JP2017072465A - Optical system of surveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a light-receiving optical system and further to reduce the size of an optical system in a surveying device.SOLUTION: An optical system 1 of a surveying device, comprises: a light projection optical system 2 for emitting range finder light; and a light-receiving optical system 3 for receiving reflected range finder light 30 from a measuring object. The light projection optical system includes a light projection optical axis 5, a range finder light source 15 for emitting range finder light, and an optical path deflection member 11 provided on the light projection optical axis. The light projection optical axis is deflected by the optical path deflection member. The range finder light is emitted via the light projection optical axis to the measuring object. The light-receiving optical system has a light reception optical axis 21 passing through the optical path deflection member, and an image formation lens 22 provided on the light reception optical axis. A mirror 24 is provided on a transmitted optical axis of the image formation lens. A range finder light receiving part 26 is provided on an optical axis deflected by the mirror. The reflected range finder light from the measuring object passes through the image formation lens and the mirror, and is imaged on the range finder light receiving part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical system of a surveying instrument.

  The optical system used in the surveying instrument uses a large-diameter lens to secure the amount of received light at a long distance. For this reason, the optical system is large and has a heavy weight.

  FIG. 7 shows an optical system 41 of a light receiving unit conventionally used.

  An imaging optical member is constituted by a lens group 42 composed of a single lens or a plurality of lenses, and incident light is imaged on the light receiving surface 43 by the refractive action of the lens.

  The lens group 42 has a focal length f1, which is determined by the performance required of the optical system of the surveying instrument.

  Accordingly, the light receiving portion is sized to accommodate the lens group 42, and the length in the optical axis direction depends on the focal length f1.

  In recent years, the surveying instrument has been reduced in size and weight, but it has been difficult to reduce the size of the optical system due to restrictions on the size of the lens group 42 and the focal length f1.

US Patent Application Publication No. 2012/0262700

  The present invention is intended to reduce the size of the light receiving optical system and to further reduce the size of the optical system in the surveying instrument.

  The present invention is an optical system of a surveying instrument comprising a light projecting optical system that emits distance measuring light and a light receiving optical system that receives reflected distance measuring light from a measurement object, and the light projecting optical system includes: A projecting optical axis, a ranging light source that emits ranging light, and an optical path deflecting member provided on the projecting optical axis, the projecting optical axis being deflected by the optical path deflecting member, The distance light is emitted toward the measurement object via the light projecting optical axis, and the light receiving optical system has a light receiving optical axis that passes through the optical path deflecting member, and an imaging lens on the light receiving optical axis. Is provided, a mirror is provided on the transmission optical axis of the imaging lens, a distance measuring light receiving unit is provided on the optical axis deflected by the mirror, and the reflected distance measuring light from the measurement object is It relates to an optical system of a surveying instrument configured to form an image on the distance measuring light receiving unit through the imaging lens and the mirror.

  In the invention, the light projecting optical system includes an illumination light source that emits illumination light, the imaging lens is a perforated lens, and an optical path dividing member is provided on the light receiving optical axis. An imaging unit is provided on the transmitted optical axis of the imaging unit, and all or a part of the imaging unit is accommodated in the hole of the imaging lens, and the distance measuring light and the illumination light are measured through the optical path dividing member. The image pickup unit is directed to an optical system of a surveying instrument configured to receive reflected illumination light that has been emitted toward an object and transmitted through the optical path dividing member.

  In the invention, it is preferable that the light projecting optical system has an illumination light source that emits illumination light, the imaging lens is a perforated lens, and is placed on the light receiving optical axis with the imaging lens sandwiched on the object side. An optical path dividing member is provided, a light projecting part mirror is provided on the image forming side, an imaging part for receiving reflected illumination light is provided on the reflected optical axis of the optical path dividing member, and the reflected optical axis of the light projecting part mirror The present invention relates to an optical system of a surveying instrument on which the light projecting optical system is provided.

  Furthermore, in the present invention, a beam splitter is provided on the light receiving optical axis, the light projecting optical system is provided on the transmitted optical axis of the beam splitter, the imaging lens on the reflected optical axis of the beam splitter, The present invention relates to an optical system of a surveying instrument provided with the mirror and the ranging light receiving unit.

