Measuring device

Abstract

To provide a surveying device that enables sighting at close range. [Solution] The system comprises a distance measuring light emission unit 23 that emits distance measuring light 31 towards the object to be measured, a distance measuring light receiving unit 24 having a light receiving element 43 that receives reflected distance measuring light 51 from the object to be measured, an imaging unit 27 that receives ambient light 66 coaxially with the reflected distance measuring light 51 and acquires an image, and a calculation control unit that controls the distance measuring light emission unit 23 and the imaging unit 27 and calculates the distance to the object to be measured based on the reception result of the reflected distance measuring light 51 to the distance measuring light receiving unit 24. The output section 23 includes a first deflection optical member 35 that deflects one of the optical axes so that the optical axis of the distance measuring light 31 and the optical axis of the imaging section 27 are coaxial, and a second deflection optical member 36 that deflects the optical axis of the distance measuring light 31 so that it is coaxial with the optical axis of the reflected distance measuring light 51. The second deflection optical member 36 is configured to have a beam splitter film formed in accordance with the field of view of the imaging section 27 and an anti-reflective film formed on the portion other than the beam splitter film.

Description

Technical Field

[0006] , , , ,

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

Background Art

[0002] Surveying instruments such as laser scanners and total stations have a function of measuring the distance to a measurement object by prism measurement using a prism having retroreflectivity as a measurement object and non-prism measurement without using a reflecting prism.

[0003] Some surveying instruments are provided with a camera coaxial with the distance measuring unit. However, it is difficult to design a camera having a sufficient angle of view and resolution for collimation at close range.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0007] According to this disclosure, it is possible to ensure a sufficient field of view and resolution for sighting at close range. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a surveying device according to the first embodiment. [Figure 2] This is a diagram showing the distance measuring unit according to the first embodiment. [Figure 3] (A) is a view from arrow A in Figure 2, and (B) is a view from arrow B in Figure 2. [Figure 4] (A) is a diagram showing the distance measuring unit according to the second embodiment, (B) is a view from arrow C in (A), and (C) is a view from arrow D in (A). [Figure 5] (A) is a diagram showing the distance measuring unit according to the third embodiment, (B) is a view from arrow E in (A), and (C) is a view from arrow F in (A). [Figure 6] (A) and (B) are explanatory diagrams showing modified versions of the window section. [Figure 7] This is a diagram showing the configuration of a distance measuring unit, illustrating a modified version with the addition of a laser pointer light emission unit. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described below with reference to the drawings.

[0010] First, a surveying apparatus according to the first embodiment of this disclosure will be described in Figure 1.

[0011] The surveying device 1 is, for example, a laser scanner and consists of a leveling unit 2 attached to a tripod (not shown) and a surveying device body 3 attached to the leveling unit 2.

[0012] The leveling unit 2 has a leveling screw 10, which levels the surveying device body 3 horizontally.

[0013] The surveying device body 3 comprises a fixed part 4, a mounting part 5, a horizontal rotation shaft 6, a horizontal rotation bearing 7, a horizontal rotation motor 8 as a horizontal rotation drive unit, a horizontal angle encoder 9 as a horizontal angle detection unit, a vertical rotation shaft 11, a vertical rotation bearing 12, a vertical rotation motor 13 as a vertical rotation drive unit, a vertical angle encoder 14 as a vertical angle detection unit, a scanning mirror 15, an operation panel 16 that serves as both an operation unit and a display unit, a calculation control unit 17, a storage unit 18, a distance measuring unit 19, etc. (houses) these components. The calculation control unit 17 may be a CPU specifically designed for this device or a general-purpose CPU.

[0014] 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.

[0015] 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.

[0016] The relative rotation angle of the bracket portion 5 with respect to the fixing portion 4 is detected by the horizontal angle encoder 9. The detection signal from the horizontal angle encoder 9 is input to the arithmetic control unit 17, and horizontal angle data is calculated by the arithmetic control unit 17. Based on the horizontal angle data, the arithmetic control unit 17 performs feedback control on the horizontal rotation motor 8.

[0017] Further, the bracket 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. Note that 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 instrument main body 3.

[0018] A concave portion 21 is formed in the bracket portion 5. One end of the vertical rotation shaft 11 extends into the concave portion 21, and the scanning mirror 15 is fixed to the one end. That is, the scanning mirror 15 is housed in the concave portion 21. Further, a vertical angle encoder 14 is provided at the other end of the vertical rotation shaft 11. Further, a tapered portion 21a is formed at the upper end of the concave portion 21 such that the width gradually increases from bottom to top.

[0019] The position on the axis 6a and facing the scanning mirror 15 is formed of a transparent material such as glass, and a window portion 22 that rotates integrally with the scanning mirror 15 is provided. The window portion 22 is inclined at a predetermined angle with respect to the axis 6a. Note that the scanning mirror 15 and the window portion 22 constitute a vertical rotation portion that is integrally rotated in the vertical direction by the vertical rotation motor 13 via the vertical rotation shaft 11.

[0020] The vertical rotation motor 13 is provided on the vertical rotation shaft 11, and the vertical rotation motor 13 is controlled by the arithmetic control unit 17. The arithmetic control unit 17 rotates the vertical rotation shaft 11 by the vertical rotation motor 13, and the scanning mirror 15 rotates about the axis 11a.

[0021] 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.

[0022] 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).

[0023] 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, a program for calculating the three-dimensional coordinates of a desired measurement point based on distance and angle, a tracking program for tracking the object to be measured, and an imaging program for controlling the imaging operation by the imaging unit described later. Furthermore, various processes are executed by executing these various programs in the calculation control unit 17.

[0024] 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.

[0025] Next, the distance measuring unit 19 will be described with reference to Figures 2, 3(A), and 3(B).

[0026] The distance measuring unit 19 includes a distance measuring light emission unit 23, a distance measuring light receiving unit 24, a tracking light emission unit 25, a tracking light receiving unit 26, and an imaging unit 27. The distance measuring unit is composed of the distance measuring light emission unit 23 and the distance measuring light receiving unit 24, and the tracking unit is composed of the tracking light emission unit 25 and the tracking light receiving unit 26.

