Measuring device

Abstract

To provide a surveying device that can adjust a quantity of surveying light.SOLUTION: A surveying device is provided with a surveying light emitting unit 23 that emits surveying light 32 to an object to be measured, a surveying light receiving unit 24 having a light receiving element 36 that receives reflected surveying light 45 from the object to be measured, and an arithmetic control unit that controls the surveying light emitting unit and calculates a distance to the object to be measured on the basis of a result of reception of the reflected surveying light performed by the light receiving element. The surveying light emitting unit has an insertable and withdrawable pinhole plate 28 with respect to an optical axis 25 of the surveying light. The pinhole plate is formed with a pinhole 33 having a predetermined diameter. The insertion and withdrawal of the pinhole plate can change a quantity and a spread angle of the surveying light.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[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 surveying instruments, in order to align the optical axis of the distance measuring light emitted toward the object to be measured with the optical axis of the reflected distance measuring light reflected from the object to be measured, the optical axis of the distance measuring light and the reflected distance measuring light is deflected by a mirror, etc. In addition, in order to make the optical system of the surveying instrument compact, the optical axis of the distance measuring light and the reflected distance measuring light may be deflected multiple times.

[0004] Some surveying instruments are capable of both prism and non-prism distance measurement. However, non-prism distance measurement requires the use of a large amount of distance measurement light to obtain a sufficient amount of reflected distance measurement light, since the reflectivity of the object being measured may be low. However, when prism distance measurement is performed using a large amount of distance measurement light, the amount of reflected distance measurement light becomes excessive, which can saturate the light receiving system and make measurement impossible. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0181494 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a surveying instrument capable of adjusting the amount of distance measuring light. [Means for solving the problem]

[0007] The present invention relates to a surveying instrument comprising a distance measurement light emitting unit that emits distance measurement light to an object to be measured, a distance measurement light receiving unit having a light receiving element that receives the reflected distance measurement light from the object to be measured, and an arithmetic control unit that controls the distance measurement light emitting unit and calculates the distance to the object to be measured based on the reception result of the reflected distance measurement light at the light receiving element, wherein the distance measurement light emitting unit has a pinhole plate that can be inserted and removed from the optical axis of the distance measurement light, and a pinhole of a predetermined diameter is formed in the pinhole plate, and the light intensity and spread angle of the distance measurement light can be changed by inserting and removing the pinhole plate.

[0008] The present invention also relates to a surveying instrument in which the distance measuring light emission unit has a reflecting prism formed by joining two prisms, and a beam splitter film having a predetermined reflectivity and transmittance is formed on the joint surface of the reflecting prism, and the reflecting prism is configured to deflect the optical axis of the distance measuring light via the beam splitter film so that it coincides with the optical axis of the reflected distance measuring light.

[0009] The present invention also relates to a surveying instrument in which the reflecting prism is inclined with respect to the optical axis of the reflected distance measuring light, and the distance measuring light is configured to be incident on the exit surface of the reflecting prism at a slight inclination.

[0010] The present invention also relates to a surveying instrument in which the distance measuring light receiving unit has a light intensity adjustment plate arranged on the optical axis of the reflected distance measuring light, and the light intensity adjustment plate is configured to form a light intensity adjustment surface that can change the transmittance at the incident position of the reflected distance measuring light.

[0011] The present invention further comprises a tracking light emitting unit that emits tracking light onto the object to be measured coaxially with the distance measuring light, and a tracking light receiving unit that has a tracking light receiving element that receives the reflected tracking light reflected from the object to be measured coaxially with the reflected distance measuring light, and a dichroic mirror that aligns the optical axis of the distance measuring light with the optical axis of the tracking light is provided on a common optical path of the distance measuring light and the tracking light, and reflection Optical axis of distance measurement light and the reflected light Tracking The present invention relates to a surveying instrument configured to have a separation surface that separates the optical axis of light.

[0012] The present invention also relates to a surveying instrument configured such that a long-pass filter that reflects visible light is provided on the exit surface of the reflecting prism from which the distance measuring light is emitted, and an imaging unit is provided on the reflected light axis of the long-pass filter.

[0013] Furthermore, the present invention relates to a surveying instrument further comprising a laser pointer light emitting unit that emits laser pointer light coaxially with the distance measuring light, and an imaging unit that separates the reflected distance measuring light from visible light. [Effects of the Invention]

[0014] According to the present invention, the device comprises a distance measurement light emitting unit that emits distance measurement light to the object to be measured, a distance measurement light receiving unit having a light receiving element that receives the reflected distance measurement light from the object to be measured, and an arithmetic control unit that controls the distance measurement light emitting unit and calculates the distance to the object to be measured based on the reception result of the reflected distance measurement light at the light receiving element, and the distance measurement light emitting unit has a pinhole plate that can be inserted and removed from the optical axis of the distance measurement light, and a pinhole of a predetermined diameter is formed in the pinhole plate, and the light intensity and spread angle of the distance measurement light can be changed by inserting and removing the pinhole plate, thereby providing the excellent effect of preventing saturation of the light receiving element when using distance measurement light with a large light intensity. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front cross-sectional view showing a surveying instrument according to a first embodiment of the present invention. [Figure 2] FIG. 1A is a configuration diagram showing a distance measuring unit according to a first embodiment of the present invention, and FIG. 1B is a side view of a reflecting prism. [Figure 3] FIG. 2 is a configuration diagram showing a distance measurement unit according to the first embodiment of the present invention. [Figure 4] FIG. 10 is a configuration diagram showing a distance measurement unit according to a second embodiment of the present invention. [Figure 5]FIG. 10 is a configuration diagram showing a distance measurement unit according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a configuration diagram showing a distance measurement unit according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a configuration diagram showing a distance measurement unit according to a fifth embodiment of the present invention. [Figure 8] FIG. 10 is a configuration diagram showing a distance measurement unit according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] First, referring to FIG. 1, a surveying instrument according to a first embodiment of the present invention will be described.