  According to the present invention, there is provided an optical system for a surveying instrument comprising a light projecting optical system for emitting distance measuring light and a light receiving optical system for receiving reflected distance measuring light from an object to be measured. The system includes a light projecting optical axis, a distance measuring light source that emits distance measuring light, and an optical path deflecting member provided on the projecting optical axis, and the projecting optical axis is deflected by the optical path deflecting member, The distance measuring light is emitted toward the measurement object via the light projecting optical axis, and the light receiving optical system has a light receiving optical axis that passes through the optical path deflecting member, and is connected to the light receiving optical axis. An image lens is provided, a mirror is provided on the transmission optical axis of the imaging lens, a distance measuring light receiving unit is provided on the optical axis deflected by the mirror, and the reflected distance measuring light from the measurement object Is formed so as to form an image on the distance measuring light receiving section through the imaging lens and the mirror. Is is shortened, there is exhibited an excellent effect that size reduction of the optical system becomes possible.

It is a schematic block diagram of the optical system which concerns on a 1st Example. It is a schematic block diagram of the optical system which concerns on a 2nd Example. (A) is a schematic block diagram of the optical system which concerns on a 3rd Example, (B) is A arrow line view of FIG. 3 (A). It is a schematic block diagram of the optical system which concerns on a 4th Example. It is a schematic block diagram of the optical system which concerns on a 5th Example. It is a schematic block diagram of the optical system which concerns on a 6th Example. It is the schematic of the light reception optical system of a prior art example. FIG. 6 is a transmission characteristic diagram of an optical filter provided in a tracking light-receiving and imaging light-receiving optical system.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of an optical system 1 of a first example of the present example, and shows a case where the optical system 1 is applied to a surveying instrument, for example, a laser scanner.

  The optical system 1 includes a light projecting optical system 2 and a light receiving optical system 3.

  The light projecting optical system 2 has a light projecting optical axis 5, and an illumination light source 6, a condenser lens 7, a first dichroic mirror 8, a second dichroic mirror 9, and a third dichroic mirror on the light projecting optical axis 5. 11 is provided. The light projecting optical axis 5 passes through the first dichroic mirror 8 and is deflected by the second dichroic mirror 9 and the third dichroic mirror 11.

  Each of the first dichroic mirror 8, the second dichroic mirror 9, and the third dichroic mirror 11 functions as an optical path dividing member that divides an optical path and also functions as an optical path deflecting member that deflects the optical path.

  A laser pointer light source 13 and a condenser lens 14 are provided on the reflected optical axis of the first dichroic mirror 8, and a distance measuring light source 15 and a condenser lens 16 are provided on the transmitted optical axis of the second dichroic mirror 9. Is provided.

  The first dichroic mirror 8 has an optical characteristic of transmitting the illumination light emitted from the illumination light source 6 and reflecting the laser pointer light emitted from the laser pointer light source 13.

  The second dichroic mirror 9 has an optical characteristic of reflecting the illumination light and the laser pointer light and transmitting the distance measuring light emitted from the distance measuring light source 15.

  The third dichroic mirror 11 has an optical characteristic that reflects the laser pointer light and the distance measuring light and is a half mirror for the illumination light.

  The light projecting optical axis 5 deflected by the third dichroic mirror 11 is further deflected by a rotating mirror 18, and the deflected optical axis extends as a distance measuring optical axis 19 toward the measurement object.

  The rotating mirror 18 rotates about the light projecting optical axis 5 as a rotation center.

  The light receiving optical system 3 has a light receiving optical axis 21. The light receiving optical axis 21 is common to the distance measuring optical axis 19, and from the rotating mirror 18 to the third dichroic mirror 11 is common to the light projecting optical axis 5.

  A first imaging lens 22, a lens 23, and a mirror 24 as a deflection member are provided on the light receiving optical axis 21. On the optical axis deflected by the mirror 24, a second imaging lens 25 and a distance measuring light receiving unit 26 are provided.

  With the cooperation of the first imaging lens 22, the lens 23, and the second imaging lens 25, an incident light beam is imaged on the distance measuring light receiving unit 26. The second imaging lens 25 can be omitted if the first imaging lens 22 and the lens 23 form an image of the light flux on the distance measuring light receiving unit 26.

  A hole 22a is provided at the center of the first imaging lens 22, and the first imaging lens 22 is a perforated lens. The size of the hole 22a is equal to the light beam portion blocked by the third dichroic mirror 11.

  An imaging unit 27 is provided on the light receiving optical axis 21 that has passed through the third dichroic mirror 11. The imaging unit 27 includes an imaging lens 28 and an imaging element 29. All or part of the imaging unit 27 is accommodated in the hole 22a.

  The operation of the first embodiment will be described.

  The ranging light source 15 emits visible or invisible laser light as ranging light, the ranging light is transmitted through the second dichroic mirror 9 and reflected by the third dichroic mirror 11; Further, the light is reflected by the rotating mirror 18 and emitted to the measurement object.

