Reflector, surveying system, and control point surveying method

Abstract

The present invention provides a reflector 1, a surveying system, and a control point surveying method that enable detection of the direction of incidence of light rays to the reflector 1, regardless of the direction of incidence of the light rays. [Solution] The prism section 2 comprises a prism that constitutes a wide-angle prism by a plurality of prisms 4 arranged in at least a part of the circumferential direction, and a direction angle detector 3 arranged in a space 5 formed within the prism section. The prism is configured to reflect a portion of the incident light ray 12 and transmit the rest. The direction angle detector includes a deflecting optical member that deflects the light ray that has passed through the prism, an imaging lens, and a light receiving sensor. The light ray deflected by the deflecting optical member enters the imaging lens, is imaged by the imaging lens and captured by the light receiving sensor, and is configured to output position information including the prism into which the light ray entered and the angle of incidence to the prism based on the light receiving position of the light receiving sensor.

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 reference point surveying method.

Background Art

[0002] In laser surveying, a reflector that retroreflects the ranging light is used as a measurement target. The reflector is provided on a pole that indicates the measurement point. Usually, as the reflector, an omnidirectional prism that retroreflects a wide range of laser beams is used.

[0003] The omnidirectional prism is composed of a combination of a plurality of corner cube prisms. Its structure is complex, and the retroreflecting point (measurement reference point) may shift slightly corresponding to the incident direction of the light beam, which has been a factor causing measurement errors in distance, vertical angle, and horizontal angle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a reflector, a surveying system, and a reference point surveying method capable of detecting the incident direction of a light beam to the reflector regardless of the incident direction of the light beam.

Means for Solving the Problems

[0006] The present invention relates to a reflector comprising a prism section comprising a plurality of prisms arranged in at least a portion of the circumferential direction to constitute a wide-angle prism, and a direction angle detector disposed in a space formed within the prism section, wherein the prism is configured to reflect a portion of the incident light ray and transmit the remainder, and the direction angle detector includes a deflection optical member that deflects the light ray that has passed through the prism, an imaging lens, and a light receiving sensor, wherein the light ray deflected by the deflection optical member is incident on the imaging lens, is imaged by the imaging lens and onto the light receiving sensor, and outputs position information including the prism on which the light ray was incident and the angle of incidence to the prism based on the light receiving position of the light receiving sensor.

[0007] Furthermore, the present invention relates to a reflector configured such that the light rays incident on the prism are received within a specific region on the light receiving sensor corresponding to each prism.

[0008] Furthermore, the present invention relates to a reflector, which is a lens that causes the light rays incident from the side to be internally reflected multiple times as a deflecting optical member.

[0009] Furthermore, the present invention relates to a reflector in which the deflection optical member is a free-form surface mirror having a free-form surface reflective surface.

[0010] Furthermore, the present invention relates to a reflector in which the deflection optical member is a fisheye lens with a field of view of 180° or more.

[0011] Furthermore, the present invention relates to a reflector in which the deflection optical member is a prism having a reflective surface that internally reflects the light rays incident from the incident surface, and the reflective surface is an axisymmetric free-form surface.

[0012] Furthermore, the present invention relates to a reflector in which the deflection optical member is a lens that internally reflects the light ray incident from the side multiple times, and the side surface is an axially symmetric free-form surface that can receive the light ray in a range of 300° excluding the vertically downward direction.

[0013] Furthermore, the present invention relates to a reflector in which the direction angle detector comprises a first direction detection unit including a first deflection optical member, a first imaging lens, and a first light receiving sensor, and a second direction detection unit including a second deflection optical member, a second imaging lens, and a second light receiving sensor, wherein the first deflection optical member and the second deflection optical member are arranged on a common optical path and have a right-angle prism having a reflective surface, and the right-angle prism is configured to reflect the light ray incident on the first direction detection unit and the light ray incident on the second direction detection unit at a right angle and in opposite directions on the front and back surfaces of the reflective surface.

[0014] The present invention also relates to a reflector configured such that the direction angle detector comprises a first direction detection unit including a first deflection optical member, a first imaging lens, and a first light receiving sensor, and a second direction detection unit including a second deflection optical member, a second imaging lens, and a second light receiving sensor, wherein the first deflection optical member and the second deflection optical member are arranged on a common optical path and have a reflective prism having two reflective surfaces, and the reflective prism reflects the light ray incident on the first direction detection unit and the light ray incident on the second direction detection unit at right angles and in opposite directions on the front and back of one of the reflective surfaces, and further reflects them at right angles and in the same direction on the other reflective surface.

[0015] Furthermore, the present invention relates to a reflector in which the prism portion further comprises a zenith prism that receives the light rays from the zenith direction.

[0016] Furthermore, the present invention relates to a reflector that further includes a zenith deflection optical member that deflects only the light rays incident from the zenith prism.

[0017] Furthermore, the present invention relates to a reflector in which the prism is a frustum-shaped prism with a triangular upper base and a trapezoidal lower base, and the prism portion is configured such that the prisms are arranged alternately in the circumferential direction while inverting their lower bases.

[0018] Furthermore, the present invention relates to a reflector in which the prism is a frustum-shaped prism with a triangular upper base and a circular lower base, and the prism section is configured such that each prism is arranged in a state where it is rotated around its axis relative to adjacent prisms.

[0019] Furthermore, the present invention relates to a reflector in which the prism section is arranged such that the eight prisms of the truncated square pyramidal base form a regular octahedron.

[0020] Furthermore, the present invention relates to a reflector in which the prism section is arranged such that the four prisms of the truncated square pyramid form a regular square pyramid.

[0021] The present invention also relates to a surveying system comprising a target device provided with the above-mentioned reflector and a surveying device capable of measuring the reflector, wherein the target device has a communication unit for transmitting light reception position information emitted by the light receiving sensor to the surveying device, the surveying device has pre-existing table data relating the angle of incidence to the prism and the amount of correction of the measurement result, and is configured to detect the incident prism and the angle of incidence to the prism based on the position information received from the target device, and to correct the measurement result of the reflector based on the angle of incidence.

[0022] The present invention also relates to a surveying system in which the target device further comprises a pole installed at a measurement point and configured such that its axis passes through the reference point of the reflector, and a tilt detector capable of detecting the verticality of the pole, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

[0023] Furthermore, in the present invention, the target device further includes a pole installed at a measurement point and configured such that its axis passes through the reference point of the reflector, and an inclination detector capable of detecting the inclination of the two axes of the pole with respect to the horizontal. The surveying device measures 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 lower end of the pole, and is configured to correct the measurement result of the measurement point based on the incident angle with respect to the prism. The present invention relates to a surveying system.

[0024] Furthermore, in the present invention, the target device further includes a pole installed at a measurement point and configured such that its axis passes through the reference point of the reflector. The direction angle detector functions as a polarization camera capable of detecting the inclination in the left - right direction with respect to the surveying device. The surveying device emits ranging light of a predetermined polarization, and measures the measurement point based on the measurement result of the reflector, the inclination angle in the left - right direction obtained by the polarization camera, the inclination angle and direction angle in the front - rear direction detected based on the incident angle with respect to the prism, and the known distance from the reference point to the lower end of the pole, and is configured to correct the measurement result of the measurement point based on the incident angle with respect to the prism. The present invention relates to a surveying system.

[0025] Furthermore, in the present invention, the target device is a handy scanner capable of acquiring point cloud data of a measurement object, and the handy scanner further includes an inclination detector capable of detecting the inclination of the two axes with respect to the horizontal. The surveying device can convert the point cloud data acquired by the handy scanner into the point cloud data based on the installation position of the surveying device based on the measurement result of the reflector and the detection result of the inclination detector, and is configured to correct the point cloud data of the measurement object based on the incident angle with respect to the prism. The present invention relates to a surveying system.

[0026] Furthermore, the present invention relates to a reference point surveying method using the above reflector, wherein the reflector according to claim 1 is installed at at least the known point 2 of the known points 1 and 2, a surveying device is installed at the new point 1, the known points 1 and 2 are measured by the surveying device, the new point 1 is made known by resection, the direction angle of the new point 1 is detected by the reflector at the known point 2, then the surveying device is installed at the new point 2, the known point 2 is measured from the new point 2, the direction angle of the new point 2 is detected by the reflector at the known point 2, and the new point 2 is made known based on the direction angle of the new point 1 detected by the reflector, the direction angle of the new point 2, and the measurement result of measuring the known point 2 from the new point 2.

Effect of the Invention

[0027] According to the present invention, there are provided a prism part that constitutes a wide-angle prism by a plurality of prisms arranged at least in part in the circumferential direction, and a direction angle detector arranged in a space formed in the prism part. The prism is configured to reflect a part of the incident light beam and transmit the remainder. The direction angle detector includes a deflection optical member that deflects the light beam transmitted through the prism, an imaging lens, and a light receiving sensor. The light beam deflected by the deflection optical member is incident on the imaging lens, is imaged on the light receiving sensor by the imaging lens, and is configured to output position information including the prism on which the light beam is incident and the incident angle with respect to the prism based on the light receiving position of the light receiving sensor. Therefore, regardless of the incident direction to the reflector, the prism on which the light beam is incident and the tilt angle with respect to the prism can be detected.