[0018] 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.

[0019] The leveling unit 2 has a leveling screw 10, and the leveling screw 10 is used to level the surveying device main body 3.

[0020] The surveying instrument main body 3 comprises 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 scanning mirror 15 as a vertical rotation section, an operation panel 16 that serves both as an operation section and a display section, a calculation control section 17, a memory section 18, a distance measurement section 19, etc. A CPU specialized for this instrument or a general-purpose CPU is used as the calculation control section 17.

[0021] 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 frame part 5 is supported by the horizontal rotation shaft 6, and the base frame part 5 rotates integrally with the horizontal rotation shaft 6 in the horizontal direction.

[0022] 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.

[0023] The relative rotation angle of the base unit 5 with respect to the fixed unit 4 is detected by the horizontal angle encoder 9. A detection signal from the horizontal angle encoder 9 is input to the arithmetic and control unit 17, which calculates horizontal angle data. The arithmetic and control unit 17 performs feedback control on the horizontal rotation motor 8 based on the horizontal angle data.

[0024] The base part 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.

[0025] A recess 22 is formed in the base frame portion 5. One end of the vertical rotation shaft 11 extends into the recess 22, and the scanning mirror 15 is fixed to the one end, and the scanning mirror 15 is housed in the recess 22. The vertical angle encoder 14 is provided on the other end of the vertical rotation shaft 11.

[0026] 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 scanning mirror 15 rotates around the axis 11a.

[0027] The rotation angle of the scanning mirror 15 is detected by the vertical angle encoder 14, and the detection signal is input to the arithmetic and control unit 17. The arithmetic and control unit 17 calculates vertical angle data of the scanning mirror 15 based on the detection signal, and performs feedback control on the vertical rotation motor 13 based on the vertical angle data.

[0028] The horizontal angle data, vertical angle data, and measurement results calculated by the calculation control unit 17 are stored in the storage unit 18. Various storage means can be used for the storage unit 18, such as a hard disk drive (HDD) as a magnetic storage device, a CD or DVD as an optical storage device, a memory card as a semiconductor storage device, a USB memory, etc. The storage 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 means (not shown).

[0029] The storage unit 18 stores various programs such as a sequence program for controlling the distance measurement operation, a calculation program for calculating distance by the distance measurement operation, a calculation program for calculating an angle based on horizontal angle data and vertical angle data, and a program for calculating three-dimensional coordinates of a desired measurement point based on the distance and angle. Furthermore, various programs are executed by the calculation control unit 17, thereby performing various processes.

[0030] 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.

[0031] Next, the distance measurement unit 19 will be described with reference to FIGS. 2(A), 2(B) and 3. FIG.

[0032] The distance measurement unit 19 has a distance measurement light emitting unit 23 and a distance measurement light receiving unit 24. The distance measurement light emitting unit 23 and the distance measurement light receiving unit 24 constitute a distance measurement unit.

[0033] The distance measurement light emitting unit 23 has a distance measurement optical axis 25. The distance measurement light emitting unit 23 also has, in order from the light emitting side, a light emitting element 26, such as a laser diode (LD), a collimator lens 27, a pinhole plate 28 serving as a spread angle adjustment member, and a reflecting prism 29, which are provided on the distance measurement optical axis 25. The scanning mirror 15 is provided on the reflected optical axis of the reflecting prism 29. A window 31 made of a transparent material is provided on the reflected optical axis of the scanning mirror 15, and the window 31 rotates integrally with the scanning mirror 15. Although the window 31 is provided in FIG. 2, the window 31 may be omitted.

[0034] The collimator lens 27, the pinhole plate 28, the reflecting prism 29, etc. constitute a projection optical system 30. In this embodiment, the distance measurement optical axis 25 and the distance measurement optical axis 25 reflected by the reflecting prism 29 are collectively referred to as the distance measurement optical axis 25.

[0035] The light emitting element 26 emits a laser beam of a predetermined wavelength as distance measuring light 32, and the collimator lens 27 is configured to convert the distance measuring light 32 into a parallel beam.

[0036] The pinhole plate 28 is, for example, a black plate material with a pinhole 33 drilled in the center. The pinhole plate 28 can be inserted into and removed from the distance measurement optical axis 25 via a drive mechanism 34, for example, a solenoid. When the pinhole plate 28 is inserted onto the distance measurement optical axis 25, the center of the pinhole 33 is positioned on the distance measurement optical axis 25. The diameter of the pinhole 33 is set appropriately, for example, in the range of φ=0.5 mm to 2 mm.

[0037] When performing prism measurement where the object to be measured is a prism or the like with retroreflective properties, the pinhole plate 28 is inserted onto the distance measurement optical axis 25, and when performing non-prism measurement where the object to be measured is something other than a prism, the pinhole plate 28 is removed from the distance measurement optical axis 25.

