JP2017072464A - 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 29 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 reflector 26 provided on the light reception optical axis. A range finder light receiving part 28 is provided on a reflection optical axis 21' of the image formation reflector. The reflected range finder light from the measuring object enters the image formation reflector via the light reception optical axis, is reflected by the image formation reflector, and 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. 6 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 object to be measured through 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 used for imaging on the light receiving optical axis. A reflecting mirror is provided, and a distance measuring light receiving unit is provided on a reflection optical axis of the imaging mirror, and the reflected distance measuring light from the measurement object passes through the light receiving optical axis and the imaging reflecting mirror. Is incident on the optical system of the surveying instrument configured to be reflected by the imaging reflecting mirror and imaged on the distance measuring light receiving unit. .

  According to the present invention, an imaging unit is provided on the light receiving optical axis between the optical path deflecting member and the imaging mirror, and the light projecting optical axis is a distance measuring light emitting optical system by an optical path dividing member, Divided into an illumination light emitting optical system, the distance measuring light is emitted from the distance measuring light emitting optical system, is emitted to the measurement object through the light projecting optical axis and the optical path deflecting member, and the illumination light emitting optical Illumination light emitted from the system is emitted to the measurement object via the light projecting optical axis and the optical path deflecting member, and reflected light from the measurement object is received by the optical system of the surveying instrument received by the imaging unit. It is concerned.

  According to the present invention, an optical path splitting member is provided on the incident side of the optical path deflecting member of the light projecting optical axis, an imaging unit is provided on one optical axis split by the optical path splitting member, and the other optical axis The present invention relates to an optical system of a surveying instrument on which the light projecting optical system is provided.

  According to the present invention, an optical path dividing member is provided on the exit side of the optical path deflecting member, an imaging unit is provided on the optical axis divided by the optical path dividing member, and the light projecting optical axis transmitted through the optical path dividing member The present invention relates to an optical system of a surveying instrument on which the light projecting optical system is provided.

  Furthermore, the present invention has an incident surface on which the reflected distance measuring light is incident, an exit surface on which the reflected distance measuring light exits, the incident surface, and a curved surface facing the exit surface, and the curved surface for imaging. The present invention relates to an optical system of a surveying instrument having a lens on which a reflecting mirror is formed.

  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 reflecting mirror is provided, and a distance measuring light receiving unit is provided on a reflection optical axis of the imaging reflecting mirror, and the reflected distance measuring light from the measurement object passes through the light receiving optical axis and is used for the imaging Since it is configured such that it enters the reflecting mirror, is reflected by the imaging reflecting mirror, and forms an image on the distance measuring light receiving unit, the light receiving optical axis is in front. Folded by the image-forming reflector, the shorter the linear length of the light receiving optical axis, there is exhibited an excellent effect that the miniaturization of the light receiving optical system can be reduced.

It is a schematic block diagram of the optical system which concerns on a 1st Example. (A) is a schematic block diagram of the optical system which concerns on a 2nd Example, (B) is A arrow line view of FIG. 2 (A). It is a schematic block diagram of the optical system which concerns on a 3rd Example. It is a schematic block diagram of the optical system which concerns on a 4th Example. It is explanatory drawing of the optical member used for the optical system which concerns on a 5th 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 and further rotates about the light receiving optical axis 21.

  The light receiving optical system 3 has the 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.

  An imaging lens 22 and an imaging device 23 are provided on the light receiving optical axis 21, and the imaging lens 22 and the imaging device 23 constitute an imaging unit 25.

  An imaging reflecting mirror 26 is provided on the light receiving optical axis 21, and an imaging lens 27 and a distance measuring light receiving unit 28 are provided on the reflecting optical axis 21 ′ of the imaging reflecting mirror 26. Further, the reflection angle of the reflected optical axis 21 'with respect to the received optical axis 21 is θ. The angle θ is set to an angle at which the light beam reflected by the imaging mirror 26 does not interfere with other components such as the imaging unit 25 and the rotary mirror 18. Preferably, θ is set to a minimum angle that does not interfere.

  The imaging mirror 26 is formed with a reflecting surface so as to form an image on the distance measuring light receiving unit 28 in cooperation with the imaging lens 27, and the reflecting surface is a paraboloid or a free-form surface. ing. Note that the imaging lens 27 may be omitted if the curved surface of the imaging mirror 26 is set so that the focusing light receiving unit 28 can be focused only by the imaging mirror 26.

