Reflector and target device

Abstract

The present invention provides a reflector and target device that allows the corner cube prism to be installed at the measurement point or vertically above the measurement point without offsetting the measurement reference point. [Solution] The device includes a deflection optical member 5 provided on the incident optical axis 3 of the measurement light and reflecting the measurement light at least once, and a retroreflector 6 that retroreflects the measurement light on the reflected optical axis 3' of the deflection optical member, configured to form a virtual image of the optical center of the retroreflector on the extension of the incident optical axis.

Description

Technical Field

[0001] The present invention relates to a reflector used as a target when performing measurement and a target device including the reflector.

Background Art

[0002] When performing light wave measurement with a measuring device, a reflector as a target is provided at the measurement point.

[0003] The reflector includes a corner cube prism, and the corner cube prism retroreflects the measurement light from the measuring device. The measuring device receives the reflected measurement light and performs distance measurement, or angle measurement, or distance and angle measurement. Further, in a measuring device having a tracking function, the reflected measurement light is received to track the reflector.

[0004] In the case of a corner cube prism, the optical center, which is the measurement reference point, exists inside the corner cube prism. Also, in order to accurately measure the measurement point using the reflector, it is necessary to install the reflector so that the position of the optical center of the corner cube prism coincides with the measurement point.

[0005] Normally, the reflector is held by a holding device, and the holding device has a housing of the reflector, a pole to which the housing is attached, and a stone pier installed at the measurement point.

[0006] The optical center of the corner cube prism is the measurement reference point, and the optical center is inside the corner cube prism. Therefore, when the stone pier is provided at the lower end of the pole, the optical center is offset from the axis of the pole (see Patent Document 2). In this case, an angular error due to the offset occurs when the reflector is not facing the measuring device.

[0007] Also, when the stone pier is provided on the vertical line passing through the optical center, it is necessary to separate the stone pier and the pole (see Patent Document 3 and Patent Document 4). In this case, the support structure of the reflector becomes complicated. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2007-187857 [Patent Document 2] Japanese Utility Model Publication No. 59-34313 [Patent Document 3] Japanese Patent Publication No. 2018-21867 [Patent Document 4] Japanese Utility Model Publication No. 6-4614 [Patent Document 5] Patent No. 3551266 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention provides a reflector and target device that can be installed at a measurement point or vertically above a measurement point without offsetting the measurement reference point of a corner cube prism. [Means for solving the problem]

[0010] The present invention relates to a reflector comprising a deflection optical member provided on the incident optical axis of the measurement light and reflecting the measurement light at least once, and a retroreflector that retroreflects the measurement light on the reflected optical axis of the deflection optical member, wherein a virtual image of the optical center of the retroreflector is formed on the extension of the incident optical axis.

[0011] Furthermore, the present invention relates to a reflector having a housing for housing the deflection optical member and the retroreflector, wherein a window glass is provided on the incident surface of the housing.

[0012] Furthermore, the present invention relates to a reflector in which the retroreflector is a prism having retroreflective properties.

[0013] Furthermore, the present invention relates to a reflector in which the retroreflector is composed of three mirrors so as to have retroreflective properties.

[0014] Furthermore, the present invention relates to a reflector in which the deflection optical member is a mirror.

[0015] Furthermore, the present invention relates to a reflector in which the deflection optical member is a reflective prism.

[0016] Furthermore, the present invention relates to a reflector in which the deflection optical member includes a mirror and a reflective prism, and is configured to reflect and deflect the measurement light at least twice.

[0017] Furthermore, the present invention relates to a reflector in which the reflective prism has at least two reflective surfaces, and the measurement light is reflected and deflected at least twice by these at least two reflective surfaces.

[0018] The present invention also relates to a target device comprising any of the above-mentioned reflectors and a pole that holds the reflector, wherein the pole has a ferrule at its tip, and the virtual image is configured to be located on the axis of the pole.

[0019] Furthermore, the present invention relates to a target device in which the reflector is movably mounted relative to the pole.

[0020] Furthermore, the present invention relates to a target device having any of the above-mentioned reflectors and a housing that houses the reflector, wherein an indicator portion is provided on the rear wall of the housing, and the indicator portion has a tip that indicates the position of the virtual image.