[0038] When the pinhole plate 28 is inserted onto the distance measurement optical axis 25, of the distance measurement light 32 incident on the pinhole plate 28, only the distance measurement light 32 incident on the pinhole 33 passes through the pinhole plate 28, and the distance measurement light 32 incident on any part other than the pinhole 33 is blocked by the pinhole plate 28. Therefore, the distance measurement light 32 is attenuated by the pinhole plate 28 and is emitted from the pinhole 33 while diverging at a predetermined divergence angle due to the diffraction effect. The divergence angle φ expanded by diffraction is, for example, 6 minutes, and the diameter of the pinhole 33 is set so that it can be appropriately set in the range of 2 to 20 minutes.

[0039] In addition, in this embodiment, the pinhole plate 28 is provided between the collimator lens 27 and the reflecting prism 29, but the pinhole plate 28 may be provided between the light emitting element 26 and the collimator lens 27.

[0040] The reflecting prism 29 is formed by joining two trapezoidal prisms, and when the two prisms are joined, the reflecting prism 29 has a rectangular parallelepiped shape. The incident surface of the distance measurement light 32 is perpendicular to the distance measurement optical axis 25, and the joint surface 35 of the reflecting prism 29 is inclined at a predetermined angle relative to the distance measurement optical axis 25. Furthermore, the exit surface of the reflecting prism 29 is configured so that the distance measurement optical axis 25 reflected by the joint surface 35 is incident at a slight inclination, for example, of about 2.5°. This prevents the distance measurement light 32 internally reflected by the exit surface of the reflecting prism 29 from being received by a light receiving element 36 (described below). The inclination angle of the joint surface 35 is set to deflect (reflect) the distance measurement optical axis 25 so that it coincides with a light receiving optical axis 37 (described below) and the axis 11a. Alternatively, the inclination angle of the bonding surface 35 may be set to 45°, and the distance measurement light 32 may be incident at an angle relative to the incident surface of the reflecting prism 29 so that the distance measurement optical axis 25 coincides with the light receiving optical axis 37 and the axis center 11a.

[0041] A beam splitter film 38 is formed at the center of the bonding surface 35, and an anti-reflection film 39 is formed on the entire front and back surfaces of the reflecting prism 29. The beam splitter film 38 has an elliptical shape to match the luminous flux of the distance measuring light 32. The size of the beam splitter film 38 is equal to or slightly larger than the luminous flux diameter of the distance measuring light 32 diverged by the pinhole 33. Furthermore, the beam splitter film 38 has optical properties such as reflecting 80% of light and transmitting 20% ​​of light, for example.

[0042] The ratio of reflectance to transmittance in the beam splitter film 38 is set appropriately depending on the application and the distance to the object to be measured. For example, when the object to be measured is close, it is desirable to select the beam splitter film 38 from a range of reflectance of 50% to 70% and a range of transmittance of 30% to 50%, and when the object to be measured is far, it is desirable to select the beam splitter film 38 from a range of reflectance of 70% to 90% and a range of transmittance of 10% to 30%.

[0043] The distance measurement light receiving unit 24 has the light receiving optical axis 37. The distance measurement light receiving unit 24 also has, in order from the light receiving side, the light receiving element 36, a light amount adjustment plate 41, and a light receiving prism 42, which are provided on the light receiving optical axis 37, and also has a light receiving lens 43, which has a predetermined NA and is provided on the light receiving optical axis 37 after light is reflected by the light receiving prism 42.

[0044] The light amount adjusting plate 41, the light receiving prism 42, the light receiving lens 43, the reflecting prism 29, etc. constitute a light receiving optical system 44. In this embodiment, the light receiving optical axis 37 and the light receiving optical axis 37 reflected by the light receiving prism 42 are collectively referred to as the light receiving optical axis 37.

[0045] The distance measurement unit 19 is controlled by the arithmetic and control unit 17. When the distance measurement light 32 is emitted in pulses from the light emitting element 26 onto the distance measurement optical axis 25, the distance measurement light 32 is converted into a parallel beam by the collimator lens 27. If the pinhole plate 28 is present on the distance measurement optical axis 25, all of the distance measurement light 32 except the light passing through the pinhole 33 is blocked by the pinhole plate 28, thereby reducing the total amount of the distance measurement light 32 and causing the distance measurement light 32 to be emitted at a predetermined divergence angle due to the diffraction effect when passing through the pinhole 33.

[0046] The distance measurement light 32 that passes through the pinhole 33 is incident on the incident surface of the reflecting prism 29 at a right angle, passes through the inside of the reflecting prism 29, and is reflected by the bonding surface 35 (beam splitter film 38) so as to be coaxial with the light receiving optical axis 37 and the axis 11a. The distance measurement light 32 that emerges from the reflecting prism 29 is deflected at a right angle by the scanning mirror 15, and is irradiated onto the measurement object through the window 31. As the scanning mirror 15 rotates around the axis 11a, the distance measurement light 32 rotates (scans) within a plane that is perpendicular to the axis 11a and includes the axis 11a.

[0047] The window 31 is inclined at a predetermined angle with respect to the optical axis of the distance measurement optical axis 25 so that the distance measurement light 32 reflected by the window 31 does not enter the light receiving element 36 .

[0048] The distance measuring light 32 reflected by the object to be measured (hereinafter referred to as reflected distance measuring light 45) is reflected at a right angle by the scanning mirror 15, passes through the light receiving optical system 44 and is received by the light receiving element 36. The light receiving element 36 is, for example, an avalanche photodiode (APD) or an equivalent photoelectric conversion element.

