Imaging device and surveying system

Abstract

This imaging device includes a guide light emitting unit (16) that emits guide light of two colors, indicating a direction to a stakeout worker, along a guide optical axis, and an imaging unit (17) that acquires an image on the basis of external light incident along the imaging optical axis (21), wherein the guide light emitting unit and the imaging unit are configured to include: a deflecting optical member (34) that deflects either one of the guide optical axis and the imaging optical axis so as to be coaxial with another of the guide optical axis and the imaging optical axis; and a light projection / reception lens group (35) provided on the imaging optical axis and the guide optical axis that have been made coaxial by the deflecting optical member.

Description

Imaging device and surveying system

[0001] The present invention relates to an imaging device and a surveying system that emits guide light to guide a worker to a surveying point and receives external light to acquire an image.

[0002] 2. Description of the Related Art In staking work, a guide light emitting device that emits guide light is known as a device for guiding a staking worker to a staking point such as a stake driving point.

[0003] The guide light emitting device is mainly provided integrally with a surveying instrument for measuring the three-dimensional coordinates of a predetermined measurement object. In addition, the surveying instrument may acquire an image with a camera and collimate the measurement object based on the acquired image.

[0004] However, since the guide light emitting device and the camera each have independent optical systems, there are concerns that the number of parts will increase and the optical system of the entire surveying device will become larger, so no device has been manufactured that integrates the guide light emitting device and the camera.

[0005] Patent No. 7178310

[0006] The present invention provides an imaging device and a surveying system that achieves a compact optical system and a compact overall device.

[0007] The present invention relates to an imaging device that includes a guide light irradiating unit that irradiates two-color guide light along a guide light axis to indicate a direction to a surveying worker, and an imaging unit that acquires an image based on external light incident along an imaging optical axis, wherein the guide light irradiating unit and the imaging unit are configured to include a deflection optical element that deflects either the guide light axis or the imaging optical axis so that it becomes coaxial with the other, and the guide light axis that is made coaxial by the deflection optical element, and a group of light emitting and receiving lenses that are provided on the imaging optical axis.

[0008] The present invention also relates to an imaging device in which the guide light irradiating unit has a first light source that emits a first guide light that is visible light, a second light source that emits visible light different from the first guide light, and a right-angle prism mirror that reflects the first guide light and the second guide light so that they each coincide or nearly coincide with the guide light axis, and the guide light of two colors is generated from the first guide light and the second guide light with the guide light axis as a boundary by being reflected by the right-angle prism mirror.

[0009] The present invention also relates to an imaging device in which the guide light irradiation unit has a light source that emits white light and a spectral plate on which color-emitting elements having two regions with different spectral characteristics are formed, and the guide light of two colors is generated from the white light by passing through the color-emitting elements, with the boundary between the two regions as the boundary.

[0010] The present invention also relates to an imaging device configured so that the guide light irradiating section and the imaging section are used alternatively.

[0011] The present invention also relates to an imaging device configured so that the guide light irradiating section further includes a guide light reflecting section that reflects the guide light toward the deflection optical member.

[0012] The present invention also relates to an imaging device in which the imaging unit further has an imaging lens arranged on the light-receiving side of the deflection optical member, and the light-emitting and receiving lens group and the imaging lens form a telephoto lens.

[0013] The present invention also relates to an imaging device in which the guide light irradiation unit and the imaging unit have a light-emitting and receiving prism formed by joining two prisms, and the deflection optical element is a beam splitter film formed on the joining surface of the two prisms.

[0014] The present invention also relates to an imaging device in which the deflection optical member is a beam splitter arranged at the intersection of the guide optical axis and the imaging optical axis.

[0015] The present invention also relates to an imaging device configured such that the guide light irradiation unit further has a light source that emits white light, the incident surface of the light projecting and receiving prism is perpendicular to the guide light axis, a coloring element having two regions with different spectral transmittances is formed on the surface, and the white light passes through the coloring element to generate the guide light of two colors with the boundary between the two regions as the boundary.

[0016] The present invention also relates to an imaging device configured such that the guide light irradiating unit has a light source that emits white light and a mirror that reflects the guide light toward the beam splitter, and a coloring element having two regions with different spectral transmittances is formed on the mirror, and the white light is reflected by the coloring element onto the mirror, thereby generating the guide light of two colors with the boundary between the two regions as the boundary.

[0017] Furthermore, the present invention relates to a surveying system having a surveying instrument, a target pole capable of communicating with the surveying instrument, and the above-mentioned imaging device installed in the surveying instrument, wherein the target pole comprises a pole installed so that its lower end coincides with a predetermined measurement point, a prism installed at the top end of the pole, and a terminal device installed halfway along the pole, and the surveying instrument comprises a distance measuring unit that irradiates a distance measuring light into a boundary plane that indicates the center of the guide light and determines the distance to the prism, a drive unit that rotates the surveying instrument horizontally and deflects the distance measuring light vertically to emit the distance measuring light in a predetermined direction, an angle measuring unit that detects the emission direction of the distance measuring light, and an arithmetic and control unit that controls the distance measuring unit, the drive unit, and the imaging device, and the arithmetic and control unit is configured to measure the prism located at the boundary between the guide lights of two colors, calculate the distance and direction from the prism to the measurement point, and transmit the calculation results to the terminal device.

[0018] According to the present invention, there is provided a guide light irradiating unit that irradiates two-color guide light along a guide light axis to indicate the direction to the surveying worker, and an imaging unit that acquires an image based on external light incident along an imaging optical axis, and the guide light irradiating unit and the imaging unit are configured to have a deflection optical element that deflects either the guide light axis or the imaging optical axis so that it becomes coaxial with the other, and a group of light emitting and receiving lenses that are provided on the guide light axis that is made coaxial by the deflection optical element and on the imaging optical axis, so there is no need to provide lenses respectively for the guide light irradiating unit and the imaging unit, which makes it possible to reduce the number of parts and make the optical system more compact.

[0019] According to the present invention, there is provided a surveying system comprising a surveying instrument, a target pole capable of communicating with the surveying instrument, and the above-mentioned imaging device provided on the surveying instrument, wherein the target pole comprises a pole installed so that its lower end coincides with a predetermined measurement point, a prism provided at the top end of the pole, and a terminal device provided midway on the pole, and the surveying instrument comprises a distance measuring unit that irradiates a distance measuring light onto a boundary surface that indicates the center of the guide light and determines the distance to the prism, a drive unit that rotates the surveying instrument horizontally and deflects the distance measuring light vertically to emit the distance measuring light in a predetermined direction, an angle measuring unit that detects the emission direction of the distance measuring light, and an arithmetic and control unit that controls the distance measuring unit, the drive unit, and the imaging device, and the arithmetic and control unit is configured to measure the prism located at the boundary between the two colors of guide light, calculate the distance and direction from the prism to the measurement point, and transmit the calculation results to the terminal device, so that the prism can be easily transported to the irradiation range of the distance measuring light.

