 may be a cemented concave lens formed by cementing together a plurality of lenses, or may be a concave lens group formed by combining a plurality of lenses.

[0037] The side surface 7a is, for example, a cylindrical surface that is coated with an anti-reflection (AR) coating and is configured to make the incident light ray 13 incident on the lower surface 7c at an angle equal to or greater than the critical angle. Note that the side surface 7a is not limited to a cylindrical surface, and may be a toric surface or an axisymmetric free-form surface.

[0038] The upper surface 7b is an axisymmetric free-form surface, such as a spherical or aspherical surface, and is entirely coated with a reflective coating. The lower surface 7c is an axisymmetric free-form surface, such as a spherical or aspherical surface, and is entirely coated with an AR coating. The lower surface 7c is configured to totally reflect the light ray 13 incident at an angle equal to or greater than the critical angle and to totally transmit the light ray 13 incident at an angle less than the critical angle.

[0039] The lower surface 7c may be coated with a beam splitter film that reflects 50% of light and transmits 50% of light, thereby allowing the light ray 13 that has passed through the side surface 7a to be reflected even if the incident angle of the light ray 13 is less than the critical angle, thereby improving the degree of freedom in design.

[0040] The first diaphragm plate 8 is a plate material in which a hole of a predetermined size is formed centered on the main optical axis O, and it allows only the light rays 13 that pass through the hole to pass through, and blocks the light rays 13 that pass through optical paths other than the hole, i.e., stray light.

[0041] The first rear lens group 9 is composed of a plurality of lenses, and forms an image of the light ray 13 that has passed through the hole in the first diaphragm plate 8 on the first light receiving sensor 12. The first external light cut filter 11 is, for example, a bandpass filter or a dichroic filter that transmits only the light ray 13, and is capable of removing light of wavelengths other than the light ray 13, such as external light.

[0042] The first light receiving sensor 12 is a 2D sensor protected by a protective glass 20 and is a collection of pixels. Each pixel has pixel coordinates (x:y) with the main optical axis O as the origin, and the pixel coordinates identify the position on the first light receiving sensor 12. Each pixel outputs position information (pixel coordinates) along with a light receiving signal. A 2D image sensor such as a CCD or CMOS is used as the first light receiving sensor 12.

[0043] Similarly, the second direction detection unit 6 has a second front lens group 14 as a second deflection optical member, a second diaphragm plate 15, a second rear lens group 16 as a second imaging lens consisting of a group of convex lenses, a second external light cut filter 17, and a second light receiving sensor 18 protected by a protective glass 30, which are arranged in this order on the main optical axis O toward the top. In the following description, in order to make the second front lens group 14 correspond to the first front lens group 7, the lower convex curved surface will be referred to as the upper surface 14b of the second front lens group 14, and the upper concave curved surface will be referred to as the lower surface 14c of the second front lens group 14.

[0044] The second front-group lens 14 is a concave lens similar to the first front-group lens 7, and has the side surface 14a onto which the light ray 13 having a predetermined wavelength that has passed through the upper prisms 4a, 4c, and 4e is incident, as well as the upper surface 14b and the lower surface 14c. The second front-group lens 14 is arranged so that the upper surface 7b of the first front-group lens 7 and the upper surface 14b of the second front-group lens 14 face each other. The second front-group lens 14 may also be a cemented concave lens formed by cementing together a plurality of lenses, or may be a concave lens group formed by combining a plurality of lenses.

[0045] Furthermore, the second diaphragm plate 15, the second rear lens group 16, the second external light cut filter 17, and the second light receiving sensor 18 are similar to the first diaphragm plate 8, the first rear lens group 9, the first external light cut filter 11, and the first light receiving sensor 12.

[0046] 1, 2(C), and 2(D), the light ray 13 incident on the reflector 1 is received by different light-receiving sensors 12 and 18 depending on which of the prisms 4a to 4f the light ray 13 is incident on. That is, the light ray 13 incident on the lower prisms 4b, 4d, and 4f is received by the first light-receiving sensor 12 via the first front-group lens 7, and the light ray 13 incident on the upper prisms 4a, 4c, and 4e is received by the second light-receiving sensor 18 via the second front-group lens 14.

[0047] Furthermore, the light receiving position with respect to the first light receiving sensor 12 or the second light receiving sensor 18 differs depending on which of the prisms 4a to 4f the light is incident on. As shown in Fig. 2(C), regions 12b, 12d, and 12f corresponding to the lower prisms 4b, 4d, and 4f are formed on the first light receiving sensor 12, and regions 18a, 18c, and 18e corresponding to the upper prisms 4a, 4c, and 4e are formed on the second light receiving sensor 18, as shown in Fig. 2(D). Furthermore, the regions 12b, 12d, and 12f do not overlap with each other on the first light receiving sensor 12, and the regions 18a, 18c, and 18e do not overlap with each other on the second light receiving sensor 18.

[0048] For example, the light ray 13 incident on any one of the upper prisms 4a, 4c, and 4e is received by any one of the regions 18a, 18c, and 18e formed so as to form parts of a ring at predetermined angular intervals within a ring-shaped region centered on the origin of the second light-receiving sensor 18. Furthermore, the light ray 13 incident on any one of the lower prisms 4b, 4d, and 4f is received by any one of the regions 12b, 12d, and 12f formed so as to form parts of a ring at predetermined angular intervals within a ring-shaped region centered on the origin of the first light-receiving sensor 12.

