Measuring device

Abstract

To provide a surveying device that can obtain a sufficient quantity of reflected 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 37 that receives reflected surveying light 43 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 a reflection prism 29 obtained by joining two prisms to each other. A beam splitter film 35 having predetermined reflectance and transmittance is formed on a joint surface of the reflection prism. The reflection prism deflects an optical axis of the surveying light to be aligned with an optical axis of the reflected surveying light through the beam splitter film.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 Art】 【0002】 Surveying instruments such as laser scanners and total stations have an optical distance measuring device that detects the distance to a measurement object by prism distance measurement using a prism having retroreflectivity as a measurement object and non-prism distance measurement without using a reflecting prism. 【0003】 In conventional surveying instruments, in order to align the optical axis of the distance measuring light emitted toward the measurement object and the optical axis of the reflected distance measuring light reflected from the measurement object, the optical axis of the distance measuring light or the reflected distance measuring light is deflected by a mirror or the like. Also, in order to miniaturize the optical system of the surveying instrument, the optical axis of the distance measuring light or the reflected distance measuring light may be deflected multiple times. 【0004】 When using a mirror for the deflection of the optical axis, it is necessary to make the mirror the size corresponding to the light beam of the distance measuring light or the reflected distance measuring light, so it is necessary to use a large mirror, which has led to the enlargement of the optical system and the increase of the device weight. 【Prior Art Documents】 【Patent Documents】 【0005】 【Patent Document 1】 U.S. Patent Application Publication No. 2021 / 0181494 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0006】 The present invention provides a surveying instrument capable of sufficiently obtaining the received light amount of the reflected distance measuring light. 【Means for Solving the Problems】 【0007】 The present invention relates to a surveying device comprising: a distance measuring light emission unit that emits distance measuring light onto an object to be measured; a distance measuring light receiving unit having a light receiving element that receives reflected distance measuring light from the object to be measured; and a calculation control unit that controls the distance measuring light emission unit and calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light on the light receiving element, wherein the distance measuring light emission unit has a reflective prism formed by joining two prisms, a beam splitter film having a predetermined reflectance and transmittance is formed on the joining surface of the reflective prism, and the reflective prism is configured to deflect the optical axis of the distance measuring light via the beam splitter film so that it aligns with the optical axis of the reflected distance measuring light. 【0008】 Furthermore, the present invention relates to a surveying device configured such that the reflective prism is inclined with respect to the optical axis of the reflected distance measuring light, and the distance measuring light is incident on the emission surface of the reflective prism at a slight inclination. 【0009】 Furthermore, the present invention relates to a surveying device in which the distance measuring light emission unit has a parallel plane plate that can be inserted into or removed from the optical axis of the distance measuring light, and the divergence angle of the distance measuring light can be changed by inserting or removing the parallel plane plate. 【0010】 Furthermore, the present invention relates to a surveying device in which the distance measuring light receiving unit has a light intensity adjustment plate provided on the optical axis of the reflected distance measuring light, and the light intensity adjustment plate is configured to have a light intensity adjustment surface that can change the transmittance at the incident position of the reflected distance measuring light. 【0011】 Furthermore, the present invention further comprises a tracking light emission unit that emits tracking light coaxially with the distance measuring light onto the object to be measured, and a tracking light receiving unit having a tracking light receiving element that receives reflected tracking light reflected coaxially from the object to be measured, a dichroic mirror that aligns the optical axis of the distance measuring light and the optical axis of the tracking light on the common optical path of the distance measuring light and the tracking light, and the reflection The optical axis of the distance measuring light and the reflection Tracking This relates to a surveying device configured to have a separation surface that separates the optical axis of light. 【0012】 The present invention also relates to a surveying device configured such that a long-pass filter that reflects visible light is provided on the emission 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 device further comprising a laser pointer light emission 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 measuring light emission unit that emits distance measuring light onto an object to be measured, a distance measuring light receiving unit having a light receiving element that receives reflected distance measuring light from the object to be measured, and a calculation control unit that controls the distance measuring light emission unit and calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light on the light receiving element. The distance measuring light emission unit has a reflective prism formed by joining two prisms, and a beam splitter film having a predetermined reflectivity and transmittance is formed on the joining surface of the reflective prism. The reflective prism is configured to deflect the optical axis of the distance measuring light through the beam splitter film so that it aligns with the optical axis of the reflected distance measuring light. As a result, a portion of the reflected distance measuring light incident on the beam splitter film can be transmitted, exhibiting the excellent effect of obtaining a sufficient amount of light even when measuring at a short distance or when