[0020] FIG. 1 is an explanatory diagram illustrating an overview of a surveying system according to a first embodiment. FIG. 2 is a configuration diagram illustrating the configuration of a surveying device according to the first embodiment. FIG. 3 is an explanatory diagram illustrating the main parts of an imaging device according to the first embodiment. FIG. 4 is an explanatory diagram illustrating the main parts of an imaging device according to a second embodiment. FIG. 5 is an explanatory diagram of coloring elements according to the second embodiment. FIG. 6 is a graph showing the spectral characteristics of white light, the film transmittance characteristics of a dichroic film, and the spectral characteristics of white light after transmission through the dichroic film according to the second embodiment. FIG. 7 is an explanatory diagram illustrating the main parts of an imaging device according to a third embodiment. FIG. 8 is an explanatory diagram of coloring elements according to the third embodiment. FIG. 9 is an explanatory diagram illustrating the main parts of an imaging device according to a fourth embodiment. FIG. 10 is an explanatory diagram illustrating the main parts of an imaging device according to a fifth embodiment.

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] First, referring to FIG. 1, an outline of a surveying system according to an embodiment of the present invention will be described.

[0023] The surveying system 1 comprises a surveying device 2 and a target pole 3. Fig. 1 shows the target pole 3 installed at a staking point 4. The surveying device 2 is installed at a setting point having known three-dimensional coordinates, and the collimation direction is set to the staking point 4.

[0024] The surveying device 2 is, for example, a total station with a tracking function, and is installed via a support device such as a tripod 5. The surveying device 2 can measure the three-dimensional coordinates of a desired measurement point with the machine center (instrument point) as the reference, and can also measure the three-dimensional coordinates of the staking point 4 at which the target pole 3 is installed with the installation point as the reference based on the height of the instrument point.

[0025] The surveying instrument 2 has a leveling unit 6 mounted on the tripod 5, and a surveying instrument main body 7 mounted on the leveling unit 6 so as to be horizontally rotatable. An imaging device 8 having a guide light irradiation function is provided on the top surface of the surveying instrument main body 7.

[0026] The leveling unit 6 has a sensor (not shown) for detecting the inclination of the leveling unit 6 and a motor (not shown) for driving a leveling screw that levels the leveling unit 6, and is configured to automatically level the leveling unit 6 based on the detection result of the sensor.

[0027] The surveying instrument main body 7 has a distance measuring unit 9 (described later). The surveying instrument main body 7 also has a vertically long slit-shaped light projection window 11, and the distance measuring unit 9 is configured to emit distance measuring light along a distance measuring optical axis 12 that can be deflected in the vertical direction, and measure the distance to an object to be measured (a prism 13 described later) based on the distance measuring light reflected by the prism 13. The surveying instrument main body 7 also has a tracking unit 20 (described later). The tracking unit 20 is configured to emit tracking light coaxially with the distance measuring light (on the distance measuring optical axis 12), and perform laser tracking based on the reflected tracking light reflected by the prism 13.

[0028] The target pole 3 has a pole 14 with a pointed lower end, the prism 13 provided at the upper end of the pole 14, and a terminal device 15 provided in the middle of the pole 14, and the target pole 3 is installed so that the lower end of the pole 14 coincides with the surveying point 4.

[0029] The prism 13 is, for example, a full-circumference prism having retroreflectivity, and the optical center of the prism 13 is located on the axis of the pole 14. In addition, the distance from the lower end of the pole 14 to the optical center of the prism 13 is known.

[0030] Furthermore, the target pole 3 has a level (not shown) such as a bubble tube, and the target pole 3 can be leveled in a vertical position via the level.

[0031] The terminal device 15 is, for example, a smartphone, and is capable of communicating with the surveying device 2 via wireless communication means such as wireless LAN or Bluetooth (registered trademark), and is capable of displaying the three-dimensional coordinates of the prism 13 measured by the surveying device 2, the three-dimensional coordinates of the staking and setting point 4 previously set by the surveying device 2, or the three-dimensional coordinates of the staking and setting point 4 directly input from the surveying device 2. The terminal device 15 is also capable of displaying the position of the staking and setting point 4 based on the position of the prism 13 calculated by the surveying device 2, i.e., the distance from the prism 13 to the staking and setting point 4, and the direction of the staking and setting point 4 based on the prism 13. Furthermore, the terminal device 15 is configured to notify the operator by an alarm such as a sound when the position of the prism 13 and the position of the staking and setting point 4 match.

[0032] The imaging device 8 includes a guide light emitting unit 16 and an imaging unit 17. The guide light emitting unit 16 is configured to emit guide light 19 so that a guide light axis 18 is located in the same plane as the distance measurement light axis 12. The guide light 19 is composed of, for example, a first guide light 19a, which is red visible light, and a second guide light 19b, which is green visible light, and is two-color visible light with the guide light axis 18 (the distance measurement light axis 12) as a boundary 19c. For example, the guide light 19 is configured so that both red and green light are visible when facing the distance measurement light axis 12 directly, and only red light is visible from the right side of the distance measurement light axis 12 and only green light is visible from the left side of the distance measurement light axis 12. The guide light axis 18 is located at the center of the boundary 19c, and the distance measurement light axis 12 is tiltable vertically with respect to the guide light axis 18. That is, the distance measurement light is irradiated within the plane formed by the boundary 19c.

[0033] The imaging unit 17 can acquire an image based on external light incident along an imaging optical axis 21 that is coaxial with the guide light 19, i.e., coaxial with the guide light axis 18. The relative rotation angle between the distance measurement optical axis 12 and the imaging optical axis 21 can be acquired by a vertical angle detector 25 (described later), and the distance between the emission position of the distance measurement light and the imaging optical axis 21 is also known. Therefore, the position of the distance measurement optical axis 12 in the image acquired by the imaging unit 17 can be identified.

[0034] Furthermore, when the guide light 19 is irradiated by the guide light irradiating unit 16, the image capturing unit 17 does not capture an image, and when the image capturing unit 17 is capturing an image, the guide light irradiating unit 16 does not irradiate the guide light 19. That is, the guide light irradiating unit 16 and the image capturing unit 17 are used alternatively.

[0035] Next, the configuration of the surveying device 2 will be described with reference to FIG.

[0036] The surveying instrument 2 has a horizontal rotation drive unit 22 for rotating the surveying instrument main body 7 relative to the leveling unit 6, a horizontal angle detector 23 for detecting the rotation angle (horizontal angle) of the surveying instrument main body 7, a vertical rotation drive unit 24 for rotating a deflection member (e.g., a mirror) for rotating the distance measuring optical axis 12 in a vertical plane, and the vertical angle detector 25 for detecting the rotation angle (vertical angle) of the deflection member. The surveying instrument 2 also has an arithmetic and control unit 26, a memory unit 27, a communication unit 28, a display unit 29, and an operation unit 31.

[0037] The horizontal rotation drive unit 22 and the vertical rotation drive unit 24 constitute the drive unit of the surveying device 2, and the horizontal angle detector 23 and the vertical angle detector 25 constitute the angle measurement unit for detecting the irradiation direction of the distance measurement light.