[0049] The angular intervals between the regions 12b, 12d, and 12f are the same as the angular intervals between the prisms 4b, 4d, and 4f in the lower row, e.g., 120°. Similarly, the angular intervals between the regions 18a, 18c, and 18e are the same as the angular intervals between the prisms 4a, 4c, and 4e in the upper row, e.g., 120°. Furthermore, since the prisms 4b, 4d, and 4f in the lower row and the prisms 4a, 4c, and 4e in the upper row are adjacent to each other and arranged alternately, the regions 12b, 12d, and 12f are also formed at the angular intervals between the adjacent prisms 4 with respect to the regions 18a, 18c, and 18e, i.e., at positions rotated 60°.

[0050] Thus, when the light ray 13 is incident on the reflector 1, a part of the light ray 13 is retroreflected, and the remainder is incident on the direction angle detector 3. Furthermore, the direction angle detector 3 can detect which of the prisms 4a to 4f the light ray 13 is incident on, based on which of the regions 12b, 12d, and 12f and the regions 18a, 18c, and 18e the light ray 13 is received in, and can also detect the angle (horizontal angle and vertical angle) at which the light ray 13 is incident with respect to the prism 4, based on which position (pixel) of the regions 12b, 12d, and 12f and the regions 18a, 18c, and 18e the light ray 13 is received in.

[0051] In addition, there are cases where the light ray 13 is incident on two or more of the prisms 4a to 4f by being incident near the boundary between the adjacent prisms 4, and is received by two or more of the areas 12b, 12d, and 12f and the areas 18a, 18c, and 18e. However, since it is possible to predict in advance from the design what kind of image will be formed on the first light-receiving sensor 12 or the second light-receiving sensor 18, accurate measurement of horizontal and vertical angles becomes possible by performing calibration in advance at the factory.

[0052] Furthermore, the detection of the prism 4 and the incident angle (horizontal angle and vertical angle) of the light ray 13 may be performed by a surveying device that measures the reflector 1 based on the light receiving signal and position information from the first light receiving sensor 12 or the second light receiving sensor 18, or by a control device separately provided in the reflector 1, or by a portable terminal (not shown) carried by the operator.

[0053] Furthermore, the entrance pupil position of the light ray 13 incident on the side surface 7a from the lower prisms 4b, 4d, and 4f and the entrance pupil position of the light ray 13 incident on the side surface 14a from the upper prisms 4a, 4c, and 4e are each located on the same circumference of a circle centered on the main optical axis O. Therefore, the entrance pupil position of the light ray 13 can be brought closer to the prisms 4a to 4f, and the transmitting surfaces (upper base surfaces) of the prisms 4a to 4f can be made smaller, thereby increasing the amount of light of the light ray 13 retroreflected by the reflector 1.

[0054] 4, a first surveying method using a surveying system 19 having the reflector 1 will be described. In the following description, the distance measuring light 22 emitted from a surveying instrument 21 is regarded as the light ray 13 incident on the reflector 1.

[0055] The surveying system 19 includes the surveying device 21 and a target device 23. The surveying device 21 is, for example, a total station capable of measurement (distance measurement and angle measurement) and tracking.

[0056] The target device 23 also has the reflector 1 supported on a pedestal 24, a pole 25 extending downward from the underside of the pedestal 24 and having a pointed lower end, a tilt detector 26, such as a bubble tube, provided on the pedestal 24, and a communication unit 27 provided on the pedestal 24 and capable of wireless communication with the surveying device 21. Note that a reference point 1a of the reflector 1 is located on the axis of the pole 25, and the distance from the reference point 1a to the lower end of the pole 25 is known.

[0057] When performing a surveying operation using the surveying instrument 21 and the target device 23, first, the surveying instrument 21 is made to emit a distance measuring light 22 of a predetermined wavelength and a tracking light 28 of a wavelength different from the distance measuring light 22, and the reflector 1 is tracked via the tracking light 28. In this state, the target device 23 is carried to a predetermined measurement point 29, and the target device 23 is set so that the measurement point 29 and the lower end of the pole 25 coincide with each other.

[0058] Furthermore, instructions for ranging and tracking may be given from the surveying device 21, or by an operator via a mobile terminal such as a smartphone or tablet (not shown), or instructions may be given from the target device 23 via the communication unit 27.

[0059] Furthermore, after the target device 23 is set to a vertical position based on the tilt detector 26, the surveying device 21 is made to measure the reflector 1. The surveying device 21 emits the distance measuring light 22 and the tracking light 28 coaxially, and measurement is performed in parallel with tracking of the reflector 1.

[0060] The distance measuring light 22 and the tracking light 28 incident at a predetermined angle on the lower base surface of a predetermined prism 4 of the reflector 1 pass through the inside of the prism 4 and are incident on the upper base surface. A part of the distance measuring light 22 and the tracking light 28 passes through the upper base surface, and the remaining part is retroreflected by reflection on three surfaces excluding the upper base surface.

[0061] The ranging light 22 and the tracking light 28 that pass through the upper bottom surface are incident on the direction angle detector 3, and the reception result of the ranging light 22 by the direction angle detector 3 is transmitted to the surveying device 21 via the communication unit 27.

[0062] That is, the distance measurement light 22 and the tracking light 28 that have passed through the upper bottom surface are incident on the first front lens group 7 or the second front lens group 14 and are internally reflected, pass through holes in the first diaphragm plate 8 or the second diaphragm plate 15, and are collected by the first rear lens group 9 or the second rear lens group 16. After external light and the tracking light 28 are removed by the first external light cut filter 11 or the second external light cut filter 17, only the distance measurement light 22 is incident on predetermined pixels in the areas 12b, 12d, and 12f or the areas 18a, 18c, and 18e on the first light-receiving sensor 12 or the second light-receiving sensor 18 that correspond to the prisms 4a to 4f.

[0063] In the first light-receiving sensor 12 or the second light-receiving sensor 18, the pixel that receives the distance measuring light 22 outputs a light-receiving signal and position information (pixel coordinates). The output light-receiving signal and position information are transmitted to the surveying instrument 21 via the communication unit 27.