the object to be measured is small. [Brief explanation of the drawing] 【0015】 [Figure 1] This is a cross-sectional view showing a surveying device according to a first embodiment of the present invention. [Figure 2] (A) is a diagram showing the configuration of a distance measuring unit according to a first embodiment of the present invention, and (B) is a side view of a reflective prism. [Figure 3] This is a diagram showing the distance measuring unit according to the first embodiment of the present invention. [Figure 4] This is a diagram showing a distance measuring unit according to a second embodiment of the present invention. [Figure 5]It is a block diagram showing a distance measurement unit according to a third embodiment of the present invention. [Figure 6] It is a block diagram showing a distance measurement unit according to a fourth embodiment of the present invention. [Figure 7] It is a block diagram showing a distance measurement unit according to a fifth embodiment of the present invention. [Figure 8] It is a block diagram showing a distance measurement unit according to a sixth embodiment of the present invention. 【Embodiments for Carrying Out the Invention】 【0016】 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 【0017】 First, in FIG. 1, a surveying device according to a first embodiment of the present invention will be described. 【0018】 The surveying device 1 is, for example, a laser scanner, and includes an alignment unit 2 attached to a tripod (not shown) and a surveying device main body 3 attached to the alignment unit 2. 【0019】 The alignment unit 2 has an alignment screw 10, and the alignment of the surveying device main body 3 is performed by the alignment screw 10. 【0020】 The surveying device main body 3 includes a fixing part 4, a bracket part 5, a horizontal rotation shaft 6, a horizontal rotation bearing 7, a horizontal rotation motor 8 as a horizontal rotation drive part, a horizontal angle encoder 9 as a horizontal angle detection part, a vertical rotation shaft 11, a vertical rotation bearing 12, a vertical rotation motor 13 as a vertical rotation drive part, a vertical angle encoder 14 as a vertical angle detection part, a scanning mirror 15 which is a vertical rotation part, an operation panel 16 that also serves as an operation part and a display part, an arithmetic control part 17, a storage part 18, a distance measurement part 19, etc. Note that as the arithmetic control part 17, a CPU specialized for this device or a general-purpose CPU is used. 【0021】 The horizontal rotating bearing 7 is fixed to the fixed part 4. The horizontal rotating shaft 6 has a vertical axis 6a, and the horizontal rotating shaft 6 is rotatably supported by the horizontal rotating bearing 7. The support part 5 is supported by the horizontal rotating shaft 6, and the support part 5 rotates in the horizontal direction integrally with the horizontal rotating shaft 6. 【0022】 A horizontal rotation motor 8 is provided between the horizontal rotation bearing 7 and the support portion 5, and the horizontal rotation motor 8 is controlled by the calculation control unit 17. The calculation control unit 17 uses the horizontal rotation motor 8 to rotate the support portion 5 around the axis 6a. 【0023】 The relative rotation angle of the support unit 5 with respect to the fixed unit 4 is detected by the horizontal angle encoder 9. The detection signal from the horizontal angle encoder 9 is input to the calculation control unit 17, and the calculation control unit 17 calculates the horizontal angle data. Based on the horizontal angle data, the calculation control unit 17 performs feedback control to the horizontal rotation motor 8. 【0024】 Furthermore, the mounting portion 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 body 3. 【0025】 A recess 22 is formed in the mounting portion 5. One end of the vertical rotation shaft 11 extends into the recess 22, and the scanning mirror 15 is fixed to this end, with the scanning mirror 15 housed in the recess 22. The other end of the vertical rotation shaft 11 is provided with the vertical angle encoder 14. 【0026】 A vertical rotation motor 13 is provided on the vertical rotation axis 11, and the vertical rotation motor 13 is controlled by the calculation control unit 17. The calculation control unit 17 rotates the vertical rotation axis 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 calculation control unit 17. The calculation control unit 17 calculates the vertical angle data of the scanning mirror 15 based on the detection signal and performs feedback control to the vertical rotation motor 13 based on the vertical angle data. 【0028】 Furthermore, 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 as the storage unit 18, such as an HDD as a magnetic storage device, a CD or DVD as an optical storage device, or a memory card or USB memory as a semiconductor storage device. The storage unit 18 may be detachable from the mounting unit 5, or it may be capable of sending 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, including a sequence program for controlling the distance measurement operation, a calculation program for calculating distance based on the distance measurement operation, a calculation program for calculating angles based on horizontal angle data and vertical angle data, and a program for calculating the three-dimensional coordinates of a desired measurement point based on distance and angle. Furthermore, various processes are executed by the calculation control unit 17 when these programs are executed. 【0030】 The aforementioned operation panel 16 is, for example, a touch panel, and serves as both an operation unit for giving instructions for distance measurement and changing measurement conditions, such as the interval between measurement points, and a display unit for displaying distance measurement results, images, etc. 【0031】 Next, the distance measuring unit 19 will be described with reference to Figures 2(A), 2(B), and 3. 【0032】 The distance measuring unit 19 includes a distance measuring light emission unit 23 and a distance measuring light receiving unit 24. The distance measuring unit is composed of the distance measuring light emission unit 23 and the distance measuring light receiving unit 24. 