  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.

  Distance measuring light reflected by the measurement object (hereinafter, reflected distance measuring light 29) is incident through the rotating mirror 18, reflected by the rotating mirror 18, and incident on the imaging reflecting mirror 26. The reflected distance measuring light 29 reflected by the imaging mirror 26 is imaged on the distance measuring light receiving unit 28 through the imaging lens 27. At this time, the reflected distance measuring light 29 is shielded by the third dichroic mirror 11, the imaging lens 22, and the like. However, the shielding is limited to the central portion, so that the measurement is not affected.

  Based on the light reception signal from the distance measuring light receiving unit 28, 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 23 by the imaging lens 22. The

  The image sensor 23 can detect the light receiving position of the reflected light. The image sensor 23 is, for example, an aggregate of pixels, and is 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 23, 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 imaging reflecting mirror 26 is used as an optical element of the ranging light receiving optical system, and the light receiving optical axis 21 is the image forming optical axis 21. The reflector 26 is folded back. Since the light receiving optical axis 21 is folded back by the imaging mirror 26, the linear length of the light receiving optical axis 21 is shortened.

  Accordingly, as is clear from the conventional light receiving optical system shown in FIG. 6, the depth of the light receiving optical system is significantly shortened, and the optical system can be miniaturized.

  In the short distance measurement of the non-prism, the reflected distance measuring light 29 becomes out-focused light, and the amount of light condensed on the distance measuring light receiving unit 28 is reduced. By changing the curvature of the peripheral portion of the lens 27 so that the out-focused light is condensed on the distance measuring light receiving unit 28, the light amount of the reflected distance measuring light 29 necessary for measurement even at a short distance. 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.

  FIGS. 2A and 2B show a second embodiment. 2A and 2B, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, the arrangement of the light projecting optical system 2 and the imaging unit 25 is changed. The imaging mirror 26 is used as an optical element of the ranging light receiving optical system, and the configuration in which the light receiving optical axis 21 is folded back by the imaging mirror 26 is the same as in the first embodiment. .

  A mirror 31 as an optical path deflecting member is disposed on the light receiving optical axis 21, and the light receiving optical axis 21 is deflected by the mirror 31 in a right angle direction. A third dichroic mirror 11 is disposed on the deflected optical axis 32 (that is, on the incident side of the mirror 31), and the light receiving optical axis 21 is further deflected in a perpendicular direction.

  The imaging unit 25 is provided on the optical axis 32 that has passed through the third dichroic mirror 11. The imaging unit 25 mainly includes an imaging lens 22 and an imaging element 23.

  The light projecting optical system 2 is provided on the light projecting optical axis 5 deflected by the third dichroic mirror 11. Since the projection optical system 2 is the same as that described in the first embodiment, the description thereof will be omitted below.

  In the second embodiment, since the optical axis 32 is deflected in a direction perpendicular to the light receiving optical axis 21, the length of the light receiving optical axis 21 is shortened by the optical axis 32 of the imaging unit 25. it can. That is, the distance between the rotating mirror 18 and the imaging reflecting mirror 26 can be shortened.

  FIG. 3 shows a third embodiment. In FIG. 3, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The third embodiment is an application of the second embodiment, and the third dichroic mirror 11 disposed on the light receiving optical axis 21 divides, deflects, and deflects the light receiving optical axis 21 in a right angle direction. The imaging unit 25 is disposed on the optical axis 32 with the optical axis as the optical axis 32.

  Further, a mirror 31 is disposed on the light projecting optical axis 5, and the light projecting optical axis 5 is deflected by the mirror 31. The deflected light projecting optical axis 5 passes through the third dichroic mirror 11 and coincides with the light receiving optical axis 21.

  The third dichroic mirror 11 functions as an optical path dividing member, transmits the light receiving optical axis 21 (the transmitted optical axis matches the light projecting optical axis 5), and deflects the light receiving optical axis 21 to The optical axis 32 is assumed. The optical axis 32 is parallel to the light projecting optical axis 5.