[0064] The regions 12b, 12d, 12f or the regions 18a, 18c, 18e onto which the distance measurement light 22 is incident and the light receiving position of the distance measurement light 22 within the regions 12b, 12d, 12f or the regions 18a, 18c, 18e are determined by the prisms 4a to 4f onto which the distance measurement light 22 is incident and the angle of incidence (horizontal angle and vertical angle) with respect to the prisms 4a to 4f. In other words, if the light receiving position of the distance measurement light 22 on the first light receiving sensor 12 or the second light receiving sensor 18 is known, the prisms 4a to 4f onto which the distance measurement light 22 is incident and the angle of incidence with respect to the prisms 4a to 4f can be specified. Therefore, the position information output from the first light receiving sensor 12 or the second light receiving sensor 18 can be considered as position information including the prisms 4a to 4f on which the light ray 13 is incident and the angle of incidence with respect to the prisms 4a to 4f.

[0065] Based on the detection results of the direction angle detector 3 received from the target device 23, i.e., the light receiving signal and position information, the surveying device 21 identifies the prism 4 on which the ranging light 22 is incident from among the prisms 4a to 4f, and calculates correction information based on the incident angle (vertical angle and horizontal angle) of the ranging light 22 with respect to the prism 4.

[0066] In addition, the surveying device 21 corrects the measurement (distance and angle) results of the reflector 1 based on the obtained correction information, and calculates the three-dimensional coordinates of the measurement point 29 based on the corrected measurement results and the known distance from the reference point 1a of the reflector 1 to the bottom end of the pole 25.

[0067] Here, an error may occur in the measurement result of the reflector 1 depending on the orientation of the reflector 1 with respect to the surveying instrument 21, i.e., on which prism 4 of the reflector 1 the distance measuring light 22 (the tracking light 28) as the light ray 13 is incident, and at what angle (horizontal angle and vertical angle) it is incident on the prism 4. The error at this time can be related to the vertical angle (tilt angle) of the distance measuring light 22 with respect to the horizontal and the horizontal angle (azimuth angle) based on the vertical axis.

[0068] For example, when correcting the distance measurement results, the distance correction amount for each horizontal angle and vertical angle of the reflector 1 is calculated in advance, or the correction amount is actually measured at the factory before shipping, and table data of distance correction amounts that correlates the horizontal angle, vertical angle, and distance correction amount is created in advance.

[0069] 5, the table data can be converted into a function of linear interpolation or quadratic variables, and the distance correction amount, which is correction information when measuring the reflector 1, can be calculated based on the function and the horizontal angle and vertical angle detected by the direction angle detector 3. Furthermore, by correcting the distance measurement result with the calculated distance correction amount, it is possible to obtain distance measurement results without error.

[0070] Similarly, for the horizontal angle and vertical angle, table data of the difference between the actual horizontal angle and vertical angle and the horizontal angle and vertical angle obtained by measurement, i.e., the angle correction amount, can be created in advance by calculation or actual measurement, and the table data can be converted into a function of linear interpolation or quadratic variables, and the angle correction amount, which is the correction information when measuring the reflector 1, can be obtained based on the function and the horizontal angle and vertical angle detected by the direction angle detector 3. In addition, by correcting the angle measurement result, i.e., the horizontal angle and vertical angle, with the obtained angle correction amount, it is possible to obtain an angle measurement result without error.

[0071] Furthermore, based on the corrected distance and angle measurement results and the known distance from the reference point 1a of the reflector 1 to the bottom end of the pole 25, the three-dimensional coordinates of the measurement point 29 can be determined with high accuracy.

[0072] The correction of the measurement results based on the correction information received from the target device 23 may be performed every time the reflector 1 is measured. Alternatively, the measurement results of the reflector 1 and the correction information from the target device 23 may be stored in association with each other, and the measurement results may be corrected after the measurement of all the measurement points 29 has been completed. In this case, the measurement results and correction information may be stored in the surveying device 21, or may be stored in a portable terminal (not shown) held by the operator.

[0073] In addition, in the first embodiment, the distance measuring light 22 is used as the light ray 13, but the tracking light 28 may also be used as the light ray 13. In other words, any light having a specific wavelength can be used as the light ray 13 in this embodiment.

[0074] As described above, in the first embodiment, the reflector 1 is composed of the prism portion 2, which is composed of multiple triangular truncated pyramidal prisms 4 with their vertices cut off, and the direction angle detector 3, which is provided in the space 10 formed in the prism portion 2 by the cut-out portions, and is configured so that a portion of the light ray 13 incident on the prism portion 2 is incident on the direction angle detector 3.

[0075] Furthermore, the direction angle detector 3 can identify the prism 4 into which the light ray 13 is incident based on the reception position of the light ray 13 at the first light receiving sensor 12 or the second light receiving sensor 18, regardless of the direction of incidence on the reflector 1, and can detect the angle of incidence (horizontal angle and vertical angle) with respect to the prism 4.

[0076] Therefore, the reflector 1 can retroreflect the incident light ray 13 and detect the prism 4 on which the light ray 13 has entered and the angle of incidence of the light ray 13 with respect to the prism 4 .

[0077] In addition, the prism portion 2 has six prisms 4a to 4f arranged alternately in the circumferential direction with their lower bases turned upside down. Therefore, the reflector 1 can receive and retroreflect the light ray 13 in a range of 360° horizontally and approximately ±70° vertically.