[0049] The arithmetic and control unit 17 measures distance for each pulse of the distance measuring light 32 based on the time difference between the light emission timing of the light emitting element 26 and the light reception timing of the light receiving element 36 (i.e., the round trip time of the pulsed light) and the speed of light (Time Of Flight). The light emission timing of the light emitting element 26, i.e., the pulse interval, can be changed via the operation panel 16.

[0050] In addition, the distance measurement unit 19 is provided with an internal reference light optical system (described later), and distance measurement is performed based on the time difference between the reception timing of the internal reference light (described later) received from the internal reference light optical system and the reflected distance measurement light 45 and the speed of light, making it possible to measure distance with higher accuracy.

[0051] The base frame 5 and the scanning mirror 15 each rotate at a constant speed, and the vertical rotation of the scanning mirror 15 and the horizontal rotation of the base frame 5 cooperate to perform two-dimensional scanning with the distance measuring light 32. Furthermore, by detecting the vertical angle and 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. The vertical angle data, horizontal angle data, and distance measuring data can be used to obtain the three-dimensional coordinates of the object to be measured and three-dimensional point cloud data corresponding to the object to be measured.

[0052] Next, we will explain the light receiving optical system 44. Note that in Figures 2(A) and 3, only the chief ray of the distance measuring light 32 (the distance measuring optical axis 25) and the chief ray of the reflected distance measuring light 45 (the light receiving optical axis 37) are shown.

[0053] The light-receiving prism 42 is a quadrangular prism having a predetermined refractive index, and has a first surface 42a onto which the reflected distance-measuring light 45 passing through the light-receiving lens 43 is incident, a second surface 42b onto which the reflected distance-measuring light 45 passing through the surface of the first surface 42a is reflected, a third surface 42c onto which the reflected distance-measuring light 45 reflected by the second surface 42b and the first surface 42a is incident, and a fourth surface 42d as a transmitting surface through which the reflected distance-measuring light 45 reflected by the third surface 42c passes in a direction intersecting the reflected distance-measuring light 45 passing through the first surface 42a. The reflected distance-measuring light 45 passing through the fourth surface 42d is incident on the light-receiving element 36.

[0054] The light amount adjusting plate 41 is, for example, a circular plate made of plastic. As a light intensity adjustment surface A circular gradation film is formed, and a part of the gradation film is arranged so as to be perpendicular to the light receiving optical axis 37. The light amount adjustment plate 41 can be rotated around a rotation axis 46 by a motor 47, and the rotation of the light amount adjustment plate 41 changes the incident position of the reflected distance measuring light 45 with respect to the light amount adjustment plate 41.

[0055] The gradation film is configured so that the transmittance gradually increases (or decreases) between θ=0° and 360°. Therefore, by driving the motor 47 and controlling the incident position of the reflected distance-measuring light 45 with respect to the light amount adjustment plate 41, the transmittance of the reflected distance-measuring light 45 can be controlled within a range of, for example, 0.0001% to 100%. The transmittance of the light amount adjustment plate 41 is set appropriately depending on the type of object to be measured and the distance to the object to be measured.

[0056] In addition, a reference prism 48 having retroreflectivity is provided below the scanning mirror 15. In the process of rotating and irradiating the distance measurement light 32 via the scanning mirror 15, a part of the distance measurement light 32 is incident on the reference prism 48. The distance measurement light 32 retroreflected by the reference prism 48 is incident on the light receiving optical system 44 via the scanning mirror 15 and is received by the light receiving element 36.

[0057] Here, the optical path length from the light-emitting element 26 to the reference prism 48 and the optical path length from the reference prism 48 to the light-receiving element 36 are known. Therefore, the distance measurement light 32 reflected by the reference prism 48 can be used as an internal reference light 49. The scanning mirror 15 and the reference prism 48 constitute an internal reference light optical system 51.

[0058] Next, a case where measurement is performed by the surveying instrument 1 having the distance measurement unit 19 will be described. Various operations of the distance measurement unit 19 are performed by the arithmetic control unit 17 executing various programs. Note that the following describes a case where prism measurement is performed.

[0059] The distance measurement light 32 emitted from the light emitting element 26 is collimated by the collimator lens 27, and then passes through the pinhole 33 in the pinhole plate 28 to be dimmed and spread at a predetermined spread angle before entering the reflecting prism 29 at a right angle.

[0060] The distance measurement light 32 incident on the reflecting prism 29 passes through the reflecting prism 29 and is deflected (reflected) by the beam splitter film 38 on the bonding surface 35 so as to be coaxial with the light-receiving optical axis 37 and the axis center 11a. At this time, since the size of the beam splitter film 38 is equal to or slightly larger than the beam diameter of the distance measurement light 32, all of the distance measurement light 32 is incident on the beam splitter film 38. In addition, since the exit surface of the reflecting prism 29 is inclined with respect to the distance measurement optical axis 25, the distance measurement light 32 reflected internally by the exit surface is not received by the light-receiving element 36.

[0061] The distance measurement light 32 reflected by the beam splitter film 38 passes through the reflecting prism 29 at a slight angle to the exit surface, and is irradiated via the scanning mirror 15 onto the object to be measured, for example, a retroreflective prism.