【0033】 The distance measuring light emission unit 23 has a distance measuring optical axis 25. The distance measuring light emission unit 23 also has, in order from the light-emitting side, a light-emitting element 26, such as a laser diode (LD), provided on the distance measuring optical axis 25, a parallel plane plate 27, a collimator lens 28, and a reflecting prism 29. The scanning mirror 15 is provided on the reflected optical axis of the reflecting prism 29. Furthermore, a window portion 31 made of a transparent material is provided on the reflected optical axis of the scanning mirror 15 and rotates integrally with the scanning mirror 15. Although the window portion 31 is provided in Figure 2, it may be omitted. 【0034】 Furthermore, the parallel plane plate 27, the collimator lens 28, the reflective prism 29, etc. constitute the light projection optical system 30. In this embodiment, the distance measuring optical axis 25 and the distance measuring optical axis 25 reflected by the reflective prism 29 are collectively referred to as the distance measuring optical axis 25. 【0035】 The parallel plane plate 27 is, for example, a glass plate having a predetermined thickness, and is arranged so that its incident surface and exit surface are perpendicular to the distance measuring optical axis 25. Furthermore, the parallel plane plate 27 can be inserted into and removed from the distance measuring optical axis 25 by a drive mechanism such as a solenoid (not shown), and the parallel plane plate 27 is inserted or removed as appropriate depending on the object to be measured. That is, when performing prism measurement, in which the object to be measured is a prism or the like which has retroreflective properties, the parallel plane plate 27 is inserted onto the distance measuring optical axis 25, and when performing non-prism measurement, in which the object to be measured is something other than a prism, the parallel plane plate 27 is removed from the distance measuring optical axis 25. 【0036】 By inserting the parallel plane plate 27 onto the distance measuring optical axis 25, the divergence angle of the distance measuring light 32 emitted from the light-emitting element 26 is expanded via the parallel plane plate 27. The divergence angle φ expanded by the parallel plane plate 27 is appropriately set between 2 and 20 minutes. In this embodiment, the divergence angle φ of the distance measuring light 32 due to the parallel plane plate 27 is 6 minutes. 【0037】 When the parallel plane plate 27 is not inserted on the distance measuring optical axis 25, the collimator lens 28 makes the distance measuring light 32 a parallel beam. When the parallel plane plate 27 is inserted on the distance measuring optical axis 25, the collimator lens 28 slightly diverges the distance measuring light 32. 【0038】 The reflective prism 29 is formed by joining two trapezoidal prisms, and when the two prisms are joined, the reflective prism 29 has a rectangular parallelepiped shape. The incident surface of the distance measuring light 32 is perpendicular to the distance measuring optical axis 25, and the joint surface 33 of the reflective prism 29 is inclined at a predetermined angle with respect to the distance measuring optical axis 25. Furthermore, the exit surface of the reflective prism 29 is configured such that the distance measuring optical axis 25 reflected by the joint surface 33 is incident at a slight inclination, for example, about 2.5°. Therefore, it is prevented that the distance measuring light 32 internally reflected at the exit surface of the reflective prism 29 is received by the light receiving element 37 (described later). The inclination angle of the joint surface 33 is such that the distance measuring optical axis 25 is deflected (reflected) so that it aligns with the light receiving optical axis 34 (described later) and the axis 11a. Alternatively, the inclination angle of the bonding surface 33 may be set to 45°, and the distance measuring light 32 may be incident on the reflecting prism 29 at an angle to the incident surface such that the distance measuring optical axis 25 coincides with the light receiving optical axis 34 and the axis 11a. 【0039】 A beam splitter film 35 is formed in the center of the bonding surface 33, and an anti-reflective film 36 is formed on the entire front and back surfaces of the reflecting prism 29. The beam splitter film 35 is elliptical in shape to match the light beam of the distance measuring light 32. Furthermore, the size of the beam splitter film 35 is equal to or slightly larger than the diameter of the light beam of the distance measuring light 32 diverged by the parallel plane plate 27. In addition, the beam splitter film 35 has optical properties such as reflecting 80% of the light and transmitting 20% ​​of the light. 【0040】 Furthermore, the ratio of reflectance to transmittance in the beam splitter film 35 is set appropriately according to the application and the distance to the object to be measured. For example, when the distance to the object to be measured is short, it is desirable to select the beam splitter film 35 from a range of, for example, a reflectance of 50% to 70% and a transmittance of 30% to 50%, and when the distance to the object to be measured is long, it is desirable to select the beam splitter film 35 from a range of, for example, a reflectance of 70% to 90% and a transmittance of 10% to 30%. 【0041】 The distance measuring light receiving unit 24 has the light receiving optical axis 34. The distance measuring light receiving unit 24 also has, in order from the light receiving side, a light receiving element 37, a light intensity adjustment plate 38, and a light receiving prism 39, and a light receiving lens 41 having a predetermined NA that is provided on the light receiving optical axis 34 and reflected by the light receiving prism 39. 【0042】 Furthermore, the light-receiving optical system 42 is composed of the light intensity adjustment plate 38, the light-receiving prism 39, the light-receiving lens 41, the reflecting prism 29, etc. Also, in this embodiment, the light-receiving optical axis 34 and the light-receiving optical axis 34 reflected by the light-receiving prism 39 are collectively referred to as the light-receiving optical axis 34. 【0043】 The distance measuring unit 19 is controlled by the calculation control unit 17. When pulsed distance measuring light 32 is emitted from the light-emitting element 26 onto the distance measuring optical axis 25, the distance measuring light 32 is incident on the collimator lens 28. If the parallel plane plate 27 is present on the distance measuring optical axis 25, the distance measuring light 32 is incident on the collimator lens 28 via the parallel plane plate 27, with its divergence angle slightly widening. 