Measuring machine
The surveying instrument uses a distance measuring light and averaging technique to correct for irregularities, ensuring precise and efficient instrument height measurement.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOPCON CORPORATION
- Filing Date
- 2022-03-30
- Publication Date
- 2026-06-29
Smart Images
Figure 0007881355000001 
Figure 0007881355000002 
Figure 0007881355000003
Abstract
Description
Technical Field
[0001] The present invention relates to a surveying instrument capable of measuring the instrument height.
Background Art
[0002] In surveying work, first, through alignment work and centering work, the surveying instrument body is horizontally placed vertically above the reference point, and then the instrument height, which is the height from the optical center of the surveying instrument body to the reference point vertically below, is obtained. There is a method in which an operator manually measures it using a tape measure or a scale (Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, measurement using a tape measure is manual work, so it is troublesome and has a problem of low accuracy. If the centering work and alignment work are not performed accurately, the error of the instrument height also becomes large. Also, when using a laser distance measuring device, if there are exactly irregularities at the measurement point, the accuracy decreases.
[0005] The present invention has been made in view of this, and an object thereof is to provide a surveying instrument capable of easily obtaining a precise instrument height.
Means for Solving the Problems
[0006] To solve the above problem, in a surveying instrument according to the present disclosure, there is an instrument height measuring unit that measures distance by emitting a distance measuring light to a distance measuring object below the vertical axis of the surveying instrument body and calculates the instrument height, and a calculation unit that analyzes the light that has been reflected back from the distance measuring object and calculates the distance to the distance measuring object and calculates the instrument height, wherein the instrument height measuring unit measures distance by irradiating the distance measuring light into a predetermined area of the distance measuring object centered on a point below the vertical axis of the surveying instrument body, and the calculation unit calculates the average value of the distance measured in the area and calculates the instrument height.
[0007] According to this embodiment, even if there are irregularities or inclines at the distance measurement point, the instrument height can be calculated by combining the surrounding area, thereby correcting for the irregularities and inclines at the distance measurement point and obtaining a distance measurement value. Furthermore, since measurements are taken multiple times in the area, the measurement accuracy can be improved by taking the average value. Precise instrument height can be easily obtained.
[0008] In one embodiment, the instrument height measuring unit includes a light transmitting unit that emits the distance measuring light toward the object to be measured, a light receiving unit that receives the distance measuring light emitted from the light transmitting unit and reflected back by the object to be measured, and a defocus lens that diffuses the incident light and is positioned in the optical path of the distance measuring light. The distance measuring light that has passed through the defocus lens is emitted downward from the vertical axis of the surveying instrument body and irradiates the object to be measured in the area centered on the point downward from the vertical axis of the surveying instrument body. The calculation unit is configured to calculate the distance to the object to be measured based on the light receiving signal from the light receiving unit, and further calculate the average value of the distances to the object to be measured, thereby calculating the instrument height using the average distance to the area irradiated by the distance measuring light as the distance to the object to be measured. By using the defocus lens, the distance measuring light is spread out over a predetermined range, and the measurement point becomes a random point in the spread-out illumination area. By taking measurements continuously, the system randomly takes multiple measurements within a predetermined range. There is no need to change the measurement point within the predetermined area; continuous measurement allows for natural measurement at different measurement points.
[0009] In one embodiment, the defocus lens is a clear, transparent lens. In this embodiment, by using a clear, transparent lens, the illumination area can be easily widened slightly. Furthermore, the range of illumination area expansion can be set by the thickness.
[0010] In one embodiment, the distance measuring light is a visible laser light, and the distance measuring light is projected as a centering spot light below the vertical axis of the surveying instrument body. In this embodiment, the distance measuring light projected below the vertical axis of the surveying instrument body also serves as a centering spot light, making the centering operation easier.
[0011] In one embodiment, the visible laser light is a green laser light. By using a highly visible green laser light, it becomes easier for the operator to align the spot light with the reference point, improving the efficiency of the centering operation.
[0012] Furthermore, in one embodiment, the instrument height measuring unit is a distance measuring device employing a pulse method. By using a pulse method, there are no limitations on the size of the irradiation area.
[0013] In one embodiment, the calculation unit calculates the average value of the measured values in the area illuminated by the distance measuring light and further corrects it using the tilt measured by the built-in tilt sensor. This corrects the tilt of the surveying instrument body around the horizontal axis.