  The rotating mirror 18 rotates in the vertical direction, and the entire optical system 1 rotates in the horizontal direction, so that the distance measuring light is scanned in a required range.

  Ranging light reflected by the measurement object (hereinafter, reflected ranging light 30) is incident through the rotating mirror 18, reflected by the rotating mirror 18, and incident on the first imaging lens 22. The reflected distance measuring light 30 transmitted through the first imaging lens 22 and the lens 23 is reflected by the mirror 24 and forms an image on the distance measuring light receiving unit 26 through the second imaging lens 25. At this time, the reflected distance measuring light 30 is shielded by the third dichroic mirror 11, the imaging unit 27, etc., but the shielding is limited to the central part, so that measurement is not affected.

  Based on the light receiving signal from the distance measuring light receiving unit 26, the distance to the measurement object is measured.

  Laser pointer light is emitted from the laser pointer light source 13. As the laser pointer light, light having a wavelength that is easy to visually recognize, such as red and green, is used so that the laser pointer light can be visually recognized.

  The laser pointer light is reflected by the first dichroic mirror 8, the second dichroic mirror 9, and the third dichroic mirror 11, and further reflected by the rotating mirror 18 on the distance measuring optical axis 19. The measurement point is irradiated with the same optical axis as the optical axis 19.

  By irradiating the laser pointer light with the same optical axis as the distance measuring optical axis 19, the measurement point and the irradiation point of the laser pointer light coincide with each other, and the measurement point and the measurement location can be easily recognized.

  Further, when a corner cube is used as a measurement object and tracking is performed, illumination light is emitted from the illumination light source 6. The illumination light passes through the first dichroic mirror 8, is reflected by the second dichroic mirror 9 and the third dichroic mirror 11, and is emitted onto the distance measuring optical axis 19 through the rotating mirror 18.

  The illumination light reflected by the corner cube passes through the distance measuring optical axis 19 and the light projecting optical axis 5, passes through the third dichroic mirror 11, and is imaged on the image sensor 29 by the imaging lens 28. The

  The imaging device 29 can detect the light receiving position of the reflected light. The image sensor 29 is, for example, an aggregate of pixels, such as a CCD or CMOS sensor, and each pixel can specify a light receiving position. Further, the distance measuring light is set so that the light receiving optical axis 21 passes through the center of the image pickup device 29, the deviation between the light receiving optical axis 21 and the light receiving position is detected, and the deviation is set to zero. Tracking can be performed by making the shaft 19 follow the corner cube.

  As described above, in the optical system 1 of the first embodiment, the mirror 24 is used as an optical element of the distance measuring light receiving optical system, and the light receiving optical axis 21 is deflected by the mirror 24 (illustrated). In this case, it is deflected in a right angle direction. Since the light receiving optical axis 21 is deflected by the mirror 24, the linear length of the light receiving optical axis 21 is shortened.

  Therefore, as is clear from the conventional light receiving optical system shown in FIG. 7, the depth of the light receiving optical system is significantly shortened, and the optical system can be downsized.

  In the short distance measurement of the non-prism, the reflected distance measuring light 30 becomes out-focused light, and the amount of light collected on the distance measuring light receiving unit 26 is reduced, but the first imaging lens 22 or the second light is reduced. By changing the curvature of the periphery of the imaging lens 25 so that the out-focused light is condensed on the distance measuring light receiving unit 26, the reflected distance measuring light 30 necessary for measurement even at a short distance. The amount of light can be secured.

  If the optical system 1 of the first embodiment is provided in a surveying instrument other than a laser scanner, for example, a total station, the rotating mirror 18 is omitted.

  FIG. 2 shows a second embodiment. 2 that are the same as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

  In the second embodiment, the arrangement of the imaging unit 27 is changed. The configuration in which the mirror 24 is used as the optical element of the light receiving optical system for the distance measuring light and the light receiving optical axis 21 is deflected by the mirror 24 is the same as in the first embodiment.

  A light projecting mirror 31 as an optical path deflecting member is disposed on the light receiving optical axis 21 and between the first imaging lens 22 and the lens 23. The light projecting optical axis 5 is deflected in a right angle direction by the light projecting mirror 31, and the deflected light projecting optical axis 5 matches the light receiving optical axis 21 and enters the rotating mirror 18. The light projecting optical system 2 is provided on the light projecting optical axis 5 in the same manner as in the first embodiment.