[0027] The distance measuring light emission unit 23 has a distance measuring optical axis 28. The distance measuring light emission unit 23 also includes, in order from the light-emitting side, a light-emitting element 29 provided on the distance measuring optical axis 28, for example a laser diode (LD) that emits distance measuring light 31 which is visible light in a predetermined wavelength band, a diffuser plate 32, a light-emitting lens 33, a dichroic mirror 34, a first beam splitter 35 as a first deflection optical member provided on the transmission optical axis of the dichroic mirror 34, and a second beam splitter 36 as a second deflection optical member provided on the reflection optical axis of the first beam splitter 35. Furthermore, the scanning mirror 15 is provided on the reflection optical axis of the second beam splitter 36, and the window portion 22 is provided on the reflection optical axis of the scanning mirror 15. Furthermore, an absorption filter 37 is provided on the transmitted optical axis of the second beam splitter 36, that is, on the opposite side of the second beam splitter 36 from the first beam splitter 35.

[0028] In this embodiment, the distance measuring optical axis 28, the distance measuring optical axis 28 reflected by the first beam splitter 35, the distance measuring optical axis 28 reflected by the second beam splitter 36, and the distance measuring optical axis 28 reflected by the scanning mirror 15 are collectively referred to as the distance measuring optical axis 28.

[0029] The diffuser plate 32 is configured to be insertable and detachable from the distance measuring optical axis 28 by a drive mechanism (not shown) such as a solenoid. When the diffuser plate 32 is inserted onto the distance measuring optical axis 28, the divergence angle of the distance measuring light 31 is widened by the diffuser plate 32. Therefore, when performing prism measurement, the diffuser plate 32 is inserted onto the distance measuring optical axis 28, and when performing non-prism measurement, the diffuser plate 32 is removed from the distance measuring optical axis 28.

[0030] The light-emitting lens 33 has optical properties that convert the distance-measuring light 31 that did not pass through the diffuser plate 32 into a parallel light beam, and convert the distance-measuring light 31 that did pass through the diffuser plate 32 into a slightly diffused light beam.

[0031] The dichroic mirror 34 has optical properties that transmit the distance measuring light 31 and reflect the tracking light 38 (described later). Furthermore, the dichroic mirror 34 is positioned on the common optical path of the distance measuring light 31 and the tracking light 38 (the intersection of the distance measuring optical axis 28 and the tracking optical axis 39 (described later)) such that the tracking light 38 is incident at an incident angle in the range of 15° to 60°, and the tracking optical axis 39 is deflected (reflected) so that it aligns with the distance measuring optical axis 28. Therefore, the distance measuring light 31 and the tracking light 38 are irradiated coaxially toward the object to be measured.

[0032] The first beam splitter 35 is a glass plate on which a beam splitter film is deposited. The first beam splitter 35 is arranged so that the distance measuring light 31 and the tracking light 38 are incident at an incident angle in the range of 15° to 60°, and is configured to deflect (reflect) the distance measuring optical axis 28 and the tracking optical axis 39 so that they are coaxial with the imaging optical axis 41 (described later). At this time, the distance measuring optical axis 28 and the tracking optical axis 39 are deflected onto a plane that intersects with the plane from which the distance measuring light 31 and the tracking light 38 are emitted.

[0033] Furthermore, the first beam splitter 35 is configured to transmit a portion of the incident light and reflect the remainder. In this embodiment, the reflectance of the first beam splitter 35 for visible wavelength light, i.e., the ranging light 31 and ambient light, is appropriately set to a range of 60% to 90%, and the transmittance is appropriately set to a range of 10% to 40%. In addition, the reflectance of invisible wavelength light, i.e., the tracking light 38 described later, is appropriately set to a range of 60% to 100%.

[0034] The second beam splitter 36 is a glass plate on which a beam splitter film 36a is deposited in part and an anti-reflection (AR) film 36b is deposited on the remaining part. The second beam splitter 36 is arranged so that the distance measuring light 31 and the tracking light 38 are incident at an incident angle in the range of 15° to 60°, and is configured to deflect (reflect) the distance measuring light axis 28 and the tracking light axis 39 so that they are coaxial with the light receiving light axis 42 (described later) and the axis 11a.

[0035] Furthermore, as shown in Figure 3(B), the second beam splitter 36 has a beam splitter film 36a deposited in its center and an AR film 36b deposited on the parts other than the center. The size of the beam splitter film 36a is designed to correspond to the field of view of the imaging unit 27, and is equal to or slightly larger than the diameter of the light beam of the ambient light received by the imaging unit 27.

[0036] Furthermore, the beam splitter film 36a is configured to transmit a portion of the incident light and reflect the remainder. In this embodiment, the reflectance of the beam splitter film 36a for light in a wavelength band including visible wavelength band and invisible wavelength band is appropriately set in the range of 50% to 95%, and the transmittance is appropriately set in the range of 5% to 50%. The reflectance and transmittance of the beam splitter film 36a are also referred to as the reflectance and transmittance of the second beam splitter 36.

[0037] The absorption filter 37 is positioned at a predetermined angle inclined with respect to the transmitted optical axis of the second beam splitter 36 and is configured to absorb the distance measuring light 31 and the tracking light 38, i.e., stray light, that have passed through the second beam splitter 36. Therefore, it prevents the distance measuring light 31 that has passed through the second beam splitter 36 and the distance measuring light 31 reflected by the absorption filter 37 from being received by the light receiving element 43 (described later). As the light receiving element 43, for example, an avalanche photodiode (APD) or an equivalent photoelectric conversion element can be used.

[0038] The distance measuring light receiving unit 24 can be the distance measuring light receiving unit shown in Patent Document 2. That is, the distance measuring light receiving unit 24 has the light receiving optical axis 42 and, in order from the light receiving side, includes a light receiving element 43 provided on the light receiving optical axis 42, a density gradient film 44, a bandpass filter 45 that transmits only light in the wavelength band of the distance measuring light 31, a light receiving prism 46, and a light receiving lens 47 provided on the light receiving optical axis 42 that is reflected by the light receiving prism 46.