[0062] The reflected distance measuring light 45 reflected by the prism is reflected at a right angle by the scanning mirror 15, passes through the reflecting prism 29, and enters the light receiving optical system 44. Here, the central light of the reflected distance measuring light 45 passes through the beam splitter film 38 on the bonding surface 35. Furthermore, the reflected distance measuring light 45 is completely transmitted through the anti-reflection film 39 at locations other than the beam splitter film 38. On the other hand, a portion of the reflected distance measuring light 45 is transmitted through the location where the beam splitter film 38 is provided. In this embodiment, the beam splitter film 38 has a transmittance of 20%, so 20% of the reflected distance measuring light 45 incident on the beam splitter film 38 is transmitted through the beam splitter film 38.

[0063] The reflected distance-measuring light 45, which has passed through the reflecting prism 29 and entered the light-receiving optical system 44, is refracted while passing through the light-receiving lens 43 and the first surface 42a. Inside the light-receiving prism 42, the reflected distance-measuring light 45 is successively reflected by the second surface 42b and the first surface 42a, and is incident on the third surface 42c. The reflected distance-measuring light 45 is also reflected by the third surface 42c toward the fourth surface 42d, i.e., in a direction intersecting the direction of the reflected distance-measuring light 45 incident from the first surface 42a. The reflected distance-measuring light 45, which has passed through the fourth surface 42d, is attenuated while passing through the light amount adjustment plate 41 and is received by the light-receiving element 36.

[0064] The calculation control unit 17 calculates the three-dimensional coordinates of the prism based on the distance measurement result of the distance measurement unit 19 and the detection results of the horizontal angle encoder 9 and the vertical angle encoder 14.

[0065] The measurement of the prism may be performed by scanning the entire circumference or the periphery of the prism with the distance measuring light 32, and measuring the position where the reflected distance measuring light 45 is received as the position of the prism.

[0066] As described above, in the first embodiment, the pinhole plate 28 is provided so as to be insertable into and detachable from the distance measurement optical axis 25, and the distance measurement light 32 can be attenuated and its divergence angle can be increased through the pinhole 33 of the pinhole plate 28.

[0067] In non-prism measurement, the distance measuring light 32 with a large light intensity is used so that even if the reflectance of the measurement object is low, a sufficient amount of the reflected distance measuring light 45 is received. On the other hand, when prism measurement is performed using the distance measuring light 32 with a large light intensity, the amount of the reflected distance measuring light 45 received becomes excessive, and the light receiving element 36 becomes saturated.

[0068] Therefore, when performing prism measurement, the pinhole plate 28 is inserted onto the distance measurement optical axis 25 to reduce the distance measurement light 32, thereby preventing saturation of the light receiving element 36. In other words, the amount of light and the spread angle of the distance measurement light 32 can be changed by inserting or removing the pinhole plate 28.

[0069] Furthermore, when the distance measuring light 32 passes through the pinhole 33, the distance measuring light 32 is diverged at a predetermined divergence angle due to the diffraction effect, so that the distance measuring light 32 can be easily irradiated onto the prism, improving workability.

[0070] Furthermore, the pinhole 33 is a hole, and the distance measurement light 32 is not refracted when passing through the pinhole 33. Therefore, it is not necessary to accurately position the pinhole plate 28 so that it is perpendicular to the distance measurement optical axis 25, and it is not necessary to make the surface of the pinhole plate 28 an accurate flat surface, which reduces manufacturing costs and improves workability.

[0071] In the first embodiment, the reflecting prism 29, which is a combination of two prisms, is used as an optical element for aligning the distance measurement optical axis 25 with the light receiving optical axis 37, and the distance measurement light 32 is deflected by the beam splitter film 38 formed on the bonding surface 35 of the reflecting prism 29.

[0072] Here, when the distance to the object to be measured is short, the amount of light in the center of the reflected distance measuring light 45 increases, and when the distance to the object to be measured is long, the amount of light in the peripheral part of the reflected distance measuring light 45 increases.

[0073] Therefore, a portion of the reflected distance measuring light 45 incident on the beam splitter film 38 passes through the beam splitter film 38, which has a predetermined transmittance, so that vignetting of the reflected distance measuring light 45 by the beam splitter film 38 can be reduced, and a sufficient amount of light can be received to enable distance measurement even in short distance measurements.

[0074] Furthermore, since vignetting of the reflected distance measuring light 45 passing through the beam splitter film 38 can be reduced, measurement is possible even when a small corner cube or the like is used as the measurement object and the beam diameter of the reflected distance measuring light 45 is small.

[0075] In addition, the light amount adjusting plate 41, whose transmittance can be changed by rotation, is provided between the light receiving prism 42 and the light receiving element 36, and by rotating the light amount adjusting plate 41, the amount of reflected distance measuring light 45 received by the light receiving element 36 can be adjusted.

[0076] Therefore, even if the amount of the reflected distance measuring light 45 is so large that the light receiving element 36 is saturated, the amount of the reflected distance measuring light 45 can be attenuated to an appropriate amount by the light amount adjusting plate 41.

[0077] Furthermore, since the exit surface of the reflecting prism 29 is slightly inclined with respect to the distance measurement optical axis 25 deflected by the beam splitter film 38, the distance measurement light 32 internally reflected by the exit surface can be prevented from being received by the light receiving element 36, thereby reducing measurement errors.

[0078] Furthermore, since the light-receiving prism 42 is provided and the reflected distance measuring light 45 is reflected multiple times within the light-receiving prism 42, the optical path length in the horizontal direction (left and right directions relative to the paper surface) can be shortened, thereby making it possible to reduce the size of the optical system of the distance measuring unit 19 and the weight of the surveying device 1.