[0028] Furthermore, according to the present invention, a surveying system comprising a target device provided with the above-mentioned reflector and a surveying device capable of measuring the reflector, wherein the target device has a communication unit for transmitting light reception position information emitted by the light receiving sensor to the surveying device, the surveying device has pre-existing table data relating the angle of incidence to the prism and the amount of correction of the measurement result, and is configured to detect the incident prism and the angle of incidence to the prism based on the position information received from the target device, and to correct the measurement result of the reflector based on the angle of incidence, thereby exhibiting the excellent effect of obtaining a measurement result with errors removed regardless of the direction of incidence to the reflector and improving measurement accuracy. [Brief explanation of the drawing]

[0029] [Figure 1] This is a cross-sectional view showing the optical system of a reflector according to the first embodiment. [Figure 2] (A) is a top view of a reflector according to the first embodiment, (B) is a cross-sectional view of the prism section, and (C) is an explanatory diagram illustrating the light-receiving area formed on the light-receiving sensor. [Figure 3] This is a configuration diagram showing the optical system of the directional angle detector according to the first embodiment. [Figure 4] This is an explanatory diagram showing the first surveying method using the reflector. [Figure 5] This graph shows the relationship between the angle of incidence of the reflector relative to the prism and the correction value for distance. [Figure 6] This is an explanatory diagram showing a second surveying method using the aforementioned reflector. [Figure 7] (A) is an explanatory diagram showing a third surveying method using the reflector, and (B) is an explanatory diagram explaining a polarizing camera. [Figure 8] This is an explanatory diagram showing a fourth surveying method using the aforementioned reflector. [Figure 9] (A) and (B) are explanatory diagrams of the conventional posterior resection method for measuring new points. [Figure 10](A) and (B) are explanatory diagrams showing a fifth surveying method for measuring a new point using the reflector. [Figure 11] This is a diagram showing the optical system of the directional angle detector according to the second embodiment. [Figure 12] This is a configuration diagram showing the optical system of the directional angle detector according to the third embodiment. [Figure 13] This is a diagram showing the optical system of the directional angle detector according to the fourth embodiment. [Figure 14] This is a configuration diagram showing the optical system of the directional angle detector according to the fifth embodiment. [Figure 15] This is a configuration diagram showing the optical system of the direction angle detector according to the sixth embodiment. [Figure 16] This is a configuration diagram showing the optical system of the directional angle detector according to the seventh embodiment. [Figure 17] (A) is a top view showing the optical system of a direction angle detector according to the eighth embodiment, and (B) is a front view of the optical system. [Figure 18] This is a cross-sectional view showing the optical system of a reflector according to the ninth embodiment. [Figure 19] (A) is a top view of a reflector according to the ninth embodiment, (B) is a cross-sectional view of the prism section, and (C) is an explanatory diagram illustrating the light-receiving area formed on the light-receiving sensor. [Figure 20] This is a configuration diagram showing the optical system of the directional angle detector according to the ninth embodiment. [Figure 21] This is a configuration diagram showing the optical system of the directional angle detector according to the tenth embodiment. [Figure 22] This is a configuration diagram showing the optical system of the directional angle detector according to the 11th embodiment. [Figure 23] This is a configuration diagram showing the optical system of the directional angle detector according to the 12th embodiment. [Figure 24] (A) is a top view showing a first modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, (B) is a perspective view of the prism section, and (C) is a cross-sectional view of the prism section. [Figure 25](A) is a top view showing a second modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, (B) is a perspective view of the prism section, and (C) is a cross-sectional view of the prism section. [Figure 26] (A) is a top view showing a third modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, (B) is a perspective view of the prism section, and (C) is a cross-sectional view of the prism section. [Figure 27] (A) is a top view showing a fourth modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, (B) is a perspective view of the prism section, and (C) is a cross-sectional view of the prism section. [Figure 28] (A) is a perspective view showing a fifth modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, and (B) is a cross-sectional view of the prism section. [Figure 29] (A) is a perspective view showing a sixth modified example of a prism section to which the direction angle detector according to an embodiment of the present invention can be applied, and (B) is a cross-sectional view of the prism section. [Modes for carrying out the invention]

[0030] The embodiments of the present invention will be described below with reference to the drawings.

[0031] Figures 1 to 3 illustrate the reflector 1 according to the first embodiment of the present invention.

[0032] The reflector 1 consists of a prism section 2 made up of multiple prisms and a direction angle detector 3 for detecting the direction of light incidence on the reflector 1.

[0033] The prism section 2 is a full-circumference prism acting as a retroreflector, and as shown in Figure 2(A), it is composed of at least a plurality of prisms 4 arranged in the circumferential direction. Each prism 4 is, for example, a truncated triangular pyramid with the vertex removed. In the following description, the surface on which light is incident is referred to as the lower base surface of the prism, and the surface that transmits or reflects the light that has passed through the lower base surface is referred to as the upper base surface. The upper base surface and the lower base surface are parallel. It is sufficient that a portion of the light that has passed through the lower base surface also passes through the upper base surface. Therefore, in order to maximize the ratio of transmitted light, the upper base surface is coated with, for example, an anti-reflective coating. On the other hand, the upper base surface may be left uncoated to reduce costs.

[0034] Of the prisms 4, the six prisms 4a to 4f are arranged alternately in the circumferential direction with their lower bases inverted vertically. That is, prisms 4a, 4c, and 4e are arranged so that the vertices of the triangles on their lower bases face downwards, while prisms 4b, 4d, and 4f are arranged so that the vertices of the triangles on their lower bases face upwards.

[0035] Furthermore, of the upper and lower recesses formed by the prisms 4a to 4f, one prism 4g is placed in the upper recess (towards the zenith). At this time, the prism 4g is positioned so that its lower surface faces towards the zenith. Note that in Figure 2(A), only prisms 4a, 4c, and 4e are shown among the prisms 4a to 4f arranged in the circumferential direction.

[0036] Accordingly, the prism section 2 is configured to allow light from all 360° in the horizontal direction to be incident on one of the six prisms 4a to 4f and retroreflected, and to allow light from above to be incident on the prism 4g and retroreflected. As a result, the prism section 2 is capable of retroreflecting light from all 360° in the horizontal direction and from a vertical angle range of approximately 300° excluding the downward direction, when the axis passing through the center of the upper and lower bottom surfaces of the prism 4g (the principal optical axis O of the direction angle detector 3, described later) is considered vertical.

[0037] Furthermore, with the prisms 4a to 4g arranged as described above, a space 5 corresponding to the cut-off vertex is formed at the center of the prism section 2, and the direction angle detector 3 is provided within this space 5. As shown in Figures 2(A) and 2(B), the six prisms 4a to 4f arranged in the circumferential direction have the same height as the vertices of the triangular pyramid before cutting, i.e., the height of the corner vertices.

[0038] Next, the details of the direction angle detector 3 will be described with reference to Figure 3. In Figure 3, the upper side relative to the plane of the paper is referred to as "up," the lower side relative to the plane of the paper is referred to as "down," the right side relative to the plane of the paper is referred to as "right," and the left side relative to the plane of the paper is referred to as "left."

[0039] The direction angle detector 3 has a principal optical axis O, which passes through the center of the upper and lower bottom surfaces of the prism 4g. The direction angle detector 3 also includes a front lens group 6 as a deflection optical element provided on the principal optical axis O, an aperture plate 7, a rear lens group 8 as an imaging lens consisting of a group of convex lenses, an ambient light cut filter 9, and a light receiving sensor 11.

[0040] The front lens group 6 is, for example, a single concave lens, and has a side surface 6a into which light rays 12 having a predetermined wavelength that have passed through the circumferentially arranged prisms 4a to 4f are incident, an upper surface 6b into which light rays 12 that have passed through the zenith-side prism 4g are incident, and a lower surface 6c in which a recess is formed. The front lens group 6 may be a bonded concave lens formed by joining multiple lenses, or a concave lens group formed by combining multiple lenses.

[0041] The side surface 6a is, for example, a cylindrical surface coated with an Anti-Reflection (AR) coating, and is configured to cause the incident light ray 12 to be incident on the lower surface 6c at an angle greater than or equal to a critical angle. Note that the side surface 6a is not limited to a cylindrical surface, but may also be a toric surface or an axisymmetric free-form surface.

[0042] The upper surface 6b is, for example, an axisymmetric free-form surface including a sphere or an aspherical surface, with an AR coating applied to the central part and a reflective coating applied to the parts excluding the central part (periphery). The light rays 12 that have passed through the prism 4g are incident on the AR-coated portion in the central part, and are further transmitted through the front lens group 6 before being incident on the lower surface 6c.

[0043] The lower surface 6c is an axisymmetric free-form surface, including, for example, a sphere or an aspherical surface, and is coated with an AR coating over its entire surface. Furthermore, the lower surface 6c is configured to totally reflect light rays 12 incident at or above a critical angle, and to totally transmit light rays 12 incident at or below a critical angle.

[0044] Furthermore, the lower surface 6c may be coated with an AR coating only in the center, while the other parts are made of a beam splitter film that reflects 50% of the light and transmits 50% of the light. This allows the light rays 12 that have passed through the side surface 6a to be reflected even if their incident angle is less than the critical angle, thereby improving the design flexibility.

[0045] The aperture plate 7 is a plate material with a hole of a predetermined size formed around the principal optical axis O, allowing only the light rays 12 passing through the hole to pass through, and blocking the light rays 12 passing through other optical paths, i.e., stray light.

[0046] The rear lens group 8 is composed of multiple lenses and forms an image of the light rays 12 that have passed through the holes in the aperture plate 7 onto the light receiving sensor 11. The ambient light cut filter 9 is, for example, a bandpass filter or a dichroic filter that transmits only the light rays 12, and is capable of removing light of wavelengths other than the light rays 12, such as ambient light.

[0047] The light-receiving sensor 11 is a 2D sensor protected by protective glass 10 and is composed of a collection of pixels. Each pixel has pixel coordinates (x:y) with the principal optical axis O as the origin, and its position on the light-receiving sensor 11 is determined by these pixel coordinates. Each pixel outputs position information (pixel coordinates) along with the received light signal. A 2D image sensor such as a CCD or CMOS is used as the light-receiving sensor 11.

[0048] Here, as shown in Figure 2(C), the light rays 12 incident on the reflector 1 have different reception positions relative to the light receiving sensor 11 depending on the prism 4 that the rays enter. That is, regions 11a to 11g corresponding to each prism 4a to 4g are formed on the light receiving sensor 11, and the light rays 12 incident on each prism 4a to 4g are configured to enter the corresponding regions 11a to 11g.