[0039] The density gradient film 44 is made of a transparent material such as glass or plastic formed in a disc shape, and is configured such that its transmittance gradually increases (or decreases) between θ = 0° and 360°. Therefore, the density gradient film 44 is rotated by a motor 49 around a rotation axis 48, and a portion of the density gradient film 44 is positioned perpendicular to the light-receiving optical axis 42. Furthermore, since the density gradient film 44 is rotatable by the motor 49 around the rotation axis 48, the transmittance of the reflected ranging light 51 (described later) can be controlled (adjusted) within a range of, for example, 0.0001% to 100% by controlling the incident position of the reflected ranging light 51 on the density gradient film 44.

[0040] The light-receiving prism 46 is composed of two prisms, a first prism 52 and a second prism 53, and a dichroic film 54 is deposited on the joint surface between the first prism 52 and the second prism 53 as a separating surface. The light-receiving prism 46 is configured to internally reflect at least once the distance-measuring light 31 (reflected distance-measuring light 51) reflected by the object to be measured and the tracking light 38 (reflected tracking light 55) incident coaxially with the reflected distance-measuring light 51. At this time, the reflected distance-measuring light 51 and the reflected tracking light 55 are internally reflected in a direction approaching the incident surface of the light-receiving prism 46. Furthermore, the dichroic film 54 has optical properties that transmit the reflected distance-measuring light 51 and reflect the reflected tracking light 55.

[0041] In this embodiment, the light-receiving optical axis 42 and the light-receiving optical axis 42 reflected by the light-receiving prism 46 are collectively referred to as the light-receiving optical axis 42.

[0042] The tracking light emission unit 25 has a tracking optical axis 39. The tracking light emission unit 25 also has, in order from the light-emitting side, a tracking light-emitting element 56 provided on the tracking optical axis 39, a laser diode that emits tracking light 38 which is, for example, near-infrared light, a tracking light projection lens 57, and a dichroic mirror 34, as well as a first beam splitter 35 provided on the reflected optical axis of the dichroic mirror 34, and a second beam splitter 36 provided on the reflected optical axis of the first beam splitter 35.

[0043] The tracking light receiving unit 26 can be the tracking light receiving unit shown in Patent Document 2. That is, the tracking light receiving unit 26 has a tracking light receiving optical axis 58, a tracking light receiving element 59 provided on the tracking light receiving optical axis 58, a bandpass filter 61 that transmits only light in the wavelength band of the tracking light 38, a light receiving prism 46, and a light receiving lens 47 provided on the reflective optical axis of the light receiving prism 46.

[0044] The tracking light-receiving element 59 is positioned at a predetermined distance from the light-receiving prism 46 to collect the reflected tracking light 55. The tracking light-receiving element 59 is a CCD or CMOS sensor, which is a collection of pixels, and the position of each pixel on the tracking light-receiving element 59 can be determined. For example, each pixel has pixel coordinates with the center of the tracking light-receiving element 59 as the origin, and its position on the tracking light-receiving element 59 is determined by these pixel coordinates.

[0045] In this embodiment, the tracking optical axis 39, the tracking optical axis 39 reflected by the dichroic mirror 34, the tracking optical axis 39 reflected by the first beam splitter 35, the tracking optical axis 39 reflected by the second beam splitter 36, and the tracking optical axis 39 reflected by the scanning mirror 15 are collectively referred to as the tracking optical axis 39. Furthermore, the tracking light receiving optical axis 58, the tracking light receiving optical axis 58 reflected by the dichroic film 54 and the light receiving prism 46, and the tracking light receiving optical axis 58 reflected by the scanning mirror 15 are collectively referred to as the tracking light receiving optical axis 58.

[0046] In this embodiment, the light-emitting element 29, etc., is arranged on the transmitting side of the dichroic mirror 34, and the tracking light-emitting element 56, etc., is arranged on the reflecting side. Alternatively, the tracking light-emitting element 56, etc., may be arranged on the transmitting side of the dichroic mirror 34, and the light-emitting element 29, etc., may be arranged on the reflecting side. Similarly, the tracking light-receiving element 59, etc., is arranged on the transmitting side of the dichroic film 54, and the light-receiving element 43, etc., is arranged on the reflecting side. Alternatively, the light-receiving element 43, etc., may be arranged on the transmitting side of the dichroic film 54, and the tracking light-receiving element 59, etc., may be arranged on the reflecting side.

[0047] In this specification, when the light-emitting element 29, etc. is mentioned, it refers to the light-emitting element 29, the diffuser plate 32, and the light-emitting lens 33, and when the tracking light-emitting element 56, etc. is mentioned, it refers to the tracking light-emitting element 56 and the tracking light-emitting lens 57.

[0048] The imaging unit 27 has the imaging optical axis 41. The imaging unit 27 also includes, in order from the light-receiving side, an image sensor 63, an IR cut filter 64, an imaging lens group 65, the first beam splitter 35, and the second beam splitter 36, all of which are located on the imaging optical axis 41. In this embodiment, the imaging optical axis 41, the imaging optical axis 41 reflected by the second beam splitter 36, and the imaging optical axis 41 reflected by the scanning mirror 15 are collectively referred to as the imaging optical axis 41. In this specification, when the image sensor etc. 63 is mentioned, it refers to the image sensor 63, the IR cut filter 64, and the imaging lens group 65.

[0049] The image sensor 63 is a 2D image sensor such as a CCD or CMOS sensor, which is a collection of pixels, and the position of each pixel on the image sensor 63 can be determined. For example, each pixel has pixel coordinates with the center of the image sensor 63 (the imaging optical axis 41) as the origin, and its position on the image sensor 63 is determined by these pixel coordinates.

[0050] The IR cut filter 64 is capable of removing infrared and near-infrared wavelength light. The IR cut filter 64 prevents infrared and near-infrared wavelength light, i.e., the reflected tracking light 55, that is incident coaxially with the ambient light 66, from being received by the image sensor 63.

[0051] The imaging lens group 65 is composed of a plurality of concave and convex lenses and is configured to allow the imaging sensor 63 to receive the ambient light 66 reflected by the second beam splitter 36 (beam splitter film 36a). Furthermore, the imaging lens group 65 is appropriately designed so that the field of view of the imaging unit 27 is within the range of 5° to 20°.

[0052] In this embodiment, the light-emitting element 29 and the tracking light-emitting element 56 are provided on the reflective side of the first beam splitter 35, and the image sensor 63 is provided on the transmissive side. Alternatively, the image sensor 63 may be provided on the reflective side of the first beam splitter 35, and the light-emitting element 29 and the tracking light-emitting element 56 may be provided on the transmissive side.

