Surveying device

Abstract

The present invention is provided with: a distance measurement unit that has a light-emitting element (28) for emitting distance measurement light and a light-receiving element for receiving distance measurement light reflected from a to-be-measured object; rotating deflection parts (15, 23, 24) that direct the distance measurement light; a vertical rotation drive unit (13) that rotates the rotating deflection parts in the vertical direction via a hollow vertical rotation shaft (11); a frame part (5) in which the rotating deflection parts are provided; a horizontal rotation drive unit (8) that rotates the frame part in the horizontal direction; and an arithmetic control unit (17) that computes the distance to the to-be-measured object on the basis of the result of the light-receiving element receiving the reflected distance measurement light. The rotating deflection parts have an emitted-light deflection section that is formed at a central portion and deflects the distance measurement light at a right angle, and a received-light deflection section that is formed at a portion other than the central portion and deflects the reflected distance measurement light at a right angle. The distance measurement light passes through the vertical rotation shaft and is then incident on the emitted-light deflection section. The reflected distance measurement light is incident on the received-light deflection section and deflected in an orientation opposite to the light-emitting element.

Description

surveying equipment

[0001] The present invention relates to a surveying instrument capable of acquiring three-dimensional coordinates of a measurement object.

[0002] Surveying instruments such as laser scanners and total stations have optical distance measuring devices that detect the distance to an object to be measured using prism distance measurement, which uses a retroreflective prism as the object to be measured, or non-prism distance measurement, which does not use a reflective prism.

[0003] In conventional optical distance measuring devices, the distance measuring light emitting section that emits the distance measuring light and the distance measuring light receiving section that receives the reflected distance measuring light are incorporated into a single optical system, and a deflecting optical member is required to make the optical axis of the distance measuring light and the optical axis of the reflected distance measuring light coaxial, which leads to an increase in the size of the optical system and the entire surveying device.

[0004] US Patent Application Publication No. 2022 / 0373685

[0005] The present invention provides a surveying instrument that allows for miniaturization of the optical system and the entire instrument.

[0006] The present invention relates to a surveying instrument comprising a distance measuring unit having a light emitting element that emits distance measuring light and a light receiving element that receives the reflected distance measuring light from the object to be measured, a rotary deflection unit that irradiates the distance measuring light, a vertical rotation drive unit that rotates the rotary deflection unit vertically via a hollow vertical rotation axis, a base unit on which the rotary deflection unit is mounted, a horizontal rotation drive unit that rotates the base unit horizontally, and an arithmetic control unit that calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light at the light receiving element, wherein the rotary deflection unit has a light projecting deflection unit formed in the center that deflects the distance measuring light at a right angle, and a light receiving deflection unit formed other than at the center that deflects the reflected distance measuring light at a right angle, and the distance measuring light passes through the vertical rotation axis and enters the light projecting deflection unit, and the reflected distance measuring light enters the light receiving deflection unit and is deflected in the direction opposite to the light emitting element.

[0007] The present invention also relates to a surveying instrument in which the light receiving deflection unit is a cylinder with a reflective surface formed at its end that deflects the optical axis of the reflected distance measuring light at a right angle, the light projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the light receiving deflection unit that is parallel to the optical axis of the distance measuring light, and a light projecting mirror provided in the through hole, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

[0008] The present invention also relates to a surveying instrument in which the light receiving deflection unit is a cylinder with a reflecting surface formed at its end that deflects the optical axis of the reflected distance measuring light at a right angle, and the light projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the light receiving deflection unit that is parallel to the optical axis of the distance measuring light, a cylinder inserted into the through hole, a light projecting mirror provided at the end of the cylinder, and an opening formed in the cylinder on the reflected optical axis of the light projecting mirror, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

[0009] The present invention also relates to a surveying instrument in which the light receiving deflection unit is a cylinder with a reflective surface formed at its end that deflects the optical axis of the reflected distance measuring light at a right angle, the light projecting deflection unit is connected to the hollow portion of the vertical rotation axis, has a through hole formed in the light receiving deflection unit that is parallel to the optical axis of the distance measuring light, and has a metamaterial provided in the through hole.

[0010] The present invention also relates to a surveying instrument in which the light receiving deflection unit is a cylinder with a reflective surface formed at its end that deflects the optical axis of the reflected distance measuring light at a right angle, and the light projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and has a through hole formed in the light receiving deflection unit that is parallel to the optical axis of the distance measuring light, and a diffraction grating provided in the through hole.

[0011] The present invention also relates to a surveying instrument in which the light receiving deflection section has a reflecting surface of an off-axis parabolic mirror.

[0012] The present invention also relates to a surveying instrument in which the light receiving deflection section is a plate-shaped mirror, the light projecting deflection section is connected to the hollow section of the vertical rotation shaft, has a through hole formed in the light receiving deflection section that is parallel to the optical axis of the distance measuring light, and a light projecting mirror provided in the through hole, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

[0013] The present invention also relates to a surveying instrument in which the light receiving deflection section is a plate-shaped mirror, the light projecting deflection section is connected to the hollow section of the vertical rotation shaft, and comprises a through hole formed in the light receiving deflection section parallel to the optical axis of the distance measuring light, a cylindrical section inserted into the through hole, a light projecting mirror provided at the end of the cylindrical section, and an opening formed in the cylindrical section on the reflected optical axis of the light projecting mirror, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

[0014] The present invention also relates to a surveying instrument in which the light receiving deflection section is a plate-shaped mirror, the light projecting deflection section is connected to the hollow section of the vertical rotation shaft, and the surveying instrument comprises a through hole formed in the light receiving deflection section parallel to the optical axis of the distance measuring light, a cylindrical section inserted into the through hole, a plate-shaped mirror provided at the end of the cylindrical section, and an opening formed on the reflected optical axis of the mirror in the cylindrical section.

[0015] The present invention also relates to a surveying instrument in which the rotary deflection section has a plate-shaped metamaterial, the center of which forms the light-projecting deflection section on which a transparent film is vapor-deposited, and the rest of the metamaterial forms the light-receiving deflection section on which a reflective film is vapor-deposited.