[0021] Furthermore, the present invention has any one of the above reflectors, a housing for housing the reflector, and a pole having a stone protrusion at its tip. An engaging protrusion is formed on the rear wall of the housing, a recess is formed in the pole, the recess and the engaging protrusion can be fitted together, and the reflector is supported by the pole by fitting the recess and the engaging protrusion together, and the virtual image of the reflector is configured to be located on the axis of the pole. It relates to a target device configured as such.

Effect of the Invention

[0022] According to the present invention, there is provided a deflection optical member provided on the incident optical axis of measurement light and reflecting the measurement light at least once, and a retroreflector that retroreflects the measurement light on the reflection optical axis of the deflection optical member. Since the virtual image of the optical center of the retroreflector is formed on the extension of the incident optical axis, the measurement reference point of the reflector can be set as the virtual image position. Furthermore, the measurement reference position exists outside the optical member, and the excellent effect that the measurement reference position can be installed at the measurement point without offset is exhibited.

Brief Description of the Drawings

[0023] [Figure 1] It is an elevation view of the target device according to this embodiment. [Figure 2] It is a plan view of the main part of the target device of this embodiment. [Figure 3] It is a front view of the main part of the target device of this embodiment. [Figure 4] It is an explanatory diagram of the measurement of the measurement point by the target device according to this embodiment. [Figure 5] It is a plan view showing a first modification of the target device. [Figure 6] It is an elevation view showing a second modification. [Figure 7] It is an elevation view of the main part of the reflector of the second embodiment. [Figure 8] It is a schematic elevation view of the target device according to another embodiment. [Figure 9] It is a schematic elevation view of the target device according to the first modification of another embodiment. [Figure 10] This is a schematic elevation view of a target device relating to a second modification of another embodiment. [Figure 11] This is a schematic plan view of a target device relating to a third modification of another embodiment. [Figure 12] This is a schematic elevation view of a target device relating to a fourth modification of another embodiment. [Figure 13] This is a schematic elevation view of a target device relating to a fifth modification of another embodiment. [Figure 14] This is a schematic elevation view of a target device relating to a sixth modification of another embodiment. [Figure 15] (A), (B), and (C) show a seventh modification of another embodiment, where (A) and (C) are side views and (B) is a top view. [Figure 16] (A), (B), and (C) are explanatory diagrams showing an eighth modification of another embodiment. [Figure 17] (A) and (B) show the ninth modification, where (A) is a plan view of the reflector module and (B) is a perspective view of the pole. [Figure 18] This is a perspective view showing a modified version of the aforementioned pole. [Figure 19] This is a schematic elevation view of a target device relating to a tenth modification of another embodiment. [Figure 20] This is a schematic elevation view of a target device relating to an eleventh modification of another embodiment. [Figure 21] This is a schematic elevation view of a target device relating to a twelfth modification of another embodiment. [Figure 22] This is a schematic elevation view of a target device relating to a 13th modification of another embodiment. [Figure 23] This is a schematic elevation view of an optical member relating to a 14th modification of another embodiment. [Figure 24] This is a schematic elevation view of an optical member relating to the 15th modification of another embodiment. [Figure 25] (A) is a schematic side view of an optical member relating to the 16th modification of another embodiment, and (B) is a view in the direction of arrow A in (A). [Figure 26]This is a schematic plan view of an optical member relating to the 17th modified example of another embodiment. [Figure 27] This is a schematic plan view of an optical member relating to the 18th modified example of another embodiment. [Modes for carrying out the invention]

[0024] The embodiments of the present invention will be described below with reference to the drawings.

[0025] Figures 1 to 3 show a first embodiment of the present invention, where 1 is the target device, 2 is the reflector, and 3 is the incident optical axis of the reflector 2. Figure 1 is an elevation view of the target device 1, and Figures 2 and 3 are diagrams in which the housing 4, which will be described later, is omitted.

[0026] First, let me explain the reflector 2.