【0044】 The collimator lens 28 corrects the distance measuring light 32 into a parallel beam when the distance measuring light 32 is incident directly on it from the light-emitting element 26. Furthermore, the collimator lens 28 slightly diverges the distance measuring light 32 when it is incident on it via the parallel plane plate 27. 【0045】 The distance measuring light 32 that has passed through the collimator lens 28 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 33 (beam splitter film 35) so that it is coaxial with the light receiving axis 34 and the axis 11a. The distance measuring light 32 emitted from the reflecting prism 29 is deflected at a right angle by the scanning mirror 15 and irradiated onto the object to be measured through the window portion 31. As the scanning mirror 15 rotates around the axis 11a, the distance measuring light 32 is perpendicular to the axis 11a and rotated (scanned) in a plane that includes the axis 6a. 【0046】 Furthermore, the window portion 31 is positioned at a predetermined angle with respect to the optical axis of the distance measuring optical axis 25 so that the distance measuring light 32 reflected by the window portion 31 does not enter the light receiving element 37. 【0047】 The distance measuring light 32 (hereinafter referred to as reflected distance measuring light 43) reflected by the object to be measured is reflected at a right angle by the scanning mirror 15 and received by the light receiving element 37 via the light receiving optical system 42. The light receiving element 37 is, for example, an avalanche photodiode (APD) or an equivalent photoelectric conversion element. 【0048】 The calculation control unit 17 performs distance measurement for each pulse of the distance measuring light 32 (Time of Flight) based on the time difference between the light emission timing of the light-emitting element 26 and the light-receiving timing of the light-receiving element 37 (i.e., the round-trip time of the pulsed light) and the speed of light. The timing of the light emission of the light-emitting element 26, i.e., the pulse interval, can be changed via the operation panel 16. 【0049】 Furthermore, the distance measuring unit 19 is provided with an internal reference light optical system (described later), and by measuring the distance based on the time difference in the timing of reception between the internal reference light (described later) received from the internal reference light optical system and the reflected distance measuring light 43, and the speed of light, more accurate distance measurement becomes possible. 【0050】 The mounting unit 5 and the scanning mirror 15 each rotate at a constant speed, and the distance measuring light 32 is scanned in two dimensions by the cooperation of the vertical rotation of the scanning mirror 15 and the horizontal rotation of the mounting unit 5. 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 acquired. From the vertical angle data, horizontal angle data and distance measuring 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 acquired. 【0051】 Next, the light-receiving optical system 42 will be described. Note that in Figures 2(A) and 3, only the principal rays of the distance-measuring light 32 (the distance-measuring optical axis 25) and the principal rays of the reflected distance-measuring light 43 (the light-receiving optical axis 34) are shown. 【0052】 The light-receiving prism 39 is a quadrangular prism having a predetermined refractive index, and has a first surface 39a into which the reflected distance-measuring light 43 that has passed through the light-receiving lens 41 is incident, a second surface 39b into which the reflected distance-measuring light 43 that has passed through the surface of the first surface 39a is reflected, a third surface 39c into which the reflected distance-measuring light 43 that has been reflected by the second surface 39b and the first surface 39a is incident, and a fourth surface 39d as a transmitting surface through which the reflected distance-measuring light 43 that has been reflected by the third surface 39c is transmitted in a direction intersecting the reflected distance-measuring light 43 that has been incident on the first surface 39a. The reflected distance-measuring light 43 that has passed through the fourth surface 39d is incident on the light-receiving element 37. 【0053】 The light intensity adjustment plate 38 is, for example, a plastic disc, and its surface has As a surface for adjusting light intensity A circular gradient film is formed, and a portion of the gradient film is positioned perpendicular to the light-receiving optical axis 34. The light intensity adjustment plate 38 is rotatable by a motor 46 around a rotation axis 45, and the rotation of the light intensity adjustment plate 38 changes the incident position of the reflected ranging light 43 on the light intensity adjustment plate 38. 【0054】 The gradient film is configured such that its transmittance gradually increases (or decreases) between θ = 0° and 360°. Therefore, by driving the motor 46 and controlling the incident position of the reflected distance measuring light 43 on the light intensity adjustment plate 38, the transmittance of the reflected distance measuring light 43 can be controlled, for example, within a range of 0.0001% to 100%. The transmittance of the light intensity adjustment plate 38 is set appropriately according to the type of object to be measured and the distance to the object to be measured. 【0055】 Furthermore, a retroreflective reference prism 47 is provided below the scanning mirror 15. During the rotational irradiation of the distance measuring light 32 via the scanning mirror 15, a portion of the distance measuring light 32 is incident on the reference prism 47. The distance measuring light 32 retroreflective by the reference prism 47 is incident on the light receiving optical system 42 via the scanning mirror 15 and is received by the light receiving element 37. 【0056】 Here, the optical path length from the light-emitting element 26 to the reference prism 47 and the optical path length from the reference prism 47 to the light-receiving element 37 are known. Therefore, the distance-measuring light 32 reflected by the reference prism 47 can be used as the internal reference light 48. The scanning mirror 15 and the reference prism 47 constitute the internal reference light optical system 49. 【0057】 Next, we will describe the case in which measurements are performed using the surveying device 1 having the distance measuring unit 19. The various operations of the distance measuring unit 19 are performed by the calculation control unit 17 executing various programs. In the following description, we will focus on the case in which prism measurement is performed. 