[0016] Furthermore, the present invention relates to a surveying instrument in which the rotary deflection unit has a plate-shaped diffraction grating, the center of which forms the light-projecting deflection unit on which a transparent film is vapor-deposited, and the area other than the center of the diffraction grating forms the light-receiving deflection unit on which a reflective film is vapor-deposited.

[0017] According to the present invention, a distance measuring device includes a light emitting element that emits distance measuring light and a light receiving element that receives the reflected distance measuring light from an object to be measured, a rotary deflector that emits the distance measuring light, a vertical rotary drive unit that rotates the rotary deflector in the vertical direction via a hollow vertical rotary shaft, a base unit on which the rotary deflector is provided, a horizontal rotary drive unit that rotates the base unit in the horizontal direction, and a calculation control unit that calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light at the light receiving element, The deflection unit has a light-projecting deflection unit formed in the center and deflecting the distance-measuring light at a right angle, and a light-receiving deflection unit formed outside the center and deflecting the reflected distance-measuring light at a right angle.The distance-measuring light passes through the vertical rotation axis and enters the light-projecting deflection unit, and the reflected distance-measuring light enters the light-receiving deflection unit and is deflected in the opposite direction to the light-emitting element.Therefore, there is no need to incorporate the light-emitting element and the light-receiving element into a single optical system, which makes it possible to miniaturize the optical system and the entire device.

[0018] FIG. 1 is a front cross-sectional view showing a surveying instrument according to a first embodiment. FIG. 2 is an enlarged view of the main parts showing the light-projecting unit and the light-receiving unit according to the first embodiment. FIG. 3(A) is an explanatory diagram showing a first modified example, FIG. 3(B) is an explanatory diagram showing a second modified example, and FIG. 3(C) is an explanatory diagram showing a third modified example. FIG. 4 is an enlarged view of the main parts showing the light-projecting unit and the light-receiving unit according to the second embodiment. FIG. 5(A) is an explanatory diagram showing a first modified example, and FIG. 5(B) is an explanatory diagram showing a second modified example. FIG. 6(A) is an explanatory diagram showing a third modified example, and FIG. 6(B) is an explanatory diagram showing a fourth modified example. FIG. 7(A) is an explanatory diagram showing a fifth modified example, and FIG. 7(B) is an explanatory diagram showing a sixth modified example.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] First, a surveying instrument according to a first embodiment of the present invention will be described with reference to FIGS.

[0021] The surveying instrument 1 is, for example, a laser scanner, and is composed of a leveling unit 2 attached to a tripod (not shown), and a surveying instrument main body 3 attached to the leveling unit 2 .

[0022] The leveling unit 2 has a leveling screw 10, which is used to level the surveying instrument main body 3 horizontally.

[0023] The surveying instrument main body 3 is equipped with (contains) a fixed section 4, a base section 5, a horizontal rotation shaft 6, a horizontal rotation bearing 7, a horizontal rotation motor 8 as a horizontal rotation drive section, a horizontal angle encoder 9 as a horizontal angle detector, a vertical rotation shaft 11, a vertical rotation bearing 12, a vertical rotation motor 13 as a vertical rotation drive section, a vertical angle encoder 14 as a vertical angle detector, a light-receiving mirror 15, an operation panel 16 that serves both as an operation section and a display section, an arithmetic and control section 17, a memory section 18, a light-projecting section 19, a light-receiving section 21, etc. The arithmetic and control section 17 may be a CPU specialized for this instrument or a general-purpose CPU.

[0024] The horizontal rotation bearing 7 is fixed to the fixed part 4. The horizontal rotation shaft 6 has a vertical axis 6a, and the horizontal rotation shaft 6 is rotatably supported by the horizontal rotation bearing 7. In addition, the base part 5 is supported by the horizontal rotation shaft 6, and the base part 5 rotates integrally with the horizontal rotation shaft 6 in the horizontal direction.

[0025] The horizontal rotation motor 8 is provided between the horizontal rotation bearing 7 and the base frame 5, and the horizontal rotation motor 8 is controlled by the arithmetic and control unit 17. The arithmetic and control unit 17 causes the horizontal rotation motor 8 to rotate the base frame 5 about the axis 6a.

[0026] The relative rotation angle of the base part 5 with respect to the fixed part 4 is detected by the horizontal angle encoder 9. A detection signal from the horizontal angle encoder 9 is input to the calculation control part 17, which calculates horizontal angle data. The calculation control part 17 performs feedback control on the horizontal rotation motor 8 based on the horizontal angle data.

[0027] The base 5 is provided with the vertical rotation shaft 11 having a horizontal axis 11a. The vertical rotation shaft 11 is rotatable via the vertical rotation bearing 12. The intersection of the axis 6a and the axis 11a is the emission position of the distance measuring light, and is the origin of the coordinate system of the surveying device main body 3.

[0028] A recess 22 is formed in the base frame 5. The vertical rotation shaft 11 is hollow, and one end thereof extends into the recess 22. The light-receiving mirror 15 is fixed to the one end of the vertical rotation shaft 11, and the light-receiving mirror 15 is housed in the recess 22.

[0029] The light-receiving mirror 15 is a cylindrical body formed by cutting the end of a cylindrical glass or metal material such as aluminum to form a reflective surface on the end. The reflective surface is an off-axis paraboloid and is configured to deflect the incident light-receiving optical axis 41 (described below) at a right angle. For example, the light-receiving mirror 15 is a rod mirror that deflects the light-receiving optical axis 41 at a right angle. A cylindrical through-hole 23 is formed in the center of the light-receiving mirror 15, communicating with the hollow portion of the vertical rotation shaft 11 and concentric with the vertical rotation shaft 11. One end of the through-hole 23 opens into the recess 22 via the reflective surface of the light-receiving mirror 15, and the lower end of the opening protrudes laterally a predetermined distance beyond the upper end of the opening. A light-projecting mirror 24 is provided at the open end of the through-hole 23 as a deflection optical member that protrudes upward from the mirror surface of the light-receiving mirror 15. The light receiving mirror 15 may have a reflective surface that is a free-form surface, or a reflective surface that is a ring-shaped free-form surface.