[0049] For example, the light ray 12 incident on the prism 4g at the zenith is received in a circular region 11g centered on the origin of the light receiving sensor 11. Also, the light ray 12 incident on the prisms 4a, 4c, and 4e is received in regions 11a, 11c, and 11e, which are formed at predetermined angular intervals to form part of a ring-shaped region around the origin of the light receiving sensor 11, without overlapping with the region 11g. Furthermore, the light ray 12 incident on the prisms 4b, 4d, and 4f is received in regions 11b, 11d, and 11f, which are formed at predetermined angular intervals to form part of a ring-shaped region around the origin of the light receiving sensor 11.

[0050] The angular spacing of regions 11a, 11c, and 11e is equivalent to the angular spacing of the prisms 4a, 4c, and 4e, for example, 120° intervals. A region is formed between regions 11a, 11c, and 11e where the light rays 12 are not received. Similarly, the angular spacing of regions 11b, 11d, and 11f is equivalent to the angular spacing of the prisms 4b, 4d, and 4f, for example, 120° intervals. A region is formed between regions 11b, 11d, and 11f where the light rays 12 are not received.

[0051] Furthermore, since the prisms 4a, 4c, 4e and prisms 4b, 4d, 4f are adjacent to each other and arranged alternately, the regions 11a, 11c, 11e are also formed at the angular interval of the adjacent prisms 4 relative to the regions 11b, 11d, 11f, i.e., at a position rotated by 60°.

[0052] Furthermore, the outer diameters of regions 11a, 11c, and 11e are larger than the inner diameters of regions 11b, 11d, and 11f, and smaller than the outer diameters of regions 11b, 11d, and 11f. Therefore, as shown in Figure 2(C), the outer circumferences of both ends of regions 11a, 11c, and 11e and the inner circumferences of both ends of regions 11b, 11d, and 11f overlap within a predetermined range on the light receiving sensor 11.

[0053] When the light ray 12 is incident on the reflector 1, a portion of the light ray 12 is retroreflected, and the remainder is incident on the direction angle detector 3. The direction angle detector 3 can detect which of the prisms 4a to 4g the light ray 12 was incident on, based on which of the regions 11a to 11g the light ray 12 was received by. Furthermore, since the position (pixel) at which the light ray 12 is received within the regions 11a to 11g is determined by the incident angle of the light ray 12, the direction angle detector 3 can detect the incident angle (horizontal angle and vertical angle) at which the light ray 12 was incident on the prism 4, based on the position information of the received pixel.

[0054] On the other hand, as described above, the regions 11a, 11c, and 11e overlap with the regions 11b, 11d, and 11f, and the light ray 12 may be received in the overlapping portion. Therefore, even if the light ray 12 is incident from one of the prisms 4a to 4f, it may be received in two regions 11a to 11g.

[0055] In the direction angle detector 3, the position information of each pixel of the light receiving sensor 11 can be associated with the angle of incidence to the prism 4. Therefore, even if the prism 4 into which the light ray 12 is incident is different, that is, even if the light ray 12 is received in the overlapping portion of the regions 11a to 11g, the angle of incidence of the light ray 12 to the prism 4 can be detected based on the position information of the pixel that received the light ray 12. In this case, it is not possible to identify which prism 4 the light ray 12 was incident on, but the direction angle detector 3 only needs to be able to detect the angle of incidence of the light ray 12 to the prism 4.

[0056] Furthermore, when the light ray 12 is incident near the boundary of adjacent prisms 4, the light ray 12 may be incident on two or more prisms 4a to 4g and received by two or more regions 11a to 11g.

[0057] In this case, multiple images are formed on the light-receiving sensor 11, and multiple images may overlap at close positions. However, the relationship between the position of the image, the incident prism 4, and the angle of incidence to the prism 4 can be known in advance through calculation or calibration. Therefore, based on the known relationship described above between the regions 11a to 11g that received the light ray 12, the incident position of the light ray 12, i.e., the position and number of images formed, it is possible to detect from which prism 4a to 4g the light ray 12 was incident, and also to detect the angle (horizontal angle and vertical angle) at which the light ray 12 was incident on the prism 4.

[0058] Furthermore, the detection of the prism 4 and the detection of the incident angle (horizontal angle and vertical angle) of the light ray 12 may be performed by a surveying device that measures the reflector 1 based on the light receiving signal and position information from the light receiving sensor 11, by a control device separately provided on the reflector 1, or by a portable terminal (not shown) held by the worker.

[0059] Furthermore, the entrance pupil positions of the light rays 12 incident on the side surface 6a from the circumferentially arranged 4a to 4f are located on the same circumference of a circle centered on the principal optical axis O. Therefore, the entrance pupil positions of the light rays 12 can be brought closer to the prisms 4a to 4f, thereby reducing the area of ​​the upper bottom surfaces of the prisms 4a to 4f and increasing the amount of light rays 12 retroreflected by the reflector 1.

[0060] Next, a first surveying method using the surveying system 13 having the reflector 1 will be described in Figure 4. In the following description, the distance measuring light 15 emitted from the surveying device 14 is referred to as the light ray 12 incident on the reflector 1.

[0061] The surveying system 13 comprises the surveying device 14 and the target device 16. The surveying device 14 is, for example, a total station capable of measurement (distance measurement and angle measurement) and tracking.

[0062] Furthermore, the target device 16 includes the reflector 1 supported on a base 17, a pole 18 extending downward from the lower surface of the base 17 with a pointed lower end, a tilt detector 19 provided on the base 17, such as a bubble tube, and a communication unit 21 provided on the base 17 that can communicate wirelessly with the surveying device 14. The reference point 1a of the reflector 1 is located on the axis of the pole 18, and the distance between the corner vertex of the prism 4 and the reference point 1a, and the distance between the reference point 1a and the lower end of the pole 18 are known. When the reflector 1 is measured, the three-dimensional coordinates of the reference point 1a are determined based on the measurement result of the prism 4 and the distance between the corner vertex and the reference point 1a.

[0063] When performing surveying work using the surveying device 14 and the target device 16, first, the surveying device 14 is made to emit a distance measuring light 15 of a predetermined wavelength and a tracking light 22 of a different wavelength from the distance measuring light 15, and the reflector 1 is tracked via the tracking light 22. In this state, the target device 16 is transported to a predetermined measurement point 23, and the target device 16 is set up so that the measurement point 23 and the lower end of the pole 18 coincide.

[0064] Furthermore, instructions for distance measurement and tracking may be given from the surveying device 14, by the operator via a mobile device such as a smartphone or tablet (not shown), or by the target device 16 via the communication unit 21.

[0065] Furthermore, after the target device 16 is positioned vertically based on the tilt detector 19, the surveying device 14 is instructed to measure the reflector 1. The surveying device 14 emits the distance measuring light 15 and the tracking light 22 coaxially, and the measurement is performed in parallel with the tracking of the reflector 1.

[0066] The distance measuring light 15 and the tracking light 22, incident at a predetermined angle of incidence on the lower bottom surface of the prism 4 of the reflector 1, pass through the inside of the prism 4 and are incident on the upper bottom surface. A portion of the distance measuring light 15 and the tracking light 22 passes through the upper bottom surface, and the remainder is retroreflected by reflection from three surfaces, with the upper bottom surface removed.

[0067] The distance measuring light 15 and the tracking light 22 that have passed through the upper bottom surface are incident on the direction angle detector 3, and the result of the direction angle detector 3 receiving the distance measuring light 15 is transmitted to the surveying device 14 via the communication unit 21.

[0068] That is, the distance measuring light 15 and the tracking light 22 that have passed through the upper bottom surface are incident on the front lens group 6 and internally reflected, pass through the holes in the aperture plate 7, and are focused by the rear lens group 8. Furthermore, after the ambient light and the tracking light 22 are removed by the ambient light cut filter 9, only the distance measuring light 15 is incident on the predetermined pixels in the regions 11a to 11g corresponding to the prisms 4a to 4g on the light receiving sensor 11.

[0069] The light receiving sensor 11 outputs position information (pixel coordinates) along with the received light signal when a pixel receives the distance measuring light 15. The output received light signal and position information are transmitted to the surveying device 14 via the communication unit 21.

[0070] Furthermore, the regions 11a to 11g that receive the distance measuring light 15 and the positions within those regions are determined by the prisms 4a to 4g to which the distance measuring light 15 is incident and the angles of incidence (horizontal and vertical angles) to the prisms 4a to 4g. That is, if the position where the distance measuring light 15 is received on the light receiving sensor 11 is known, the prisms 4a to 4g to which the distance measuring light 15 is incident and the angles of incidence to the prisms 4a to 4g can be determined from the known relationship between the receiving position or the formed image and the angle of incidence. Therefore, the position information output from the light receiving sensor 11 can be considered as position information including the prisms 4a to 4g to which the light ray 12 is incident and the angles of incidence to the prisms 4a to 4g.

[0071] The surveying device 14 identifies the prism 4 into which the distance measuring light 15 was incident from among the prisms 4a to 4g based on the detection result of the direction angle detector 3 received from the target device 16, i.e., the received light signal and position information, calculates the incident angle (vertical angle and horizontal angle) of the distance measuring light 15 to the prism 4, and obtains correction information based on the incident angle.

[0072] Furthermore, the surveying device 14 corrects the measurement (distance measurement and angle measurement) results of the reflector 1 based on the obtained correction information, and calculates the three-dimensional coordinates of the measurement point 23 based on the corrected measurement results and the known distance from the reference point 1a of the reflector 1 to the lower end of the pole 18.

[0073] Here, the measurement results of the reflector 1 may be subject to errors depending on the orientation of the reflector 1 relative to the surveying device 14, that is, which prism 4 of the reflector 1 the distance measuring light 15 (the tracking light 22) as the light ray 12 is incident on, and at what angle (horizontal angle and vertical angle) it is incident on the prism 4. This error can be related to the vertical angle (angle of inclination) of the distance measuring light 15 with respect to the horizontal and the horizontal angle (azimuth angle) with respect to the vertical axis.