[0038] The arithmetic control unit 26 may be a CPU specialized for this embodiment, or a general-purpose CPU, an embedded CPU, a microprocessor, etc. The storage unit 27 may be a semiconductor storage memory such as RAM, ROM, Flash ROM, or DRAM, a magnetic storage memory such as HDD, or an optical storage memory such as CD-ROM.

[0039] The storage unit 27 stores programs such as a sequence program for controlling distance measurement operation, a distance measurement program for calculating distance by distance measurement operation, an angle measurement program for calculating the extension direction (angle) of the distance measurement optical axis 12 based on the detection results of the horizontal angle detector 23 and the vertical angle detector 25, a measurement program for calculating three-dimensional coordinates of a desired measurement point based on the distance and angle, a leveling program for causing the leveling unit 6 to perform leveling, a tracking program for causing the tracking unit 20 to track the prism 13, a communication program for communicating with the terminal device 15, a drive control program for controlling the horizontal rotation drive unit 22 and the vertical rotation drive unit 24, a guide light irradiation program for causing the guide light irradiating unit 16 to irradiate guide light, an image acquisition program for causing the imaging unit 17 to acquire an image, and a display program for displaying measurement results and the like on the display unit 29.

[0040] The storage unit 27 also stores data such as measurement data (distance measurement data and angle measurement data) obtained when measuring a predetermined measurement point, and three-dimensional coordinate data of the staking point 4. The calculation control unit 26 develops and executes various programs stored in the storage unit 27, and performs various processes.

[0041] The communication unit 28 has a function of transmitting data from the surveying device 2 to the terminal device 15, or receiving data from the terminal device 15 to the surveying device 2. The data transmitted between the surveying device 2 and the terminal device 15 includes, for example, the measurement results by the surveying device 2 and the images acquired by the imaging unit 17. The operation unit 31 allows the input of measurement conditions, etc., and the display unit 29 is configured to display a setting screen, measurement results, etc.

[0042] Next, the configuration of the imaging device 8 will be described with reference to Fig. 3. The imaging device 8 is controlled by the arithmetic and control unit 26.

[0043] 3, the guide light irradiating unit 16 includes a first light source 32, a right-angle prism mirror 33 provided on the emission optical axis of the first light source 32, a beam splitter 34 as a deflection optical member provided on the reflection optical axis of the right-angle prism mirror 33, a group of light projecting and receiving lenses 35, and a window 36. The guide light irradiating unit 16 also includes a second light source 37 provided symmetrically to the first light source 32 across the right-angle prism mirror 33. The right-angle prism mirror 33 is located on the emission optical axis of the second light source 37, and the beam splitter 34, the group of light projecting and receiving lenses 35, and the window 36 are located on the reflection optical axis of the right-angle prism mirror 33.

[0044] The right-angle prism mirror 33 is a right-angle isosceles triangular prism having two reflecting surfaces 33a and 33b. The first light source 32 is, for example, an LD or an LED, and is configured to irradiate red visible light as a first guide light 19a (see FIG. 1) along a first guide optical axis 18a toward the vicinity of the tip of the reflecting surface 33a, and the first guide light 19a is reflected at a right angle by the reflecting surface 33a. The second light source 37 is, for example, an LD or an LED, and is configured to irradiate green visible light as a second guide light 19b (see FIG. 1) along a second guide optical axis 18b toward the vicinity of the tip of the reflecting surface 33b, and the second guide light 19b is reflected at a right angle by the reflecting surface 33b.

[0045] The first guide optical axis 18a of the first guide light 19a reflected by the reflecting surface 33a and the second guide optical axis 18b of the second guide light 19b reflected by the reflecting surface 33b coincide with or are parallel to and approximately coincide with the guide optical axis 18 passing through the vertex (ridge line) of the right-angle prism mirror 33.

[0046] The first guide light 19a and the second guide light 19b reflected by the right-angle prism mirror 33 enter the beam splitter 34 as the two-color guide light 19 separated by the boundary 19c in the same plane as the guide light axis 18.

[0047] The beam splitter 34 has optical properties of transmitting 50% of the incident light and reflecting 50%, and transmits a portion of the incident guide light 19. In addition, the guide light 19 is deflected by a predetermined distance in the process of transmitting through the beam splitter 34.

[0048] The guide light 19 transmitted through the beam splitter 34 is deflected by the light projecting and receiving lens group 35 so as to have a predetermined divergence angle, and is irradiated to the outside of the imaging device 8 through the window portion 36 .

[0049] It should be noted that, for example, a double Gauss lens with a long back focus is used as the light projecting and receiving lens group 35. The first light source 32 and the second light source 37 are each provided at or near the focal position of the light projecting and receiving lens group 35. Furthermore, the spread angle of the guide light 19 is larger than the angle of view of the tracking light emitted from the tracking unit 20.

[0050] The guide light irradiating unit 16 is configured to irradiate two colors of visible light, red and green, coaxially or approximately coaxially with the guide light axis 18 passing through the vertex (ridge line) of the right-angle prism mirror 33 by using the right-angle prism mirror 33. That is, the guide light 19 is two colors of visible light consisting of the first red guide light 19a and the second green guide light 19b, and is configured so that the color of the guide light 19 when facing the optical axis of the distance measuring light emitted from the surveying instrument 2, the color of the guide light 19 when viewed from the left side of the optical axis of the distance measuring light, and the color of the guide light 19 when viewed from the right side of the optical axis of the distance measuring light are all different colors.

[0051] The imaging unit 17 has an imaging optical axis 21. The imaging unit 17 has, in order from the light-receiving side, a light-receiving element 38 provided on the imaging optical axis 21, the beam splitter 34, the light-emitting and light-receiving lens group 35 provided on the reflected optical axis of the beam splitter 34, and the window portion 36.

[0052] In this embodiment, the imaging optical axis 21 and the imaging optical axis 21 deflected at a right angle by the beam splitter 34 are collectively referred to as the imaging optical axis 21. The imaging optical axis 21 is deflected by the beam splitter 34 so as to coincide with the guide optical axis 18. That is, the beam splitter 34 and the light projecting and receiving lens group 35 are located on a common optical path of the guide light irradiating unit 16 and the imaging unit 17. The imaging unit 17 is configured so that external light (background light) is incident along the imaging optical axis 21 coaxially with the guide light 19 irradiated along the guide optical axis 18.

[0053] The light receiving element 38 is a CCD or CMOS sensor that is a collection of pixels, and the position of each pixel can be identified on the light receiving element 38. For example, each pixel has pixel coordinates with the center of the light receiving element 38 as the origin, and the position on the light receiving element 38 is identified by the pixel coordinates.

[0054] When the surveying instrument main body 7 is in a horizontal position and the distance measurement optical axis 12 is deflected horizontally, the guide optical axis 18 becomes parallel to the distance measurement optical axis 12. The positional relationship (offset distance) at this time is known. That is, the distance measurement optical axis 12 and the guide optical axis 18 are located in the same plane, and the distance measurement optical axis 12 and the imaging optical axis 21 are also located in the same plane. Furthermore, the relative rotation angle of the distance measurement optical axis 12 with respect to the imaging optical axis 21 can also be calculated based on the detection result of the vertical angle detector 25.

[0055] Next, a process for guiding a survey worker during survey work using the surveying system 1 will be described.