[0078] In the first embodiment, the prisms 4 are arranged in the prism section 2 so that the positions of the corner apexes of adjacent prisms 4, 4 are shifted vertically. That is, the prisms 4 are arranged alternately in the circumferential direction in the upper and lower rows. Therefore, in the vicinity of the horizontal plane where the reflector 1 is frequently used, the height of the retroreflected light ray 13 can be adjusted regardless of the prism 4 on which the light ray 13 is incident, thereby suppressing errors in the vertical angle caused by differences in the prism 4 on which the light ray 13 is incident.

[0079] Furthermore, when performing prism surveying using the reflector 1, the distance and angle errors that occur when measuring the measurement results of the reflector 1 can be corrected based on the correction information received from the direction angle detector 3, so that the errors can be removed from the measurement results and measurement accuracy can be improved.

[0080] Furthermore, since the target device 23 only needs to be installed in a vertical position, there is no need to consider the direction of the reflector 1 relative to the surveying device 21 or the angle of the reflector 1 relative to the surveying device 21, which improves the workability of the surveying work.

[0081] In the first embodiment, the lower end of the pole 25 is aligned with the measurement point 29, the target device 23 is in a vertical position, and the reflector 1 is measured. However, the surveying method using the reflector 1 is not limited to this.

[0082] 6 shows a second surveying method using the surveying system 19, in which a tilt detector 31 capable of detecting tilt on two axes relative to the horizontal, such as a tilt sensor, may be provided on the base 24. By configuring the tilt detector 31 to be capable of detecting tilt on two axes, it becomes possible to measure the reflector 1 without placing the target device 23 in a vertical position.

[0083] That is, in addition to the tilt angle (pitch) in the forward / backward direction relative to the surveying instrument 21 and the tilt angle (roll) in the left / right direction relative to the surveying instrument 21, which can be detected by the tilt detector 31, the direction angle detector 3 detects a direction angle (yaw) that cannot be detected by the tilt detector 31, thereby making it possible to measure the reflector 1. The tilt angle in the forward / backward direction relative to the surveying instrument 21 can also be calculated based on the detection result of the direction angle detector 3 and the vertical angle when the surveying instrument 21 measured the reflector 1.

[0084] Therefore, even for the measurement point 29 in a location where the target device 23 cannot be installed in a vertical position, such as a corner of a room 32, the measurement results can be corrected based on the detection results of the direction angle detector 3 and the tilt detector 31, making it possible to perform highly accurate measurements.

[0085] In the case of the tilt detector 31, it is not possible to determine whether the bottom end of the pole 25 is above or below the reference point 1a of the reflector 1, so when making measurements, it is necessary to separately input the up and down positions relative to the reflector 1.

[0086] 7(A) and 7(B) show a third surveying method using the surveying system 19, in which a polarization camera may be used to detect the left-right tilt angle (roll) of the target device 23 relative to the surveying device 21. In this case, the first light-receiving sensor 12 and the second light-receiving sensor 18 of the direction angle detector 3 are replaced with polarization sensors 33 as shown in FIG. 7(B), and the distance-measuring light 22 or the tracking light 28 used as the light beam 13 is polarized light having a predetermined polarization direction.

[0087] The polarization sensor 33 has different light-receiving pixels corresponding to the polarization direction of the incident light beam 13. For example, when the polarization direction is 0°, the area 33a receives the most light, the area 33c receives the least light, and the areas 33b and 33d receive half the amount of light received by the area 33a (the area with the most light). When the polarization direction of the light beam 13 is perfectly aligned with any of 0°, 45°, 90°, and 135°, light-receiving signals are obtained from three of the areas 33a to 33d. On the other hand, when the polarization direction of the light beam 13 is not perfectly aligned with any of 0°, 45°, 90°, and 135°, light-receiving signals are obtained from all four of the areas 33a to 33d. Therefore, the polarization direction of the light beam 13 can be calculated based on the area from which the light-receiving sensor 33 emits a light-receiving signal and the amount of light received in each area.

[0088] The polarization direction of the light beam 13 incident on the direction angle detector 3 changes depending on the tilt angle (roll) in the left-right direction with respect to the surveying device 21. Therefore, by identifying the areas 33a to 33d from which the polarization sensor 33 emits a light reception signal and further calculating the ratio of the amount of light received for each of the areas 33a to 33d, the tilt angle in the left-right direction of the target device 23 can be calculated.

[0089] Furthermore, the direction angle and the tilt angle in the forward and backward directions of the target device 23 can be obtained based on the detection result of the direction angle detector 3. Therefore, high-precision measurement with error correction becomes possible without installing the target device 23 in a vertical position.

[0090] When a polarization camera is used, the tilt detector 31 can be omitted. As in the case where the tilt detector 31 is provided, it is necessary to separately input the up and down directions relative to the reflector 1.

[0091] 8 shows a fourth surveying method using the surveying system 19, in which the reflector 1 may be provided in a portable handheld scanner 34 as a target device, instead of the target device 23. The handheld scanner 34 is capable of acquiring three-dimensional point cloud data of a predetermined measurement object 35 based on the mechanical center of the handheld scanner 34, and is also capable of transmitting the three-dimensional point cloud data to the surveying device 21. The handheld scanner 34 also has a built-in tilt detector (not shown) equivalent to the tilt detector 31, and is capable of detecting two-axial tilt angles relative to the horizontal.

[0092] When the surveying instrument 21 measures the reflector 1, the direction angle (yaw) relative to the surveying instrument 21 can be found based on the detection results of the direction angle detector 3, and the tilt angle relative to the horizontal can be detected by an inclination detector. Therefore, the surveying instrument 21 can calculate three-dimensional point cloud data of the measurement object 35 based on the surveying instrument 21, based on the two-axis tilt angles and direction angles and the measurement results of the reflector 1, and can further calculate highly accurate three-dimensional point cloud data in which errors have been corrected based on the detection results of the direction angle detector 3.