[0027] The reflector 2 includes a housing 4, which houses and holds optical components. These optical components include a mirror 5 and a corner cube prism 6, the corner cube prism 6 functioning as a retroreflector that retroreflects measurement light (see Figure 4) from a measuring device. The front surface of the housing 4 (the surface into which the measurement light enters) is open. The measurement light includes distance measuring light for measuring distance, measurement light for measuring angle, or tracking light for tracking the reflector 2.

[0028] The mirror 5, acting as a deflecting optical element, is positioned on the incident optical axis 3 and deflects the incident optical axis 3. The corner cube prism 6 is positioned on the deflected incident optical axis 3 (reflection optical axis 3').

[0029] The mirror 5 uses surface reflection, and the incident optical axis 3 is incident on the mirror 5 at a required angle. In the illustration, the measurement light is incident at 45° and reflected upward at 90°. The incident optical axis 3 is deflected upward by 90°, but the deflection angle does not have to be 90° and can be changed as appropriate, for example, depending on the shape of the housing 4.

[0030] The corner cube prism 6 is installed such that the reflected optical axis 3' passes through the optical center O of the corner cube prism 6.

[0031] Furthermore, prisms and mirrors with retroreflective properties can be used as retroreflectors. For example, in addition to the corner cube prism 6 with three orthogonal reflective surfaces (angles of the three reflective surfaces being 90°90°90°), there are prisms with angles of 90°90°90° / n (natural number) and 90°60°45°, and these prisms may be used as retroreflectors. Alternatively, three mirrors configured with angles of three reflective surfaces similar to those of the above-mentioned prisms, or the mirrors shown in Patent Document 5, may be used as retroreflectors.

[0032] The incident optical axis 3 is reflected and deflected by the mirror 5, forming an apparent optical center (a virtual image of the optical center; hereinafter referred to as virtual image O') on the extension of the incident optical axis 3. The distance between the reflection position (deflection position) R of the incident optical axis 3 and the optical center O is equal to the distance between the reflection position R and the position where the virtual image O' is formed.

[0033] When measuring the reflector 2, the virtual image O' can be used as the measurement reference point for the reflector 2.

[0034] The position where the virtual image O' is formed is a space where the mirror 5 and the corner cube prism 6 do not exist. Therefore, by providing a member or means at the position of the virtual image O' to transfer the virtual image O' to the measurement point, the optical center (measurement reference point) of the reflector 2 can be set to the measurement point directly or without offsetting.

[0035] Next, the target device 1 equipped with the reflector 2 will be described.

[0036] In the target device 1, the reflector 2 is mounted on a pole 8 and held by the pole 8. The pole 8 serves as a holding member for the reflector 2.

[0037] The pole 8 is inserted through the housing 4 from above and below, and the housing 4 is slidable relative to the pole 8. In the illustration, the pole 8 is provided so as to be inserted through the inside of the housing 4, but it may also be provided on the outside of the housing 4.

[0038] A ferrule 9 is provided at the lower end of the pole 8, and the tip of the ferrule 9 is positioned on the axis 10 of the pole 8. The ferrule 9 has a tapered shape, and its tip is pointed, concave, or spherical to facilitate the indication of the measurement point. Furthermore, the positional relationship between the pole 8 and the housing 4 is set such that the virtual image O' is positioned on the axis 10 of the pole 8.

[0039] Furthermore, the housing 4 is provided with a sliding fixing screw 11 that can contact the pole 8. When the sliding fixing screw 11 is loosened, the reflector 2 can slide along the pole 8, and by tightening the sliding fixing screw 11, the reflector 2 can be fixed to any position on the pole 8. Note that the pole 8 may be marked with a scale to check the distance from the tip of the ferrule 9.

[0040] A bubble tube 12 is provided on the upper surface of the housing 4 to check the verticality of the pole 8.

[0041] Figure 4 shows the case where a measurement point is measured using the target device 1. In Figure 4, 15 indicates the measuring device.

[0042] The measuring device 15 is installed at a known point, and the target device 1 is installed at the measurement point P.