[0014] Furthermore, in one embodiment, the illumination area of the distance measuring light at a position 1 m away from the bottom surface of the surveying instrument body has a maximum outer diameter of 5 mm to 30 mm. This allows for distance measurement within a suitable range without extending beyond the measurement target.
[0015] Also, in one aspect, the instrument height measurement unit is a distance image sensor that acquires distance image information within a predetermined range, the distance measuring light is infrared light, the distance image sensor has a plurality of imaging elements for acquiring the distance image information, and the calculation unit calculates the distance for each of the imaging elements from the signals received by the imaging elements, calculates the average value of the distances of the imaging elements within a predetermined range, and configures it as the distance to the distance measurement object. Both the centering operation and the distance measurement operation can be performed using the distance image sensor.
Advantages of the Invention
[0016] As is clear from the above description, it is possible to provide a surveying instrument that can easily acquire precise instrument height.
Brief Description of the Drawings
[0017] [Figure 1] It is a perspective view of a surveying instrument and a target related to a preferred embodiment of the present invention. [Figure 2] It is an explanatory diagram showing the schematic configuration of a surveying instrument and a target. It is a partially broken view. [Figure 3] Shows the optical configuration of the instrument height measurement unit. [Figure 4] It is an enlarged view around the target 2 in FIG. 1. [Figure 5] It is a diagram for explaining the operation and effect of the surveying instrument. [Figure 6] It is a modification.
Modes for Carrying Out the Invention
[0018] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The embodiments are illustrative and not limiting, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. Also, in the following descriptions of the embodiments and modifications, the same components are denoted by the same reference numerals, and duplicate descriptions are omitted as appropriate.
[0019] (Surveying Instrument 1) FIG. 1 is a perspective view of the surveying instrument 1 and the target 2 according to the first embodiment. FIG. 2 is an explanatory view showing the schematic configuration of the surveying instrument 1 and the target 2. In FIG. 2, it is a partially broken view.
[0020] The surveying instrument 1 is a total station equipped with a distance measuring and angle measuring function. The target 2 is a surveying reference point and is provided on the point of the monument 3.
[0021] The surveying instrument 1 includes a main body casing 12 as a casing of the surveying instrument. The main body casing 12 corresponds to the surveying instrument main body of the claims of this case. The main body casing 12 includes two columns 14, and between the two columns 14, a sighting telescope 16 is pivotally supported so as to be rotatable about a horizontal axis H.
[0022] A display 20 and an operation key group 21 are arranged at the lower part of the main body casing 12. The display 20 displays necessary information on the screen. The operation key group 21 is an input means for inputting necessary setting conditions and commands.
[0023] Further, the main body casing 12 is arranged on a leveling base 25, and the leveling base 25 is fixed to the tripod 8 in a state of being placed on the tripod 8.
[0024] A shaft cylinder 26 is arranged at a fixing portion 24 at the lower part of the main body casing 12. A vertical shaft 28 provided perpendicular to the main body casing 12 is inserted inside the shaft cylinder 26 and is pivotally supported by the fixing portion 24 via a ball bearing so as to be rotatable. Thereby, the main body casing 12 can be rotated about the vertical shaft 28 with respect to the fixing portion 24. The leveling base 25 has an adjustment screw for finely adjusting the inclination, and the fixing portion 24 is fixed thereon. By rotating the adjustment screw, the surveying instrument 1 is adjusted horizontally.
[0025] Flange portions facing each other are formed at the upper end portion of the shaft cylinder 26 and the upper end portion of the vertical shaft 28, and a rotary encoder 22 is provided here. The rotary encoder 22 is a horizontal angle sensor, and the rotation amount of the main body casing 12 is detected.
[0026] The surveying instrument 1 is also equipped with a tilt sensor 80 that detects inclination. A conventional configuration may be used for the tilt sensor 80.
[0027] The vertical axis 28 is formed in a hollow cylindrical shape, and the center line V of the vertical axis 28 is perpendicular to the horizontal axis H on its extension. The point where the horizontal axis H and the center line V are perpendicular is defined as the center point O of the surveying instrument 1. Since the main casing 12 that pivotally supports the sighting telescope 16 rotates around the center line V, the angle sensor 18 provided on the horizontal axis H and the rotary encoder 22 detect the amount of rotation of the sighting telescope 16 around the horizontal axis H and the amount of rotation around the center line V. In other words, the center line V is the vertical axis of the surveying instrument body.