[0030] The light projecting mirror 24 is a cylindrical body formed by cutting the end of a cylindrical glass or metal material to form a reflecting surface. The reflecting surface is configured to deflect the horizontally incident distance measurement light axis 27 (described later) at a right angle. For example, the light projecting mirror 24 is a 45° rod mirror that deflects the distance measurement light axis 27 at a right angle. The intersection of the axis 6a and the axis 11a, i.e., the mechanical center (origin of the coordinate system) of the surveying device main body 3, is located on the reflecting surface. The peripheral surface of the light projecting mirror 24 is cylindrical in shape to match the shape of the through-hole 23, and the light projecting mirror 24 is bonded to fit into the through-hole 23. The end face of the light projecting mirror 24 opposite the vertical rotation axis 11 is a vertical surface parallel to the axis 6a, and the light projecting mirror 24 is positioned so that the lower end of the end face coincides or nearly coincides with the lower end of the opening end of the through-hole 23. That is, a gap 30 of a predetermined dimension is formed between the upper end of the opening end of the through hole 23 and the upper end of the end face of the light projecting mirror 24. The gap 30 is larger than the beam diameter of a distance measuring light 29 (described later) and a tracking light 33 (described later).

[0031] In the above description, the through hole 23 is cylindrical, but the through hole 23 is not limited to a cylindrical shape and may be, for example, a hole having a rectangular cross section. The light projecting mirror 24 is appropriately designed to have a rectangular shape or the like in accordance with the shape of the through hole 23.

[0032] The vertical angle encoder 14 is provided at the other end of the vertical rotation shaft 11. The light projecting unit 19 is provided at a position separated from the other end of the vertical rotation shaft 11. The light projecting unit 19 is composed of a distance measuring light emitting unit 25 and a tracking light emitting unit 26.

[0033] The distance measurement light emitting unit 25 has the distance measurement optical axis 27. The distance measurement light emitting unit 25 also has, in order from the light emitting side, a light emitting element 28 provided on the distance measurement optical axis 27, for example, a laser diode (LD) that emits near-infrared light of a predetermined wavelength as the distance measurement light 29, a light projecting lens 31, a dichroic mirror 32, and the light projecting mirror 24 provided on the transmission optical axis of the dichroic mirror 32.

[0034] The dichroic mirror 32 has optical properties that allow the distance measurement light 29 to pass through and the tracking light 33 to reflect. The dichroic mirror 32 is provided on a common optical path of the distance measurement light 29 and the tracking light 33 (at the intersection of the distance measurement optical axis 27 and a tracking optical axis 34 (described later)). The dichroic mirror 32 deflects (reflects) the tracking optical axis 34 so that the tracking optical axis 34 coincides with the distance measurement optical axis 27 that has passed through the dichroic mirror 32. Therefore, the distance measurement light 29 and the tracking light 33 are incident on the light projecting mirror 24 coaxially and are reflected by the light projecting mirror 24 at a right angle.

[0035] The distance measurement optical axis 27 is deflected in the process of passing through the dichroic mirror 32, and the deflected distance measurement optical axis 27 coincides with the axis center 11a. Therefore, the tracking optical axis 34 reflected by the dichroic mirror 32 also coincides with the axis center 11a.

[0036] The tracking light emitting unit 26 has the tracking optical axis 34. The tracking light emitting unit 26 also has, in order from the light emitting side, a tracking light emitting element 35 provided on the tracking optical axis 34, for example, a laser diode (LD) that emits near-infrared light having a wavelength different from that of the distance measuring light 29 as the tracking light 33, a tracking projection lens 36, the dichroic mirror 32, and the projection mirror 24 provided on the reflected optical axis of the dichroic mirror 32.

[0037] Also, on the axis 6a at a position facing the light-receiving mirror 15, there is provided a window 37 made of a transparent material such as glass, which rotates integrally with the light-receiving mirror 15. The window 37 is inclined at a predetermined angle with respect to the axis 6a. The light-receiving mirror 15 constitutes a light-receiving deflection section, and the through-hole 23 and the light-projecting mirror 24 constitute a light-projecting deflection section. Furthermore, the light-receiving deflection section and the light-projecting deflection section constitute a rotary deflection section which is rotated integrally in the vertical direction by the vertical rotary motor 13 via the vertical rotation shaft 11.

[0038] The vertical rotation motor 13 is provided on the vertical rotation shaft 11, and the vertical rotation motor 13 is controlled by the arithmetic and control unit 17. The arithmetic and control unit 17 rotates the vertical rotation shaft 11 using the vertical rotation motor 13, and the light receiving mirror 15 and the light projecting mirror 24 rotate around the axis 11a.

[0039] The rotation angle of the light-receiving mirror 15 is detected by the vertical angle encoder 14, and the detection signal is input to the calculation control unit 17. The calculation control unit 17 calculates vertical angle data of the light-receiving mirror 15 based on the detection signal, and performs feedback control on the vertical rotation motor 13 based on the vertical angle data.

[0040] The horizontal angle data, vertical angle data, and measurement results calculated by the calculation control unit 17 are stored in the memory unit 18. The memory unit 18 may be a magnetic storage device such as an HDD, an optical storage device such as a CD or DVD, a semiconductor storage device such as a memory card, or a USB memory. The memory unit 18 may be detachable from the base unit 5, or may be capable of transmitting data to an external storage device or external data processing device via a communication device (not shown).

[0041] The storage unit 18 stores various programs such as a sequence program for controlling the distance measurement operation, an arithmetic program for calculating distance by the distance measurement operation, an arithmetic program for calculating an angle based on horizontal angle data and vertical angle data, a program for calculating the three-dimensional coordinates of a desired measurement point based on the distance and angle, a tracking program for tracking a target, etc. Furthermore, various processes are performed by the arithmetic control unit 17 executing the various programs.

[0042] The operation panel 16 is, for example, a touch panel, and serves as both an operation section for issuing distance measurement instructions and changing measurement conditions, such as the measurement point interval, and a display section for displaying distance measurement results, images, and the like.

[0043] Next, the light receiving section 21 will be described with reference to Fig. 2. In this embodiment, a target having retroreflectivity, such as a prism, is used as the object to be measured.