[0056] First, the surveying device 2 is installed at a setting point having known three-dimensional coordinates and pointed in any direction. At this time, the imaging unit 17 may be caused to acquire an image, and the aiming direction of the surveying device 2 may be selected based on the image. For example, the acquired image is transmitted to the terminal device 15 in real time, and the operator refers to the image displayed on the terminal device 15 and moves the target pole 3 so that the prism 13 is positioned at the center of the image.

[0057] Next, the three-dimensional coordinates of the staking point 4 are input to the surveying device 2 via the operation unit 31, or the staking point 4 stored in the memory unit 27 is specified, and the calculation control unit 26 is caused to start processing.

[0058] The arithmetic and control unit 26 drives the horizontal rotation drive unit 22 and the vertical rotation drive unit 24 to point the guide light axis 18 toward the measurement point 4, and also drives the first light source 32 and the second light source 37 to emit the guide light 19. In parallel with the emission of the guide light 19, the surveying device 2 causes the distance measuring unit 9 and the tracking unit 20 to emit distance measuring light and tracking light. Note that while the guide light 19 is being emitted, image acquisition by the imaging unit 17 is stopped.

[0059] Here, the tracking light is irradiated coaxially with the distance measurement light, and the distance measurement light axis 12 is located in the same plane as the guide light axis 18. That is, the distance measurement light axis 12 and the optical axis of the tracking light are located on the boundary 19c, and the distance measurement light and the tracking light are irradiated onto the boundary 19c.

[0060] The worker transports the target pole 3 while referring to the guide light 19. Here, when the target pole 3 is located to the right of the boundary 19c, the target pole 3 is located within the irradiation range of the first guide light 19a, and the worker only sees the red first guide light 19a. When the target pole 3 is located to the left of the boundary 19c, the target pole 3 is located within the irradiation range of the second guide light 19b, and the worker only sees the green second guide light 19b.

[0061] If the visible guide light 19 is red, the worker moves the target pole 3 to the left, and if it is green, the worker moves the target pole 3 to the right. The worker continues to move the target pole 3 up to the boundary 19c, that is, until both the first guide light 19a and the second guide light 19b can be seen.

[0062] The amount of reflected tracking light (reflected tracking light) when the tracking light is reflected by the prism 13 is significantly increased compared to the amount of reflected tracking light when it is irradiated on an object other than the prism 13. Therefore, when the calculation control unit 26 detects an increase in the amount of received reflected distance measuring light, it causes the tracking unit 20 to start tracking the prism 13.

[0063] Moreover, since the distance measuring light is emitted coaxially with the tracking light, the calculation control unit 26 causes the distance measuring unit 9 to measure (measure distance and angle) the prism 13 in parallel with tracking the prism 13. That is, the three-dimensional coordinates of the prism 13 are calculated in real time.

[0064] The calculation control unit 26 calculates the position of the surveying point 4 relative to the measurement results (three-dimensional coordinates) of the target pole 3, i.e., the distance and direction to the surveying point 4, and transmits it to the terminal device 15 via the communication unit 28.

[0065] The worker transports the target pole 3 toward the staking point 4 based on the distance and direction to the staking point 4 displayed on the terminal device 15. Here, since the prism 13 is measured in real time in parallel with tracking, the distance and direction to the staking point 4 are updated in real time.

[0066] When the distance to the staking point 4 becomes 0, that is, when the target pole 3 is moved onto the staking point 4, the terminal device 15 issues an alarm by sound or the like to indicate that guidance is complete, and the guidance process for the target pole 3 is completed. If there are other staking points 4 to be guided, the surveying device 2 performs guidance processing to the next staking point.

[0067] As described above, in the first embodiment, the light projecting and receiving lens group 35 provided in the imaging device 8 is disposed on the guide optical axis 18 and the imaging optical axis 21. That is, it is located on a common optical path of the guide light 19 irradiated along the guide optical axis 18 and the external light incident along the imaging optical axis 21.

[0068] Therefore, there is no need to provide a lens for expanding the guide light 19 to a predetermined spread angle and a lens for focusing external light onto the light receiving element 38, so the number of parts is reduced, which reduces manufacturing costs and allows the optical system to be made smaller.

[0069] Moreover, the imaging device 8 is configured to selectively use the guide light emitting unit 16 and the imaging unit 17. Therefore, it is possible to prevent the guide light 19 reflected by the window unit 36 ​​from being received by the light receiving element 38 as stray light, and it is possible to improve the accuracy of image acquisition.

[0070] Moreover, since the distance measurement optical axis 12 is positioned on the boundary 19c of the guide light 19, the prism 13 can be easily transported to the irradiation range of the distance measurement light.

[0071] In the first embodiment, the surveying device 2 is configured to automatically direct the guide optical axis 18 toward the staking and setting point 4 based on the three-dimensional coordinates of the staking and setting point 4 input from the operation unit 31 or based on the three-dimensional coordinates of the staking and setting point 4 stored in the memory unit 27. On the other hand, the direction of the guide optical axis 18 may be specified based on an image acquired by the imaging unit 17.

[0072] In the first embodiment, the target pole 3 is transported so that it is located on the boundary 19c, i.e., so that the prism 13 is within the irradiation range of the tracking light, and tracking of the prism 13 is automatically started when the amount of reflected tracking light increases, i.e., the prism 13 is detected. On the other hand, the image acquired by the imaging unit 17 may be received by the terminal device 15, and the orientation of the surveying device 2 may be specified based on the image received by the terminal device 15 so that the prism 13 is within the irradiation range of the tracking light. In this case, the operator can make the surveying device 2 start tracking the prism 13 without transporting the target pole 3.

[0073] In addition, in the first embodiment, the imaging device 8, i.e., the guide light irradiating unit 16 and the imaging unit 17, is controlled by the arithmetic and control unit 26 of the surveying device 2, but a separate arithmetic and control unit may be provided in the imaging device 8, and the guide light irradiating unit 16 and the imaging unit 17 may be controlled by the arithmetic and control unit.

[0074] In the first embodiment, the surveying device 2 is configured to automatically start tracking the prism 13 when the prism 13 is transported within the irradiation range of the tracking light. On the other hand, the position when the measurement data is received by the terminal device 15 may be determined to be the position of the distance measurement light axis 12, and the target pole 3 may be transported to the installation point 4 while maintaining the positional relationship between the prism 13 and the distance measurement light axis 12. In this case, the tracking unit 20 may be omitted.

[0075] Furthermore, in the first embodiment, the guide light irradiating unit 16 is arranged on the transmission side of the beam splitter 34, and the imaging unit 17 is arranged on the reflection side, but it goes without saying that the imaging unit 17 may be arranged on the transmission side, and the guide light irradiating unit 16 may be arranged on the reflection side.

[0076] Next, a second embodiment of the present invention will be described with reference to Fig. 4. In Fig. 4, the same components as those in Fig. 3 are given the same reference numerals, and the description thereof will be omitted.