[0053] In this embodiment, the distance measuring light receiving unit 24 and the tracking light receiving unit 26 are arranged on the transmission side of the second beam splitter 36, and the distance measuring light emission unit 23, the tracking light emission unit 25, and the imaging unit 27 are arranged on the reflection side of the second beam splitter 36. Alternatively, the distance measuring light emission unit 23, the tracking light emission unit 25, and the imaging unit 27 may be arranged on the transmission side of the second beam splitter 36, and the distance measuring light receiving unit 24 and the tracking light receiving unit 26 may be arranged on the reflection side of the second beam splitter 36. In this case, the transmittance and reflectance of the beam splitter film 36a are reversed, and the AR film 36b becomes a reflective film.

[0054] Next, the measurement of an object to be measured using the surveying device 1 will be described. In the following description, the case in which light in the visible wavelength range, such as green light, is used as the distance measuring light 31 and non-prism measurement is performed will be described.

[0055] The various processes performed by the distance measuring unit 19 are controlled by the calculation control unit 17. When pulsed distance measuring light 31 is emitted from the light-emitting element 29 onto the distance measuring optical axis 28, the distance measuring light 31 is incident on the light-emitting lens 33. At this time, the diffuser plate 32 is removed from the distance measuring optical axis 28.

[0056] The distance measuring light 31 that has passed through the projection lens 33 has passed through the dichroic mirror 34 and is then deflected (reflected) by the first beam splitter 35 so that the distance measuring optical axis 28 and the imaging optical axis 41 are coaxial. The distance measuring light 31 is further reflected by the beam splitter film 36a of the second beam splitter 36 so that it is coaxial with the light receiving optical axis 42 and the axis 11a.

[0057] At this time, a portion of the distance measuring light 31 passes through the second beam splitter 36. However, since the absorption filter 37 is positioned on the transmission light axis of the second beam splitter 36 at a slight inclination with respect to the transmission light axis, it is possible to prevent the distance measuring light 31 that has passed through the second beam splitter 36 from becoming stray light and being received by the light receiving element 43.

[0058] The distance measuring light 31 reflected by the second beam splitter 36 is deflected at a right angle by the scanning mirror 15 and irradiated onto the object to be measured through the window 22. At this time, since the diffuser plate 32 is not present on the distance measuring light axis 28, the distance measuring light 31 is irradiated onto the object to be measured as a parallel or approximately parallel beam. If the diffuser plate 32 is present on the distance measuring light axis 28, the distance measuring light 31 is irradiated onto the object to be measured while slightly spreading out.

[0059] Furthermore, when measuring a predetermined measurement point with the surveying device 1, the distance measuring light 31 can be projected in the desired direction by the cooperation of the horizontal rotation of the mounting unit 5 and the vertical rotation of the scanning mirror 15. Also, when acquiring three-dimensional point cloud data with the surveying device 1, the scanning mirror 15 rotates around the axis 11a, causing the distance measuring light 31 to be perpendicular to the axis 11a and rotate (scan) within a plane including the axis 6a. In this state, by rotating the mounting unit 5 horizontally, the entire 360° circumference can be scanned with the distance measuring light 31.

[0060] Here, the window portion 22 is inclined at a predetermined angle with respect to the distance measuring optical axis 28, so that the distance measuring light 31 reflected by the window portion 22 does not enter the light receiving element 43. Furthermore, the reflection position of the distance measuring light 31 on the scanning mirror 15, that is, the irradiation position of the distance measuring light 31, is the mechanical center of the surveying device 1, and this mechanical center is the intersection of the axis 6a and the axis 11a.

[0061] The reflected distance measuring light 51, reflected by the object being measured, passes through the window portion 22, is reflected at a right angle by the scanning mirror 15, and enters the second beam splitter 36. Of the reflected distance measuring light 51, the portion that enters the beam splitter film 36a is partially transmitted and the remainder is reflected at a right angle or approximately a right angle, based on the optical properties of the beam splitter film 36a. The reflected distance measuring light 51 that enters the AR film 36b is completely transmitted.

[0062] The reflected distance-measuring light 51 that has passed through the second beam splitter 36 is incident on the distance-measuring light receiving unit 24. That is, the reflected distance-measuring light 51 is incident on the light-receiving prism 46 via the light-receiving lens 47, internally reflected within the light-receiving prism 46, then passes through the dichroic film 54, and is received by the light-receiving element 43 after passing through the bandpass filter 45 and the density gradient film 44. At this time, stray light passing outside the optical path of the reflected distance-measuring light 51, such as the external light 66 that has passed through the beam splitter film 36a, is removed by the bandpass filter 45, and the system is configured so that only the reflected distance-measuring light 51 is received by the light-receiving element 43. Furthermore, the reflected distance-measuring light 51 is adjusted to a predetermined light intensity during the process of passing through the density gradient film 44 and is received by the light-receiving element 43 without saturation.

[0063] The calculation control unit 17 performs distance measurement for each pulse of the distance measuring light 31 (Time of Flight) based on the time difference between the light emission timing of the light-emitting element 29 and the light-receiving timing of the light-receiving element 43 (i.e., the round-trip time of the pulsed light) and the speed of light, and calculates the distance to the object to be measured. Furthermore, the calculation control unit 17 can calculate the three-dimensional coordinates of the measurement point irradiated by the distance measuring light 31, i.e., the object to be measured, based on the distance measurement result and the horizontal angle data and vertical angle data obtained by the horizontal angle encoder 9 and the vertical angle encoder 14.

[0064] Furthermore, the timing of the light emission of the light-emitting element 29, i.e., the pulse interval, can be changed via the operation panel 16. Accordingly, by emitting the distance measuring light 31 at predetermined pulse intervals and rotating the mounting unit 5 and the scanning mirror 15 at a constant speed, the distance measuring light 31 is scanned in two dimensions through the cooperation of the vertical rotation of the scanning mirror 15 and the horizontal rotation of the mounting unit 5. In addition, vertical angle data and horizontal angle data can be acquired 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. 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 from the vertical angle data, horizontal angle data and distance measuring data.