[0028] Above the vertical axis 28, an instrument height measuring unit 40 is positioned to calculate the instrument height T of the surveying instrument 1. The instrument height measuring unit 40 is a non-prism optical distance measuring device that emits a distance measuring light L towards the object to be measured, analyzes the reflected light, and measures the distance to the object. The optical axis of the instrument height measuring unit 40 is configured to coincide with the center line V, and the distance measuring light L emitted from the instrument height measuring unit 40 passes through the hollow part of the vertical axis 28 and is emitted downward from the bottom surface of the surveying instrument 1.
[0029] (Instrument height measurement unit 40) Figure 3 is a diagram showing the configuration of the optical system of the instrument height measuring unit 40.
[0030] The instrument height measuring unit 40 includes a light transmitting unit 51, a collimating lens 52, a beam splitter 53, a light receiving unit 54, a shutter 55, a defocusing lens 56, and an objective lens 57.
[0031] The light-transmitting unit 51 is a light source that emits distance-measuring light L, and consists of a laser diode (LD).
[0032] The collimating lens 52 is an optical component that emits incident light as parallel light. The collimating lens 52 is positioned in front of the light transmitting unit 51, and the distance measuring light L emitted from the light transmitting unit 51 becomes parallel light in the collimating lens 52. The optical axis of the collimating lens 52 coincides with the center line V, and the optical axis is configured to pass through the center point O of the surveying instrument 1. The beam splitter 53, defocus lens 56, and objective lens 57 are arranged in this order on the optical axis of the collimating lens 52.
[0033] The beam splitter 53 is a half-mirror that reflects a portion of the incident light and allows the remaining portion to pass through. The distance measuring light L emitted from the collimating lens 52 enters the beam splitter 53, where a portion is reflected to become the reference light R, which is guided to the reference light path toward the light receiving unit 54. The remaining distance measuring light L that passes through the beam splitter 53 without being reflected is sent to the distance measuring light path. The reference light R is directed toward the light receiving unit 54 and is received by the light receiving unit 54.
[0034] The shutter 55 selectively switches between the distance measuring optical path and the reference optical path by moving a switching plate.
[0035] The defocus lens 56 is an optical component that diffuses and emits incident light. In this embodiment, the defocus lens 56 is a clear lens. The distance measuring light L, which is focused from the light transmitting unit 51 and emitted as laser light, and becomes parallel light by the collimating lens 52, is slightly diffused by the defocus lens 56 to widen the irradiation radius before being emitted.
[0036] The distance measuring light L emitted from the defocus lens 56 heads toward the objective lens 57, passes through it, and is emitted downwards from the main body of the surveying instrument. It is then reflected by the object to be measured by the surveying instrument 1 (the measurement target 2 in this embodiment), and returns to the surveying instrument 1 along the same path. This time, it is reflected by the beam splitter 53 and heads toward the light receiving unit 54, where it is received.
[0037] The light-receiving unit 54 consists of an avalanche photodiode (APD). The light-receiving signal from the light-receiving unit 54 is output to the calculation unit 90 (see Figure 2).
[0038] The calculation unit 90 is a microcomputer having memory and a CPU. The analysis program is stored in the memory. The calculation unit 90 analyzes the received light signals from the distance measuring light L and reference light R received by the light receiving unit 54 and calculates the distance to the target 2. Conventional and well-known methods such as the phase difference method and the spot method can be used for the analysis, and the type is not limited. The instrument height measuring unit 40 calculates the distance to the target 2. The distance from the center point O to the instrument height measuring unit 40 is added to this to calculate the instrument height T.