[0077] 4 shows the configuration of an imaging device 41. In the second embodiment, a prism 42 is used as the deflection optical element. The prism 42 is a square prism formed by bonding two triangular prisms together, and a beam splitter film 43 is provided on the bonding surface between the triangular prisms. Similar to the beam splitter 34 in the first embodiment, the beam splitter film 43 has the optical property of transmitting 50% of the incident light and reflecting 50%.

[0078] In the second embodiment, the image capturing unit 17 is disposed on the transmission side of the prism 42, and the guide light emitting unit 44 is disposed on the reflection side.

[0079] The guide light irradiation unit 44 has a light source 46 provided on a guide light axis 45, a spectroscopic plate 47, the prism 42, a light projecting / receiving lens group 35 provided on the reflected light axis of the beam splitter film 43, and a window portion 36. The guide light axis 45 and the guide light axis 45 reflected by the beam splitter film 43 are collectively referred to as the guide light axis 45.

[0080] The light source 46 is a broadband light source that emits light having a broad band of wavelengths including red visible light and blue visible light, and is, for example, an LED that emits white light in the visible light range.

[0081] The spectral plate 47 is a plate made of a transparent material, such as glass, and has color-producing elements 48 formed on the exit surface of the spectral plate 47 from which the white light enters. The color-producing elements 48 are located on the optical path of the white light and are larger than the luminous flux of the white light. Therefore, the white light that has passed through the spectral plate 47 enters the prism 42 as guide light 49.

[0082] 5, the coloring element 48 has optical characteristics in which the spectral transmittance differs between regions 48a and 48b on the left and right of a boundary 48c through which the guide optical axis 45 passes. As the coloring element 48, for example, a dichroic film evaporated on the spectral plate 47 is used.

[0083] The color-producing element 48 is a dichroic film, and for example, the left region 48a is not provided with a dichroic film or is provided with an AR (Anti-Reflection) coating, while the right region 48b is vapor-deposited with a dichroic film having a spectral transmission wavelength of 350 nm to 450 nm (blue).

[0084] 6 shows an example of the relationship between the spectral characteristics of white light, the transmittance characteristics of the dichroic film in the region 48b, and the spectral characteristics of the second guide light 49b after passing through the dichroic film. In FIG. 6, a solid line A shows the spectral characteristics of the white light, a dashed line B shows the transmittance characteristics of the dichroic film, and a dashed line C shows the spectral characteristics of the second guide light 49b after passing through the dichroic film.

[0085] The dichroic film of the region 48b transmits light with wavelengths of 350 nm to 450 nm, so the second guide light 49b transmitted through the region 48b is blue light. Although not shown, the region 48a is configured to transmit all white light, so the first guide light 49a transmitted through the region 48a is white light.

[0086] The white light emitted from the light source 46 is transmitted through the color-producing element 48 while passing through the spectral plate 47. Therefore, the white light is incident on the beam splitter film 43 of the prism 42 as two-color guide light 49, which is made up of the first guide light 49a of white light transmitted through the region 48a and the second guide light 49b of blue light transmitted through the region 48b across the boundary 48c.

[0087] The guide light 49 reflected by the beam splitter film 43 is deflected by the light projecting and receiving lens group 35 to a predetermined divergence angle, and is irradiated toward the staking point 4 .

[0088] The guide light 49 irradiated to the measurement point 4 is configured so that the first guide light 49a is white on the left side and the second guide light 49b is blue on the right side, and the boundary between the first guide light 49a and the second guide light 49b indicates the position of the guide light axis 45.

[0089] In the process of guiding the surveying worker during the surveying work, if the surveying worker recognizes the guide light 49 as white, it can be determined that he is on the left side of the surveying point 4, and the worker can be guided to the surveying point 4 by moving to the right. Similarly, if the surveying worker recognizes the guide light 49 as blue, it can be determined that he is on the right side of the surveying point 4, and the worker can be guided to the surveying point 4 by moving to the left. The surveying work is carried out until the surveying worker recognizes the guide light 49 as two-color light, white and blue, and the prism 13 (see FIG. 1) is within the irradiation range of the tracking light.

[0090] In this embodiment, a dichroic film is deposited only on the region 48b, but dichroic films with different transmittance characteristics may be formed on the region 48a and the region 48b. For example, a dichroic film with a spectral transmission wavelength of 650 nm to 750 nm (red) may be formed on the region 48a. In this case, the guide light 49 becomes two-color light consisting of the first red guide light 49a and the second blue guide light 49b.

[0091] In the second embodiment as well, the light projecting and receiving lens group 35 is located on the common optical path of the image capturing unit 17 and the guide light irradiating unit 44, so there is no need to provide lenses for the image capturing unit 17 and the guide light irradiating unit 44, and the number of parts is reduced, which leads to a reduction in manufacturing costs and a miniaturization of the optical system.

[0092] In the second embodiment, the color-producing element 48, which is, for example, a dichroic film, generates the two-color guide light 49 from the broadband white light emitted from the single light source 46.

[0093] Therefore, since there is no need to use two light sources to generate the two-color guide light 49, the number of parts can be reduced, the manufacturing cost can be reduced, and the optical system can be made smaller.

[0094] In the second embodiment, the imaging unit 17 is arranged on the transmission side of the beam splitter film 43, and the guide light irradiating unit 44 is arranged on the reflection side, but the guide light irradiating unit 44 may be arranged on the transmission side, and the imaging unit 17 may be arranged on the reflection side.

[0095] Next, a third embodiment of the present invention will be described with reference to Fig. 7. In Fig. 7, the same components as those in Fig. 3 are given the same reference numerals, and the description thereof will be omitted.

[0096] The guide light irradiating unit 51 has a guide light axis 52. The guide light irradiating unit 51 also has, in order from the light-emitting side, a light source 53 provided on the guide light axis 52, a light-emitting / receiving prism 54, and a group of light-emitting / receiving lenses 55 provided on the reflected light axis of the light-emitting / receiving prism 54. The guide light axis 52 and the guide light axis 52 reflected by the light-emitting / receiving prism 54 are collectively referred to as the guide light axis 52.

[0097] The light source 53 is a broadband light source that emits light having a wide band of wavelengths, and is, for example, an LED that emits white light that includes light in the visible light range, such as red light, blue light, and green light.

[0098] The light projecting and receiving prism 54 is a pentagonal prism formed by joining a first prism 56 having a rectangular cross section and a second prism 57 having a right-angled isosceles triangular cross section. The light projecting and receiving prism 54 is configured to internally reflect the guide light 58 and deflect it in a required direction.

[0099] The light projecting and receiving lens group 55 is a convex lens group that combines, for example, a plano-concave lens that is made up of a flat surface and a concave curved surface, and a convex lens, and is configured to deflect the guide light 58 so that it is diffused at a predetermined spread angle. The light projecting and receiving lens group may be a convex lens group, and may be a combination of a concave lens and a convex lens, or a combination of convex lenses.

[0100] The imaging unit 17 also has a light receiving element 38 arranged on the imaging optical axis 21, an imaging lens 59, and the light projecting and receiving prism 54, as well as the light projecting and receiving lens group 55 arranged on the imaging optical axis 21 reflected by the light projecting and receiving prism 54.