[0065] Furthermore, the distance measuring unit 19 is provided with an internal reference light optical system 67. The internal reference light optical system 67 has a reflecting element 68 provided on the bottom surface of the recess 21, and the optical path length from the light-emitting element 29 to the reflecting element 68 and the optical path length from the reflecting element 68 to the light-receiving element 43 are known. Therefore, by considering the distance measuring light 31 reflected by the reflecting element 68 as the internal reference light and performing distance measurement based on the time difference in the reception timing and light flux between the internal reference light and the reflected distance measuring light 51, more accurate distance measurement becomes possible.

[0066] In parallel with the range measurement operation, when the tracking light 38 of near-infrared wavelength is emitted from the tracking light-emitting element 56, it is slightly diverged by the tracking light projection lens 57 and then deflected (reflected) by the dichroic mirror 34 so that it is coaxial with the range measurement light 31.

[0067] The tracking light 38, i.e., the reflected tracking light 55, is irradiated onto the object to be measured coaxially with the distance measuring light 31 and reflected by the object to be measured. In the process of passing through the light receiving prism 46, it is separated (reflected) from the reflected distance measuring light 51 by the dichroic film 54 and received by the tracking light receiving element 59 via the bandpass filter 61. Furthermore, a tracking image (not shown) can be obtained by receiving the reflected tracking light 55 on the tracking light receiving element 59. At this time, stray light such as the ambient light 66 that has passed through the second beam splitter 36 is removed by the bandpass filter 61, and the system is configured so that only the reflected tracking light 55 is received by the tracking light receiving element 59.

[0068] The calculation control unit 17 calculates the positional deviation between the center of the tracking light receiving element 59 and the position where the reflected tracking light 55 is received by the tracking light receiving element 59. Based on this positional deviation, it drives the horizontal rotation motor 8 and the vertical rotation motor 13 to track the object to be measured.

[0069] Furthermore, when distance measurement and tracking are performed by the distance measuring unit 19, the ambient light 66 is incident on the surveying device body 3 coaxially with the reflected distance measuring light 51 and the reflected tracking light 55. The ambient light 66 incident on the surveying device body 3 is reflected at a right angle by the scanning mirror 15 and incident on the beam splitter film 36a of the second beam splitter 36.

[0070] Of the ambient light 66 incident on the second beam splitter 36, a portion is transmitted through the beam splitter film 36a, and the remainder is reflected by the beam splitter film 36a. The ambient light 66 that has been transmitted through the beam splitter film 36a is removed by the bandpass filter 45 or the bandpass filter 61.

[0071] Furthermore, the ambient light 66 reflected by the beam splitter film 36a is received by the image sensor 63 via the first beam splitter 35, the imaging lens group 65, and the IR cut filter 64, and an image is acquired with the imaging optical axis 41 as the center, that is, with the distance measuring optical axis 28 (the tracking optical axis 39) as the center. The acquired image is stored in the storage unit 18.

[0072] At this time, the reflected ranging light 51 and the reflected tracking light 55 are incident coaxially with the ambient light 66, and based on the optical properties of the beam splitter film 36a, a portion of the reflected ranging light 51 and the reflected tracking light 55 are reflected by the beam splitter film 36a. Of the reflected ranging light 51 and the reflected tracking light 55, the reflected tracking light 55 is near-infrared light and is therefore removed by the IR cut filter 64. The reflected ranging light 51 is visible light and passes through the IR cut filter 64, and is received by the image sensor 63. The reflected ranging light 51 is displayed as a light point in the image acquired by the imaging unit 27.

[0073] As described above, in the first embodiment, the imaging unit 27 is provided coaxially with the distance measuring unit and the tracking unit, and the imaging lens group 65 is designed so that the field of view of the imaging unit 27 is appropriately selected within the range of 5° to 20°.

[0074] Therefore, the imaging unit 27 can secure a sufficient field of view and resolution for sighting at close range, allowing the object to be measured to be sighted based on the image acquired by the imaging unit 27, thus enabling easy sighting.

[0075] Furthermore, since the beam splitter film 36a formed on the second beam splitter 36 is configured to transmit a portion of the reflected ranging light 51, the light receiving element 43 can receive not only the reflected ranging light 51 that has passed through the AR film 36b, but also the reflected ranging light 51 that has passed through the beam splitter film 36a.

[0076] Therefore, the amount of reflected distance measuring light 51 received by the light-receiving element 43 can be increased, thereby extending the distance that the distance measuring unit 19 can measure. Furthermore, even when measuring short distances where the amount of light in the center of the light beam is large, the amount of reflected distance measuring light 51 can be secured, improving the measurement accuracy at short distances of up to 100m, and enabling measurements at distances of 1m to 5m.

[0077] Furthermore, the first beam splitter 35 is configured to deflect the distance measuring optical axis 28 and the tracking optical axis 39 onto a plane that intersects with the plane from which the distance measuring light 31 and the tracking light 38 are emitted. That is, the light-emitting element 29, the diffuser plate 32, the light-emitting lens 33, the dichroic mirror 34, the tracking light-emitting element 56, and the tracking light-emitting lens 57 are arranged three-dimensionally with respect to the distance measuring light receiving unit 24, the tracking light receiving unit 26, and the imaging unit 27.

[0078] Therefore, the design flexibility of the optical system of the distance measuring unit 19 is improved, and the optical system can be miniaturized.

[0079] Furthermore, the distance measuring unit 19 has a diffuser plate 32 that can be inserted into and removed from the distance measuring optical axis 28, and by inserting or removing the diffuser plate 32, it is possible to switch between prism measurement and non-prism measurement.

[0080] Furthermore, the surveying device 1 also functions as a laser scanner by emitting the distance measuring light 31 at predetermined pulse intervals while rotating the mounting unit 5 and the scanning mirror 15 at a low speed. Therefore, the versatility of the surveying device 1 can be improved.

[0081] Furthermore, since visible light is used as the distance measuring light 31, the irradiation position of the distance measuring light 31 can be visually confirmed without providing a laser pointer light irradiation unit coaxial with the distance measuring light emission unit 23, thereby enabling miniaturization of the optical system and reduction of the number of parts.