[0043] When the target device 1 is placed at the measurement point P, the tip of the pole 9 is brought into contact with the measurement point P, and the direction of the incident optical axis 3 is directed toward the measuring device 15. The reflector 2 is set to a predetermined height, and once the vertical state of the pole 8 is confirmed by the bubble tube 12, the measurement is performed. Therefore, the pole 8 functions as an indicator that points to the measurement point.

[0044] At this time, even if the reflector 2 is not precisely facing the measuring device 15 and the measurement light is incident on the reflector 2 at an angle, the virtual image O' (measurement reference point) is located on the axis 10 of the pole 8, that is, the measurement reference point is vertically above the measurement point P, so no measurement error occurs.

[0045] Therefore, human error by operators is reduced, and measurement accuracy is improved without requiring operators to have a high level of skill.

[0046] Furthermore, since the pole 8 is simply a structure through which the reflector 2 is inserted, the structure of the target device 1 is simplified.

[0047] Figure 5 shows a first modified example of the target device 1, and Figure 5 is a plan view of the reflector 2. In Figure 5, components equivalent to those shown in Figure 1 are given the same reference numerals, and their descriptions are omitted.

[0048] The reflector 2 has the same configuration as in the above embodiment. In the first modified example, the reflector 2 is rotated 90° around the incident optical axis 3, and the incident optical axis 3 is deflected horizontally by the mirror 5.

[0049] The pole 8 is inserted vertically through the reflector 2, and its axis 10 passes through the virtual image O'. Therefore, in Figure 5, the pole 8 is perpendicular to the plane of the paper.

[0050] Figure 6 shows a second modified example. In this second modified example, a window glass 16 is provided on the front surface of the housing 4 (the incident surface of the measurement light). By providing the window glass 16, the mirror 5 and the corner cube prism 6 can be protected from dirt and deterioration.

[0051] The housing 4 has a sealed structure, and cleaning only requires removing dirt from the window glass 16. Alternatively, the window glass 16 may be made removable, allowing for cleaning of the mirror 5 and the corner cube prism 6.

[0052] Figure 7 shows the main parts of the reflector 17 of the second embodiment.

[0053] In the reflector 17, a reflective triangular prism 18 is used as the deflection optical element instead of the mirror 5. Note that structural members such as the housing 4 are omitted from the illustration in Figure 7.

[0054] The reflective triangular prism 18 has an incident surface 18a perpendicular to the incident optical axis 3, and the reflective surface 18b reflects and deflects the incident optical axis 3 at a predetermined angle. In the figure, the incident angle of the incident optical axis 3 with respect to the incident surface 18a is 45° and the deflection angle is 90°. The exit surface 18c is perpendicular to the reflected optical axis 3'.

[0055] A corner cube prism 6 is provided on the ejection surface 18c, and the optical center O of the corner cube prism 6 is set to be located on the reflected optical axis 3'. Furthermore, by providing the corner cube prism 6 on the reflected triangular prism 18, the optical center O'' of the composite of the corner cube prism 6 and the reflected triangular prism 18 shifts to the reflection position R side. In addition, a virtual image O' (measurement reference point) is formed on the extension of the incident optical axis 3 and at a position symmetrical with respect to the reflected surface 18b.

[0056] The reflector 17 is attached to the pole 8 such that the axis 10 of the pole 8 is perpendicular to the extension of the incident light axis 3.

[0057] Furthermore, the corner cube prism 6 may be attached to the emission surface 18c by joining them, by placing them in close contact, or by leaving a gap between them. If a gap is left, the corner cube prism 6 and the reflective triangular prism 18 become separate components, and the virtual image O' is formed on the extension of the incident optical axis 3 and at a position symmetrical with respect to the optical center O and the reflective surface 18b.

[0058] Furthermore, a reflective film may or may not be formed on the reflective surface.

[0059] In the second embodiment, further miniaturization is possible by using the reflective triangular prism 18.

[0060] In the above embodiment, a triangular pyramidal shape was used as the corner cube prism 6, but it is not limited to a triangular pyramidal shape, and a corner cube with cylindrical sides may also be used.

[0061] Furthermore, the corner cube is not limited to a triangular pyramidal shape; any optical component with retroreflective properties is acceptable.