[0101] In this embodiment, the imaging optical axis 21 and the imaging optical axis 21 reflected by the light projecting and receiving prism 54 are collectively referred to as the imaging optical axis 21. The imaging optical axis 21 is deflected by the light projecting and receiving prism 54 so as to coincide with the guide optical axis 52. That is, the light projecting and receiving prism 54 and the light projecting and receiving lens group 55 are located on a common optical path of the guide light irradiating unit 51 and the imaging unit 17. The imaging unit 17 is configured so that external light (background light) is incident along the imaging optical axis 21 coaxially with the guide light 58 irradiated along the guide optical axis 52.

[0102] The imaging lens 59 is a lens having, for example, a concave curved surface on the surface facing the light projecting and receiving prism 54 and a convex curved surface on the surface facing the light receiving element 38. By using the front light projecting and receiving lens group 55 and the rear light projecting and receiving lens group 59 as a camera lens, the imaging unit 17 becomes a camera having a telephoto type lens (telephoto lens). The imaging lens 59 may be a concave lens group in which a plurality of lenses are cemented together to have a concave curved surface, or may be a concave lens group made up of a plurality of lenses including at least one concave lens.

[0103] The imaging unit 17 is configured to acquire an image from external light incident coaxially with the guide light axis 52 when the guide light irradiating unit 51 is not irradiating the guide light 58, and the angle (field angle) of the external light incident on the light emitting / receiving lens group 55 is larger than the field angle (e.g., 1° to 3°) of the tracking unit 20 (see FIG. 2). That is, the guide light irradiating unit 51 and the imaging unit 17 are used alternatively, and the image acquired by the imaging unit 17 is stored in a storage unit 27 (see FIG. 2) and transmitted to the terminal device 15 (see FIG. 1).

[0104] Next, a detailed description will be given of the light projecting and receiving prism 54. In Fig. 7, the right side of the paper surface will be referred to as the right side, and the left side of the paper surface will be referred to as the left side.

[0105] The first prism 56 has a first surface 56a facing the light source 53, on which white light from the light source 53 is incident as the guide light 58 via a color-emitting element 61 (described later), a second surface 56b facing the first surface 56a, on which the guide light 58 that has passed through the first surface 56a is incident, a third surface 56c formed between the left end of the first surface 56a and the left end of the second surface 56b, on which the guide light 58 that has been internally reflected by the second surface 56b is incident, and a fourth surface 56d facing the third surface 56c, formed between the right end of the first surface 56a and the right end of the second surface 56b.

[0106] The second prism 57 has the same area as the third surface 56c, a first surface 57a that is joined to the third surface 56c, a second surface 57b that serves as a guide light reflecting portion onto which the guide light 58 that has passed through the first surface 57a is incident, and a third surface 57c that is formed between the first surface 57a and the second surface 57b.

[0107] The first surface 56a is configured to be perpendicular to the guide light axis 52, and the guide light 58 is incident at a right angle, that is, an incident angle of 0°, on the first surface 56a.

[0108] The second surface 56b faces the first surface 56a and deflects the guide optical axis 52 so that the guide light 58 is incident at a right angle, that is, an incident angle of 0°, on the light projecting and receiving lens group 55. In addition, the incident angle of the guide light 58 with respect to the second surface 56b is small, and the angle formed by the guide optical axis 52 and the guide optical axis 52 reflected by the second surface 56b is an acute angle.

[0109] The third surface 56c, which is the bonding surface with the second prism 57, is inclined at, for example, 45° with respect to the guide optical axis 52 deflected by the second surface 56b, and a beam splitter film 62 serving as a deflection optical member is vapor-deposited on the surface. The beam splitter film 62 has optical properties such as transmitting 50% of visible light and reflecting 50% of the visible light, and is located at the intersection of the guide optical axis 52 and the imaging optical axis 21. Therefore, the beam splitter film 62 transmits 50% of the guide light 58 incident on the third surface 56c and reflects 50% of external light incident on the third surface 56c at a right angle toward the third surface 57c.

[0110] The second surface 57b is perpendicular to the guide light axis 52 that has passed through the beam splitter film 62 and entered the second prism 57. Therefore, the second surface 57b is configured so that the guide light 58 is incident at a right angle, that is, an incident angle of 0°, and exits from the second prism 57. That is, the second surface 57b serves as an exit surface for the guide light 58.

[0111] Furthermore, the coloring elements 61 are formed on the first surface 56a of the first prism 56. The coloring elements 61 are located on the optical path of the white light emitted from the light source 53 and are larger than the luminous flux of the white light. Therefore, the white light passes through the coloring elements 61 on its way to the first surface 56a, and the white light that has passed through the coloring elements 61, i.e., the guide light 58, is incident on the first surface 56a.

[0112] 8, the coloring element 61 has optical characteristics in which the spectral transmittance differs between regions 61a and 61b on the left and right sides of a boundary 61c through which the guide optical axis 52 passes. As the coloring element 61, for example, a dichroic film vapor-deposited on the first surface 56a is used.

[0113] In addition, in Figure 7, the color-emitting element 61 is provided at the focal position of the light-emitting and receiving lens group 55, and the light source 53 is provided near the focal position, but the light source 53 may be provided at the focal position of the light-emitting and receiving lens group 55, and the color-emitting element 61 may be provided near the focal position.

[0114] The color-producing element 61 is a dichroic film, and the spectral transmission wavelength of the left region 61a is set to 650 nm to 750 nm (red), and the spectral transmission wavelength of the right region 61b is set to 400 nm to 500 nm (blue).

[0115] The white light emitted from the light source 53 passes through the color-producing element 61 while entering the first prism 56. The transmittance characteristics of the dichroic film in the region 61b transmit wavelengths of 400 nm to 500 nm, and the transmittance characteristics of the dichroic film in the region 61a transmit wavelengths of 650 nm to 750 nm, so the white light that passes through the region 61a becomes the red first guide light 58a, and the white light that passes through the region 61b becomes the blue second guide light 58b. Therefore, the white light enters the first surface 56a of the first prism 56 as the two-color guide light 58 consisting of the red first guide light 58a and the blue second guide light 58b across the boundary 61c.

[0116] The guide light 58 incident on the first surface 56a is reflected by the second surface 56b toward the beam splitter film 62 and is incident on the beam splitter film 62 (the third surface 56c, the first surface 57a) at an incident angle of 45°. The guide light 58 transmitted through the beam splitter film 62 and incident on the second prism 57 is incident on the second surface 57b at a right angle, that is, at an incident angle of 0°, and is emitted from the light-emitting and receiving prism 54.

[0117] The guide light 58 emitted from the light projecting and receiving prism 54 passes through the light projecting and receiving prism 54 and is irradiated onto the measurement point 4 (see FIG. 1) as the guide light 58 having a predetermined spread angle.

[0118] The guidance process for the surveying worker during the surveying work is the same as in the first embodiment. First, with the surveying device 2 facing in any direction, the target pole 3 (see FIG. 1) is transported so that the prism 13 (see FIG. 1) is positioned at the center of the image by referring to the image acquired by the imaging unit 17. After that, the guide light emitting unit 51 is driven to emit the guide light 58 along the guide light axis 52 at a predetermined spread angle.