[0074] For example, when correcting the distance measurement results, the distance correction amount for each horizontal and vertical angle of the reflector 1 is calculated in advance, or the correction amount is measured at the factory before shipment, thereby creating a table of distance correction amounts that relates the horizontal and vertical angles to the distance correction amount.

[0075] Furthermore, as shown in Figure 5, the table data can be linearly interpolated or converted into a quadratic function, and based on this function and the horizontal and vertical angles detected by the direction angle detector 3, a distance correction amount, which is correction information when measuring the reflector 1, can be determined. In addition, by correcting the distance measurement result with the determined distance correction amount, an error-free distance measurement result can be obtained.

[0076] Similarly, for the horizontal and vertical angles, table data representing the difference between the measured horizontal and vertical angles and the actual horizontal and vertical angles, i.e., the angle correction amount, can be created in advance through calculation or actual measurement. This table data can then be converted into a function of a quadratic variable using linear interpolation, and the angle correction amount, which is the correction information when measuring the reflector 1, can be determined based on this function and the horizontal and vertical angles detected by the direction angle detector 3. Furthermore, by correcting the angle measurement results, i.e., the horizontal and vertical angles, with the determined angle correction amount, error-free angle measurement results can be obtained.

[0077] Furthermore, based on the corrected distance measurement results and angle measurement results, and the known distance from the reference point 1a of the reflector 1 to the lower end of the pole 18, the three-dimensional coordinates of the measurement point 23 can be determined with high accuracy.

[0078] Furthermore, the correction of the measurement result based on the correction information received from the target device 16 may be performed each time the reflector 1 is measured. Alternatively, the measurement result of the reflector 1 and the correction information from the target device 16 may be associated and saved, and the measurement result may be corrected after all the measurements of the measurement points 23 have been completed. In this case, the measurement result and correction information may be stored in the surveying device 14, or they may be stored in a portable terminal (not shown) held by the operator.

[0079] Furthermore, in the first embodiment, the distance measuring light 15 is used as the light ray 12, but the tracking light 22 may also be used as the light ray 12. In other words, any light having a specific wavelength can be used as the light ray 12 in this embodiment.

[0080] As described above, in the first embodiment, the reflector 1 is composed of a prism section 2 made up of a plurality of truncated triangular prisms 4 with their vertices cut off, and a direction angle detector 3 provided in the space 5 formed within the prism section 2 by the cut-off portion, and is configured such that a portion of the light ray 12 incident on the prism section 2 is incident on the direction angle detector 3.

[0081] Furthermore, the direction angle detector 3 can identify the prism 4 into which the light ray 12 was incident, based on the position where the light ray 12 was received by the light receiving sensor 11, regardless of the direction of incidence to the reflector 1, and can also detect the angle of incidence (horizontal angle and vertical angle) to the prism 4.

[0082] Therefore, the reflector 1 retroreflects the incident light ray 12 and can detect the incident angle of the light ray 12 with respect to the incident prism 4.

[0083] Furthermore, the prism section 2 has six prisms 4a to 4f arranged alternately in the circumferential direction with their lower bases inverted vertically, and the prism 4g is positioned in the upper recess formed by the prisms 4a to 4f with its lower base facing zenith. Therefore, the reflector 1 can receive and retroreflect the light rays 12 in a range of 360° horizontally and 300° vertically excluding the downward direction.

[0084] Furthermore, when performing prism measurement using the reflector 1, the distance and angle errors that occur when measuring the measurement result of the reflector 1 can be corrected based on the correction information received from the direction angle detector 3. This allows for the removal of errors from the measurement result and improves measurement accuracy.

[0085] Furthermore, since the target device 16 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 14 or the angle of the reflector 1 relative to the surveying device 14, thus improving the work efficiency in surveying operations.

[0086] Furthermore, since the direction angle detector 3 is composed of only one of each component, such as the front lens group 6 which is a deflection optical element, the rear lens group 8, and the light receiving sensor 11, the number of components is minimized, enabling miniaturization and reduction of manufacturing costs.

[0087] In the first embodiment, the case in which the lower end of the pole 18 is aligned with the measurement point 23 and the target device 16 is in a vertical position to measure the reflector 1 was described, but the surveying method using the reflector 1 is not limited to this.

[0088] For example, Figure 6 shows a second surveying method using the surveying system 13, in which a tilt detector 24 capable of detecting a two-axis tilt with respect to the horizontal, such as a tilt sensor, may be provided on the base 17. By configuring the tilt detector 24 to be capable of detecting a two-axis tilt, it becomes possible to measure the reflector 1 without having to position the target device 16 vertically.

[0089] In other words, in addition to the tilt angle in the front-to-back direction (pitch) and the tilt angle in the left-to-right direction (roll) relative to the surveying device 14, which can be detected by the tilt detector 24, the direction angle detector 3 detects the direction angle (yaw), which cannot be detected by the tilt detector 24, thereby enabling measurement of the reflector 1. The tilt angle in the front-to-back direction relative to the surveying device 14 can also be calculated based on the detection result of the direction angle detector 3 and the vertical angle when the surveying device 14 measures the reflector 1.

[0090] Therefore, even at measurement points 23 in locations where the target device 16 cannot be installed in a vertical position, such as the corners of room 25, the measurement results can be corrected based on the detection results of the direction angle detector 3 and the tilt detector 24, enabling highly accurate measurements.

[0091] In the case of the tilt detector 24, it is not possible to determine whether the lower end of the pole 18 is above or below the reference point 1a of the reflector 1. Therefore, when taking measurements, it is necessary to input the vertical position relative to the reflector 1 separately.

[0092] Furthermore, Figures 7(A) and 7(B) show a third surveying method using the surveying system 13, in which a polarizing camera may be used to detect the tilt angle (roll) of the target device 16 relative to the surveying device 14 in the left-right direction. In this case, the light receiving sensor 11 of the direction angle detector 3 is a polarizing sensor 26 as shown in Figure 7(B), and the distance measuring light 15 or tracking light 22 used as the light ray 12 is polarized light with a predetermined polarization direction.

[0093] The polarization sensor 26 has different pixels capable of receiving light depending on the polarization direction of the incident light ray 12. For example, if the polarization is 0°, the amount of light received is greatest in region 26a, closest to 0 in region 26c, and half as much in regions 26b and 26d as in region 26a (the region with the greatest amount of light received). If the polarization direction of the light ray 12 perfectly matches 0°, 45°, 90°, or 135°, light received signals can be obtained from three of the regions 26a to 26d. On the other hand, if the polarization direction of the light ray 12 does not perfectly match 0°, 45°, 90°, or 135°, light received signals can be obtained from all four of the regions 26a to 26d. Therefore, the polarization direction of the light ray 12 can be calculated based on the region from which the light received signal is emitted from the light receiving sensor 11 and the amount of light received in each region.

[0094] The polarization direction of the light ray 12 incident on the direction angle detector 3 changes with the left-right tilt angle (roll) relative to the surveying device 14. Therefore, by identifying the regions 26a to 26d from which the light received signal is emitted from the polarization sensor 26, the left-right tilt angle of the target device 16 can be calculated. If light received signals are emitted from multiple regions 26a to 26d, the left-right tilt angle of the target device 16 can be calculated by identifying the regions 26a to 26d and determining the ratio of the amount of light received for each region 26a to 26d.

[0095] Furthermore, based on the detection results of the direction angle detector 3, the direction angle and the tilt angle in the front-rear direction of the target device 16 can be determined. Therefore, highly accurate measurements with error correction become possible without having to position the target device 16 in a vertical orientation.

[0096] Furthermore, when using a polarizing camera, the tilt detector 24 can be omitted. Also, as with the case where the tilt detector 24 is provided, it is necessary to separately input the up and down direction relative to the reflector 1.

[0097] Figure 8 shows a fourth surveying method using the surveying system 13, in which the reflector 1 may be provided on a portable handheld scanner 27 as a target device instead of the target device 16. The handheld scanner 27 is capable of acquiring 3D point cloud data of a predetermined object to be measured 28 with respect to the machine center of the handheld scanner 27, and is capable of transmitting the 3D point cloud data to the surveying device 14. Furthermore, the handheld scanner 27 incorporates a tilt detector (not shown) equivalent to the tilt detector 24, and is capable of detecting the tilt angle of two axes with respect to the horizontal.

[0098] The direction angle (yaw) relative to the surveying device 14 when the surveying device 14 measures the reflector 1 can be determined based on the detection result of the direction angle detector 3, and the inclination angle with respect to the horizontal can be detected by the inclination detector 24. Therefore, the surveying device 14 can calculate three-dimensional point cloud data of the object to be measured 28 with the surveying device 14 as the reference, based on the two-axis inclination angle and direction angle and the measurement result of the reflector 1, and can further calculate highly accurate three-dimensional point cloud data with errors corrected based on the detection result of the direction angle detector 3.

[0099] Furthermore, the surveying device 14 is not limited to a total station; a laser scanner or a laser tracker may also be used. In the case of a conventional laser tracker, it is necessary to provide a light-emitting element such as an LED on the handheld scanner 27, have the laser tracker capture the light from the light-emitting element, and determine the orientation of the handheld scanner 27 based on the position of the light in the image. On the other hand, in this embodiment, the orientation of the handheld scanner 27 can be determined regardless of the orientation of the handheld scanner 27, thus improving work efficiency.

[0100] Furthermore, similar to Figures 7(A) and 7(B), it is also possible to determine the orientation of the handheld scanner 27 based on the detection results of the polarization camera and the direction angle detector 3. In this case, the tilt detector can be omitted.

[0101] Furthermore, by making the light receiving sensor 11 a color or monochrome sensor, the direction angle detector 3 can be a camera that is substantially coaxial with the reflector 1. When a camera is used, the approximate orientation of the surveying device 14 relative to the target device 16, that is, the approximate orientation of the target device 16 relative to the surveying device 14, can be determined based on the acquired image.