[0079] 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(A) are given the same reference numerals, and their description will be omitted.

[0080] In the second embodiment, the distance measurement optical axis 25 is deflected twice, so that the distance measurement optical axis 25 coincides with the light receiving optical axis 37 and the axis center 11a. That is, in the second embodiment, a reflecting mirror 52 that deflects (reflects) the distance measurement optical axis 25 at a right angle is provided between the pinhole plate 28 and the reflecting prism 29.

[0081] The distance measurement light 32 emitted from the light emitting element 26 is deflected at a right angle by the reflecting mirror 52, and then perpendicularly enters the reflecting prism 29. The process after entering the reflecting prism 29 is the same as in the first embodiment.

[0082] In the second embodiment, the reflecting mirror 52 is provided to deflect the distance measurement optical axis 25 at a right angle, thereby shortening the optical path length in the direction of the axis 6a (up and down relative to the paper surface, see Figure 1), and making it possible to miniaturize the optical system of the distance measurement unit 19.

[0083] Next, a third embodiment of the present invention will be described with reference to Fig. 5. In Fig. 5, the same components as those in Fig. 2(A) are given the same reference numerals, and their description will be omitted.

[0084] In the third embodiment, similar to the second embodiment, the distance measurement optical axis 25 is deflected twice and is aligned with the light receiving optical axis 37 and the axis 11a. On the other hand, in the third embodiment, the reflecting prism 53 is a trapezoidal prism formed by joining two prisms.

[0085] The reflecting prism 53 has a reflecting surface 54 that reflects (deflects) the distance measurement light 32 incident at a right angle to the reflecting prism 53 toward the bonding surface 35. The distance measurement light 32 reflected by the reflecting surface 54 is deflected by the beam splitter film 38 on the bonding surface 35 so as to coincide with the light receiving optical axis 37 and the axis center 11a. The processes after the light is incident on the beam splitter film 38 are the same as those in the first embodiment.

[0086] In the third embodiment, the reflecting prism 53 has the reflecting surface 54 that deflects the distance measurement optical axis 25 toward the beam splitter film 38. Therefore, the optical path length in the direction of the axis 6a (the vertical direction on the paper surface) can be shortened, and the optical system of the distance measurement unit 19 can be made compact.

[0087] Furthermore, since a prism is used instead of a mirror as the optical element for deflecting the distance measurement optical axis 25 toward the beam splitter film 38, deviation of the optical axis (deflection angle error) due to temperature changes in the surveying device main body 3 is suppressed, thereby improving measurement accuracy.

[0088] Next, a fourth embodiment of the present invention will be described with reference to Fig. 6. In Fig. 6, the same components as those in Fig. 2(A) are given the same reference numerals, and their description will be omitted.

[0089] The fourth embodiment has a configuration in which a tracking function is added to the surveying instrument of the first embodiment, and the distance measurement unit 19 has a tracking light emitting unit 55 and a tracking light receiving unit 56.

[0090] The tracking light emitting unit 55 has a tracking optical axis 57. The tracking light emitting unit 55 also has a tracking light emitting element 58, a collimator lens 59, a dichroic mirror 61, and a reflecting prism 29, which are arranged on the tracking optical axis 57 in this order from the light emitting side. In this embodiment, the tracking optical axis 57 and the tracking optical axis 57 reflected by the reflecting prism 29 are collectively referred to as the tracking optical axis 57. Furthermore, the distance measurement light emitting unit 23, i.e., the light emitting element 26, the collimator lens 27, and the pinhole plate 28 are provided on the reflecting side of the dichroic mirror 61.

[0091] The tracking light emitting element 58 is, for example, a laser diode (LD), and is configured to emit tracking light 62 of a near-infrared wavelength different from the distance measuring light 32. The dichroic mirror 61 is configured to transmit the tracking light 62 and reflect the distance measuring light 32.

[0092] That is, the dichroic mirror 61 is provided on a common optical path of the distance measurement light 32 and the tracking light 62 (at the intersection of the distance measurement optical axis 25 and the tracking optical axis 57), and deflects (reflects) the distance measurement optical axis 25 so that the distance measurement optical axis 25 coincides with the tracking optical axis 57. Therefore, the distance measurement light 32 and the tracking light 62 are irradiated coaxially toward the object to be measured.

[0093] The tracking light receiving unit 56 has a tracking light receiving optical axis 63. The tracking light receiving unit 56 also has a tracking light receiving element 64, a light receiving prism 65, and a light receiving lens 43, which are arranged on the tracking light receiving optical axis 63 in this order from the light receiving side.

[0094] The light-receiving prism 65 is formed by joining together a first prism 66, which is a rectangular prism having a predetermined refractive index, and a second prism 67, which is a triangular prism having a predetermined refractive index. A dichroic filter film is provided on a joining surface 68 between the first prism 66 and the second prism 67, and the joining surface 68 is configured to transmit the reflected distance-measuring light 45 and reflect the tracking light 62 (reflected tracking light 69) reflected by the object to be measured. In other words, the joining surface 68 serves as a separation surface for separating the reflected distance-measuring light 45 from the reflected tracking light 69. The first, second, and third surfaces of the light-receiving prism 65 have the same configurations as the first, second, and third surfaces 42a, 42b, and 42c of the light-receiving prism 42 in the first embodiment.