[0119] When the surveying worker recognizes the guide light 58 as red, he can determine that he is located to the left of the surveying point 4, and by moving to the right, he is guided to the surveying point 4. Similarly, when the surveying worker recognizes the guide light 58 as blue, he can determine that he is located to the right of the surveying point 4, and by moving to the left, he is guided to the surveying point 4. The surveying work is carried out until the surveying worker recognizes the guide light 58 as two-color light, red and blue, and the prism 13 (see FIG. 1) comes within the irradiation range of the tracking light. When the prism 13 comes within the irradiation range of the tracking light, the calculation control unit 26 starts tracking the prism 13, and measurement is carried out in parallel with the tracking, and the three-dimensional coordinates of the prism 13 are calculated in real time.

[0120] The calculation control unit 26 calculates the distance and direction from the target pole 3 to the surveying point 4 based on the measurement results of the prism 13, and the surveying worker transports the target pole 3 toward the surveying point 4 based on the distance and direction obtained from the surveying device 2.

[0121] In the third embodiment, the light projecting and receiving lens group 55 is also located on a common optical path between the image capturing unit 17 and the guide light irradiating unit 51, so there is no need to provide lenses for the image capturing unit 17 and the guide light irradiating unit 51. This reduces the number of parts, reduces manufacturing costs, and enables the optical system to be made more compact. Furthermore, the miniaturization of the optical system allows the guide light irradiating unit 51 and the image capturing unit 17 to be integrated into the same device.

[0122] Moreover, the imaging device 8 is configured to selectively use the guide light irradiating unit 51 and the imaging unit 17. Therefore, it is possible to prevent the guide light 58 reflected by a window (not shown) provided on the guide light axis 52 from being received by the light receiving element 38 as stray light, and it is possible to improve the accuracy of image acquisition.

[0123] Furthermore, since the distance measurement optical axis 12 (see FIG. 1) and the guide optical axis 52 are located on the boundary 58c of the guide light 58, the prism 13 (see FIG. 1) can be easily transported to the irradiation range of the distance measurement light.

[0124] In the third embodiment, the guide light irradiating unit 51 has the light projecting and receiving prism 54, which is configured to internally reflect the guide light 58 at an acute angle so that the guide light 58 is coaxial with the imaging optical axis 21. Therefore, there is no need to secure a space equivalent to the focal length of the light projecting and receiving lens group 55 in a direction parallel to the imaging optical axis 21 reflected by the light projecting and receiving prism 54 (horizontal direction), so that the optical system of the guide light irradiating unit 51 can be made compact, and the entire imaging device 8 can be made compact.

[0125] Furthermore, of the camera lens of the imaging unit 17, i.e., the light projecting and receiving lens group 55 and the imaging lens 59, only the light projecting and receiving lens group 55 is shared with the guide light irradiating unit 51. Therefore, the focal length can be made shorter than when the entire camera lens is shared with the guide light irradiating unit 51, so that the spread angle of the guide light 58 can be made larger and the optical system can be made even more compact.

[0126] Furthermore, by sharing only the light projecting and receiving lens group 55 of the camera lenses of the imaging unit 17 with the guide light irradiating unit 51 , a lens with a short back focus can be used as the imaging lens 59 .

[0127] In the third embodiment, after the surveying device 2 is directed in an arbitrary direction, the operator carries the target pole 3 toward the front of the surveying device 2 based on the image or the guide light 58, and starts automatic tracking. On the other hand, the surveying device 2 may be automatically directed toward the staking point 4 based on the input or stored three-dimensional coordinates of the staking point 4. In this case, after the target pole 3 is carried based on the image or the guide light 58 and automatic tracking is started, it is only necessary to carry the target pole 3 back and forth.

[0128] In the third embodiment, the region 61a and the region 61b are formed with dichroic films having different transmittance characteristics. On the other hand, either the region 61a or the region 61b, for example, the region 61a, may not be formed with a dichroic film or may only be formed with an AR coating. In this case, the guide light 58 becomes two-color light consisting of a white first guide light 58a and a blue second guide light 58b.

[0129] Next, a fourth embodiment of the present invention will be described with reference to Fig. 9. In Fig. 9, the same components as those in Fig. 7 are designated by the same reference numerals, and their description will be omitted.

[0130] In the fourth embodiment, a beam splitter 63 is used as the deflection optical member, which is disposed at the intersection of the guide optical axis 52 and the imaging optical axis 21. The beam splitter 63 has the optical property of transmitting 50% of the incident light and reflecting 50%. The transmission side of the beam splitter 63 serves as the guide light irradiation unit 51, and the reflection side of the beam splitter 63 serves as the imaging unit 17.

[0131] The guide light irradiating unit 51 has, in order from the light emitting side, a light source 53 provided on the guide light axis 52, a mirror 64 as a guide light reflecting unit, and the beam splitter 63 and a light projecting / receiving lens group 55 provided on the reflected light axis of the mirror 64. The guide light axis 52 and the guide light axis 52 reflected by the mirror 64 are collectively referred to as the guide light axis 52.

[0132] A coloring element 61 is formed on the mirror 64. As in the third embodiment, the coloring element 61 has a diameter larger than the beam diameter of the white light incident on the mirror 64. In the process of the white light being reflected by the mirror 64, it passes through the coloring element 61, and a guide light 58 consisting of two colors, for example, blue light and red light, is generated.

[0133] The guide light 58 is reflected by the mirror 64 toward the beam splitter 63, deflected as it passes through the beam splitter 63 to coincide with the imaging optical axis 21, deflected by the light projecting and receiving lens group 55 to a predetermined spread angle, and irradiated onto a predetermined staking point 4 (see FIG. 1). The other configurations are the same as those of the third embodiment.

[0134] In the fourth embodiment as well, the light projecting and receiving lens group 55 is arranged on the guide optical axis 52 and the imaging optical axis 21, and is configured to be shared by the guide light irradiating unit 51 and the imaging unit 17. Therefore, there is no need to provide lenses for the guide light irradiating unit 51 and the imaging unit 17, so the number of parts is reduced, which reduces manufacturing costs and enables the optical system to be made smaller. Furthermore, by making the optical system smaller, the guide light irradiating unit 51 and the imaging unit 17 can be integrally incorporated into the same device.

[0135] The guide light 58 (white light) is configured to be reflected by the mirror 64 toward the beam splitter 63. Therefore, there is no need to secure a space equivalent to the focal length of the light projecting and receiving lens group 55 in a direction (horizontal direction) parallel to the imaging optical axis 21 reflected by the beam splitter 63, and therefore it is possible to reduce the size of the optical system of the guide light irradiating unit 51 and the entire imaging device 8.

[0136] Next, a fifth embodiment of the present invention will be described with reference to Fig. 10. In Fig. 10, the same components as those in Fig. 7 are designated by the same reference numerals, and their description will be omitted.

[0137] In the fifth embodiment, the light projecting and receiving prism 65 is a quadrangular prism formed by joining a first prism 66 having a trapezoidal cross section and a second prism 57 similar to that of the third embodiment.