[0044] The light receiving section 21 has a distance measuring light receiving section 38 and a tracking light receiving section 39. The distance measuring light emitting section 25 and the distance measuring light receiving section 38 form a distance measuring section, and the tracking light emitting section 26 and the tracking light receiving section 39 form a tracking section.

[0045] The distance measurement light receiving section 38 has a light receiving optical axis 41. The distance measurement light receiving section 38 also has, in order from the light receiving side, a light receiving element 42 and a light receiving prism 43 provided on the light receiving optical axis 41.

[0046] The light-receiving prism 43 has a dichroic film 44 as a separation surface. The light-receiving prism 43 is configured to internally reflect at least once the distance-measuring light 29 (reflected distance-measuring light 45) reflected by the object to be measured and the tracking light 33 (reflected tracking light 46) incident coaxially with the reflected distance-measuring light 45. The dichroic film 44 has optical properties that reflect the reflected distance-measuring light 45 and transmit the reflected tracking light 46.

[0047] In this embodiment, the light receiving optical axis 41 and the light receiving optical axis 41 reflected by the light receiving prism 43 and the dichroic film 44 are collectively referred to as the light receiving optical axis 41 .

[0048] The tracking light receiving unit 39 has a tracking light receiving optical axis 47. The tracking light receiving unit 39 also has, in order from the light receiving side, a tracking light receiving element 48 provided on the tracking light receiving optical axis 47, and the light receiving prism 43. In this embodiment, the tracking light receiving optical axis 47 and the tracking light receiving optical axis 47 reflected by the light receiving prism 43 are collectively referred to as the tracking light receiving optical axis 47.

[0049] The tracking light receiving element 48 is a CCD or CMOS sensor that is a collection of pixels, and the position of each pixel can be specified on the tracking light receiving element 48. For example, each pixel has pixel coordinates with the center of the tracking light receiving element 48 as the origin, and the position on the tracking light receiving element 48 is specified by the pixel coordinates.

[0050] The light-projecting unit 19 and the light-receiving unit 21 are controlled by the arithmetic and control unit 17. When the pulsed distance-measuring light 29 is emitted from the light-emitting element 28 onto the distance-measuring optical axis 27, it passes through the light-projecting lens 31 and the dichroic mirror 32, passes through the interior of the vertical rotation shaft 11 and the through-hole 23, and is incident on the reflecting surface of the light-projecting mirror 24. The distance-measuring light 29 is deflected at a right angle by the light-projecting mirror 24, passes through the gap 30, and passes through the window 37 to be irradiated onto the measurement object. As the light-projecting mirror 24 rotates integrally with the light-receiving mirror 15 around the axis 11a, the distance-measuring light 29 rotates (scans) within a plane perpendicular to the axis 11a and including the axis 6a.

[0051] The reflected distance measuring light 45 reflected by the object to be measured passes through the window 37 and enters the light receiving mirror 15 coaxially with the distance measuring light 29. The reflected distance measuring light 45 is reflected by the light receiving mirror 15 at a right angle and so as to be collected, is reflected by the dichroic film 44 while passing through the light receiving prism 43, and is received by the light receiving element 42.

[0052] The light receiving optical axis 41 of the reflected distance measuring light 45 reflected by the light receiving mirror 15 is coaxial with the distance measuring optical axis 27 transmitted through the dichroic mirror 32. That is, the distance measuring optical axis 27 and the light receiving optical axis 41 coincide with the axis 11a.

[0053] Furthermore, since the window portion 37 is inclined at a predetermined angle with respect to the distance measurement optical axis 27, the distance measurement light 29 reflected by the window portion 37 is prevented from being reflected by the light receiving mirror 15 and received by the light receiving element 42.

[0054] The calculation control unit 17 measures the distance for each pulse of the distance measuring light 29 (Time Of Flight) based on the time difference between the light emission timing of the light emitting element 28 and the light reception timing of the light receiving element 42 (i.e., the round-trip time of the pulsed light) and the speed of light, and calculates the distance to the object to be measured. The light emission timing of the light emitting element 28, i.e., the pulse interval, can be changed via the operation panel 16. Furthermore, the three-dimensional coordinates of the object to be measured can be calculated based on the distance measurement result and the horizontal angle data and vertical angle data obtained by the horizontal angle encoder 9 and the vertical angle encoder 14.

[0055] Furthermore, by rotating the base frame 5 and the light-receiving mirror 15 (the light-projecting mirror 24) at a constant speed while emitting the distance-measuring light 29 at a predetermined pulse interval, the vertical rotation of the light-receiving mirror 15 and the horizontal rotation of the base frame 5 cooperate to perform two-dimensional scanning with the distance-measuring light 29. Furthermore, by detecting the vertical angle and the horizontal angle for each pulse of light using the vertical angle encoder 14 and the horizontal angle encoder 9, vertical angle data and horizontal angle data can be obtained. From the vertical angle data, horizontal angle data and distance measurement data, the three-dimensional coordinates of the object to be measured and three-dimensional point cloud data corresponding to the object to be measured can be obtained.

[0056] In parallel with the distance measurement operation, the tracking light 33, which is near-infrared light having a different wavelength from the distance measurement light 29 and is emitted from the tracking light emitting element 35, is slightly diverged by the tracking projection lens 36, and then deflected by the dichroic mirror 32 so as to be coaxial with the distance measurement light 29. Furthermore, the tracking light 33 passes through the inside of the vertical rotation shaft 11 and the through hole 23, is reflected at a right angle by the projection mirror 24, passes through the gap 30 and the window portion 37, and is irradiated onto the object to be measured.

[0057] The reflected tracking light 46 is irradiated onto the measurement object coaxially with the distance measuring light 29 and reflected by the measurement object, passes through the window 37, is reflected by the light receiving mirror 15 at a right angle and is collected, and is incident on the light receiving prism 43. In the process of passing through the light receiving prism 43, the reflected tracking light 46 incident on the light receiving prism 43 is separated from the reflected distance measuring light 45 by the dichroic film 44, passes through the dichroic film 44, and is received by the tracking light receiving element 48. In addition, a tracking image (not shown) can be obtained by receiving the reflected tracking light 46 at the tracking light receiving element 48.