[0062] Furthermore, the retroreflector doesn't necessarily have to be a prism; it could also be composed of three mirrors that reflect light from their surface.

[0063] Next, Figure 8 will describe a target device 21 according to another embodiment. In Figure 8, components equivalent to those shown in Figure 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0064] The target device 21 is designed to be installed without using a pole 8. In the target device 21, an indicator unit, which will be described later, is added to the reflector 2, and the device is configured to function as a target device.

[0065] In the target device 21, the housing 4 functions as a holder for the optical element and also functions as an indicator that indicates the position of the virtual image O', as will be described later.

[0066] The rear wall 4a on the non-incident side (rear side) of the housing 4 is made to protrude backward to form a projection, and a tip 24 is formed on the projection, and the tip 24 is set to be located on the extension of the incident optical axis 3, and the position of the tip 24 coincides with the virtual image O'. As for the method of forming the tip 24, as shown in Figure 8, the rear wall 4a may be made conical and its apex may be the tip 24, or a part of the rear wall 4a may be made to protrude and the tip 24 may be formed on the projection.

[0067] In this embodiment, the protruding portion and the tip 24 constitute the indicator portion.

[0068] Figure 9 shows a target device 21 according to the first modification of the other embodiment described above.

[0069] In the first modification, the shape of the rear wall 4a forming the tip 24 is made even sharper. By making the shape of the side wall sharper, it becomes easier to align the tip 24 with the measurement point, and there is no wasted space inside the housing 4, allowing the target device 21 to be made smaller.

[0070] Furthermore, Figure 10 shows a target device 21 according to a second modification of the other embodiment described above. In the second modification as well, an indicator unit is added to the reflector 2 to constitute the target device 21.

[0071] In the second modification, the projection formed on the rear wall 4a of the housing 4 is shaped to enclose the mirror 5 and the corner cube prism 6, and a probe 25 is formed on the projection along the extension of the incident optical axis 3, with the tip 24 of the probe 25 aligned with the position of the virtual image O'. In the figure, the probe 25 is hollow, but it may be a solid material. In the second modification, the projection and the probe 25 constitute the indicator.

[0072] In the second modification described above, it becomes even easier to align the tip 24 of the probe 25 with the measurement point, and the target device 21 can be further miniaturized.

[0073] Figure 11 shows a target device 21 according to a third modification. In this third modification, the indicator unit is separately attached to the housing 4. Note that Figure 11 is a plan view, and in Figure 11, components equivalent to those shown in Figure 1 are given the same reference numerals and their descriptions are omitted. In the third modification, the reflected light axis 3' is deflected in the horizontal direction, and the pole 8 is perpendicular to the plane of the paper.

[0074] In the third modification, an adapter for positioning the virtual image O' (measurement reference point) at the measurement point is detachably provided on the rear wall 4a of the housing 4.

[0075] The adapter shown in Figure 11 is a pole holder 26, which is detachably attached to the rear surface of the housing 4 and has a hole 27 through which a pole can be inserted. When the pole holder 26 is attached to the housing 4, the center of the hole 27 coincides with the position of the virtual image O'.

[0076] By inserting a pole having a ferrule at its lower end into the hole 27, a target device having the same function as the target device 1 shown in Figure 1 is constructed. In the third modified example, the pole holder 26 and the pole 8 constitute the indicator section.

[0077] Figure 12 shows a target device 21 relating to a fourth modified example.

[0078] The indicator shown in Figure 12 is a probe 28 that is detachably attached to the rear wall 4a of the housing 4. The probe 28 is positioned on the extension of the incident optical axis 3, and has a tip 24, which is positioned to coincide with the position of the virtual image O'.

[0079] When the probe 28 is attached to the housing 4, it has the same function as the target device 21 of the second modified example shown in Figure 10. The probe 28 functions as an indicator that points to the virtual image O'.

[0080] Furthermore, while the pole holder 26 and the probe 28 may be fixedly mounted on the housing 4, the mounting structure of the pole holder 26 and the probe 28 may be the same, and the pole holder 26 and the probe 28 may be replaced depending on the measurement situation.

[0081] Figure 13 shows a target device 21 according to the fifth modified example.