[0138] The first prism 66 has a first surface 66a facing the light source 53, a second surface 66b facing the first surface 66a, a third surface 66c serving as a guide light reflecting portion formed between the right end of the first surface 66a and the right end of the second surface 66b, and a fourth surface 66d facing the third surface 66c and formed between the left end of the first surface 66a and the left end of the second surface 66b.

[0139] The first surface 66a is configured to be perpendicular to the guide light axis 52 and to receive the guide light 58 at an incident angle of 0°. The first surface 66a is also formed with coloring elements 61 similar to those in the third embodiment, and as the white light emitted from the light source 53 enters, it passes through the coloring elements 61 and enters the first surface 66a as two-color guide light 58 of, for example, blue light and red light. That is, the first surface 66a serves as the incident surface for the guide light 58.

[0140] The second surface 66b is parallel to the first surface 66a and has a narrower horizontal width than the first surface 66a. Therefore, the third surface 66c is inclined downward in a direction approaching the light projecting and receiving lens group 55, and reflects the guide light 58 transmitted through the first surface 66a toward the light projecting and receiving lens group 55, for example, at a right angle.

[0141] The fourth surface 66d has the same area as the first surface 57a, and a beam splitter film 62 serving as a deflection optical member is vapor-deposited on the surface. The fourth surface 66d is inclined downward so as to move away from the light-emitting and receiving lens group 55, and is bonded to the first surface 57a. By bonding the fourth surface 66d and the first surface 57a, the first prism 66 and the second prism 57 are integrated, and the third surface 57c and the second surface 66b are flush with each other.

[0142] The white light emitted from the light source 53 passes through the color-emitting element 61 as it enters the first surface 66a, and enters the first prism 66 as guide light consisting of two colors, for example, blue light and red light.

[0143] The guide light 58 is reflected by the third surface 66c toward the beam splitter film 62 so as to coincide with the imaging optical axis 21, passes through the beam splitter film 62, is deflected by the light projecting and receiving lens group 55 so as to have a predetermined spread angle, and is irradiated onto a predetermined sizing point 4 (see FIG. 1). The other configurations are the same as those of the third embodiment.

[0144] In the fifth embodiment, the light projecting and receiving lens group 55 is also arranged on the guide light axis 52 and the imaging light axis 21, and is configured to be shared by the guide light irradiating unit 51 and the imaging unit 17. Therefore, there is no need to provide lenses for the guide light irradiating unit 51 and the imaging unit 17, so the number of parts is reduced, which reduces manufacturing costs and enables the optical system to be made smaller. Furthermore, by making the optical system smaller, the guide light irradiating unit 51 and the imaging unit 17 can be integrally incorporated into the same device.

[0145] The guide light 58 (white light) is configured to be deflected by the light projecting and receiving prism 65 toward the light projecting and receiving lens group 55. Therefore, there is no need to secure a space equivalent to the focal length of the light projecting and receiving lens group 55 in the direction parallel to the imaging optical axis 21 reflected by the beam splitter film 62 (horizontal direction), so that the optical system of the guide light irradiating unit 51 can be made compact, and the entire imaging device 8 can be made compact.

[0146] REFERENCE SIGNS LIST 1 Surveying system 2 Surveying device 3 Target pole 4 Surveying point 8 Imaging device 15 Terminal device 16 Guide light emitting unit 17 Imaging unit 18 Guide light axis 19 Guide light 21 Imaging light axis 26 Arithmetic control unit 32 First light source 33 Right-angle prism mirror 34 Beam splitter 35 Light-emitting and receiving lens group 37 Second light source 38 Light-receiving element

Claims

1. An imaging device having a guide light irradiation unit that irradiates two-color guide light along a guide light axis to indicate direction to a surveying worker, and an imaging unit that acquires an image based on external light incident along an imaging optical axis, wherein the guide light irradiation unit and the imaging unit are configured to have a deflection optical element that deflects either the guide light axis or the imaging optical axis so as to be coaxial with the other, and the guide light axis that is made coaxial by the deflection optical element, and a group of light projecting and receiving lenses provided on the imaging optical axis.

2. The imaging device of claim 1, wherein the guide light irradiation unit has a first light source that emits a first visible guide light, a second light source that emits visible light different from the first guide light, and a right-angle prism mirror that reflects the first guide light and the second guide light so that they each coincide or nearly coincide with the guide light axis, and is configured so that the guide light of two colors is generated from the first guide light and the second guide light with the guide light axis as a boundary by being reflected by the right-angle prism mirror.

3. The imaging device of claim 1, wherein the guide light irradiation unit has a light source that emits white light and a spectral plate on which color-producing elements having two regions with different spectral characteristics are formed, and the guide light of two colors, with the boundary between the two regions being the boundary, is generated from the white light by transmitting through the color-producing elements.

4. The imaging device according to claim 1, wherein the guide light irradiation section and the imaging section are configured to be used alternatively.

5. The imaging device according to claim 1, wherein said guide light emitting section further comprises a guide light reflecting section for reflecting said guide light toward said deflection optical member.

6. The imaging device according to claim 5, wherein said imaging section further comprises an imaging lens arranged on the light-receiving side of said deflection optical member, said light-projecting and receiving lens group and said imaging lens forming a telephoto lens.

7. The imaging device of claim 5, wherein the guide light irradiation section and the imaging section have a light projecting and receiving prism formed by joining two prisms, and the deflecting optical member is a beam splitter film formed on the joining surface of the two prisms.

8. The imaging device according to claim 5, wherein said deflection optical member is a beam splitter disposed at the intersection of said guide optical axis and said imaging optical axis.

9. The imaging device of claim 7, wherein the guide light irradiation section further has a light source that emits white light, the incident surface of the light projecting and receiving prism is perpendicular to the guide light axis, a coloring element having two regions with different spectral transmittances is formed on the surface, and the white light passes through the coloring element to generate the guide light of two colors with the boundary between the two regions as the boundary.

10. The imaging device of claim 8, wherein the guide light irradiation section has a light source that emits white light and a mirror that reflects the guide light toward the beam splitter, a coloring element having two regions with different spectral transmittances is formed on the mirror, and the white light is reflected by the coloring element onto the mirror, generating the guide light of two colors with the boundary between the two regions as the boundary.

11. A surveying system having a surveying device, a target pole capable of communicating with said surveying device, and an imaging device according to any one of claims 1 to 10 provided on said surveying device, wherein said target pole comprises a pole installed so that its lower end coincides with a predetermined measurement point, a prism provided at the upper end of said pole, and a terminal device provided midway on said pole, said surveying device comprising a distance measuring unit which irradiates a distance measuring light into a boundary surface which indicates the center of said guide light and determines the distance to said prism, a drive unit which rotates said surveying device horizontally and deflects the distance measuring light vertically to emit said distance measuring light in a predetermined direction, an angle measuring unit which detects the emission direction of said distance measuring light, and a calculation and control unit which controls said distance measuring unit, said drive unit, and said imaging device, wherein said calculation and control unit measures the prism located at the boundary between two colors of guide light, calculates the distance and direction from said prism to said measurement point, and transmits the calculation results to said terminal device.

Images