[0082] Furthermore, the distance measuring light receiving unit 24 and the tracking light receiving unit 26 each have a light receiving prism 46, and the light receiving prism 46 is configured to internally reflect the reflected distance measuring light 51 and the reflected tracking light 55 in a direction close to the incident surface. Therefore, the length of the light receiving optical axis 42 (axis 11a) of the distance measuring unit 19 can be shortened, making it possible to miniaturize the optical system and the entire surveying device 1.

[0083] Furthermore, a density gradient film 44 is provided between the light-receiving element 43 and the bandpass filter 45, and the amount of reflected ranging light 51 received by the light-receiving element 43 can be adjusted by the density gradient film 44. Therefore, it is possible to prevent the light-receiving element 43 from receiving more reflected ranging light 51 than the allowable amount and becoming saturated.

[0084] In the first embodiment, the distance measuring light 31 is visible light, while the distance measuring light 31 may be near-infrared light with a different wavelength from the tracking light 38. In this case, the visible light transmittance of the first beam splitter 35 is appropriately selected within the range of 10% to 90%, the visible light reflectance is appropriately selected within the range of 10% to 90%, and the near-infrared light reflectance is appropriately selected within the range of 60% to 100%.

[0085] Furthermore, the first beam splitter 35 may have a polarizing beam splitter film deposited on it. When the distance measuring light 31 is S-polarized visible light to the first beam splitter 35 and the reflection tracking light 55 is S-polarized near-infrared light, the first beam splitter 35 is appropriately selected so that the reflectance of S-polarized light is in the range of 80% to 100%, and the transmittance of P-polarized light (the external light 66) is in the range of 80% to 100%. Furthermore, when the distance measuring light 31 is S-polarized near-infrared light to the first beam splitter 35 and the reflection tracking light 55 is S-polarized near-infrared light of a different wavelength than the distance measuring light 31, the first beam splitter 35 is appropriately selected so that the reflectance of S-polarized light is in the range of 80% to 100%, and the transmittance of P-polarized light (the external light 66) is in the range of 80% to 100%.

[0086] Next, a surveying apparatus according to a second embodiment of this disclosure will be described in Figures 4(A) to 4(C). In Figures 4(A) to 4(C), components equivalent to those in Figures 2, 3(A), and 3(B) are denoted by the same reference numerals, and their descriptions are omitted.

[0087] In the distance measuring unit 19 of the second embodiment, a first deflection plate 69 is used as the first deflection optical member instead of the first beam splitter 35 in the first embodiment, and a second deflection plate 71 is used as the second deflection optical member instead of the second beam splitter 36. The other configurations are the same as in the first embodiment. Although the distance measuring light receiving unit and the tracking light receiving unit are not shown in Figure 4(A), the distance measuring unit 19 has the same distance measuring light receiving unit and tracking light receiving unit as in the first embodiment.

[0088] The first deflection plate 69 is composed of two plate-shaped transparent materials, such as glass plates 69a and 69b, joined together in an overlapping manner, and a beam splitter film 69c deposited on the joint surface of the glass plates 69a and 69b. The optical properties of the beam splitter film 69c are the same as those of the first beam splitter 35.

[0089] The second deflection plate 71 is composed of two plate-shaped transparent materials, such as glass plates 71a and 71b, joined together in an overlapping manner, and a beam splitter film 71c and an AR film 71d deposited on the joint surface of the glass plates 71a and 71b. As shown in Figure 4(B), the beam splitter film 71c is deposited in the center of the joint surface, and the AR film 71d is deposited on the portion other than where the beam splitter film 71c is deposited.

[0090] The size of the beam splitter film 71c is equal to or slightly larger than the beam of incident ambient light 66, in accordance with the field of view of the imaging unit 27, and the optical characteristics of the beam splitter film 71c are the same as those of the beam splitter film 36a of the second beam splitter 36.

[0091] In the second embodiment, the same effects as in the first embodiment can be obtained. Furthermore, in the second embodiment, both the first deflection plate 69 and the second deflection plate 71 are formed by depositing a beam splitter film onto the joint surface of two glass plates. Therefore, a non-polarizing film in the wavelength band used for the ranging light 31 and tracking light 38 can be easily designed and manufactured.

[0092] Next, a surveying apparatus according to a third embodiment of this disclosure will be described in Figures 5(A) to 5(C). In Figures 5(A) to 5(C), components equivalent to those in Figures 2, 3(A), and 3(B) are denoted by the same reference numerals, and their descriptions are omitted.

[0093] In the distance measuring unit 19 of the third embodiment, a first deflection prism 72 is used as the first deflection optical element instead of the first beam splitter 35 in the first embodiment, and a second deflection prism 73 is used as the second deflection optical element instead of the second beam splitter 36. The other configurations are the same as in the first embodiment. Although the distance measuring light receiving unit and the tracking light receiving unit are not shown in Figure 5(A), the distance measuring unit 19 has the same distance measuring light receiving unit and tracking light receiving unit as in the first embodiment.

[0094] The first deflection prism 72 consists of two triangular prisms 72a and 72b joined together, and a beam splitter film 72c deposited on the joint surface of the triangular prisms 72a and 72b. The optical properties of the beam splitter film 72c are the same as those of the first beam splitter 35.

[0095] Furthermore, as shown in Figure 5(C), the tracking light emission unit 25 is positioned at a slight inclination relative to the first deflection prism 72, i.e., at an angle of approximately 0.5° to 5°. Therefore, the tracking light 38 is incident on the second deflection prism 73 at a predetermined incident angle.

[0096] The second deflection prism 73 is a rectangular parallelepiped prism and consists of two trapezoidal square prisms 73a and 73b joined together, and a beam splitter film 73c deposited on the joining surface of the square prisms 73a and 73b.

[0097] As shown in Figure 5(B), the beam splitter film 73c is deposited on the junction surface at the position where the ambient light 66 is incident. In addition, an AR film is deposited on the incident and exit surfaces of the second deflection prism 73, i.e., the surface into which the reflected ranging light 51, the reflected tracking light 55, and the ambient light 66 are incident and the surface into which they are emitted.

[0098] Furthermore, the size of the beam splitter film 73c is equal to or slightly larger than the beam of incident ambient light 66, in accordance with the field of view of the imaging unit 27, and the optical characteristics of the beam splitter film 73c are the same as those of the beam splitter film 36a of the second beam splitter 36.