[0102] Therefore, by transmitting the specified orientation to the surveying device 14 in real time via the communication unit 21, the time it takes for the tracking light 22 to acquire the reflector 1 can be shortened, thereby speeding up the surveying work.

[0103] Figures 9(A) and 9(B) show a conventional surveying method, while Figures 10(A) and 10(B) show a fifth surveying method using the surveying system 13. The fifth surveying method is a control point surveying method that uses a laser scanner as the surveying device 14.

[0104] First, we will explain the conventional surveying method for conducting control point surveys, as shown in Figures 9(A) and 9(B).

[0105] STEP 01: Install the surveying device 14 at new point 1, install the reflector 1 at known point 1 and known point 2, measure known point 1 and known point 2 with the surveying device 14, find the coordinates of new point 1 using the resection method and make new point 1 known. The now known point is designated as known point 3.

[0106] STEP 02: Install the surveying device 14 at new point 2, leave the reflective target at known point 2 as is, and install a reflective target at known point 3. From new point 2, measure known points 2 and known points 3 using the surveying device 14, and make new point 2 known in the same way as in STEP 01.

[0107] Next, the method for measuring reference points according to the present invention using the reflector 1 of the above embodiment will be explained in Figures 10(A) and 10(B).

[0108] STEP 11: Install the surveying device 14 at new point 1, install the reflective target at known point 1, install the reflector 1 (including the direction angle detector 3) of the present invention at known point 2, determine the coordinates of new point 1 using the resection method and make new point 1 known. The newly known new point 1 is designated as known point 3.

[0109] STEP 12 At this time, the direction angle detector 3 of the reflector 1 receives the distance measuring light 15 and detects the direction angle of the installation point (known point 3) of the surveying device 14 from the light reception result. Let the direction angle (horizontal angle) at this time be A.

[0110] STEP 13: Move the surveying device 14 to the next measurement point (new point 2) and install it at new point 2. At this time, the reflector 1 at known point 2 will remain in its initial installation state.

[0111] STEP 14: The surveying device 14 measures the known point 2 from the new point 2. The reflector 1 (direction angle detector 3) receives the distance measuring light 15 and detects the direction angle (horizontal angle) B of the new point 2 from the known point 2 from the light reception result. The horizontal angle C between the known point 3 and the new point 2 is determined by (BA).

[0112] From this horizontal angle C and the measurement results of known point 2 by the surveying device 14 at new point 2, new point 2 is identified as a known point.

[0113] In this embodiment, when a new point 2 is identified, it is not necessary to set a target at the known point 3, thus shortening the measurement time. Furthermore, since the measurement results can be corrected based on the detection results of the direction angle detector 3, highly accurate measurements with errors removed can be performed.

[0114] Next, a reflector 29 according to a second embodiment of the present invention will be described in Figure 11. In Figure 11, components equivalent to those in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0115] In the second embodiment, a zenith front lens group 32 is added to the directional angle detector 31 as a zenith deflection optical element. The other configurations are the same as those of the reflector 1 in the first embodiment. A portion of the light ray 12 incident on the reflector 29 is retroreflected, and the remainder is incident on the directional angle detector 31.

[0116] The zenith front lens group 32 is located on the opposite side of the light receiving sensor 11, with the front lens group 6 in between, and is configured so that only the light rays 12 incident from the prism 4g positioned at the zenith are incident on the zenith front lens group 32.

[0117] That is, the light rays 12 that have passed through the prism 4g at the zenith first enter the front lens group 32 at the zenith, and then sequentially pass through the front lens group 6, the rear lens group 8, etc., before being received by the light receiving sensor 11.

[0118] The light ray 12 is incident on the light receiving sensor 11 at a predetermined position in the regions 11a to 11g corresponding to the prisms 4a to 4g, and the light receiving sensor 11 emits a light reception signal and position information in response to the reception of the light ray 12. Furthermore, based on this position information, it is possible to detect which prism 4 of the prisms 4a to 4g the light ray 12 is incident on and at what angle.

[0119] In the second embodiment, since the zenith front lens group 32 is provided, which receives only the light rays 12 incident from the prism 4g positioned in the zenith direction, it is not necessary to adjust the incident pupil position of the light rays 12 incident from the circumferentially arranged prisms 4a to 4f and the incident pupil position of the light rays 12 incident from the zenith-side prism 4g using only the front lens group 6.

[0120] Therefore, the entrance pupil position of the light ray 12 incident from the prism 4g can be easily adjusted by design, and the aberration correction accuracy can be improved compared to using only the front lens group 6. As a result, the reachable distance of the light ray 12 in the zenith direction can be extended, improving workability.

[0121] Next, a reflector 33 according to a third embodiment of the present invention will be described in Figure 12. In Figure 12, components equivalent to those in Figure 11 are denoted by the same reference numerals, and their descriptions are omitted.

[0122] In the third embodiment, the direction angle detector 34 has a perforated free-form mirror 35 as a deflection optical element, instead of the front lens group 6 in the second embodiment. The other configurations are the same as those of the reflector 29 in the second embodiment. A portion of the light ray 12 incident on the reflector 33 is retroreflected, and the remainder is incident on the direction angle detector 34.

[0123] The perforated free-form mirror 35 has a hole 35a formed in its center. The hole 35a is larger than the diameter of the light ray 12 that passes through the front zenith lens group 32, and is configured to allow the light ray 12 to pass through. Furthermore, the perforated free-form mirror 35 is configured to reflect the light ray 12 that enters from the prisms 4a to 4f and passes through, toward the rear lens group 8, by a reflective surface 35b formed on the lower surface around the hole 35a.

[0124] That is, the light rays 12 that have passed through the prisms 4a to 4f are reflected by the reflective surface 35b of the perforated free-form mirror 35, and are received by the light receiving sensor 11 after passing through the rear lens group 8, etc. Also, the light rays 12 that have passed through the zenith prism 4g are incident on the zenith front lens group 32, pass through the hole 35a, and are received by the light receiving sensor 11 after passing through the rear lens group 8, etc.

[0125] The light ray 12 is incident on the light receiving sensor 11 at a predetermined position in the regions 11a to 11g corresponding to the prisms 4a to 4g. Based on the light receiving signal and position information emitted in response to the reception of the light ray 12, the light receiving sensor 11 can detect which prism 4 of the prisms 4a to 4g the light ray 12 is incident on and at what angle.

[0126] In the third embodiment, the perforated free-form mirror 35 is used instead of a lens as a deflection optical element for reflecting the light rays 12 that have passed through the prisms 4a to 4f, thereby reducing manufacturing costs.

[0127] Furthermore, in the third embodiment as well, the front zenith lens group 32 allows for easy adjustment of the entrance pupil position of the light ray 12 incident from the prism 4g, improving the accuracy of aberration correction and extending the reach of the light ray 12 in the zenith direction, thereby improving workability.

[0128] Next, a reflector 36 according to a fourth embodiment of the present invention will be described in Figure 13. In Figure 13, components equivalent to those in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0129] In the fourth embodiment, the direction angle detector 37 has a fisheye lens 38 as a deflection optical element instead of the front lens group 6 in the first embodiment. The other configurations are the same as those of the reflector 1 in the first embodiment.

[0130] The fisheye lens 38 is, for example, a fisheye lens with a field of view exceeding 180°. By using the fisheye lens 38, the reflector 36 can secure a full 360° horizontal field of view and a vertical angle ranging from the zenith to approximately -35° vertically.

[0131] Light rays 12 that have passed through the circumferentially arranged prisms 4a to 4f enter the upper surface 38a of the fisheye lens 38 except for the center, and after passing through the fisheye lens 38, are received by the light receiving sensor 11 via the rear lens group 8. Also, light rays 12 that have passed through the prism 4g arranged in the zenith direction enter the center of the upper surface 38a, and after passing through the fisheye lens 38, are received by the light receiving sensor 11 via the rear lens group 8. Based on the receiving position of the light rays 12 on the light receiving sensor 11 at this time, it is possible to detect which prism 4 the light rays 12 entered at what angle of incidence.

[0132] In the fourth embodiment, since the fisheye lens 38 is used as the deflection optical element, the configuration is simpler and the design can be easily carried out.

[0133] Next, a reflector 39 according to the fifth embodiment of the present invention will be described in Figure 14. In Figure 14, components equivalent to those in Figure 11 are denoted by the same reference numerals, and their descriptions are omitted.

[0134] In the fifth embodiment, the direction angle detector 41 has a free-form prism 42 as a deflection optical element instead of the front lens group 6 in the second embodiment. Also, the zenith front lens group 43 is composed of multiple lenses, including one concave lens. The other configurations are the same as the reflector 29 in the second embodiment.

[0135] The free-form prism 42 has an incident surface 42a into which the light ray 12 is incident, a reflecting surface 42b that internally reflects the light ray 12 incident from the incident surface 42a, and a transmitting surface 42c into which the light ray 12 reflected by the reflecting surface 42b is incident and transmitted. Since the light ray 12 is incident on the reflector 39 from all 360° in the horizontal direction, the incident surface 42a, the reflecting surface 42b, and the transmitting surface 42c are formed all 360° around the principal optical axis O.

[0136] Furthermore, the free-form prism 42 has a circular upper surface 42d that is parallel to the transmitting surface 42c and surrounded by the upper end of the reflecting surface 42b, and an inclined surface 42e that slopes upward from the peripheral end of the transmitting surface 42c so as to move away from the principal optical axis O, and the incident surface 42a is provided continuously from the upper end of the inclined surface 42e. Moreover, a cylindrical surface 42f is formed between the incident surface 42a and the reflecting surface 42b, which is oriented in a direction parallel to the principal optical axis O.

[0137] The incident surface 42a is, for example, an axially symmetric free-form surface coated with an AR coating; the reflective surface 42b is, for example, an axially symmetric free-form surface with a reflective film deposited on it; the transmissive surface 42c is, for example, an axially symmetric free-form surface coated with an AR coating; and the upper surface 42d is, for example, an axially symmetric free-form surface coated with an AR coating.