[0039] (Effects and Benefits) The distance measurement using the distance measuring light L will be explained in detail using Figure 4. Figure 4 is an enlarged view of the area around the measurement target 2 in Figure 1. In this embodiment, the illumination radius of the distance measuring light L is slightly widened by the defocus lens 56. Therefore, when it is shone on the object to be measured, it is visible as light in the illumination area LA. The distance measuring light L is reflected at one of the points on the illumination area LA and received by the light receiving unit 54. For example, the first measurement result is distance point P1, the next measurement result is distance point P2, the next measurement result is distance point P3, and so on, with any point within the illumination area LA designated as distance point P and the distance to distance point P calculated as the measurement result. The distance point P to be measured is a point on the optical axis of the illumination area, that is, the point below the vertical axis of the surveying instrument body in the illumination area LA is designated as reference point CP, and the distance point P is randomly selected within the illumination area LA with reference point CP as the center. The calculation unit 90 calculates the average distance to the illumination area LA by averaging the distance measurement results from the received light signals reflected at these random distance measurement points P. The calculation unit 90 calculates the distance to the illumination area LA as the distance to the measurement target 2, and adds the height from the center point O to the instrument height measurement unit 40 to this calculation result to obtain the instrument height T. The calculated instrument height T is displayed on the display 20. The instrument height measurement unit 40 can measure distance to a random point within the illumination area LA simply by performing distance measurements continuously, and the distance measurement point changes each time a measurement is taken within the illumination area LA. The instrument height measurement unit 40 performs distance measurements continuously using the distance measuring light L. The calculation unit 90 calculates the average distance to the illumination area LA by calculating the average value of multiple continuously measured distance measurement results, and uses this as the distance to the measurement target 2.
[0040] The averaging of the distance measurement results by the calculation unit 90 may be the average of the values measured within a predetermined measurement time, or it may be the result of always obtaining the average of the measured values and measuring until the fluctuation range of the average value converges to a predetermined range.
[0041] By calculating the average distance to the irradiation area LA, rather than the point of irradiation by the laser beam, subtle irregularities and inclinations at the irradiation point are corrected, allowing for precise measurement of the distance to the survey target 2. Furthermore, subtle tilts from the horizontal of the surveying instrument 1, which cannot be corrected manually, are also corrected. Therefore, the instrument height T can be easily and precisely measured.
[0042] It is preferable to calculate the instrument height T more precisely by averaging the distance to the illumination area LA and then correcting it with the tilt measured by the tilt sensor 80 built into the surveying instrument 1, especially the tilt around the horizontal axis H. This will be explained using Figure 5. Figure 5 shows the inclination state of the surveying instrument 1 or the survey marker 2. Figure 5(A) shows the state in which the surveying instrument 1 is inclined with respect to the horizontal axis H. Figure 5(B) shows the state in which the survey marker 2 is inclined with respect to the horizontal axis H.
[0043] The surveying instrument 1 is equipped with a horizontal bubble level parallel to the horizontal axis H. During leveling, the tilt of the surveying instrument 1 is adjusted so that the bubble in the horizontal bubble level is in the center. Because the tilt is adjusted based on the horizontal axis H, it may be slightly tilted around the horizontal axis H (see Figure 5(A)). Also, the survey target 2 may have tilt or unevenness (see Figure 5(B)). In other words, the surveying instrument 1 and survey target 2 may not be horizontal relative to the horizontal axis H, in which case an error occurs in the instrument height T. This error can be canceled by calculating the distance to the illumination area LA. If the surveying instrument 1 is tilted (Figure 5(A)), the angle of inclination θ is measured by the built-in tilt sensor 80, and a more accurate instrument height T can be obtained by correcting the instrument height T calculated using the angle θ. If the survey target 2 has tilt or unevenness (Figure 5(B)), this is corrected by averaging the distance measurement values in the illumination area LA.
[0044] The illumination area LA should preferably be of an appropriate size and not extend beyond the measurement target 2. For this reason, the maximum outer diameter of the illumination area LA on a virtual plane located 1 m away from the bottom surface of the surveying instrument 1 should preferably be about 2 mm to 30 mm, and more preferably 5 mm to 20 mm. The defocus lens 56 is not limited to a simple through lens; a lens with a calculated curved surface may be used, or multiple lenses may be used. The illumination radius of the distance measuring light L may be widened and emitted as parallel light. The size of the illumination area LA may be configured to be changeable.
[0045] The distance at which the instrument height measuring unit 40 is used is the installation height of the surveying instrument 1, that is, roughly the height of the worker's line of sight. With diffused light, the illumination area expands infinitely with distance, but the instrument height measuring unit 40 has a limited purpose of use, a short operating distance, and a narrow operating range, so the size of the illumination area LA that the distance measuring light L illuminates on the object to be measured can be set within a predetermined range.