[0058] The calculation control unit 17 is configured to calculate the position deviation between the center of the tracking light receiving element 48 and the receiving position of the reflected tracking light 46 relative to the tracking light receiving element 48, and based on the position deviation, drive the horizontal rotation motor 8 and the vertical rotation motor 13 to track the object to be measured.

[0059] As described above, in the first embodiment, the light-projecting unit 19 and the light-receiving unit 21 are arranged on opposite sides of the light-receiving mirror 15. Therefore, it is not necessary to incorporate the light-projecting unit 19 and the light-receiving unit 21 into one optical system, and a deflecting optical member for deflecting the distance measuring light 29 and the reflected distance measuring light 45 so that they are coaxial is not required, which reduces the number of parts and enables the optical system and the surveying instrument 1 as a whole to be made smaller.

[0060] The vertical rotation shaft 11 is hollow, and the light-receiving mirror 15 is formed with the through-hole 23 that is concentric with the vertical rotation shaft 11 and communicates with the hollow portion. The light-projecting mirror 24 that rotates integrally with the light-receiving mirror 15 and deflects the distance-measuring light 29 at a right angle is provided in the through-hole 23.

[0061] Therefore, the distance measuring optical axis 27 and the light receiving optical axis 41 can be made coaxial, and measurement accuracy can be improved.

[0062] Moreover, since it is only necessary to form the through-hole 23 in the light-receiving mirror 15 and provide the light-projecting mirror 24 in the through-hole 23, the manufacturing is easy and the manufacturing cost can be reduced.

[0063] Furthermore, since the light-receiving mirror 15 is an off-axis parabolic mirror, there is no need to provide a light-receiving lens for converging the reflected distance-measuring light 45, which reduces the number of parts and also shortens the focal length of the light-receiving unit 21, thereby enabling the light-receiving unit 21 to be made smaller.

[0064] In the first embodiment, the light projecting unit 19 and the light receiving unit 21 are provided with the tracking light emitting unit 26 and the tracking light receiving unit 39, respectively, but the tracking light emitting unit 26 and the tracking light receiving unit 39 may be omitted.

[0065] In this case, the dichroic mirror 32 is not necessary, and the light-emitting element 28 and the light-projecting lens 31 are the only components of the light-projecting unit 19, so the light-projecting unit 19 can be placed within the vertical rotation axis 11, and the optical system and the surveying device 1 can be made even smaller.

[0066] 3A to 3C each show a modified example of the first embodiment.

[0067] 3A shows a first modification of the first embodiment. In the first modification, a cylindrical tube portion 51 having approximately the same diameter as the through hole 23 is inserted into the through hole 23 and bonded thereto.

[0068] The cylindrical portion 51 is formed of a non-transparent material, and the end of the cylindrical portion 51 on the light receiving portion 21 side is located closer to the light receiving portion 21 than the upper end of the light receiving portion 21 side end of the through hole 23, and is located closer to the light projecting portion 19 than the lower end.

[0069] Furthermore, the light projecting mirror 24 is provided at the end of the cylindrical portion 51 on the light receiving portion 21 side, and an opening 52 is formed on the distance measuring light axis 27 deflected by the light projecting mirror 24 of the cylindrical portion 51. The size of the opening 52 is larger than the light fluxes of the distance measuring light 29 and the tracking light 33. In the first modified example, the light receiving mirror 15 constitutes a light receiving deflection portion, and the through hole 23, the cylindrical portion 51, the opening 52, and the light projecting mirror 24 constitute a light projecting deflection portion.

[0070] In the first variant, the cylindrical portion 51 and the light-emitting mirror 24 provided on the cylindrical portion 51 can be unitized, so that it is only necessary to insert the cylindrical portion 51, on which the light-emitting mirror 24 has already been provided, into the through hole 23, thereby improving workability.

[0071] Furthermore, since it is not necessary to incorporate the light projecting unit 19 and the light receiving unit 21 into one optical system, the optical system of the distance measuring unit can be made compact, and the surveying device 1 as a whole can be made compact.

[0072] 3B shows a second modification of the first embodiment. In the second modification, a metamaterial 53 as a deflection optical member is provided at the end of the through-hole 23 on the light receiving unit 21 side instead of the light projecting mirror 24.

[0073] The metamaterial 53 is configured to have a refraction angle of 90° and a negative refractive index. Therefore, the distance measurement light 29 incident on the metamaterial 53 is deflected by 90° (a right angle) while passing through the metamaterial 53, and is then irradiated onto the object to be measured. In the second modified example, the light receiving mirror 15 forms a light receiving deflection unit, and the through hole 23 and the metamaterial 53 form a light projecting deflection unit.

[0074] Since the distance measurement light 29 is deflected by the metamaterial 53, the distance measurement optical axis 27 of the distance measurement light 29 incident on the metamaterial 53 does not coincide with the light receiving optical axis 41 of the reflected distance measurement light 45 reflected by the light receiving mirror 15, and a predetermined deviation occurs. However, since the amount of deviation between the distance measurement optical axis 27 and the light receiving optical axis 41 is known, the calculation control unit 17 can correct the distance measurement result by calculation based on the known amount of deviation after distance measurement is performed.

[0075] In the second variant, there is also no need to incorporate the light-emitting unit 19 and the light-receiving unit 21 into a single optical system, so the optical system of the distance measuring unit can be made smaller, and the entire surveying device 1 can be made smaller.

[0076] 3C shows a third modification of the first embodiment. In this modification, a diffraction grating 54 is provided as a deflection optical member at the open end of the through hole 23 in place of the light projecting mirror 24.

[0077] The diffraction grating 54 is a transmission type diffraction grating with a diffraction angle of 90°. Therefore, the distance measurement light 29 incident on the diffraction grating 54 is deflected by 90° (a right angle) while passing through the diffraction grating 54, and is then irradiated onto the object to be measured. In the third modified example, the light receiving mirror 15 forms a light receiving deflection section, and the through hole 23 and the diffraction grating 54 form a light projecting deflection section.