[0138] In the fifth embodiment, the light rays 12 incident on the circumferentially arranged prisms 4a to 4f enter the free-form prism 42 from the incident surface 42a, are internally reflected by the reflective surface 42b, and after passing through the transmissive surface 42c, are received by the light receiving sensor 11 via the rear lens group 8, etc. Also, the light rays 12 incident on the prism 4g arranged in the zenith direction enter the free-form prism 42 from the upper surface 42d, pass through the transmissive surface 42c, and are received by the light receiving sensor 11 via the rear lens group 8, etc.

[0139] Therefore, based on the light-receiving position of the light ray 12 to the light-receiving sensor 11, that is, which region of regions 11a to 11g it incident on, and where within those regions 11a to 11g it incident on, it is possible to detect which prism 4 it incident on and at what angle of incidence.

[0140] Furthermore, in the fifth embodiment, the free-form surface prism 42 is used as the deflection optical member. By using the free-form surface prism 42, the position of the incident pupil of the light ray 12 incident from the incident surface 42a can be designed to be at a position away from the principal optical axis O.

[0141] Therefore, the area of ​​the transmission surface, i.e., the upper bottom surface, of the prism 4 can be reduced, and the amount of light rays 12 retroreflected by the reflector 39 can be increased. In other words, the distance over which the reflector 39 can be measured can be extended.

[0142] Next, a reflector 43 according to the sixth embodiment of the present invention will be described in Figure 15. In Figure 15, components equivalent to those in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0143] In the sixth embodiment, the direction angle detector 44 has a free-form surface lens 45 as a deflection optical element, instead of the front lens group 6 in the first embodiment. The other configurations are the same as in the first embodiment.

[0144] The free-form surface lens 45 has a side surface 45a into which light rays 12 transmitted through prisms 4a to 4g are incident, a lower surface 45b formed so as to be surrounded by the lower end of the side surface 45a and into which the transmitted light rays 12 are incident, an upper surface 45c formed so as to be surrounded by the upper end of the side surface 45a and into which light rays 12 reflected by the lower surface 45b are incident, and a transmissive surface 45d formed in the center of the lower surface 45b and through which light rays 12 reflected by the upper surface 45c are transmitted.

[0145] The side surface 45a is, for example, an axially symmetric free-form surface coated with an AR coating, and allows the light ray 12 to be incident on it in a range of approximately 300° in the vertical direction, excluding the downward direction. Furthermore, the lower surface 45b and the upper surface 45c are, for example, axially symmetric free-form surfaces that utilize total internal reflection with or without a deposited reflective film. In addition, the transmissive surface 45d is, for example, a concave surface coated with an AR coating.

[0146] Furthermore, the side surface 45a is inclined at a predetermined angle so as to be close to the principal optical axis O in the upward direction. Therefore, the free-form surface lens 45 can obtain a field of view of 90° or more in the zenith direction when the direction perpendicular to the principal optical axis O is defined as 0°.

[0147] In the sixth embodiment, the light rays 12 that have passed through the prisms 4a to 4g enter the free-form surface lens 45 from the side surface 45a of the free-form surface lens 45, are sequentially internally reflected by the lower surface 45b and the upper surface 45c, and after passing through the transmission surface 45d, are received by the light receiving sensor 11 via the rear lens group 8, etc.

[0148] Therefore, based on the light-receiving position of the light ray 12 to the light-receiving sensor 11, that is, which region of regions 11a to 11g it incident on, and where within those regions 11a to 11g it incident on, it is possible to detect which prism 4 it incident on and at what angle of incidence.

[0149] Furthermore, since the side surface 45a is inclined upward at a predetermined angle to be close to the principal optical axis O, the light rays 12 from the zenith direction can also be incident on the side surface 45a alone, and the optical element for inducing the light rays 12 from the zenith direction can be omitted.

[0150] Next, a reflector 46 according to the seventh embodiment of the present invention will be described in Figure 16. In Figure 16, components equivalent to those in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0151] In the seventh embodiment, the direction angle detector 47 is composed of a first direction detection unit 48 and a second direction detection unit 49.

[0152] The first direction detection unit 48 includes a first light receiving sensor 51, a first ambient light cut filter 52, a first rear lens group 53, a first aperture plate 54, a right-angle prism 55, and a first front lens group 56 provided on the reflected optical axis of the right-angle prism 55, all arranged in order from the light receiving side on the main optical axis O. The second direction detection unit 49 includes a second light receiving sensor 57, a second ambient light cut filter 58, a second rear lens group 59, a second aperture plate 61, the right-angle prism 55, and a second front lens group 62 provided on the reflected optical axis of the right-angle prism 55, all arranged in order from the light receiving side on the main optical axis O.

[0153] Furthermore, the first light receiving sensor 51 and the second light receiving sensor 57, the first ambient light cut filter 52 and the second ambient light cut filter 58, the first rear lens group 53 and the second rear lens group 59, and the first aperture plate 54 and the second aperture plate 61 have the same configuration as the light receiving sensor 11, ambient light cut filter 9, rear lens group 8 and aperture plate 7 in the first embodiment, respectively, so their description is omitted.

[0154] The first front lens group 56 and the second front lens group 62 are each fisheye lenses with an angle of view exceeding 180°, and are arranged, for example, symmetrically with respect to the principal optical axis O. Therefore, for example, light rays 12 that pass through prisms 4a to 4c are incident on the first front lens group 56, and light rays 12 that are incident on prisms 4d to 4f are incident on the second front lens group 62. Furthermore, light rays 12 that pass through prism 4g are incident on either the first front lens group 56 or the second front lens group 62 depending on the incident position on prism 4g.

[0155] Furthermore, the optical axis of the light ray 12 incident on the first front lens group 56 and the optical axis of the light ray 12 incident on the second front lens group 62 coincide or substantially coincide. The first front lens group 56 and the second front lens group 62 constitute a 360° spherical lens that can receive light from all directions (360°) in both the horizontal and vertical directions.

[0156] Furthermore, the first front lens group 56 and the second front lens group 62 do not need to be symmetrical with respect to the principal optical axis O, as long as they can receive the light rays 12 from all directions.

[0157] The right-angle prism 55 is a square prism formed by joining two triangular prisms, and the joining surface serves as a reflective surface 55a for reflecting the incident light ray 12 at a right angle. Furthermore, the right-angle prism 55 is located on the common optical path of the first direction detection unit 48 and the second direction detection unit 49, and is configured to reflect the light ray 12 incident from the first front lens group 56 and the light ray 12 incident from the second front lens group 62 at a right angle on the front and back surfaces of the reflective surface 55a, respectively. Thus, the first front lens group 56 and the right-angle prism 55 constitute the first deflection optical member, and the second front lens group 62 and the right-angle prism 55 constitute the second deflection optical member.

[0158] Furthermore, both the first direction detection unit 48 and the second direction detection unit 49 are provided on the principal optical axis O, and the right-angle prism 55 is provided on the common optical path of the first direction detection unit 48 and the second direction detection unit 49. Therefore, the incident positions of the light rays 12 incident on the first front lens group 56 and the light rays 12 incident on the second front lens group 62 with respect to the reflective surface 55a are substantially the same.

[0159] In the seventh embodiment, the light rays 12 incident on a portion of the prisms 4a to 4c and prism 4g are incident on the first front lens group 56, reflected at a right angle by the right-angle prism 55, and received by the first light receiving sensor 51 via the first rear lens group 53, etc. Also, the light rays 12 incident on the remaining portion of the prisms 4c to 4f and prism 4g are incident on the second front lens group 62, reflected at a right angle by the right-angle prism 55, and received by the second light receiving sensor 57 via the second rear lens group 59, etc. Therefore, based on the light receiving position of the light rays 12 to the first light receiving sensor 51 or the second light receiving sensor 57, it is possible to detect which prism 4 the light rays were incident on at what angle.

[0160] In the seventh embodiment, the first direction detection unit 48 and the second direction detection unit 49 enable the reception of light rays 12 from all directions. Therefore, since it is not necessary to receive the light rays 12 with a single direction detection unit, the constraints on lens design are reduced, and lens design can be simplified.

[0161] Next, a reflector 63 according to the eighth embodiment of the present invention will be described in Figures 17(A) and 17(B). In Figures 17(A) and 17(B), components equivalent to those in Figure 16 are denoted by the same reference numerals, and their descriptions are omitted.

[0162] In the eighth embodiment, the direction angle detector 64 has a reflective prism 65 instead of a right-angle prism 55. The other configurations are the same as in the seventh embodiment.

[0163] The reflective prism 65 is a trapezoidal square prism formed by joining two more triangular prisms, in contrast to the right-angle prism 55, which is a square prism formed by joining two triangular prisms.

[0164] The reflective prism 65 has a reflective surface 65a that reflects the light ray 12 incident on the first front lens group 56 at a right angle and on the same plane, and a reflective surface 65b that reflects the light ray 12 reflected by the reflective surface 65a at a right angle and in a direction perpendicular to the direction of incidence of the light ray 12 to the first front lens group 56. The reflective prism 65 also has a reflective surface 65a that reflects the light ray 12 incident on the second front lens group 62 at a right angle and on the same plane, and a reflective surface 65c that reflects the light ray 12 reflected by the reflective surface 65a at a right angle and in a direction perpendicular to the direction of incidence of the light ray 12 to the second front lens group 62.

[0165] Therefore, in the eighth embodiment, the first direction detection unit 48 and the second direction detection unit 49 are not arranged on the same principal optical axis, but rather the first direction detection unit 48 is arranged on the first principal optical axis and the second direction detection unit 49 is arranged on the second principal optical axis.