[0046] In this embodiment, the light emitted by the light transmitting unit 51 is visible light, and the distance measuring light L irradiated below the surveying instrument 1 is also used as a centering laser beam. That is, the optical axis of the collimating lens 52 coincides with the center line V of the vertical axis 28, and the distance measuring light L is emitted from the bottom surface of the surveying instrument 1 downwards along the vertical axis of the surveying instrument body. Therefore, the distance measuring light L irradiated onto the object to be measured is visible as a centering spot light, which is a marker below the vertical axis of the surveying instrument body passing through the center point O. In centering operations, the surveying instrument 1 can be positioned on the vertical axis of the surveying instrument 2 by aligning the center of the light in the irradiated area LA with the center of the surveying target 2.
[0047] When an operator sets up the surveying instrument 1 using the survey marker 2 as a reference point, the surveying instrument 1 is positioned on a tripod 8 approximately vertically above the survey marker 2, and the adjustment screw on the leveling base 25 is used to level the surveying instrument 1. Next, a distance measuring light L is emitted from the instrument height measuring unit 40 downwards along the vertical axis of the surveying instrument body and illuminates the survey marker 2 as light in the illumination area LA. While maintaining the leveled state, the surveying instrument 1 is slid so that the center of the survey marker 2 aligns with the center of the distance measuring light L illuminated on the survey marker 2, and the position is adjusted. This centering operation may cause the instrument to tilt from the horizontal state, so the leveling and centering operations are repeated until the surveying instrument 1 is positioned horizontally vertically above the survey marker 2. Once the centering operation is complete, the distance is measured by the instrument height measuring unit 40, the distance to the survey marker 2 is calculated, and the instrument height T is obtained.
[0048] Both leveling and centering operations can be performed by the operator facing the surveying instrument 1, and the instrument height T is calculated automatically, thus reducing the burden on the operator in centering operations and setting up the surveying instrument 1.
[0049] The visible laser light used for centering is preferably a highly visible green laser light. This improves the efficiency of the centering operation, which involves aligning the emitted light with the reference point. It is not limited to green laser light; red laser light or other colored laser light are also acceptable.
[0050] Furthermore, a pulse method is preferable for the distance measurement method. With the phase difference method, there may be limitations on the size of the irradiation area, so a pulse method that does not depend on the size of the irradiation area is preferable.
[0051] In this embodiment, the instrument height measurement unit 40 is equipped not only with an instrument height measurement function but also with a centering laser light irradiation function for centering operations. However, it is not limited to this, and the instrument height measurement unit 40 may be equipped only with an instrument height measurement function, with the centering operation being performed separately. For example, it is acceptable to use a conventional configuration for centering operations, such as equipping a centering telescope.
[0052] In this embodiment, the instrument height measuring unit 40 is positioned above the vertical axis 28, and all of its optical components are also positioned above the vertical axis 28. However, it is not limited to this, and some of the optical components of the instrument height measuring unit 40 may be positioned on the vertical axis 28 or the fixing unit 24, for example, by attaching the light transmitting unit 51 to the main body casing 12 and arranging the collimating lens 52 and objective lens 57 inside the hollow vertical axis 28. The defocus lens 56 is positioned in front of the beam splitter 53, but it is sufficient to position it on the forward path of the distance measuring optical path, and it may also be positioned behind the beam splitter 53.
[0053] Furthermore, in this embodiment, the irradiation shape is expanded into a roughly circular shape by using a pass-through lens to enlarge the point beam light. However, the shape of the irradiation area LA is not limited to a circle; it may be a random diffuse shape, or it may be set to a desired shape using a lens.
[0054] (modified version) The instrument height measurement unit may use a distance image sensor that acquires distance image information within a predetermined range. The distance image sensor acquires an image of the object to be measured, as well as its depth, i.e., distance, as information. For distance calculation, known methods may be used, such as the time-of-flight method, which determines the distance from the time it takes for light projected onto an object to reflect back, or the pattern projection method, which projects a predetermined pattern of light onto the object to be measured and determines the distance from the degree of distortion in the reflected image. The calculation unit 90 calculates the average value of the distance in a predetermined area centered on the optical axis of the imaging range and obtains the instrument height T.