  A third dichroic mirror 11 is provided between the rotating mirror 18 and the first imaging lens 22 on the light projecting optical axis 5 (the light receiving optical axis 21). The imaging unit 27 is provided on the optical axis branched by the third dichroic mirror 11. The light projecting mirror 31 is a total reflection mirror, and the third dichroic mirror 11 transmits distance measuring light and laser pointer light, and is a half mirror for illumination light.

  Also in the second embodiment, the light receiving optical axis 21 is deflected by the mirror 24, and the linear length of the light receiving optical axis 21 is shortened.

  When the tracking function is not necessary, the third dichroic mirror 11 and the imaging unit 27 are omitted.

  3 (A) and 3 (B) show a third embodiment. 3A and 3B, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In the third embodiment, a normal lens without a hole is used as the first imaging lens 22. Further, the arrangement of the light projecting optical system 2 and the imaging unit 27 is changed.

  On the light receiving optical axis 21, a light projecting mirror 31 is provided between the rotary mirror 18 and the first imaging lens 22. A third dichroic mirror 11 as an optical path dividing member is provided on the reflection optical axis of the light projecting mirror 31.

  The third dichroic mirror 11 reflects the distance measuring light and the laser pointer light, and has optical characteristics of partially transmitting and partially reflecting the illumination light.

  The imaging unit 27 is provided on the optical axis that passes through the third dichroic mirror 11. The optical axis divided by the third dichroic mirror 11 and deflected in the direction perpendicular to the paper surface in FIG. 3A is a light projecting light axis 5. A projection optical system 2 is provided on the top.

  The projection optical system 2 is disposed outside the optical path of the reflected distance measuring light 30 so as not to block the reflected distance measuring light 30.

  Also in the third embodiment, the light receiving optical axis 21 is deflected by the mirror 24, and the linear length of the light receiving optical axis 21 is shortened.

  FIG. 4 shows a fourth embodiment. 4 that are the same as those shown in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted. The fourth embodiment is a modification of the third embodiment.

  A light projecting mirror 31 is provided between the rotating mirror 18 and the first imaging lens 22, and the third dichroic mirror 11 is provided on the reflection optical axis of the light projecting mirror 31. The third dichroic mirror 11 is a half mirror for illumination light and is totally reflected for laser pointer light and distance measuring light.

  The light projecting optical axis 5 of the light projecting optical system 2 is parallel to the light receiving optical axis 21 and is deflected by the third dichroic mirror 11 and the light projecting part mirror 31 to match the light receiving optical axis 21. The light is deflected by the rotating mirror 18 and extends in the measurement direction as a distance measuring optical axis 19.

  An imaging unit 27 is provided on the optical axis that passes through the third dichroic mirror 11. The reflected light of the illumination light is transmitted through the third dichroic mirror 11 and received by the imaging unit 27.

  Tracking is performed based on the reflected light received by the imaging unit 27.

  FIG. 5 shows a fifth embodiment. 5 that are the same as those shown in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted. The fifth embodiment is a further modification of the fourth embodiment.

  In the fifth embodiment, a light projecting mirror 31 is provided on the light receiving optical axis 21, and the third dichroic mirror 11 is provided between the light projecting mirror 31 and the rotating mirror 18.

  An imaging unit 27 is provided on the optical axis divided by the third dichroic mirror 11 at right angles to the light receiving optical axis 21. The optical axis deflected by the light projecting mirror 31 is a light projecting optical axis 5, and the light projecting optical system 2 is provided on the light projecting optical axis 5.

  FIG. 6 shows a sixth embodiment. In FIG. 6, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted.

  In the sixth embodiment, a beam splitter 35 is disposed to face the rotating mirror 18. The beam splitter 35 has optical characteristics as a beam splitter only at the center, and the other part is a simple glass plate.

  The reflected optical axis of the beam splitter 35 is a light receiving optical axis 21, and the light receiving optical axis 21 is deflected in a right angle direction by the beam splitter 35. A light receiving optical system 3 is provided on the light receiving optical axis 21 deflected by the beam splitter 35. A mirror 24 which is an optical element of the light receiving optical system 3 further deflects the light receiving optical axis 21 by 90 °. Accordingly, the light receiving optical axis 21 is deflected by 180 ° by the beam splitter 35 and the mirror 24.

  The optical axis that passes through the beam splitter 35 is the light projecting optical axis 5, and the light projecting optical system 2 is provided on the light projecting optical axis 5. In the sixth embodiment, the laser pointer light projecting portion is omitted.

  A second dichroic mirror 9 is provided on the light projection optical axis 5, an illumination light source 6 and a condenser lens 7 are provided on the transmission optical axis of the second dichroic mirror 9, and reflected light of the second dichroic mirror 9. A ranging light source 15 and a condenser lens 16 are provided on the axis. The second dichroic mirror 9 has an optical characteristic of transmitting illumination light and reflecting distance measuring light.