[0166] In the eighth embodiment, the light rays 12 incident on a portion of the prisms 4a-4c and prism 4g are incident on the first front lens group 56, reflected at a right angle by the reflective surface 65a of the reflecting prism 65, reflected again at a right angle by the reflective surface 65b, and received by the first light receiving sensor 51 via the first rear lens group 53, etc. Also, the light rays 12 incident on the remaining portion of the prisms 4d-4f and prism 4g are incident on the second front lens group 62, reflected at a right angle by the reflective surface 65a of the reflecting prism 65, reflected again by the reflective surface 65c, and received by the second light receiving sensor 57 via the second rear lens group 59, etc. Therefore, based on the light receiving position of the light rays 12 to the first light receiving sensor 51 or the second light receiving sensor 57, it is possible to detect which prism 4 the light rays were incident on at what angle.

[0167] In the eighth embodiment as well, the first direction detection unit 48 and the second direction detection unit 49 enable reception of the light rays 12 from all directions. Therefore, since it is not necessary to receive the light rays 12 with a single direction detection unit, the constraints on lens design are reduced, and lens design can be simplified.

[0168] Furthermore, since the first direction detection unit 48 and the second direction detection unit 49 are arranged in three dimensions, it is not necessary to secure a focal length in one direction, and the direction angle detector 64 can be miniaturized.

[0169] Next, a reflector 66 according to the ninth embodiment of the present invention will be described in Figures 18 to 20. In Figures 18 to 20, components equivalent to those in Figures 1 to 3 are denoted by the same reference numerals, and their descriptions are omitted.

[0170] The reflector 66 of the ninth embodiment has a prism section 67 composed of six prisms 4a to 4f, and does not have the prism 4g positioned in the zenith direction as in the first embodiment. Also, the upper surface 6b of the front lens group 6 in the direction angle detector 68 is coated with a reflective coating over its entire surface. The other configurations are the same as in the first embodiment.

[0171] Although the reflector 66 does not have the prism 4g, the prisms 4a to 4f can ensure a vertical angle of up to approximately ±70° when the principal optical axis O is vertical, except in the zenith direction and downwards.

[0172] Furthermore, the regions on the light-receiving sensor 11 corresponding to the prisms 4a to 4f are regions 11a to 11f, as shown in Figure 19(C), and the circular region 11g centered on the origin in the first embodiment does not exist.

[0173] In the ninth embodiment, the light rays 12 that have passed through the prisms 4a to 4f enter the front lens group 6, are internally reflected multiple times by the front lens group 6, and then pass through the rear lens group 8, etc., to be received in the regions 11a to 11f on the light receiving sensor 11. The light receiving sensor 11 emits a light receiving signal and position information corresponding to the light receiving position, and based on this position information, it is possible to detect which prism 4 of the prisms 4a to 4f the light rays 12 entered at what angle.

[0174] Next, a reflector 69 according to the tenth embodiment of the present invention will be described in Figure 21. In Figure 21, components equivalent to those in Figure 20 are denoted by the same reference numerals, and their descriptions are omitted.

[0175] In the tenth embodiment, the direction angle detector 71 has a free-form mirror 72 as a deflection optical element, instead of the front lens group 6 in the ninth embodiment. The other configurations are the same as those of the reflector 66 in the ninth embodiment.

[0176] The free-form mirror 72 has an axisymmetric free-form reflective surface 72a formed on its lower surface. The light rays 12 that have passed through the prisms 4a to 4f are reflected by the reflective surface 72a toward the rear lens group 8. The light rays 12 reflected by the reflective surface 72a are incident on predetermined positions in the regions 11a to 11f on the light receiving sensor 11 that correspond to the prisms 4a to 4f. The light receiving sensor 11 can detect which prism 4 of the prisms 4a to 4f the light rays 12 are incident on and at what angle, based on the light receiving signal and position information emitted in response to the reception of the light rays 12.

[0177] In the tenth embodiment as well, since the free-form mirror 72 is used instead of a lens as a deflecting optical element for deflecting the light ray 12, the manufacturing cost can be reduced.

[0178] Next, a reflector 73 according to the 11th embodiment of the present invention will be described in Figure 22. In Figure 22, components equivalent to those in Figure 13 are denoted by the same reference numerals, and their descriptions are omitted.

[0179] In the eleventh embodiment, the reflector 73 does not have a prism 4g positioned in the zenith direction, and is configured so that light rays 12 do not enter the fisheye lens 38 of the direction angle detector 74 from the zenith direction. The other configurations are the same as in the fourth embodiment.

[0180] Therefore, the reflector 73 can ensure a full 360° horizontal angle and a vertical angle of approximately ±35° vertically.

[0181] Light rays 12 that have passed through the circumferentially arranged prisms 4a to 4f enter the fisheye lens 38 except at the center of the upper surface 38a, and after passing through the fisheye lens 38, are received by the light receiving sensor 11 via the rear lens group 8. Based on the receiving position of the light rays 12 at this time, the light receiving sensor 11 can detect which prism 4 the light rays 12 entered at what angle of incidence.

[0182] Next, a reflector 75 according to the twelfth embodiment of the present invention will be described in Figure 23. In Figure 23, components equivalent to those in Figure 14 are denoted by the same reference numerals, and their descriptions are omitted.

[0183] In the twelfth embodiment, the reflector 75 does not have a prism 4g positioned in the zenith direction, and the direction angle detector 76 does not have a zenith front lens group 43 (see Figure 14) for receiving light rays 12 incident from the zenith direction. The other configurations are the same as in the fifth embodiment.

[0184] In the 12th embodiment, the light rays 12 incident from circumferentially arranged prisms 4a to 4f enter the free-form prism 42 from the incident surface 42a of the free-form prism 42, are internally reflected by the reflective surface 42b, and after passing through the transmissive surface 42c, are received by the light receiving sensor 11 via the rear lens group 8, etc.

[0185] Based on the position where the light ray 12 is received by the light receiving sensor 11 at this time, that is, which region of regions 11a to 11g it is incident on and which pixel in regions 11a to 11g it is received by, the prism 4 into which the light ray 12 is incident and the angle of incidence of the light ray 12 to the prism 4 can be detected.

[0186] In the twelfth embodiment as well, by using the free-form surface prism 42, the position of the incident pupil of the light ray 12 incident from the incident surface 42a can be designed to be at a position away from the principal optical axis O. Therefore, the area of ​​the transmitting surface of the prism 4, i.e., the upper bottom surface, can be reduced, and the amount of light ray 12 retroreflected by the reflector 75 can be increased. In other words, the distance over which the reflector 75 can be measured can be extended.

[0187] As described above, in the first to seventh embodiments, a prism section 2 consisting of prisms 4a to 4g is used, and in the eighth to twelfth embodiments, a prism section 67 consisting of prisms 4a to 4f is used. However, the prism sections applicable to each embodiment are not limited to these.

[0188] For example, Figures 24(A) to 24(C) show a prism section 86 according to the first modified example, and a reflector 87 may be constructed by combining the prism section 86 with the direction angle detector according to the first to seventh embodiments.

[0189] The prism section 86, which functions as a full-circumference prism, consists of six frustum-shaped prisms 88a to 88f, each having a triangular upper base and a trapezoidal lower base (incident surface), and one frustum-shaped prism 88g, each having a triangular upper and lower base.

[0190] Prisms 88a to 88f are arranged alternately in the circumferential direction with their lower surfaces inverted vertically. That is, prisms 88a, 88c, and 88e are arranged so that the shorter side of their lower surfaces faces upward, while prisms 88b, 88d, and 88f are arranged so that the shorter side of their lower surfaces faces downward. Furthermore, a direction angle detector is placed in the space formed by prisms 88a to 88f, and prism 88g is placed from above in this space so that its lower surface faces the zenith.

[0191] In the case of the reflector 87, a region corresponding to the prisms 88a to 88g is formed on the light receiving sensor 11, and the incident angle to the prisms 88a to 88g can be detected based on the light receiving position within that region.

[0192] Furthermore, Figures 25(A) to 25(C) show a prism section 89 according to a second modified example, and the reflector 91 may be constructed by combining the prism section 89 with the direction angle detector according to the eighth to twelfth embodiments. The prism section 89, as an all-around prism, is composed of six prisms 88a to 88f arranged in the circumferential direction, and is configured by removing the prism 88g, which is located on the zenith side, from the prism section 86. The other configurations of the reflector 91 are the same as those of the reflector 87.

[0193] Furthermore, Figures 26(A) to 26(C) show a prism section 92 according to a third modified example, and the reflector 93 may be constructed by combining this prism section 92 with the direction angle detector according to the first to seventh embodiments.

[0194] The prism section 92, which functions as a full-circumference prism, is composed of frustum-shaped prisms 94a to 94g, each having a triangular upper base and a circular lower base (incident surface). The prisms 94a to 94g each have three inclined surfaces, and the triangular upper base is formed by cutting off the corner vertices. As shown in Figure 26(C), the prisms 94a to 94g may be chamfered on the parts of the lower base that protrude in the vertical direction to reduce their vertical size.

[0195] The prisms 94a to 94g are arranged circumferentially, rotated by a predetermined angle relative to adjacent prisms around an axis passing through the center of the upper base and the center of the lower base. For example, prism 94b is positioned rotated 60° around the axis of prism 94a. Similarly, prism 94c is positioned rotated 60° around the horizontal axis relative to prism 94b, prism 94d is positioned rotated 60° around the horizontal axis relative to prism 94c, prism 94e is positioned rotated 60° around the horizontal axis relative to prism 94d, and prism 94a is positioned rotated 60° around the horizontal axis relative to prism 94e. The horizontal axes of each prism 94a to 94f intersect or nearly intersect at, for example, the reference point of the reflector 93.

[0196] Furthermore, a direction angle detector is placed in the space formed by the prisms 94a to 94f, and the prism 94g is placed from above in the space such that its lower surface faces the zenith.

[0197] In the case of the reflector 93, a region corresponding to the prisms 94a to 94g is formed on the light receiving sensor 11, and the angle of incidence to the prisms 94a to 94g can be detected based on the light receiving position within that region.