[0055] Figure 6 shows the optical configuration of the instrument height measurement unit 140 as an example of a modified example using a distance image sensor.
[0056] The instrument height measuring unit 140 has a light transmitting unit 151 that emits infrared light and transmits it toward the object to be measured (target 2). The instrument height measuring unit 140 has a light receiving unit 154 which has multiple image sensors 154a arranged in a matrix. The distance measuring light L emitted from the light transmitting unit 151 is reflected by the target 2, passes through the imaging lens 158, and is received by the light receiving unit 154. The calculation unit 90 calculates the distance measurement result for each image sensor 154a from the received signal of each image sensor 154a received by the light receiving unit 154. In this way, along with the image projected by the distance measuring light L, the depth (distance) to the constituent points of the image is also acquired. The reference point CP2 of the target 2 is also acquired in the image. The calculation unit 90 calculates the instrument height T as the distance to the target 2 by averaging the distances of pixels in a predetermined area LA2 centered on a point on the optical axis. To obtain the average value of the measurement results, the operator may specify a reference point CP2 or a predetermined area LA2 from the acquired image. Within the measurement range of the instrument height T, a distance image sensor can measure with sufficient accuracy and can be implemented at a relatively low cost.
[0057] Although preferred embodiments of the present invention have been described above, these embodiments are merely examples of the present invention, and it is possible to combine them based on the knowledge of those skilled in the art, and such forms are also included within the scope of the present invention. [Explanation of Symbols]
[0058] 1:Surveying machine 2: Survey Marker 28: Vertical axis 40: Instrument height measurement unit 51: Light transmitting unit 54: Light receiving part 56: Defocus lens 80: Tilt sensor 90: Arithmetic section 140: Instrument height measurement unit 151: Light transmitting unit 154: Light receiving section 154a: Image sensor L: Ranging light LA: irradiation area T: Instrument height
Claims
1. A surveying instrument having a height measuring unit that measures distance by emitting a distance measuring light to a distance measuring object below the vertical axis of the surveying instrument body, and a calculation unit that analyzes the light that has been reflected back from the distance measuring object to calculate the distance to the distance measuring object and calculate the instrument height, The instrument height measuring unit performs distance measurement by irradiating the distance measuring light onto a predetermined area of the object to be measured, centered on the lower vertical axis point of the surveying instrument body. The calculation unit calculates the average value of the distance measurement values in the region to calculate the instrument height, The aforementioned instrument height measuring unit is A light-transmitting unit that emits the distance-measuring light toward the object to be measured, A light receiving unit consisting of one light receiving element receives the distance measuring light emitted from the light transmitting unit, reflected back by the object to be measured, and is received by the light receiving unit, A defocus lens that diffuses incident light is placed in the optical path of the distance measuring light, It has, The distance measuring light that has passed through the defocus lens is emitted downward from the vertical axis of the surveying instrument body and irradiates the object to be measured in the area centered on the point downward from the vertical axis of the surveying instrument body. The calculation unit calculates the distance to the object to be measured based on the light received signal of the light receiving unit, and further calculates the average value of the distances to the object to be measured, thereby using the average distance to the area irradiated by the measuring light as the distance to the object to be measured, and calculating the instrument height. A surveying instrument characterized by the following features.
2. The aforementioned defocus lens is a clear, unfiltered lens. The surveying instrument according to feature 1.
3. The distance measuring light is visible laser light, The distance measuring light is projected as a centering spot light below the vertical axis of the surveying instrument body. The surveying apparatus according to claim 1 or 2.
4. The visible laser light is green laser light. The surveying instrument according to feature 3.
5. The aforementioned instrument height measuring unit is a distance measuring device employing a pulse method. A surveying instrument according to any one of claims 1 to 4.
6. The calculation unit calculates the average value of the measured values in the area irradiated by the distance measuring light, Furthermore, it performs correction using the tilt measured by the built-in tilt sensor. A surveying instrument according to any one of claims 1 to 5.
7. The illumination area of the distance measuring light at a position 1 m away from the bottom surface of the surveying instrument body has a maximum outer diameter of 5 mm to 30 mm. A surveying instrument according to any one of claims 1 to 6.