[0093] The surveying device 21 is not limited to a total station, and may be a laser scanner or a laser tracker. In the case of a conventional laser tracker, it is necessary to provide a light-emitting element such as an LED in the handheld scanner 34, have the laser tracker capture the light from the light-emitting element, and determine the attitude of the handheld scanner 34 based on the position of the light in the image. On the other hand, in the case of this embodiment, the attitude of the handheld scanner 34 can be identified regardless of the orientation of the handheld scanner 34, thereby improving workability.

[0094] 7(A) and 7(B), it is also possible to determine the attitude of the handy scanner 34 based on the detection results of the polarization camera and the direction angle detector 3. In this case, the tilt detector can be omitted.

[0095] Furthermore, by using color or monochrome sensors as the first light receiving sensor 12 and the second light receiving sensor 18, the direction angle detector 3 can be a camera that is approximately coaxial with the reflector 1. When a camera is used, the approximate orientation of the surveying instrument 21 relative to the target device 23, i.e., the approximate orientation of the target device 23 relative to the surveying instrument 21, can be determined based on the acquired image.

[0096] Therefore, by transmitting the specified orientation to the surveying device 21 in real time via the communication unit 27, the time it takes for the tracking light 28 to capture the reflector 1 can be shortened, thereby speeding up the surveying work.

[0097] 9(A) and 9(B) show a conventional surveying method, and Fig. 10(A) and Fig. 10(B) show a fifth surveying method using the surveying system 19. The fifth surveying method is a control point surveying method that uses a laser scanner as the surveying device 21.

[0098] First, a conventional surveying method for performing control point surveying will be described with reference to FIGS. 9(A) and 9(B).

[0099] STEP: 01 The surveying device 21 is installed at new point 1, and the reflector 1 is installed at known point 1 and known point 2. Known point 1 and known point 2 are measured using the surveying device 21, and the coordinates of new point 1 are determined by the method of intersection, making new point 1 known. The point that has been made known is called known point 3.

[0100] STEP: 02: Install the surveying device 21 at new point 2, leave the reflective target at known point 2 as it is, and install a reflective target at known point 3. Using the surveying device 21, measure known points 2 and 3 from new point 2, and make new point 2 known in the same way as in STEP: 01.

[0101] Next, a control point surveying method of the present invention using the reflector 1 of the above embodiment will be described with reference to FIGS. 10(A) and 10(B).

[0102] STEP 11: The surveying device 21 is installed at new point 1, a reflective target is installed at known point 1, the reflector 1 (including direction angle detector 3) of the present invention is installed at known point 2, and the coordinates of new point 1 are obtained by the method of intersection to make new point 1 known. The known new point 1 is made known point 3.

[0103] STEP 12 At this time, the direction angle detector 3 of the reflector 1 receives the distance measuring light 22 and detects the direction angle of the installation point (known point 3) of the surveying instrument 21 from the light reception result. The direction angle (horizontal angle) at this time is defined as A.

[0104] STEP 13: The surveying instrument 21 is moved to the next measurement point (new point 2) and installed at new point 2. At this time, the reflector 1 at known point 2 is maintained in the initial installation state.

[0105] STEP 14: Known point 2 is measured from new point 2 using the surveying device 21. The reflector 1 (direction angle detector 3) receives the distance measuring light 22 and detects the direction angle (horizontal angle) B of new point 2 from known point 2 based on the received light. The horizontal angle C between known point 3 and new point 2 is calculated as (BA).

[0106] From this horizontal angle C and the measurement result of known point 2 by the surveying instrument 21 of new point 2, new point 2 is made known.

[0107] In this embodiment, when making new point 2 known, there is no need to set a target at known point 3, thereby reducing the measurement time. Also, since the measurement result can be corrected based on the detection result of the direction angle detector 3, it is possible to perform highly accurate measurements with errors removed.

[0108] Next, a reflector 36 according to a second embodiment of the present invention will be described with reference to Fig. 11. In Fig. 11, the same components as those in Fig. 3 are given the same reference numerals, and their description will be omitted.

[0109] In the second embodiment, a first direction detection unit 38 of a direction angle detector 37 has a first free-form curved mirror 39 as a first deflection optical member instead of the first front group lens 7 (see FIG. 3), and a second direction detection unit 41 has a second free-form curved mirror 42 as a second deflection optical member instead of the second front group lens 14 (see FIG. 3). The other configurations are the same as those of the reflector 1 of the first embodiment.

[0110] The first free-form surface mirror 39 protrudes toward the first rear lens group 9, and a reflecting surface 39a is formed on the surface facing the first rear lens group 9. The reflecting surface 39a is an axially symmetric free-form surface including a spherical surface or an aspherical surface, and is configured to deflect the light ray 13 that has passed through the lower prisms 4b, 4d, and 4f toward the first rear lens group 9. Similarly, the second free-form surface mirror 42 has a reflecting surface 42a that protrudes toward the second rear lens group 16. The reflecting surface 42a is an axially symmetric free-form surface including a spherical surface or an aspherical surface, and is configured to deflect the light ray 13 that has passed through the upper prisms 4a, 4c, and 4e toward the second rear lens group 16.

[0111] In the second embodiment, the first free-form surface mirror 39 is used as the first deflection optical member instead of a lens, and the second free-form surface mirror 42 is used as the second deflection optical member instead of a lens.

[0112] Therefore, the structure is simple and the design is easy. Furthermore, since mirrors are used instead of lenses, the first and second deflection optical members can be made inexpensive, which reduces the manufacturing costs.

[0113] Next, a reflector 43 according to a third embodiment of the present invention will be described with reference to Fig. 12. In Fig. 12, the same components as those in Fig. 3 are given the same reference numerals, and their description will be omitted.