[0198] Furthermore, Figures 27(A) to 27(C) show a prism section 95 according to a fourth modified example, and a reflector 96 may be constructed by combining this prism section 95 with the direction angle detector according to the eighth to twelfth embodiments. The prism section 95, as an all-around prism, is composed of six prisms 94a to 94f arranged in the circumferential direction, and is configured by removing the prism 94g, which is located on the zenith side, from the prism section 92. The other configurations of the reflector 96 are the same as those of the reflector 93.

[0199] Furthermore, Figure 28(A) shows a prism section 97 according to a fifth modified example, and the reflector 98 may be constructed by combining this prism section 97 with the direction angle detector according to the first to twelfth embodiments. The prism section 97, as a full-circumference prism, is a full-circumference octahedron prism using eight truncated square pyramidal prisms 4. In this case, as shown in Figure 28(B), the direction angle detector is arranged in the space 5 formed inside. The light rays 12 incident from the prisms 4 are deflected by the polarizing optical member and received by the light receiving sensor 11.

[0200] Furthermore, in the case of the reflector 98, if the light rays 12 from the zenith direction are not required, such as by installing a GPS in the zenith direction, the direction angle detector according to the 8th to 12th embodiments can be applied, and if the light rays 12 from the zenith direction are required, the direction angle detector according to the 1st to 7th embodiments can be applied.

[0201] Furthermore, Figure 29(A) shows a prism section 99 according to a sixth modified example, and the reflector 101 may be constructed by combining this prism section 99 with the direction angle detector according to the first to twelfth embodiments. The prism section 99 is a full-circumference prism of a regular square pyramid using four truncated square pyramidal prisms 4. In this case, as shown in Figure 29(B), the direction angle detector is arranged in a space 5 formed in the center of the lower surface. The light rays 12 incident from the prisms 4 are deflected by the polarizing optical member and received by the light receiving sensor 11.

[0202] Furthermore, similar to the reflector 98, if the reflector 101 does not require the light rays 12 from the zenith direction, such as by installing a GPS in the zenith direction, the direction angle detector according to the 8th to 12th embodiments can be applied. If the light rays 12 from the zenith direction are required, the direction angle detector according to the 1st to 7th embodiments can be applied.

[0203] Furthermore, it goes without saying that the direction angle detectors according to the first to twelfth embodiments may be combined with prism sections having configurations other than those described above to form a reflector.

[0204] Furthermore, in the first to twelfth embodiments and their modifications, the full-circumference prism (prism section) is composed of at least six prisms arranged in the circumferential direction. However, the prism section of the reflector of the present invention is not limited to a full-circumference prism. For example, a full-circumference prism may be composed of four prisms arranged in the circumferential direction, or of eight prisms arranged in the circumferential direction. That is, a full-circumference prism can be composed of multiple (at least two or more) prisms arranged in the circumferential direction and applied to the reflector in the first to twelfth embodiments.

[0205] Furthermore, the prism section is not limited to a full-circumference prism. For example, in the first to twelfth embodiments, one prism may be removed from the six circumferentially arranged prisms, and a wide-angle prism may be constructed using the five circumferentially arranged prisms, which can then be applied to the reflector in the first to twelfth embodiments. Here, "wide angle" means, for example, a range of 120° to 315°. The wide-angle prism may be constructed using four or fewer prisms arranged in the circumferential direction, or it may be constructed using seven or more prisms arranged in the circumferential direction. That is, a wide-angle prism can be constructed using at least multiple (at least two or more) prisms arranged in the circumferential direction and applied to the reflector in the first to twelfth embodiments. [Explanation of Symbols]

[0206] 1 reflector 2 Prism section 3-way angle detector 4 prisms 5 Space 11. Light receiving sensor 12 rays 29 Reflector 33 Reflector 36 Reflectors 39 Reflector 43 Reflector 46 Reflectors 63 Reflector 66 Reflector 73 Reflector 75 Reflector

Claims

1. A reflector comprising a prism section comprising a plurality of prisms arranged in at least a portion of the circumferential direction to constitute a wide-angle prism, and a direction angle detector disposed in a space formed within the prism section, wherein the prism is configured to reflect a portion of the incident light ray and transmit the remainder, and the direction angle detector includes a deflection optical member that deflects the light ray that has passed through the prism, an imaging lens, and a light receiving sensor, wherein the light ray deflected by the deflection optical member is incident on the imaging lens, is imaged by the imaging lens and onto the light receiving sensor, and outputs position information including the prism on which the light ray was incident and the angle of incidence to the prism based on the light receiving position of the light receiving sensor.

2. The reflector according to claim 1, configured such that the light rays incident on the prism are received within a specific region on the light receiving sensor corresponding to each prism.

3. The reflector according to claim 1, wherein the deflection optical member is a lens that internally reflects the light rays incident from the side multiple times.

4. The reflector according to claim 1, wherein the deflection optical member is a free-form mirror having a free-form reflective surface.

5. The reflector according to claim 1, wherein the deflection optical member is a fisheye lens with a field of view of 180° or more.

6. The deflection optical member is a prism having a reflective surface that internally reflects the light rays incident from the incident surface, and the reflecting surface is an axisymmetric free-form surface as described in claim 1.

7. The reflector according to claim 1, wherein the deflection optical member is a lens that internally reflects the light ray incident from the side multiple times, and the side is an axially symmetric free-form surface that can receive the light ray in a range of 300° excluding the vertically downward direction.

8. The directional angle detector comprises a first direction detection unit including a first deflection optical member, a first imaging lens, and a first light receiving sensor, and a second direction detection unit including a second deflection optical member, a second imaging lens, and a second light receiving sensor, wherein the first deflection optical member and the second deflection optical member are arranged on a common optical path and have a right-angle prism having a reflective surface, and the right-angle prism is configured to reflect the light ray incident on the first direction detection unit and the light ray incident on the second direction detection unit at a right angle and in opposite directions on the front and back surfaces of the reflective surface, as described in claim 1.

9. The directional angle detector comprises a first direction detection unit including a first deflection optical member, a first imaging lens, and a first light receiving sensor, and a second direction detection unit including a second deflection optical member, a second imaging lens, and a second light receiving sensor, wherein the first deflection optical member and the second deflection optical member are arranged on a common optical path and have a reflective prism having two reflective surfaces, and the reflective prism is configured to reflect the light ray incident on the first direction detection unit and the light ray incident on the second direction detection unit at right angles and in opposite directions on the front and back of one of the reflective surfaces, and further reflect at a right angle and in the same direction on the other reflective surface, as described in claim 1.

10. The reflector according to any one of claims 1 to 7, wherein the prism portion further comprises a zenith prism that receives the light rays from the zenith direction.

11. The reflector according to claim 10, wherein the direction angle detector further comprises a zenith deflection optical member that deflects only the light rays incident from the zenith prism.

12. The reflector according to any one of claims 1 to 7, wherein the prism is a frustum-shaped prism with a triangular upper base and a trapezoidal lower base, and the prism portion is configured such that the prisms are alternately arranged in the circumferential direction while inverting their lower bases vertically.

13. The reflector according to any one of claims 1 to 7, wherein the prism is a frustum-shaped prism with a triangular upper base and a circular lower base, and the prism portion is configured such that each prism is arranged in a state where it is rotated about an axis relative to adjacent prisms.

14. The reflector according to any one of claims 1 to 7, wherein the prism section is arranged such that the eight prisms of the truncated square pyramid form a regular octahedron.

15. The reflector according to any one of claims 1 to 7, wherein the prism section is arranged such that the four prisms of the truncated square pyramid form a regular square pyramid.

16. A surveying system comprising a target device provided with a reflector according to claim 1, and a surveying device capable of measuring the reflector, wherein the target device has a communication unit for transmitting light reception position information emitted by the light receiving sensor to the surveying device, the surveying device has pre-existing table data relating the angle of incidence to the prism and the amount of correction of the measurement result, and is configured to detect the incident prism and the angle of incidence to the prism based on the position information received from the target device, and to correct the measurement result of the reflector based on the angle of incidence.

17. The surveying system according to claim 16, wherein the target device further comprises a pole installed at a measurement point and configured such that its axis passes through a reference point of the reflector, and a tilt detector capable of detecting the verticality of the pole, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

18. The surveying system according to claim 16, wherein the target device further comprises a pole installed at a measurement point and configured such that its axis passes through a reference point of the reflector, and a tilt detector capable of detecting the two-axis tilt of the pole with respect to the horizontal, and the surveying device is configured to measure the measurement point based on the measurement result of the reflector, the detection result of the tilt detector, and a known distance from the reference point to the lower end of the pole, and to correct the measurement result of the measurement point based on the angle of incidence to the prism.

19. The surveying system according to claim 16, wherein the target device further comprises a pole installed at the measurement point and configured such that its axis passes through the reference point of the reflector, the direction angle detector functions as a polarizing camera capable of detecting a left-right tilt relative to the surveying device, the surveying device emits distance measuring light of a predetermined polarization, measures the measurement point based on the measurement result of the reflector, the left-right tilt angle obtained by the polarizing camera, the front-back tilt angle and direction angle detected based on the angle of incidence to the prism, and a known distance from the reference point to the lower end of the pole, and corrects the measurement result of the measurement point based on the angle of incidence to the prism.

20. The surveying system according to claim 16, wherein the target device is a handheld scanner capable of acquiring point cloud data of an object to be measured, the handheld scanner further includes a tilt detector capable of detecting a two-axis tilt with respect to the horizontal, and the surveying device 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 device, based on the measurement result of the reflector and the detection result of the tilt detector, and to correct the point cloud data of the object to be measured based on the angle of incidence to the prism.

21. A method for surveying a reference point using a reflector according to claim 1, wherein the reflector according to claim 1 is installed at least known point 2 of known points 1 and 2, a surveying device is installed at new point 1, the known points 1 and 2 are measured by the surveying device, new point 1 is made known by the resection method, the direction angle of new point 1 is detected with the reflector at known point 2, then the surveying device is installed at new point 2, the 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 angle of new point 1 detected by the reflector, the direction angle of new point 2, and the measurement result obtained by measuring the known point 2 from new point 2.

Images