[0078] Incidentally, when the diffraction grating 54 is used, as in the second modified example, a predetermined deviation occurs between the distance measurement optical axis 27 of the distance measurement light 29 incident on the diffraction grating 54 and the light receiving optical axis 41 of the reflected distance measurement light 45 reflected by the light receiving mirror 15. In the third modified example as well, the amount of deviation between the distance measurement optical axis 27 and the light receiving optical axis 41 is known, so the calculation control unit 17 can correct the distance measurement result based on the known amount of deviation.

[0079] In the third variant, too, there is no need to incorporate the light-emitting unit 19 and the light-receiving unit 21 into a single optical system, so the optical system of the distance measuring unit can be made smaller, and the entire surveying device 1 can be made smaller.

[0080] Next, a second embodiment of the present invention will be described with reference to Fig. 4. In Fig. 4, the same components as those in Fig. 2 are given the same reference numerals, and their description will be omitted.

[0081] In the second embodiment, a plate-shaped mirror having a flat reflecting surface is used as the light receiving mirror 55. A through hole 56 parallel to the distance measurement optical axis 27 is formed in the center of the light receiving mirror 55.

[0082] The through-hole 56 is larger than the beam diameter of the distance measuring light 29 and the tracking light 33, and the light projecting mirror 24 is adhered to the lower surface of the through-hole 56. A gap 57 of a predetermined size is formed between the upper end of the through-hole 56 and the upper end of the light projecting mirror 24, and the gap 57 is larger than the beam diameter of the distance measuring light 29 and the tracking light 33. In the second embodiment, the light receiving mirror 55 constitutes a light receiving deflection section, and the through-hole 56 and the light projecting mirror 24 constitute a light projecting deflection section.

[0083] A light-receiving lens 58 is disposed between the light-receiving mirror 55 and the light-receiving prism 43. The light-receiving lens 58 is configured to collect the reflected distance measuring light 45 and the reflected tracking light 46 reflected by the light-receiving mirror 55 at a predetermined focal length.

[0084] The distance measurement light 29 emitted from the light-emitting element 28 passes through the light-projecting lens 31 and the dichroic mirror 32, is reflected by the light-projecting mirror 24 at a right angle via the through-hole 56, and is irradiated onto the object to be measured through the gap 57 and the window portion 37. The reflected distance measurement light 45 reflected by the object to be measured is reflected by the light-receiving mirror 55 at a right angle so as to be coaxial with the distance measurement light axis 27, is collected by the light-receiving lens 58, passes through the light-receiving prism 43, and is received by the light-receiving element 42.

[0085] Similarly, the tracking light 33 emitted from the tracking light-emitting element 35 passes through the tracking light-projecting lens 36, is reflected successively by the dichroic mirror 32 and the light-projecting mirror 24, and is irradiated onto the object to be measured. The reflected tracking light 46 reflected by the object to be measured is reflected at a right angle by the light-receiving mirror 55 so as to be coaxial with the tracking light axis 34, is collected by the light-receiving lens 58, passes through the light-receiving prism 43, and is received by the tracking light-receiving element 48.

[0086] In the second embodiment, the light-receiving mirror 55 is a plate-shaped mirror with a flat reflecting surface, so the reflected distance-measuring light 45 and the reflected tracking light 46 are reflected at a right angle by the light-receiving mirror 55 without being condensed. Therefore, in order to have the reflected distance-measuring light 45 and the reflected tracking light 46 received by the light-receiving element 42 and the tracking light-receiving element 48, it is necessary to provide the light-receiving lens 58 between the light-receiving mirror 55 and the light-receiving prism 43.

[0087] On the other hand, in the second embodiment as well, the light-projecting unit 19 and the light-receiving unit 21 are arranged on opposite sides of the light-receiving mirror 55. Therefore, it is not necessary to incorporate the light-projecting unit 19 and the light-receiving unit 21 into one optical system, and a deflecting optical member for deflecting the distance-measuring light 29 and the reflected distance-measuring light 45 coaxially is not required, so that the number of parts can be reduced and the optical system and the surveying instrument 1 as a whole can be made smaller.

[0088] Furthermore, since the light projecting mirror 24 is provided in the through hole 56 provided on the optical paths of the distance measuring light 29 and the tracking light 33, the distance measuring optical axis 27 and the light receiving optical axis 41, and the tracking optical axis 34 and the tracking light receiving optical axis 47 can be made coaxial, thereby improving the measurement accuracy and tracking accuracy.

[0089] FIGS. 5A, 5B, 6A, 6B, 7A, and 7B each show a modified example of the second embodiment.

[0090] 5A shows a first modification of the second embodiment. In the first modification, a cylindrical tube portion 59 having approximately the same diameter as the through hole 56 is inserted into the through hole 56 and bonded thereto.

[0091] The cylindrical portion 59 is formed of a non-transparent material, and the end of the cylindrical portion 59 on the light receiving unit 21 side is located closer to the light receiving unit 21 than the upper end of the through hole 56. The cylindrical portion 59 has a predetermined length, for example, a length that is approximately the same as the horizontal distance from the upper end of the through hole 56 on the light projecting unit 19 side to the lower end of the through hole 56 on the light receiving unit 21 side.

[0092] The light-projecting mirror 24 is provided at the end of the cylindrical portion 59 on the light-receiving portion 21 side. An opening 61 is formed on the circumferential surface of the cylindrical portion 59 on the distance-measuring light axis 27 deflected by the light-projecting mirror 24. The size of the opening 61 is larger than the light fluxes of the distance-measuring light 29 and the tracking light 33. In the first modified example, the light-receiving mirror 55 constitutes a light-receiving deflection portion, and the through-hole 56, the cylindrical portion 59, the opening 61, and the light-projecting mirror 24 constitute a light-projecting deflection portion.

[0093] In the first variant, the cylindrical portion 59 and the light-emitting mirror 24 provided on the cylindrical portion 59 can be unitized, so that it is only necessary to insert the cylindrical portion 59, on which the light-emitting mirror 24 has already been provided, into the through hole 23, thereby improving workability.

[0094] Furthermore, since it is not necessary to incorporate the light projecting unit 19 and the light receiving unit 21 into one optical system, the optical system of the distance measuring unit can be made compact, and the surveying device 1 as a whole can be made compact.