[0099] Furthermore, the second deflection prism 73 is tilted slightly, for example, by about 0.5° to 5°, with respect to the light-receiving optical axis 42 deflected by the scanning mirror 15, and the rangefinder light emission unit 23, the tracking light emission unit 25, and the imaging unit 27 are also tilted in accordance with the tilt of the second deflection prism 73. Therefore, the reflected rangefinder light 51, the reflected tracking light 55, and the ambient light 66 reflected by the scanning mirror 15 are incident on the second deflection prism 73 at a predetermined incident angle.

[0100] In the third embodiment, the same effects as in the first embodiment can be obtained. Furthermore, in the third embodiment, both the first deflection prism 72 and the second deflection prism 73 are formed by depositing a beam splitter film on their bonding surfaces. Therefore, a non-polarizing film in the wavelength band used for the distance measuring light 31 and the tracking light 38 can be easily designed and manufactured.

[0101] Furthermore, since the first deflection prism 72 is tilted with respect to the tracking optical axis 39 and the second deflection prism 73 is tilted with respect to the light receiving optical axis 42, it is possible to suppress the light incident on the first deflection prism 72 and the second deflection prism 73 from becoming reflected light.

[0102] It goes without saying that the first deflection optical member and the second deflection optical member of the first to third embodiments may be appropriately combined, such as by combining the first beam splitter 35 of the first embodiment with the second deflection plate 71 of the second embodiment.

[0103] In the surveying apparatus according to the first to third embodiments, the window portion 22 is configured to rotate integrally with the scanning mirror 15. Alternatively, the scanning mirror 15 may rotate alone. By having only the scanning mirror 15 rotate, the number of components rotated by the vertical rotation motor 13 (see Figure 1) is reduced, thereby suppressing runout of the vertical rotation axis 11.

[0104] For example, as shown in Figure 6(A), a window portion 74 may be formed by joining three plate-shaped transparent materials, and the window portion 74 may be provided in the recess 21 (see Figure 1) so as to surround the scanning mirror 15. In this case, the scanning mirror 15 rotates inside the window portion 74, and the distance measuring light 31 and the tracking light 38 reflected by the scanning mirror 15 are irradiated onto the object to be measured through the window portion 74. Alternatively, a window portion with a triangular cross-section may be formed using two transparent materials, or the window portion may be removed.

[0105] Alternatively, as shown in Figure 6(B), the window portion 75 may be formed by a cone with a portion of its circumferential surface removed, or by a cylinder with a portion of its circumferential surface removed. In either case, the window portion 75 is positioned in the recess 21 such that its axis is parallel to the axis 11a. The scanning mirror 15 rotates inside the window portion 75, and the distance measuring light 31 and tracking light 38 reflected by the scanning mirror 15 are irradiated onto the object to be measured through the window portion 75.

[0106] Furthermore, in the surveying apparatus according to the first to third embodiments, the distance measuring unit 19 has a distance measuring unit and a tracking unit. On the other hand, the distance measuring unit 19 may have only the distance measuring unit, or it may have components other than the distance measuring unit and the tracking unit. For example, as shown in Figure 7, the distance measuring unit 19 may have a laser pointer light emission unit 76 in addition to the distance measuring unit and the tracking unit.

[0107] The laser pointer light emission unit 76 has a laser pointer optical axis 77. The laser pointer light emission unit 76 also has, in order from the light-emitting side, a laser pointer light-emitting element 78 provided on the laser pointer optical axis 77, for example, a laser diode (LD) that emits laser pointer light 79 which is visible light with a different wavelength from the distance measuring light 31 and the tracking light 38, a laser pointer projection lens 81, and a dichroic mirror 82 positioned between the projection lens 33 and the dichroic mirror 34. Although not shown in the figures, the laser pointer light emission unit 76 also has a first beam splitter 35 (see Figure 2) provided on the transmitted optical axis of the dichroic mirror 34, and a second beam splitter 36 (see Figure 2) provided on the reflected optical axis of the first beam splitter 35, similar to the distance measuring light emission unit 23 and the tracking light emission unit 25. In this specification, when the term "laser pointer light-emitting element 78, etc." is used, it refers to the laser pointer light-emitting element 78 and the laser pointer projection lens 81.

[0108] The laser pointer light 79, emitted from the laser pointer light-emitting element 78 and formed into a parallel beam of a predetermined diameter by the laser pointer projection lens 81, is deflected by the dichroic mirror 82 so as to be coaxial with the distance measuring light 31 that has passed through the dichroic mirror 82, and is irradiated onto the object to be measured coaxially with the distance measuring light 31 and the tracking light 38.

[0109] By separately providing the laser pointer light emission unit 76, the irradiation position of the distance measuring light 31 can be visually confirmed even when the distance measuring light 31 is invisible light or when the distance measuring light 31 is difficult to see.

[0110] In the modified configuration described above, the dichroic mirror 82 is provided between the light-emitting lens 33 and the dichroic mirror 34, the light-emitting element 29 etc. is arranged on the transmitting side of the dichroic mirror 82, and the laser pointer light-emitting element 78 etc. is arranged on the reflecting side of the dichroic mirror 82. However, the arrangement of the distance measuring unit 19 is not limited to this arrangement.

[0111] For example, the laser pointer light-emitting element 78 may be placed on the transmissive side of the dichroic mirror 82, and the light-emitting element 29 may be placed on the reflective side of the dichroic mirror 82; or the laser pointer light-emitting element 78 may be placed on the reflective side of the dichroic mirror 34, and the tracking light-emitting element 56 may be placed on the reflective side of the dichroic mirror 82. In addition, the light-emitting elements 29, the tracking light-emitting element 56, and the laser pointer light-emitting element 78 can be freely arranged on the reflective side of the dichroic mirror 34, and on the transmissive and reflective sides of the dichroic mirror 82.

[0112] The embodiments of this disclosure have been described above with reference to the drawings, but these are merely examples, and various other configurations can be adopted.