[0082] The fifth modified example shown in Figure 13 involves separating the probe 25 from the housing 4 in the second modified example shown in Figure 10, making the probe 25 a separate component, and further providing a fitting portion 25' on the probe 25 so that it can be attached to and detached from the housing 4. Note that the fitting portion 25' is not limited to the shape shown.

[0083] Furthermore, when the probe 25 is attached to the housing 4, it has the same function as the second modified example, and the tip 24 of the probe 25 is in a position where a virtual image O' is formed.

[0084] The sixth modification shown in Figure 14 involves attaching a pole holder 29 to the area where the probe 25 was removed. A pole 8 can be inserted through the pole holder 29, and the pole 8 can be fixed in any position (see Figure 1). Furthermore, the virtual image O' is positioned on the axis 10 of the pole 8.

[0085] The pole holder 29 is also configured to be detachable from the housing 4 and interchangeable with the probe 25. Therefore, the probe 25 and the pole holder 29 may be exchanged depending on the measurement conditions.

[0086] Figures 15(A) and 15(B) show the seventh modified example, with Figure 15(A) being a side view and Figure 15(B) being a top view. In Figures 15(A) and 15(B), components equivalent to those shown in Figure 1 are denoted by the same reference numerals.

[0087] In Figures 15(A), 15(B), and 15(C), 30 shows a reflector module in which the optical components, including the deflection optical element and the corner cube prism, and the housing are integrated.

[0088] A pole holder 31 is provided on the pole 8 so as to be slidable, and the pole holder 31 can be fixed at any position on the pole 8 by a sliding fixing screw 11.

[0089] A connecting member 32 is provided on the rear wall 4a of the reflector module 30, and the connecting member 32 is rotatably connected to the pole holder 31 via a horizontal rotation axis 33. The axis 34 of the horizontal rotation axis 33 is perpendicular to the axis 10 of the pole 8 and also passes through the position of the virtual image O'. Therefore, the position where the virtual image O' is formed is the intersection of the axis 10 and the axis 34.

[0090] The reflector module 30 is rotatable vertically relative to the pole 8 via the horizontal rotation axis 33. Since the rotation center of the reflector module 30 is at the position of the virtual image O', the position of the virtual image O' (measurement reference point) does not change due to the rotational movement of the reflector module 30. That is, even if the reflector module 30 slides or rotates, the measurement reference point always remains on the axis 10.

[0091] Furthermore, the connecting member 32 is provided with a rotating fixing screw 35, which allows the reflector module 30 to be fixed at any angle.

[0092] Figure 15(C) shows the reflector module 30 rotated upward by the required angle.

[0093] Figures 16(A), 16(B), and 16(C) show the eighth modified example.

[0094] A connector 37 is provided on the rear wall 4a of the reflector module 30.

[0095] The pole holder 31 is incorporated into the pole 8 and unitized as an indicator unit 39a. The pole holder 31 is provided with a connector 37 and a detachable connector 38, and the reflector module 30 and the indicator unit 39a are integrated by connecting the connector 37 and the detachable connector 38. In the integrated state, the position of the virtual image O' of the reflector module 30 is located on the axis of the pole 8, and is the same as the seventh embodiment shown in Figure 15(A) (see Figure 16(B)).

[0096] Furthermore, the connection between the connector 37 and the connected component 38 is configured to be detachable when rotated relative to each other by 90° or 180°. With this configuration, the reflector module 30 can be attached to the indicator unit 39a when rotated by 90° or 180°.

[0097] Next, the probe 25 capable of indicating a measurement point, the connector 37, and the detachable connector 38 are unitized as an indicator unit 39b. The detachable connector 38 of the indicator unit 39b and the detachable connector 38 of the indicator unit 39a have a common structure.

[0098] When the indicator unit 39b is attached to the reflector module 30, the tip of the probe 25 becomes the virtual image position of the reflector module 30, and the reflector module 30 can be directly placed at the measurement point (see Figure 16(C)).

[0099] Therefore, the reflector module 30 can be attached to both the indicator unit 39a and the indicator unit 39b.