【0058】 The distance measuring light 32 emitted from the light-emitting element 26 is incident on the reflecting prism 29 at a right angle via the parallel plane plate 27 and the collimator lens 28. 【0059】 The distance measuring light 32 incident on the reflective prism 29 passes through the reflective prism 29 and is deflected (reflected) by the beam splitter film 35 on the bonding surface 33 so that it is coaxial with the light receiving axis 34 and the axis 11a. At this time, the size of the beam splitter film 35 is equal to or slightly larger than the diameter of the light beam of the distance measuring light 32, so all of the distance measuring light 32 is incident on the beam splitter film 35. Furthermore, since the emission surface of the reflective prism 29 is inclined with respect to the distance measuring axis 25, the distance measuring light 32 reflected internally from the emission surface is not received by the light receiving element 37. 【0060】 The distance measuring light 32 reflected by the beam splitter film 35 is transmitted at a slight inclination relative to the emission surface of the reflecting prism 29 and is irradiated onto the object to be measured, such as a retroreflective prism, via the scanning mirror 15. 【0061】 The reflected distance measuring light 43 reflected by the prism is reflected at a right angle by the scanning mirror 15, passes through the reflection prism 29, and enters the light receiving optical system 42. Here, the light from the center of the reflected distance measuring light 43 passes through the bonding surface 33. Furthermore, of the reflected distance measuring light 43 that passes through the bonding surface 33, the reflected distance measuring light 43 is completely transmitted in the areas where the anti-reflective film 36 is provided. On the other hand, in the areas where the beam splitter film 35 is provided, a portion of the reflected distance measuring light 43 is transmitted. In this embodiment, since the beam splitter film 35 has a transmittance of 20%, 20% of the reflected distance measuring light 43 incident on the beam splitter film 35 passes through the beam splitter film 35. 【0062】 The reflected distance-measuring light 43, which has passed through the reflective prism 29 and entered the light-receiving optical system 42, is refracted as it passes through the light-receiving lens 41 and the first surface 39a. The reflected distance-measuring light 43 is sequentially reflected by the second surface 39b and the first surface 39a inside the light-receiving prism 39 and enters the third surface 39c. The reflected distance-measuring light 43 is also reflected by the third surface 39c toward the fourth surface 39d, that is, in a direction intersecting the reflected distance-measuring light 43 that entered from the first surface 39a. The reflected distance-measuring light 43 that has passed through the fourth surface 39d is received by the light-receiving element 37 while being attenuated as it passes through the light intensity adjustment plate 38. 【0063】 The calculation control unit 17 calculates the three-dimensional coordinates of the prism based on the distance measurement result of the distance measuring unit 19, the detection results of the horizontal angle encoder 9 and the vertical angle encoder 14. 【0064】 Furthermore, 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 43 is received as the position of the prism. 【0065】 As described above, in the first embodiment, a reflective prism 29, which is a combination of two prisms, is used as an optical element to align the distance measuring optical axis 25 with the light receiving optical axis 34, and the distance measuring light 32 is deflected by the beam splitter film 35 formed on the bonding surface 33 of the reflective prism 29. 【0066】 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 43 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 43 increases. 【0067】 Therefore, since a portion of the reflected ranging light 43 incident on the beam splitter film 35 passes through the beam splitter film 35 which has a predetermined transmittance, vignetting of the reflected ranging light 43 by the beam splitter film 35 can be reduced, and a sufficient amount of received light that enables ranging can be obtained even in short-range measurements. 【0068】 Furthermore, since vignetting of the reflectance measuring light 43 passing through the beam splitter film 35 can be reduced, measurement becomes possible even when a small corner cube or the like is used as the object to be measured and the beam diameter of the reflectance measuring light 43 is small. 【0069】 Furthermore, a parallel plane plate 27 that can be inserted into or removed from the distance measuring optical axis 25 is provided, and the divergence angle of the distance measuring light 32 can be adjusted using the parallel plane plate 27. Therefore, it is possible to switch between non-prism measurement using the distance measuring light 32 with a small beam diameter and high light intensity, and prism measurement using the distance measuring light 32 with a large beam diameter. 【0070】 Furthermore, a light intensity adjustment plate 38, whose transmittance can be changed by rotation, is provided between the light-receiving prism 39 and the light-receiving element 37, and the amount of reflected distance-measuring light 43 received by the light-receiving element 37 can be adjusted by rotating the light intensity adjustment plate 38. 【0071】 Therefore, even if the amount of light in the reflected distance measuring light 43 is so large that the light receiving element 37 becomes saturated, the amount of light in the reflected distance measuring light 43 can be attenuated to an appropriate level by the light intensity adjustment plate 38. 【0072】 Furthermore, since the emission surface of the reflective prism 29 is slightly inclined with respect to the distance measuring optical axis 25 deflected by the beam splitter film 35, it is possible to prevent the distance measuring light 32 internally reflected at the emission surface from being received by the light receiving element 37, thereby reducing measurement errors. 【0073】 Furthermore, by providing the light-receiving prism 39 and reflecting the reflected distance-measuring light 43 multiple times within the light-receiving prism 39, the optical path length in the horizontal direction (left-right direction with respect to the paper plane) can be shortened, thereby enabling miniaturization of the optical system of the distance-measuring unit 19 and weight reduction of the surveying device 1. 