[0095] 5B shows a second modified example of the second embodiment. In the second modified example, a plate-shaped light-projecting mirror 62 is provided instead of the light-projecting mirror 24, which is a cylinder having a reflective surface that deflects the distance-measuring optical axis 27 at a right angle in the first modified example. The other configurations are the same as those of the first modified example. In the second modified example, the light-receiving mirror 55 constitutes a light-receiving deflection section, and the through-hole 56, the cylinder 59, the opening 61, and the light-projecting mirror 62 constitute a light-projecting deflection section.

[0096] 6A shows a third modification of the second embodiment, in which a cylindrical light-receiving mirror 63 having a flat reflecting surface that deflects the light-receiving optical axis 41 at a right angle is used instead of the plate-shaped light-receiving mirror 55.

[0097] The light receiving mirror 63 communicates with the hollow portion of the vertical rotation shaft 11 (see FIG. 1 ), and has a cylindrical through-hole 64 formed therein that is concentric with the vertical rotation shaft 11, and the light projecting mirror 24 is provided at the end of the through-hole 64 on the light receiving unit 21 side. In addition, a gap 65 that is larger than the beam diameter of the distance measuring light 29 and the tracking light 33 is formed between the upper end of the light projecting mirror 24 and the upper end of the through-hole 64 on the light receiving unit 21 side.

[0098] In the third modified example, the distance measuring light 29 and the tracking light 33 pass through the vertical rotation shaft 11 and the through-hole 64, are reflected by the light projecting mirror 24, and are irradiated onto the measurement object via the gap 65 and the window portion 37. In the third modified example, the light receiving mirror 63 constitutes a light receiving deflection portion, and the through-hole 64 and the light projecting mirror 24 constitute a light projecting deflection portion.

[0099] In the third modified example, the light projecting unit 19 and the light receiving unit 21 are also arranged on opposite sides of the light receiving mirror 63, so that the optical system and the entire surveying instrument 1 can be made smaller.

[0100] 6B shows a fourth modification of the second embodiment, in which a cylindrical tube portion 66 having approximately the same diameter as the through hole 64 is inserted into the through hole 64 and bonded thereto.

[0101] The end of the cylindrical portion 66 on the light receiving unit 21 side protrudes toward the light receiving unit 21 beyond the upper end of the through hole 64 on the light receiving unit 21 side, and the light projecting mirror 24, which has a 45° reflecting surface formed on its end, is provided at the end of the through hole 64 on the light receiving unit 21 side. Also, an opening 67 is formed on the circumferential surface of the cylindrical portion 66 on the distance measuring light axis 27 deflected by the light projecting mirror 24. The size of the opening 67 is larger than the luminous fluxes of the distance measuring light 29 and the tracking light 33. In the fourth modified example, the light receiving mirror 63 constitutes a light receiving deflection portion, and the through hole 64, the cylindrical portion 66, the opening 67, and the light projecting mirror 24 constitute a light projecting deflection portion.

[0102] In the fourth variant, as in the first variant, the tubular portion 66 and the light-emitting mirror 24 provided on the tubular portion 66 can be unitized, so that it is only necessary to insert the tubular portion 66, on which the light-emitting mirror 24 has already been provided, into the through hole 64, thereby improving workability.

[0103] 7A shows a fifth modification of the second embodiment, in which a plate-shaped metamaterial 68 is provided as a rotary deflector.

[0104] The metamaterial 68 is configured to have a refractive index of 90° and a negative refractive index, similar to the second modification of the first embodiment. A transmitting film is deposited on the center of the metamaterial 68 to form a light-projecting deflection section 68a, and a reflective film is deposited on the rest of the metamaterial 68 to form a light-receiving deflection section 68b.

[0105] Therefore, the distance measuring light 29 and the tracking light 33 incident on the light projecting deflection unit 68a are transmitted through the light projecting deflection unit 68a, deflected by 90° (at a right angle) during transmission, and then irradiated onto the object to be measured. The reflected distance measuring light 45 and the reflected tracking light 46 reflected by the object to be measured are incident on the light receiving deflection unit 68b and reflected at a right angle toward the light receiving unit 21.

[0106] That is, the metamaterial 68 serves as both the light projecting deflection section 68a, which deflects the ranging light 29 and the tracking light 33 at right angles toward the object to be measured, and the light receiving deflection section 68b, which reflects the reflected ranging light 45 and the reflected tracking light 46 at right angles toward the light receiving section 21.

[0107] In the fifth modified example, there is a predetermined deviation between the distance measurement optical axis 27 and the light receiving optical axis 41. However, since the amount of deviation between the distance measurement optical axis 27 and the light receiving optical axis 41 is known, the calculation control unit 17 can correct the distance measurement result by calculation based on the known amount of deviation after distance measurement is performed.

[0108] Also, in the fifth variant, since there is no need to incorporate the light-projecting unit 19 and the light-receiving unit 21 into a single optical system, the optical system of the distance measuring unit can be made smaller, and the surveying device 1 as a whole can be made smaller.

[0109] 7B shows a sixth modification of the second embodiment, in which a diffraction grating 69 is provided as a rotary deflector.

[0110] The diffraction grating 69 is a transmission type diffraction grating with a diffraction angle of 90°, as in the third modification of the first embodiment. A transmission film is vapor-deposited in the center of the diffraction grating 69 to form a light-projecting deflection section 69a, and a reflective film is vapor-deposited in the other parts to form a light-receiving deflection section 69b.

[0111] Therefore, the distance measuring light 29 and the tracking light 33 incident on the light projecting deflection unit 69a are transmitted through the light projecting deflection unit 69a, deflected by 90° (at a right angle) during transmission, and then irradiated onto the object to be measured. The reflected distance measuring light 45 and the reflected tracking light 46 reflected by the object to be measured are incident on the light receiving deflection unit 69b and reflected at a right angle toward the light receiving unit 21.

[0112] That is, the diffraction grating 69 serves as the light projecting deflection section 69a, which deflects the distance measuring light 29 and the tracking light 33 at right angles toward the object to be measured, and as the light receiving deflection section 69b, which reflects the reflected distance measuring light 45 and the reflected tracking light 46 at right angles toward the light receiving section 21.