  In the third embodiment, the imaging unit 25 exists in the optical path of the reflected distance measuring light 29, and the reflected distance measuring light 29 is blocked by the imaging unit 25. The reflected distance measuring light 29 that is blocked by the imaging unit 25 is very small and does not hinder measurement.

  FIG. 4 shows a fourth embodiment. 4 that are the same as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

  In the fourth embodiment, the optical axis 32 deflected by the third dichroic mirror 11 is extended, and the imaging unit 25 is provided outside the optical path of the reflected distance measuring light 29.

  According to the fourth embodiment, since only the third dichroic mirror 11 and the mirror 31 block the reflected distance measuring light 29, the amount of the reflected distance measuring light 29 reaching the distance light receiving unit 28 is reduced. Increase.

  In the fourth embodiment, the laser pointer light source 13 and the optical system of the laser pointer light source 13 are omitted, but they may be added as in the third embodiment.

  FIG. 5 shows a fifth embodiment. In FIG. 5, only the imaging optical member 34 used in the light receiving optical system 3 is shown.

  The optical member 34 has a reflecting surface R2 corresponding to the reflecting surface of the imaging mirror 26, an incident surface R1 that intersects with the light receiving optical axis 21, and an exit surface R3 that intersects with the reflected optical axis 21 '. doing.

  In the optical member 34, the reflected distance measuring light 29 is imaged on the distance measuring light receiving unit 28 by the refracting action at the incident surface R 1 and the exit surface R 3 and the reflecting action at the reflecting surface R 2.

  In addition, by setting the peripheral portion of the incident surface R1 and the peripheral portion of the exit surface R3 to have a required curvature, the reflected distance measuring light 29 can be used even when the reflected distance measuring light 29 is out-of-focus in short distance measurement. The light can be condensed on the distance measuring light receiving unit 28, and the amount of the reflected distance measuring light 29 necessary for measurement can be secured even at a short distance.

  The imaging unit 25 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 25.

  By providing this filter, it is possible to acquire a natural color image from the image sensor 23 and to receive reflected reflected light (infrared light). Accordingly, tracking can be performed based on the signal from the image sensor 23.

  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 Ranging optical axis 21 Receiving optical axis 21 'Reflecting optical axis 22 Imaging lens 23 Imaging element 25 Imaging part 26 Imaging reflecting mirror 28 Ranging light receiving part 29 Reflecting ranging light 31 Mirror 32 Optical axis 34 Optical member

Claims (5)

  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-receiving optical system has a light-receiving optical axis that passes through the optical path deflecting member, and an imaging mirror is provided on the light-receiving optical axis. A distance measuring light receiving unit is provided on the reflection optical axis of the imaging reflecting mirror, and the reflected distance measuring light from the measurement object is incident on the imaging reflecting mirror through the light receiving optical axis, An optical system of a surveying instrument configured to be reflected by the imaging mirror and imaged on the distance measuring light receiving unit.   An imaging unit is provided on the light receiving optical axis between the optical path deflecting member and the imaging mirror, and the light projecting optical axis is a distance measuring light emitting optical system and an illumination light emitting optical system by an optical path dividing member. The distance measuring light is emitted from the distance measuring light emission optical system, emitted to the measurement object via the light projection optical axis and the optical path deflecting member, and emitted from the illumination light emission optical system The optical system of the surveying instrument according to claim 1, wherein light is emitted to the measurement object through the light projecting optical axis and the optical path deflecting member, and reflected light from the measurement object is received by the imaging unit. .   An optical path dividing member is provided on the incident side of the optical path deflecting member of the light projecting optical axis, an imaging unit is provided on one optical axis divided by the optical path dividing member, and the light projecting is provided on the other optical axis. The optical system of a surveying instrument according to claim 1, further comprising an optical system.   An optical path dividing member is provided on the exit side of the optical path deflecting member, an imaging unit is provided on the optical axis divided by the optical path dividing member, and the light projecting light is transmitted on the light projecting optical axis that has passed through the optical path dividing member The optical system of a surveying instrument according to claim 1, further comprising an optical system.   An incident surface on which the reflected distance measuring light is incident, an exit surface on which the reflected distance measuring light exits, the incident surface, and a curved surface facing the exit surface, and the imaging reflecting mirror is formed on the curved surface. The optical system of a surveying instrument according to claim 1, further comprising a lens.

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