  A third dichroic mirror 11 is provided on the light receiving optical axis 21 between the rotating mirror 18 and the beam splitter 35. The third dichroic mirror 11 is a half mirror for illumination light, and an imaging unit 27 is provided on the reflected optical axis of the third dichroic mirror 11.

  In the sixth embodiment, since the light receiving optical axis 21 is deflected twice by the beam splitter 35 and the mirror 24, the linear length of the light receiving optical axis 21 is further shortened.

  Next, in the first to sixth embodiments, the imaging unit 27 may be provided with the following optical filters.

  The RGB sensitivity of a light receiving sensor provided in a commonly used camera is as shown in FIG.

  Although the wavelength of visible light is 400 nm to 700 nm, the light receiving sensor has sensitivity also in the infrared region, and particularly in the wavelength range of 810 nm to 840 nm, although the sensitivity is low, RGB has the same sensitivity.

  When infrared light having a wavelength of, for example, 810 nm to 840 nm is used as illumination light for tracking using this characteristic, the transmission characteristic indicated by a curve 49 in FIG. 7, that is, a wavelength in the visible region is transmitted and 810 nm to A filter that transmits a wavelength in the range of 840 nm is created, and the filter is provided at a required position of the imaging unit 27.

  By providing this filter, an image having a natural color can be acquired from the image pickup element 29 and the reflected reflected light (infrared light) can be received. Accordingly, tracking can be performed based on the signal from the image sensor 29.

  The dichroic mirror may be a beam splitter, or a part of the wavelength region may be a dichroic mirror and a part may be an optical element having the characteristics of a beam splitter.

  The light receiving optical system may use a single aspheric lens.

DESCRIPTION OF SYMBOLS 1 Optical system 2 Light projection optical system 3 Light reception optical system 5 Light projection optical axis 6 Illumination light source 7 Condensing lens 11 3rd dichroic mirror 13 Light source for laser pointers 14 Condensing lens 15 Ranging light source 16 Condensing lens 18 Rotating mirror DESCRIPTION OF SYMBOLS 19 Distance measuring optical axis 21 Light receiving optical axis 22 1st imaging lens 24 Mirror 26 Distance measuring light-receiving part 27 Image pick-up part 29 Image pick-up element 30 Reflective distance measuring light 31 Light projection part mirror 35 Beam splitter

Claims (4)

  An optical system of a surveying instrument comprising: a light projecting optical system that emits distance measuring light; and a light receiving optical system that receives reflected distance measuring light from a measurement object, the light projecting optical system comprising: An optical path deflecting member provided on the projecting optical axis, the projecting optical axis is deflected by the optical path deflecting member, and the ranging light is The light is emitted toward the measurement object via a light projecting optical axis, the light receiving optical system has a light receiving optical axis that passes through the optical path deflecting member, and an imaging lens is provided on the light receiving optical axis, A mirror is provided on the transmission optical axis of the imaging lens, a ranging light receiving unit is provided on the optical axis deflected by the mirror, and the reflected ranging light from the measurement object is the imaging lens, An optical system of a surveying instrument configured to form an image on the ranging light receiving unit through the mirror.   The projection optical system includes an illumination light source that emits illumination light, the imaging lens is a perforated lens, an optical path dividing member is provided on the light receiving optical axis, and the optical path dividing member is on a transmission optical axis The imaging unit is provided, and all or a part of the imaging unit is accommodated in the hole of the imaging lens, and the distance measuring light and the illumination light are emitted toward the measurement object through the optical path dividing member. The optical system of the surveying instrument according to claim 1, wherein the imaging unit is configured to receive reflected illumination light transmitted through the optical path dividing member.   The light projecting optical system includes an illumination light source that emits illumination light, the imaging lens is a perforated lens, and an optical path dividing member is provided on an object side of the light receiving optical axis with the imaging lens interposed therebetween. A projection mirror on the imaging side, an imaging unit for receiving reflected illumination light on the reflection optical axis of the optical path dividing member, and the projection on the reflection optical axis of the projection mirror. The optical system of a surveying instrument according to claim 1, further comprising an optical system.   A beam splitter is provided on the light receiving optical axis, the light projecting optical system is provided on the transmitted optical axis of the beam splitter, and the imaging lens, the mirror, and the distance measuring device are provided on the reflected optical axis of the beam splitter. The optical system of a surveying instrument according to claim 1, further comprising a light receiving unit.

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