[0114] In the third embodiment, a first direction detection unit 45 of a direction angle detector 44 has a first fisheye lens 46 as a first deflection optical member instead of the first front lens group 7 (see FIG. 3), and a second direction detection unit 47 has a second fisheye lens 48 as a second deflection optical member instead of the second front lens group 14 (see FIG. 3). The other configurations are the same as those of the reflector 1 of the first embodiment.

[0115] The first fisheye lens 46 and the second fisheye lens 48 are lenses of the same configuration, and are fisheye lenses with an angle of view of, for example, more than 180°. By using the first fisheye lens 46 and the second fisheye lens 48, the reflector 43 can secure a full 360° horizontal angle and a vertical angle of approximately ±35° in the vertical direction.

[0116] The light ray 13 transmitted through the upper prisms 4a, 4c, and 4e is incident on the upper surface 48a of the second fisheye lens 48, and after transmitting through the second fisheye lens 48, is received by the second light-receiving sensor 18 via the second rear lens group 16. Meanwhile, the light ray 13 transmitted through the lower prisms 4b, 4d, and 4f is incident on the upper surface 46a of the first fisheye lens 46, and after transmitting through the first fisheye lens 46, is received by the first light-receiving sensor 12 via the first rear lens group 9. Based on the light-receiving position on the first light-receiving sensor 12 or the second light-receiving sensor 18 at this time, it is possible to detect which prism 4 the light ray 13 is incident on and at what angle of incidence.

[0117] In the third embodiment, the first fisheye lens 46 is used as the first deflection optical element, and the second fisheye lens 48 is used as the second deflection optical element, so the configuration is simple and can be easily designed.

[0118] Next, a reflector 51 according to a fourth embodiment of the present invention will be described with reference to Fig. 13. In Fig. 13, the same components as those in Fig. 3 are given the same reference numerals, and their description will be omitted.

[0119] In the fourth embodiment, a first direction detection unit 53 of a direction angle detector 52 has a first prism 54 as a first deflection optical member instead of the first front group lens 7 (see FIG. 3), and a second direction detection unit 55 has a second prism 56 as a second deflection optical member instead of the second front group lens 14 (see FIG. 3). The other configurations are the same as those of the reflector 1 of the first embodiment.

[0120] The first prism 54 has an incident surface 54a onto which the light ray 13 is incident, a reflecting surface 54b that internally reflects the light ray 13 incident from the incident surface 54a, and a transmitting surface 54c onto which the light ray 13 reflected by the reflecting surface 54b is incident and transmits. Since the light ray 13 is incident on the reflector 51 from all around 360° in the horizontal direction, the incident surface 54a, the reflecting surface 54b, and the transmitting surface 54c are formed all around 360° around the main optical axis O.

[0121] The first prism 54 is formed with an inclined surface 54d that slopes upward from the peripheral edge of the transmitting surface 54c so as to move away from the main optical axis O, and the incident surface 54a is provided continuous with the upper end of the inclined surface 54d. The incident surface 54a is further formed with a cylindrical surface 54e that extends in a direction parallel to the main optical axis O, and the reflecting surface 54b is formed continuous with the cylindrical surface 54e.

[0122] The incident surface 54a is, for example, an axially symmetric free-form surface to which an AR coating is applied, the reflecting surface 54b is, for example, an axially symmetric free-form surface to which a reflective film is vapor-deposited, and the transmitting surface 54c is, for example, an axially symmetric free-form surface to which an AR coating is applied.

[0123] The second prism 56 is a prism having the same configuration as the first prism 54, and portions not described below also have configurations corresponding to those of the first prism 54. The second prism 56 has an incident surface 56a onto which the light ray 13 is incident, a reflecting surface 56b that internally reflects the light ray 13 incident from the incident surface 56a, and a transmitting surface 56c onto which the light ray 13 reflected by the reflecting surface 56b is incident and which transmits the light ray 13.

[0124] In the fourth embodiment, the light ray 13 incident on the upper prisms 4a, 4c, and 4e (see FIG. 2A) enters the second prism 56 from the entrance surface 56a thereof, is internally reflected by the reflecting surface 56b, transmits through the transmitting surface 56c, and is then received by the second light-receiving sensor 18 via the second rear lens group 16 and the like. Meanwhile, the light ray 13 incident on the lower prisms 4b, 4d, and 4f (see FIG. 2A) enters the first prism 54 from the entrance surface 54a thereof, is internally reflected by the reflecting surface 54b, transmits through the transmitting surface 54c, and is then received by the first light-receiving sensor 12 via the first rear lens group 9 and the like. Therefore, based on the light receiving position of the light ray 13 relative to the first light receiving sensor 12 or the second light receiving sensor 18, it is possible to detect which prism 4 the light ray 13 is incident on and at what incident angle.

[0125] In the fourth embodiment, the first prism 54 and the second prism 56 are used as the first and second deflection optical members. By using the first prism 54 and the second prism 56, it is possible to design the entrance pupil position of the light ray 13 incident from the entrance surfaces 54a and 56a to be a position away from the main optical axis O.

[0126] Therefore, the area of ​​the transmitting surface of the prism 4, i.e., the upper and lower surfaces, can be reduced, and the light rays 13 retroreflected by the reflector 51 can be increased. That is, the distance that can be measured by the reflector 51 can be extended.

[0127] Next, a reflector 57 according to a fifth embodiment of the present invention will be described with reference to Fig. 14. In Fig. 14, the same components as those in Fig. 3 are given the same reference numerals, and their description will be omitted.