【0074】 Furthermore, if the attenuation of the reflected distance measuring light 43 is insufficient with only the light intensity adjustment plate 38, an attenuation film may be formed on the parallel plane plate 27. Normally, when performing prism measurements, the amount of reflected distance measuring light 43 is greater than when performing non-prism measurements. That is, the amount of reflected distance measuring light 43 increases to the point where the light receiving element 37 becomes saturated only in the case of prism measurements. Therefore, by forming an attenuation film on the parallel plane plate 27, the amount of reflected distance measuring light 43 received during prism measurements can be reduced. 【0075】 Next, a second embodiment of the present invention will be described in Figure 4. In Figure 4, components equivalent to those in Figure 2(A) are denoted by the same reference numerals, and their descriptions are omitted. 【0076】 In the second embodiment, the distance measuring optical axis 25 is deflected twice so that it aligns with the light receiving optical axis 34 and the axis 11a. That is, in the second embodiment, a reflective mirror 51 is provided between the collimator lens 28 and the reflective prism 29 to deflect (reflect) the distance measuring optical axis 25 at a right angle. 【0077】 The distance measuring light 32 emitted from the light-emitting element 26 is deflected at a right angle by the reflective mirror 51 and then incident perpendicularly on the reflective prism 29. The process after the light is incident on the reflective prism 29 is the same as in the first embodiment. 【0078】 In the second embodiment, since the reflective mirror 51 that deflects the distance measuring optical axis 25 at a right angle is provided, the optical path length in the direction of the axis 6a (up and down direction with respect to the plane of the paper) can be shortened, and the optical system of the distance measuring unit 19 can be miniaturized. 【0079】 Next, a third embodiment of the present invention will be described in Figure 5. In Figure 5, components equivalent to those in Figure 2(A) are denoted by the same reference numerals, and their descriptions are omitted. 【0080】 In the third embodiment, similar to the second embodiment, the distance measuring optical axis 25 is deflected twice to align with the light receiving optical axis 34 and the axis 11a. On the other hand, in the third embodiment, the reflecting prism 52 is a trapezoidal prism formed by joining two prisms. 【0081】 The reflective prism 52 has a reflective surface 53 that reflects (deflects) the distance measuring light 32 incident perpendicular to the reflective prism 52 toward the bonding surface 33. The distance measuring light 32 reflected by the reflective surface 53 is deflected by the beam splitter film 35 of the bonding surface 33 so as to coincide with the light receiving optical axis 34 and the axis 11a. The process after the light is incident on the beam splitter film 35 is the same as in the first embodiment. 【0082】 In the third embodiment, the reflective prism 52 has a reflective surface 53 that deflects the distance measuring optical axis 25 toward the beam splitter film 35. Therefore, the optical path length in the axial direction 6a (up and down direction with respect to the plane of the paper) can be shortened, and the optical system of the distance measuring unit 19 can be miniaturized. 【0083】 Furthermore, since a prism is used instead of a mirror as the optical element for deflecting the distance measuring optical axis 25 toward the beam splitter film 35, deviation of the optical axis (declination error) due to temperature changes relative to the surveying device body 3 is suppressed, and measurement accuracy can be improved. 【0084】 Next, a fourth embodiment of the present invention will be described in Figure 6. In Figure 6, components equivalent to those in Figure 2(A) are denoted by the same reference numerals, and their descriptions are omitted. 【0085】 The fourth embodiment is a configuration in which a tracking function is added to the surveying device of the first embodiment, and the distance measuring unit 19 has a tracking light emission unit 54 and a tracking light receiving unit 55. 【0086】 The tracking light emission unit 54 has a tracking optical axis 56. The tracking light emission unit 54 also has, in order from the light-emitting side, a tracking light-emitting element 57, a collimator lens 58, a dichroic mirror 59, and a reflective prism 29, all located on the tracking optical axis 56. In this embodiment, the tracking optical axis 56 and the tracking optical axis 56 reflected by the reflective prism 29 are collectively referred to as the tracking optical axis 56. Furthermore, a distance measuring light emission unit 23, i.e., a light-emitting element 26, a parallel plane plate 27, and a collimator lens 28, are provided on the reflective side of the dichroic mirror 59. 【0087】 The tracking light-emitting element 57 is, for example, a laser diode (LD) and is configured to emit tracking light 61 with a near-infrared wavelength different from the distance-measuring light 32. The dichroic mirror 59 is configured to transmit the tracking light 61 and reflect the distance-measuring light 32. 【0088】 Specifically, the dichroic mirror 59 is positioned on the common optical path of the distance measuring light 32 and the tracking light 61 (at the intersection of the distance measuring optical axis 25 and the tracking optical axis 56), and deflects (reflects) the distance measuring optical axis 25 so that it aligns with the tracking optical axis 56. Consequently, the distance measuring light 32 and the tracking light 61 are coaxially directed toward the object to be measured. 【0089】 The tracking light receiving unit 55 has a tracking light receiving optical axis 62. The tracking light receiving unit 55 also has, in order from the light receiving side, a tracking light receiving element 63, a light receiving prism 64, and a light receiving lens 41. 【0090】 The light-receiving prism 64 is constructed by joining and integrating a first prism 65, which is a square prism having a predetermined refractive index, and a second prism 66, which is a triangular prism having a predetermined refractive index. In the integrated state, the light-receiving prism 64 has the same external shape as the light-receiving prism 39 in the first embodiment. A dichroic filter film is provided on the joining surface 67 of the first prism 65 and the second prism 66, and the joining surface 67 is configured to transmit the reflected ranging light 43 and reflect the tracking light 61 (reflected tracking light 68) reflected by the object to be measured. In other words, the joining surface 67 is a separation surface for separating the reflected ranging light 43 and the reflected tracking light 68. Furthermore, the first surface 65a, the second surface 65b, and the third surface 65c have the same configuration as the first surface 39a, the second surface 39b, and the third surface 39c of the light-receiving prism 39 in the first embodiment. 