[0095] Furthermore, the light amount adjustment plate 41 and the light receiving element 36 are provided on the transmission side of the bonding surface 68, and the tracking light receiving element 64 is provided on the reflection side of the bonding surface 68. That is, the bonding surface 68 is located on a common optical path of the reflected distance measuring light 45 and the reflected tracking light 69 (at the intersection of the light receiving optical axis 37 and the tracking light receiving optical axis 63), and separates the reflected distance measuring light 45 and the reflected tracking light 69 which are coaxially incident on the light receiving prism 65.

[0096] The tracking light receiving element 64 is a CCD or CMOS sensor that is a collection of pixels, and the position of each pixel can be identified on the tracking light receiving element 64. For example, each pixel has pixel coordinates with the center of the tracking light receiving element 64 as the origin, and the position on the tracking light receiving element 64 is identified by the pixel coordinates.

[0097] When tracking the object to be measured, the calculation control unit 17 irradiates the tracking light 62 coaxially with the distance measurement light 32, calculates the incident position of the reflected tracking light 69 reflected by the object to be measured with respect to the tracking light receiving element 64, and Incident position and center Based on the deviation, the horizontal rotation motor 8 and the vertical rotation motor 13 are controlled so that the incident position of the reflected tracking light 69 is at the center of the tracking light receiving element 64. This causes the surveying instrument main body 3 to track the object to be measured.

[0098] In the fourth embodiment, some of the optical members for distance measurement and tracking are shared, and the distance measurement light 32 and the tracking light 62 are irradiated coaxially. Therefore, even if a tracking function is added to the surveying instrument 1, the optical system of the distance measurement unit 19 can be made smaller.

[0099] The transmission side of the dichroic mirror 61 may be the distance measurement light emitting section 23 and the reflection side may be the tracking light emitting section 55, or the transmission side of the bonding surface 68 may be the tracking light receiving section 56 and the reflection side may be the distance measurement light receiving section 24.

[0100] Next, a fifth embodiment of the present invention will be described with reference to Fig. 7. In Fig. 7, the same components as those in Fig. 6 are given the same reference numerals, and their description will be omitted.

[0101] In the fifth embodiment, in addition to the distance measurement light emitting unit 23, distance measurement light receiving unit 24, tracking light emitting unit 55, and tracking light receiving unit 56 similar to those in the fourth embodiment, a laser pointer light emitting unit 71 and an imaging unit 72 are arranged coaxially.

[0102] The laser pointer light emitting unit 71 has a light projecting lens 75 provided on the laser pointer light (laser pointer optical axis 74) emitted from the laser pointer light emitting element 73, a beam splitter 76, a mirror 77 provided on the reflected optical axis of the beam splitter 76, and a short pass filter plate 78 provided on the reflected optical axis of the mirror 77. In this embodiment, the laser pointer optical axis 74 and the laser pointer optical axis 74 reflected by the mirror 77 and the short pass filter plate 78 are collectively referred to as the laser pointer optical axis 74.

[0103] The laser pointer light emitting element 73 is, for example, a laser diode that emits a laser beam in the visible light region. The beam splitter 76 deflects the laser pointer optical axis 74 coaxially with an imaging optical axis 79 (described later). That is, the beam splitter 76 is disposed at the intersection of the laser pointer optical axis 74 and the imaging optical axis 79. In addition, the mirror 77 reflects the laser pointer optical axis 74 toward the short-pass filter plate 78.

[0104] The short-pass filter plate 78 has optical properties of transmitting visible light and reflecting the distance measurement light 32 (reflected distance measurement light 45) and the tracking light 62 (reflected tracking light 69). The short-pass filter plate 78 also deflects the distance measurement optical axis 25 and the tracking optical axis 57 so that they are coaxial with the laser pointer optical axis 74 that has passed through the short-pass filter plate 78. Furthermore, the short-pass filter plate 78 deflects the imaging optical axis 79 so that they are coaxial with the light receiving optical axis 37 and the tracking receiving optical axis 57. Optical axis 63 That is, the short-pass filter plate 78 is disposed on a common optical path of the distance measuring light 32 (the tracking light 62) and the laser pointer light.

[0105] The imaging unit 72 includes an imaging element 81 and the imaging element 81 The imaging optical axis 79 is the optical axis of the background light received by the imaging lens group 82, the beam splitter 76, the mirror 77, and the short-pass filter plate 78.

[0106] The imaging element 81 is a CCD or CMOS sensor that is a collection of pixels, and the position of each pixel can be specified on the imaging element 81. For example, each pixel has pixel coordinates with the center of the imaging element 81 as the origin, and the position on the imaging element 81 is specified by the pixel coordinates.

[0107] The reflected distance measuring light 45, the reflected tracking light 69, and the reflected laser pointer light, which are irradiated coaxially and reflected coaxially, enter the distance measuring unit 19 together with background light, and the reflected laser pointer light and background light are separated by the short-pass filter plate 78.

[0108] Furthermore, the laser pointer light and background light that pass through the short-pass filter plate 78 are reflected by the mirror 77, and are focused on the image sensor 81 via the beam splitter 76 and the light-receiving lens group 82, thereby acquiring an image.

[0109] In the fifth embodiment, the laser pointer light emitting unit 71 and the imaging unit 72 are provided so as to be coaxial with the distance measurement optical axis 25 and the tracking optical axis 57. Therefore, some of the optical members used for distance measurement, tracking, imaging, etc. can be shared, which makes it possible to reduce the size of the optical system and the number of parts.