[0113] Incidentally, when the diffraction grating 69 is used, as in the fifth modified example, a predetermined deviation occurs between the distance measurement optical axis 27 of the distance measurement light 29 incident on the diffraction grating 69 and the light receiving optical axis 41 of the reflected distance measurement light 45 reflected by the diffraction grating 69. In the sixth modified example as well, the amount of deviation between the distance measurement optical axis 27 and the light receiving optical axis 41 is known, so the calculation control unit 17 can correct the distance measurement result based on the known amount of deviation.

[0114] In the sixth variant, there is also no need to incorporate the light-emitting unit 19 and the light-receiving unit 21 into a single optical system, so the optical system of the distance measuring unit can be made smaller, and the entire surveying device 1 can be made smaller.

[0115] In the first embodiment and its modifications, and the second embodiment and its modifications, the light-projecting unit 19 has the distance-measuring light emitting unit 25 and the tracking light emitting unit 26, and the light-receiving unit 21 has the distance-measuring light receiving unit 38 and the tracking light receiving unit 39, but if tracking of the object to be measured is not required, the tracking light emitting unit 26 and the tracking light receiving unit 39 may be omitted. By omitting the tracking light emitting unit 26, the distance-measuring light emitting unit 25 can be provided inside the vertical rotation shaft 11, and the optical system of the distance measuring unit can be further miniaturized.

[0116] REFERENCE SIGNS LIST 1 Surveying instrument 3 Surveying instrument main body 5 Base section 11 Vertical rotation axis 15 Light receiving mirror 17 Calculation control section 19 Light projecting section 21 Light receiving section 23 Through hole 24 Light projecting mirror 25 Distance measuring light emitting section 29 Distance measuring light 38 Distance measuring light receiving section 45 Reflected distance measuring light

Claims

1. A surveying device comprising a distance measuring unit having a light emitting element that emits distance measuring light and a light receiving element that receives the reflected distance measuring light from the object to be measured, a rotary deflection unit that irradiates the distance measuring light, a vertical rotary drive unit that rotates the rotary deflection unit in the vertical direction via a hollow vertical rotary shaft, a base unit on which the rotary deflection unit is mounted, a horizontal rotary drive unit that rotates the base unit in the horizontal direction, and a calculation control unit that calculates the distance to the object to be measured based on the result of the reflected distance measuring light being received by the light receiving element, wherein the rotary deflection unit has a light projecting deflection unit formed in the center and deflecting the distance measuring light at a right angle, and a light receiving deflection unit formed other than at the center and deflecting the reflected distance measuring light at a right angle, wherein the distance measuring light passes through the vertical rotary shaft and enters the light projecting deflection unit, and the reflected distance measuring light enters the light receiving deflection unit and is deflected in the opposite direction to the light emitting element.

2. The surveying device of claim 1, wherein the light receiving deflection unit is a cylinder having a reflective surface formed at its end for deflecting the optical axis of the reflected distance measuring light at a right angle, and the light projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the light receiving deflection unit parallel to the optical axis of the distance measuring light, and a light projecting mirror provided in the through hole, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

3. The surveying device of claim 1, wherein the light receiving deflection unit is a cylinder having a reflective surface formed at its end for deflecting the optical axis of the reflected distance measuring light at a right angle, and the light projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the light receiving deflection unit parallel to the optical axis of the distance measuring light, a cylinder inserted into the through hole, a light projecting mirror provided at the end of the cylinder, and an opening formed on the reflected optical axis of the light projecting mirror of the cylinder, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

4. The surveying device of claim 1, wherein the receiving deflection unit is a cylinder having a reflective surface formed at its end for deflecting the optical axis of the reflected distance measuring light at a right angle, and the projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the receiving deflection unit parallel to the optical axis of the distance measuring light, and a metamaterial provided in the through hole.

5. The surveying device of claim 1, wherein the receiving deflection unit is a cylinder having a reflective surface formed at its end for deflecting the optical axis of the reflected distance measuring light at a right angle, and the projecting deflection unit is connected to the hollow portion of the vertical rotation shaft and comprises a through hole formed in the receiving deflection unit parallel to the optical axis of the distance measuring light, and a diffraction grating provided in the through hole.

6. A surveying instrument according to any one of claims 2 to 5, wherein the light receiving deflection unit has a reflecting surface of an off-axis parabolic mirror.

7. A surveying device as claimed in claim 1, wherein the light receiving deflection section is a plate-shaped mirror, the light projecting deflection section is connected to the hollow section of the vertical rotation shaft, and comprises a through hole formed in the light receiving deflection section parallel to the optical axis of the distance measuring light, and a light projecting mirror provided in the through hole, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

8. A surveying device as claimed in claim 1, wherein the light receiving deflection section is a plate-shaped mirror, the light projecting deflection section is connected to the hollow section of the vertical rotation shaft, and comprises a through hole formed in the light receiving deflection section parallel to the optical axis of the distance measuring light, a cylindrical section inserted into the through hole, a light projecting mirror provided at the end of the cylindrical section, and an opening formed on the reflected optical axis of the light projecting mirror of the cylindrical section, and the light projecting mirror is configured to deflect the optical axis of the distance measuring light at a right angle.

9. A surveying device as claimed in claim 1, wherein the light receiving deflection section is a plate-shaped mirror, and the light projecting deflection section is connected to the hollow section of the vertical rotation shaft and comprises a through hole formed in the light receiving deflection section parallel to the optical axis of the distance measuring light, a cylindrical section inserted into the through hole, a plate-shaped mirror provided at the end of the cylindrical section, and an opening formed on the reflected optical axis of the mirror of the cylindrical section.

10. The surveying device of claim 1, wherein the rotating deflection section has a plate-shaped metamaterial, the central portion of which forms the light-projecting deflection section on which a transparent film is vapor-deposited, and the portion other than the central portion of the metamaterial forms the light-receiving deflection section on which a reflective film is vapor-deposited.

11. The surveying instrument of claim 1, wherein the rotary deflection section has a plate-shaped diffraction grating, the central portion of which forms the light-projecting deflection section on which a transparent film is vapor-deposited, and the portion other than the central portion of the diffraction grating forms the light-receiving deflection section on which a reflective film is vapor-deposited.

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