【0091】 Furthermore, a light intensity adjustment plate 38 and a light receiving element 37 are provided on the transmission side of the bonding surface 67, and the tracking light receiving element 63 is provided on the reflection side of the bonding surface 67. That is, the bonding surface 67 is located on the common optical path of the reflected distance measuring light 43 and the reflected tracking light 68 (at the intersection of the light receiving optical axis 34 and the tracking light receiving optical axis 62), and separates the reflected distance measuring light 43 and the reflected tracking light 68 that are incident coaxially on the light receiving prism 64. 【0092】 The tracking light-receiving element 63 is a CCD or CMOS sensor, which is a collection of pixels, and the position of each pixel on the tracking light-receiving element 63 can be determined. For example, each pixel has pixel coordinates with the center of the tracking light-receiving element 63 as the origin, and its position on the tracking light-receiving element 63 is determined by these pixel coordinates. 【0093】 When tracking an object to be measured, the calculation control unit 17 irradiates the tracking light 61 coaxially with the distance measuring light 32, calculates the incident position of the reflected tracking light 68 reflected by the object to be measured onto the tracking light receiving element 63, and The relationship between the incident position and the centerBased 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 68 is at the center of the tracking light receiving element 63. As a result, the surveying device body 3 tracks the object to be measured. 【0094】 In the fourth embodiment, a portion of the optical elements for distance measurement and tracking are shared, and the distance measuring light 32 and the tracking light 61 are configured to illuminate coaxially. Therefore, even when a tracking function is added to the surveying device 1, the optical system of the distance measuring unit 19 can be miniaturized. 【0095】 Alternatively, the transmitting side of the dichroic mirror 59 may be designated as the distance measuring light emission unit 23 and the reflecting side as the tracking light emission unit 54, or the transmitting side of the bonding surface 67 may be designated as the tracking light receiving unit 55 and the reflecting side as the distance measuring light receiving unit 24. 【0096】 Next, a fifth embodiment of the present invention will be described in Figure 7. In Figure 7, components equivalent to those in Figure 6 are denoted by the same reference numerals, and their descriptions are omitted. 【0097】 In the fifth embodiment, in addition to the distance measuring light emission unit 23, distance measuring light receiving unit 24, tracking light emission unit 54, and tracking light receiving unit 55 similar to those in the fourth embodiment, a laser pointer light emission unit 69 and an imaging unit 71 are provided coaxially. 【0098】 The laser pointer light emission unit 69 includes a light projection lens 74 provided on the laser pointer light (laser pointer optical axis 73) emitted from the laser pointer light-emitting element 72, a beam splitter 75, a mirror 76 provided on the reflected optical axis of the beam splitter 75, and a short-pass filter plate 77 provided on the reflected optical axis of the mirror 76. In this embodiment, the laser pointer optical axis 73 and the laser pointer optical axis 73 reflected by the mirror 76 and the short-pass filter plate 77 are collectively referred to as the laser pointer optical axis 73. 【0099】 The laser pointer light-emitting element 72 is, for example, a laser diode that emits a laser beam in the visible light region. The beam splitter 75 deflects the laser pointer optical axis 73 coaxially with the imaging optical axis 78 (described later). That is, the beam splitter 75 is positioned at the intersection of the laser pointer optical axis 73 and the imaging optical axis 78. The mirror 76 reflects the laser pointer optical axis 73 toward the short-pass filter plate 77. 【0100】 The short-pass filter plate 77 has optical properties that transmit visible light and reflect the distance measuring light 32 (reflected distance measuring light 43) and the tracking light 61 (reflected tracking light 68). Furthermore, the short-pass filter plate 77 deflects the distance measuring light axis 25 and the tracking light axis 56 so that they are coaxial with the laser pointer optical axis 73 that has passed through the short-pass filter plate 77. In addition, the short-pass filter plate 77 directs the imaging light axis 78 to the light receiving light axis 34 and the tracking light receiving light axis. Optical axis 62 To separate them. That is, the short-pass filter plate 77 is placed on the common optical path of the distance measuring light 32 (the tracking light 61) and the laser pointer light. 【0101】 The imaging unit 71 is an image sensor 79 and the image sensor 79 The system includes a group of light-receiving lenses 81 positioned on the optical axis of the background light received by the system (the imaging optical axis 78), the beam splitter 75, the mirror 76, and the short-pass filter plate 77. 【0102】 The image sensor 79 is a CCD or CMOS sensor, which is a collection of pixels, and the position of each pixel on the image sensor 79 can be determined. For example, each pixel has pixel coordinates with the center of the image sensor 79 as the origin, and its position on the image sensor 79 is determined by these pixel coordinates. 【0103】 The reflected distance measuring light 43, the reflected tracking light 68, and the reflected laser pointer light, which are irradiated coaxially and reflected coaxially, enter the distance measuring unit 19 together with the background light, and the reflected laser pointer light and the background light are separated by the short-pass filter plate 77. 【0104】 Furthermore, the laser pointer light and background light that have passed through the short-pass filter plate 77 are reflected by the mirror 76 and imaged onto the image sensor 79 via the beam splitter 75 and the light-receiving lens group 81, thereby acquiring an image. 