[0113] Some or all of the above examples may also be described as follows, but are not limited to the following: 1. A measuring 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; an imaging unit that receives ambient light coaxially with the reflected distance measuring light and acquires an image; and a calculation control unit that controls the distance measuring light emission unit and the imaging unit and calculates the distance to the object to be measured based on the result of the reflected distance measuring light being received by the distance measuring light receiving unit, wherein the distance measuring light emission unit has a first deflection optical member that deflects one of the optical axes so that the optical axis of the distance measuring light and the optical axis of the imaging unit are coaxial, and a second deflection optical member that deflects the optical axis of the distance measuring light so that it is coaxial with the optical axis of the reflected distance measuring light, wherein the second deflection optical member has a beam splitter film formed in correspondence with the field of view of the imaging unit and an anti-reflective film formed on the portion other than the beam splitter film. 2. The surveying device described in 1 above, wherein the beam splitter film has a predetermined transmittance and reflectance, and is configured to transmit and reflect the ambient light and the reflected distance measuring light based on the transmittance and reflectance, and the reflected distance measuring light that passes through the anti-reflective film and a portion of the reflected distance measuring light that passes through the beam splitter film are received by the light receiving element. 3. A surveying device according to item 1 or 2 above, wherein the first deflection optical member is configured to deflect the optical axis of the distance measuring light in three dimensions. 4. A surveying device according to any one of items 1 to 3 above, wherein the second deflection optical member is formed by two plate-shaped transparent materials joined together, and the beam splitter film and the anti-reflective film deposited on the joining surface of the transparent materials. 5. A surveying device according to any one of items 1 to 3 above, wherein the second deflection optical member is formed by two trapezoidal rectangular prisms joined together, and the beam splitter film and the anti-reflective film deposited on the joining surface of the rectangular prisms. 6. The surveying device described in item 5 above, wherein the second deflection optical member is configured such that an anti-reflective coating is deposited on the incident surface and the exit surface of the reflected distance measuring light and the ambient light, respectively. 7. A surveying device according to item 5 or 6 above, wherein the second deflection optical member is configured to be positioned at a predetermined angle inclined with respect to the optical axis of the reflected distance measuring light. 8. A surveying device according to any one of items 1 to 7 above, 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, wherein the distance measuring light receiving unit and the tracking light receiving unit are configured to have a light receiving prism having a separation surface that separates the reflected distance measuring light and the reflected tracking light. 9. The surveying device described in 8 above, wherein the light-receiving prism is configured to internally reflect the reflected distance-measuring light and the reflected tracking light at least once. 10. A surveying device according to any one of items 1 to 9 above, further comprising a laser pointer light emission unit that emits a laser pointer light coaxially with the distance measuring light onto the object to be measured. 11. A surveying device described in any one of items 1 to 10 above, wherein the distance measuring light is visible light. 12. A surveying device according to any one of items 1 to 11 above, further comprising an absorption filter provided on the opposite side of the first deflection optical member, with the second deflection optical member in between. 13. A surveying device according to any one of items 1 to 12 above, wherein the distance measuring light receiving unit is configured to have a density gradient film capable of adjusting the transmittance of the reflected distance measuring light. 14. A surveying device according to any one of items 1 to 13 above, wherein the distance measuring light receiving unit is configured to have a bandpass filter that transmits light in the wavelength band of the reflected distance measuring light. 15. A surveying device according to any one of items 1 to 14 above, further comprising a scanning mirror that is rotatable about a vertical axis and deflects the distance measuring light toward the object to be measured, and a window that rotates integrally with the scanning mirror. 16. A surveying device according to any one of items 1 to 15 above, further comprising a scanning mirror that is rotatable about a vertical axis and deflects the distance measuring light toward the object to be measured, and a window that is fixedly provided so as to surround the scanning mirror. [Explanation of symbols]

[0114] 1 Surveying equipment 17. Arithmetic Control Unit 23 Distance measurement light emission part 24 Distance measurement light receiver 27 Imaging Unit 28 Ranging optical axis 31 Ranging light 35. First Beam Splitter 36. Second Beam Splitter 41. Imaging optical axis 42 Receiving optical axis 43. Photodetector 51 Reflected ranging light 66. Outdoor light

Claims

1. A measuring 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; an imaging unit that receives ambient light coaxially with the reflected distance measuring light and acquires an image; and a calculation control unit that controls the distance measuring light emission unit and the imaging unit and calculates the distance to the object to be measured based on the result of the reflected distance measuring light being received by the distance measuring light receiving unit, wherein the distance measuring light emission unit has a first deflection optical member that deflects one of the optical axes so that the optical axis of the distance measuring light and the optical axis of the imaging unit are coaxial, and a second deflection optical member that deflects the optical axis of the distance measuring light so that it is coaxial with the optical axis of the reflected distance measuring light, wherein the second deflection optical member has a beam splitter film formed in correspondence with the field of view of the imaging unit and an anti-reflective film formed on the portion other than the beam splitter film.

2. The beam splitter film has a predetermined transmittance and reflectance, and is configured to transmit and reflect the ambient light and the reflected distance measuring light based on the transmittance and reflectance, and the reflected distance measuring light that passes through the anti-reflective film and a portion of the reflected distance measuring light that passes through the beam splitter film are received by the light receiving element, as described in claim 1.

3. The surveying apparatus according to claim 1, wherein the first deflection optical member is configured to deflect the optical axis of the distance measuring light in three dimensions.

4. The surveying apparatus according to claim 1, wherein the second deflection optical member is formed by two plate-shaped transparent materials joined together, and the beam splitter film and the anti-reflective film deposited on the joining surface of the transparent materials.

5. The surveying apparatus according to claim 1, wherein the second deflection optical member is formed by two trapezoidal square prisms joined together, and the beam splitter film and the anti-reflective film deposited on the joining surface of the square prisms.

6. The measuring device according to claim 5, wherein the second deflection optical member is configured such that an anti-reflective coating is deposited on the incident surface and the exit surface of the reflected distance measuring light and the ambient light, respectively.

7. The surveying device according to claim 5, wherein the second deflection optical member is configured to be positioned at a predetermined angle inclined with respect to the optical axis of the reflected distance measuring light.

8. The surveying apparatus according to claim 1, 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, wherein the distance measuring light receiving unit and the tracking light receiving unit are configured to have a light receiving prism having a separation surface that separates the reflected distance measuring light and the reflected tracking light.

9. The surveying apparatus according to claim 1, further comprising a laser pointer light emission unit that emits laser pointer light coaxially with the distance measuring light onto the object to be measured.

10. The surveying apparatus according to claim 1, wherein the distance measuring light is visible light.

Images