[0110] Next, a sixth embodiment of the present invention will be described with reference to Fig. 8. In Fig. 8, the same components as those in Fig. 6 are given the same reference numerals, and their description will be omitted.

[0111] In the sixth embodiment, in addition to the distance measurement light emitting section 23, the distance measurement light receiving section 24, the tracking light emitting section 55, and the tracking light receiving section 56, an imaging section 72 is added.

[0112] In the sixth embodiment, the reflecting prism 83 is inclined at about 35° with respect to the axis 11a, and the exit surface (the surface on the left side of the drawing) of the reflecting prism 83 is a long-pass filter surface 84 provided with a long-pass filter. The lower part of the reflecting prism 83 is chamfered.

[0113] The long-pass filter surface 84 has optical properties of reflecting visible light and transmitting infrared light and near-infrared light. That is, the long-pass filter surface 84 is a separation surface that reflects background light incident coaxially and transmits the reflected distance measuring light 45 and the reflected tracking light 69.

[0114] The optical axis of the background light separated and reflected by the long-pass filter surface 84 is the imaging optical axis 79, and the light-receiving lens group 82 and the imaging element 81 are disposed on the imaging optical axis 79. Therefore, the background light incident on the reflecting prism 83 is reflected by the long-pass filter surface 84 and enters the imaging element 81. The other configurations are substantially the same as those of the sixth embodiment.

[0115] In the sixth embodiment, the long-pass filter surface 84 provided on the exit surface of the reflecting prism 83 serves as a separation surface for separating background light. Therefore, there is no need to provide a separate mirror or prism for separating background light, which reduces the number of parts and enables the optical system to be made more compact.

[0116] It goes without saying that in the present invention, the first to sixth embodiments may be combined as appropriate.

[0117] In the first to sixth embodiments, the pinhole 33 is a hole physically drilled in the pinhole plate 28, but the pinhole may be an opening formed by an electrowetting mask or a mask formed by depositing chromium on a glass plate. When electrowetting is used, the size of the pinhole can be changed by applying a voltage, allowing for more precise adjustment of the light intensity. [Explanation of symbols]

[0118] 1 Surveying equipment 3 Surveying device body 6 horizontal rotation axis 11 Vertical rotation axis 15 Scanning mirror 17 Calculation control unit 19 Distance measurement unit 23 Distance measurement light emission part 24 Distance measurement light receiver 28 Pinhole Plate 29 Reflecting Prism 32 Ranging light 33 Pinhole 35 Joint surface 38 Beam splitter film 41 Light amount adjustment plate 45 Reflected ranging light 53 Reflecting Prism 54 Reflective surface

Claims

1. A surveying instrument comprising a distance measurement light emitting unit that emits distance measurement light to an object to be measured, a distance measurement light receiving unit having a light receiving element that receives the reflected distance measurement light from the object to be measured, and an arithmetic control unit that controls the distance measurement light emitting unit and calculates the distance to the object to be measured based on the reception result of the reflected distance measurement light by the light receiving element, wherein the distance measurement light emitting unit has a pinhole plate that can be inserted and removed from the optical axis of the distance measurement light, and a pinhole of a predetermined diameter is formed in the pinhole plate, and the light intensity and spread angle of the distance measurement light can be changed by inserting and removing the pinhole plate.

2. The surveying instrument of claim 1, wherein the distance measuring light emission unit has a reflecting prism formed by joining two prisms, and a beam splitter film having a predetermined reflectivity and transmittance is formed on the joint surface of the reflecting prism, and the reflecting prism is configured to deflect the optical axis of the distance measuring light via the beam splitter film so that it coincides with the optical axis of the reflected distance measuring light.

3. 3. A surveying instrument according to claim 2, wherein the reflecting prism is inclined with respect to the optical axis of the reflected distance measuring light, and the distance measuring light is made to enter the exit surface of the reflecting prism at a slight incline.

4. The surveying device according to any one of claims 1 to 3, wherein the distance measuring light receiving unit has a light intensity adjustment plate arranged on the optical axis of the reflected distance measuring light, and the light intensity adjustment plate is configured to form a light intensity adjustment surface that can change the transmittance at the incident position of the reflected distance measuring light.

5. The surveying device according to any one of claims 1 to 4, further comprising a tracking light emitting unit that emits tracking light onto the object to be measured coaxially with the distance measuring light, and a tracking light receiving unit having a tracking light receiving element that receives the reflected tracking light reflected from the object to be measured coaxially with the reflected distance measuring light, wherein a dichroic mirror that aligns the optical axis of the distance measuring light with the optical axis of the tracking light is provided on a common optical path of the distance measuring light and the tracking light, and a separation surface that separates the optical axis of the reflected distance measuring light from the optical axis of the reflected tracking light is provided on the common optical path of the reflected distance measuring light and the reflected tracking light.

6. A surveying device as described in any one of claims 2 to 5, configured such that a long-pass filter that reflects visible light is provided on the exit surface of the reflecting prism from which the distance measurement light is emitted, and an imaging unit is provided on the reflected light axis of the long-pass filter.

7. A surveying device according to any one of claims 1 to 5, further comprising: a laser pointer light emitting unit that emits laser pointer light coaxially with the distance measuring light; and an imaging unit that separates the reflected distance measuring light from visible light.

Images