[0128] In the fifth embodiment, a first direction detection unit 59 of a direction angle detector 58 has a first free-form curved mirror 61 as a first deflection optical member instead of the first front lens group 7 (see FIG. 3), and a second direction detection unit 62 has a second free-form curved mirror 63 as a second deflection optical member instead of the second front lens group 14 (see FIG. 3). The other configurations are the same as those of the reflector 1 of the first embodiment.

[0129] Although only one first free-form surface mirror 61 is shown in Fig. 14, three first free-form surface mirrors 61 are arranged at predetermined angular intervals on a circumference centered on the main optical axis O. The first free-form surface mirrors 61 are arranged so as to sandwich the main optical axis O between themselves and the prism 4 (see Fig. 2(A)). That is, the first free-form surface mirrors 61 are provided corresponding to the lower prisms 4b, 4d, and 4f (see Fig. 2(A)), respectively, and the angular intervals between the first free-form surface mirrors 61 match the angular intervals of the lower prisms 4b, 4d, and 4f.

[0130] The first free-form surface mirror 61 has a reflecting surface 61a that reflects the light ray 13 that has passed through the prisms 4b, 4d, and 4f. The reflecting surface 61a is a free-form surface that is not axially symmetric, and is configured so that the light ray 13 that has passed through the lower prisms 4b, 4d, and 4f is reflected by the reflecting surface 61a corresponding to the prisms 4b, 4d, and 4f toward the first rear lens group 9 and is received by the first light-receiving sensor 12.

[0131] The second free-form surface mirrors 63 have the same configuration as the first free-form surface mirror 61, and three of them are arranged at predetermined angular intervals on a circle centered on the main optical axis O. The second free-form surface mirrors 63 are provided corresponding to the upper prisms 4a, 4c, and 4e (see FIG. 2(A)), respectively, and the angular intervals between the second free-form surface mirrors 63 match the angular intervals between the upper prisms 4a, 4c, and 4e. In other words, the second free-form surface mirrors 63 are arranged at positions offset from the first free-form surface mirror 61 by the angular interval between the adjacent prisms 4, i.e., by 60° around the main optical axis O.

[0132] The second free-form surface mirror 63 has a reflecting surface 63a that reflects the light ray 13 that has passed through the prisms 4a, 4c, and 4e. The reflecting surface 63a is a free-form surface that is not axially symmetric, and is configured so that the light ray 13 that has passed through the upper prisms 4a, 4c, and 4e is reflected by the reflecting surface 63a corresponding to the prisms 4a, 4c, and 4e toward the second rear lens group 16 and is received by the second light-receiving sensor 18.

[0133] In the fifth embodiment, the reflecting surfaces of the free-form surface mirrors 61 and 63 are arranged so that the main optical axis O is located between them and the corresponding prisms, and the focal positions of the free-form surface mirrors 61 and 63 become the entrance pupil position of the light ray 13.

[0134] Therefore, by adjusting the focal positions of the free-form surface mirrors 61 and 63, the free-form surface mirrors 61 and 63 can be designed so that the entrance pupil position is located away from the main optical axis O, and therefore the area of ​​the transmitting surface of the prism 4, i.e., the upper and bottom surfaces, can be reduced, and the light rays 13 retroreflected by the reflector 57 can be increased. In other words, the distance that can be measured by the reflector 57 can be extended.

[0135] Furthermore, since the reflecting surfaces 61a and 63a do not need to be axisymmetric free-form surfaces, the degree of freedom in designing the free-form surface mirrors 61 and 63 can be improved, and aberrations occurring when the light ray 13 passes through the prism 4 can be easily corrected.

[0136] It goes without saying that the first to fifth surveying methods can be implemented even when using the reflectors of the second to fifth embodiments.

[0137] Furthermore, in the first to fifth embodiments, the full-circumference prism is formed by six prisms in the shape of a truncated quadrangular pyramid, but the number of prisms is not limited to six.

[0138] For example, as shown in Fig. 15(A), a regular octahedron full-circumference prism may be formed using eight truncated quadrangular pyramidal prisms 4 as the prism section 64. In this case, as shown in Fig. 15(B), a direction angle detector is placed in a space 10 formed inside. The light beam 13 incident from the four prisms 4 on the upper side (upper row) is deflected by the second polarization optical member and received by the second light-receiving sensor 18, and the light beam 13 incident from the four prisms 4 on the lower side (lower row) is deflected by the first deflection optical member and received by the first light-receiving sensor 12.

[0139] All of the direction angle detectors in the first to fifth embodiments can be applied as the direction angle detector arranged in the space 10. In Fig. 15(B), the direction angle detector 3 in the first embodiment is shown as an example.

[0140] In the above configuration, the prism can be easily arranged and manufactured. In addition, the prism structure has high symmetry, so the direction angle detector can be easily arranged, improving workability.

[0141] Furthermore, in the first to fifth embodiments and their modifications, the full-circumference prism (prism portion) is formed by six prisms arranged in the circumferential direction, but the prism portion of the reflector of the present invention is not limited to a full-circumference prism. For example, the full-circumference prism may be formed by four prisms arranged in the circumferential direction, or may be formed by eight prisms arranged in the circumferential direction. In other words, a full-circumference prism may be formed by multiple (at least two or more) prisms arranged in the circumferential direction, and this can be applied to the reflectors in the first to fifth embodiments.