【0105】 In the fifth embodiment, the laser pointer light emission unit 69 and the imaging unit 71 are arranged to be coaxial with the distance measuring optical axis 25 and the tracking optical axis 56. Therefore, some of the optical components used for distance measuring, tracking, imaging, etc., can be shared, which allows for miniaturization of the optical system and a reduction in the number of parts. 【0106】 Next, a sixth embodiment of the present invention will be described in Figure 8. In Figure 8, components equivalent to those in Figure 6 are denoted by the same reference numerals, and their descriptions are omitted. 【0107】 In the sixth embodiment, an imaging unit 71 is added in addition to the distance measuring light emission unit 23, distance measuring light receiving unit 24, tracking light emission unit 54, and tracking light receiving unit 55. 【0108】 In the sixth embodiment, the reflective prism 82 is tilted at approximately 35° with respect to the axis 11a, and the ejection surface of the reflective prism 82 (the left side relative to the paper plane) is a long-pass filter surface 83 equipped with a long-pass filter. Furthermore, the lower part of the reflective prism 82 is chamfered. 【0109】 The long-pass filter surface 83 has optical properties that reflect visible light and transmit infrared and near-infrared light. In other words, the long-pass filter surface 83 is a separation surface that reflects coaxially incident background light and transmits reflected ranging light 43 and reflected tracking light 68. 【0110】 The optical axis of the background light separated and reflected by the long-pass filter surface 83 becomes the imaging optical axis 78, and the light-receiving lens group 81 and the image sensor 79 are arranged on the imaging optical axis 78. Therefore, the background light incident on the reflective prism 82 is reflected by the long-pass filter surface 83 and incident on the image sensor 79. The other configurations are substantially the same as in the sixth embodiment. 【0111】 In the sixth embodiment, the long-pass filter surface 83 provided on the exit surface of the reflective prism 82 is used as a separation surface for separating background light. Therefore, since there is no need to separately provide mirrors or prisms to separate background light, the number of parts can be reduced and the optical system can be miniaturized. 【0112】 It goes without saying that, in the present invention, the first to sixth embodiments may be combined as appropriate. [Explanation of Symbols] 【0113】 1 Surveying equipment 3 Surveying device body 6. Horizontal rotation axis 11 Vertical rotation axis 15 Scanning mirror 17. Arithmetic Control Unit 19 Distance measuring unit 23 Distance measurement light emission part 24 Distance measurement light receiver 29 Reflecting prism 32 Ranging light 33 Joint surface 35 Beam splitter film 38 Light amount adjustment plate 43 Reflected ranging light 51 Reflective mirror 52 Reflecting prism 53 Reflective surface

Claims

[Claim 1] The system comprises a distance measuring light emission unit that emits distance measuring light towards an object to be measured, a distance measuring light receiving unit having a light receiving element that receives reflected distance measuring light from the object to be measured, and a calculation control unit that controls the distance measuring light emission unit and calculates the distance to the object to be measured based on the result of receiving the reflected distance measuring light to the light receiving element, wherein the distance measuring light emission unit has a reflective prism formed by joining two prisms, a beam splitter film having a predetermined reflectance and transmittance is formed on the joining surface of the reflective prism, and the reflective prism is configured to deflect the optical axis of the distance measuring light via the beam splitter film so that it aligns with the optical axis of the reflected distance measuring light. The surveying device is configured such that the reflective prism is inclined with respect to the optical axis of the reflected distance measuring light, the distance measuring light is incident perpendicular to the incident surface of the reflective prism, and is incident at a slight inclination with respect to the exit surface of the reflective prism. [Claim 2] The surveying device according to claim 1, wherein the distance measuring light emission unit has a parallel plane plate that can be inserted into or removed from the optical axis of the distance measuring light, and the divergence angle of the distance measuring light can be changed by inserting or removing the parallel plane plate. [Claim 3] The measuring device according to claim 1 or 2, wherein the distance measuring light receiving unit has a light intensity adjustment plate provided on the optical axis of the reflected distance measuring light, and the light intensity adjustment plate is configured to have a light intensity adjustment surface that can change the transmittance at the incident position of the reflected distance measuring light. [Claim 4] A measuring device according to any one of claims 1 to 3, further comprising: a tracking light emission unit that emits tracking light coaxially with the distance measuring light to the object to be measured; and a tracking light receiving unit having a tracking light receiving element that receives reflected tracking light reflected coaxially from the object to be measured; a dichroic mirror provided on the common optical path of the distance measuring light and the tracking light to align the optical axis of the distance measuring light and the optical axis of the tracking light; and a separation surface provided on the common optical path of the reflected distance measuring light and the reflected tracking light to separate the optical axis of the reflected distance measuring light and the optical axis of the reflected tracking light. [Claim 5] The surveying apparatus according to any one of claims 1 to 4, wherein a long-pass filter that reflects visible light is provided on the emission 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. [Claim 6] The surveying apparatus according to any one of claims 1 to 4, further comprising a laser pointer light emission unit that emits a laser pointer light coaxially with the distance measuring light, and an imaging unit that separates the reflected distance measuring light from the visible light.

Images