[0142] Furthermore, the prism portion is not limited to a full-circumferential prism. For example, in the first to fifth embodiments, one prism may be removed from the six circumferentially arranged prisms, leaving five circumferentially arranged prisms to form a wide-angle prism, and this wide-angle prism may be applied to the reflectors in the first to fifth embodiments. Here, wide angle means, for example, a range of 120° to 315°. The wide-angle prism may be formed of four or fewer circumferentially arranged prisms, or may be formed of seven or more circumferentially arranged prisms. In other words, a wide-angle prism may be formed of multiple (at least two or more) circumferentially arranged prisms, and may be applied to the reflectors in the first to fifth embodiments. [Explanation of symbols]

[0143] 1 reflector 2 Prism section 3-direction angle detector 4 Prism 5 First direction detector 6 Second direction detector 12 First light receiving sensor 13 rays of light 18 Second light receiving sensor 36 Reflector 43 Reflector 51 Reflector 57 Reflector

Claims

1. The optical system includes a prism section that forms a wide-angle prism with a plurality of prisms arranged at least in a portion of the circumferential direction, and a direction angle detector arranged in a space formed within the prism section, the prisms being configured to reflect a portion of incident light rays and transmit the remainder, and the prisms are arranged alternately in upper and lower rows so that the heights of the corner vertices are different, and the direction angle detector includes a first direction detection section that includes a first deflection optical member that deflects the light rays that have passed through the prisms on the upper row side, a first imaging lens, and a first light receiving sensor, and a second deflection optical member that deflects the light rays that have passed through the prisms on the lower row side. a second direction detection unit including a deflecting optical member, a second imaging lens, and a second light-receiving sensor, wherein the light ray deflected by the first deflecting optical member is incident on the first imaging lens and is imaged by the first imaging lens on the first light-receiving sensor, the light ray deflected by the second deflecting optical member is incident on the second imaging lens and is imaged by the second imaging lens on the second light-receiving sensor, and the reflector is configured to output positional information including the prism on which the light ray is incident and the angle of incidence with respect to the prism based on the light-receiving position of the first light-receiving sensor or the second light-receiving sensor.

2. 2. The reflector according to claim 1, wherein the light beam incident on the prism is received in a specific area on the first light receiving sensor or the second light receiving sensor corresponding to the prism.

3. 3. The reflector according to claim 1, wherein the first deflection optical member and the second deflection optical member are lenses that internally reflect the light beam incident from a side surface multiple times.

4. 3. The reflector according to claim 1, wherein the first deflection optical member and the second deflection optical member are free-form surface mirrors each having an axisymmetric free-form reflecting surface.

5. 3. The reflector according to claim 1, wherein the first deflection optical member and the second deflection optical member are each a fisheye lens having an angle of view of 180 degrees or more.

6. 3. The reflector according to claim 1, wherein the first deflection optical element and the second deflection optical element are prisms each having a reflective surface that internally reflects the light rays incident from an incident surface, and the reflective surface is an axially symmetric free-form surface.

7. 3. The reflector according to claim 1, wherein the first deflection optical member and the second deflection optical member are a plurality of free-form surface mirrors provided at predetermined angular intervals corresponding to the prisms arranged in the upper and lower stages, respectively, and the free-form surface mirrors are arranged so that the main optical axis of the direction angle detector is positioned between the corresponding prisms.

8. A surveying system having a target device provided with the reflector of claim 1 and a surveying instrument capable of measuring the reflector, wherein the target device has a communication unit for transmitting light receiving position information emitted by the first light receiving sensor or the second light receiving sensor to the surveying instrument, the surveying instrument having in advance table data correlating the angle of incidence with respect to the prism with the amount of correction for the measurement result, the surveying system being configured to detect the incident prism and the angle of incidence with respect to the prism based on the position information received from the target device, and correct the measurement result of the reflector based on the angle of incidence.

9. The surveying system according to claim 8, wherein the target device further comprises a pole that is installed at the measurement point and whose axis passes through the reference point of the reflector, and a tilt detector that can detect the verticality of the pole, and the surveying instrument is configured to measure the measurement point based on the measurement result of the reflector and the known distance from the reference point to the bottom end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence with respect to the prism.

10. The surveying system according to claim 8, wherein the target device further comprises a pole that is installed at the measurement point and whose axis passes through a reference point of the reflector, and an inclination detector that can detect two-axial inclination of the pole with respect to the horizontal, and the surveying instrument is configured to measure the measurement point based on the measurement result of the reflector, the detection result of the inclination detector, and the known distance from the reference point to the bottom end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence with respect to the prism.

11. 9. The surveying system according to claim 8, wherein the target device further comprises a pole installed at the measurement point and configured so that its axis passes through the reference point of the reflector, the direction angle detector functions as a polarized camera capable of detecting tilt in the left and right directions relative to the surveying instrument, the surveying instrument emits distance measuring light of a predetermined polarization, measures the measurement point based on the measurement results of the reflector, the left and right tilt angle obtained by the polarized camera, the forward and backward tilt angle and direction angle detected based on the angle of incidence to the prism, and the known distance from the reference point to the bottom end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence to the prism.

12. The surveying system according to claim 8, wherein the target device is a handheld scanner capable of acquiring point cloud data of the object to be measured, the handheld scanner further having an inclination detector capable of detecting inclination of two axes relative to the horizontal, and the surveying instrument is configured to convert the point cloud data acquired by the handheld scanner into point cloud data based on the installation position of the surveying instrument based on the measurement results of the reflector and the detection results of the inclination detector, and to correct the point cloud data of the object to be measured based on the angle of incidence with respect to the prism.

13. A control point surveying method using the reflector of claim 1, comprising the steps of: installing the reflector of claim 1 at at least known point 2 of known points 1 and 2; installing a surveying instrument at new point 1; measuring known points 1 and 2 with the surveying instrument; making new point 1 known by resection; detecting a direction angle of new point 1 with a reflector at known point 2; installing the surveying instrument at new point 2; measuring known point 2 from new point 2; detecting a direction angle of new point 2 with a reflector at known point 2; and making new point 2 known based on the direction angle of new point 1 and the direction angle of new point 2 detected by the reflector and the measurement results of measuring known point 2 from new point 2.

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