[0100] Furthermore, the connector 37 and the connected device 38 may be a fitting-type coupling or a screw-type coupling, as long as they can be easily attached and detached.

[0101] Figures 17(A) and 17(B) show the ninth modified example. In the ninth modified example, pole 8 is used as the indicator. In Figure 17(A), parts equivalent to those shown in Figure 10 are given the same reference numerals, and their explanations are omitted.

[0102] An engaging projection 44 is formed on the rear wall 4a of the reflector module 30, extending along the extension of the incident optical axis 3. In addition, a groove 43 is provided as a recess in the pole 8, and the groove 43 is formed along the axis of the pole 8.

[0103] The engaging projection 44 can be fitted into any position in the groove 43 and fixed in the groove 43 at any position, so that the reflector module 30 is supported by the pole 8 at any position. Furthermore, when the engaging projection 44 is fitted into the groove 43, the position where the virtual image O' is formed is on the axis of the pole 8.

[0104] As a means of fixing, the engaging projection 44 is made into a magnet, and the fitted state with the groove 43 is maintained by attraction. Alternatively, as a means of fixing, an elastic material such as a leaf spring that presses against the groove 43 is provided on the engaging projection 44, and the engaging projection 44 is fixed to the groove 43 by frictional force.

[0105] Furthermore, to enable determination of the fixed position of the reflector module 30 (the position of the virtual image O'), a scale indicating the distance from the tip of the foot 9 may be engraved on the pole 8. Alternatively, the engaging projection 44 may be used as a probe, with the tip of the engaging projection 44 positioned at the location where the virtual image O' is formed, allowing the reflector module 30 to be installed at the measurement point by itself.

[0106] Figure 18 shows a modified example of the pole 8, in which a plurality of fitting holes 45 are drilled as recesses instead of the groove 43. The number of fitting holes 45 are provided at known positions and known intervals from the tip of the ferrule 9, and are capable of fitting with the engaging projection 44. By making the engaging projection 44 a magnet, the fitted state between the engaging projection 44 and the fitting holes 45 is maintained. Alternatively, the shape of the fitting holes 45 is such that the fitted state is maintained when the engaging projection 44 is fitted. Furthermore, the pole 8 may be engraved with a scale.

[0107] It goes without saying that the shape of the recess is not limited to the shape described above.

[0108] Figure 19 shows the tenth modified example. In Figure 19, components equivalent to those shown in Figure 9 are given the same reference numerals, and their explanations are omitted.

[0109] In the tenth modification, the incident optical axis 3 is deflected multiple times to cause the virtual image O' to be formed at a more divergent position.

[0110] Multiple mirrors are used as deflecting optical elements that deflect the light multiple times. In the tenth modified example, two mirrors 5 and 5a are used, and the reflected optical axis 3' is deflected by 90° by mirror 5a. That is, the incident optical axis 3 is deflected twice by the mirrors 5 and 5a.

[0111] In this modified example, the deflection angles are 90° for mirrors 5 and 5a, but they are not limited to 90°. Also, in this modified example, the deflection direction by mirrors 5 and 5a is within the same plane (parallel to the plane of the paper), but it may be deflected in a direction perpendicular to the plane of the paper. Furthermore, in this modified example, the settings are changed twice, but it goes without saying that they may be changed three or four times.

[0112] The tenth modification shown in Figure 19 corresponds to the first modification in Figure 9, in which a mirror 5a is provided opposite the mirror 5, and the reflected optical axis 3' is further deflected by the mirror 5a. A corner cube prism 6 is provided on the reflected optical axis 3'' deflected by the mirror 5a. The reflected optical axis 3'' is set to pass through the optical center O of the corner cube prism 6.

[0113] The virtual image O' of the optical center O is formed on the extension of the incident optical axis 3, and the distance from the reflection position R in the mirror 5 to the optical center O is equal to the distance from the reflection position R to the virtual image O'.

[0114] As the incident optical axis 3 is deflected twice, the distance from the reflection position R to the optical center O increases, and the distance from the reflection position R to the virtual image O' also increases. As a result, the rear wall 4a forming the tip 24 becomes sharper, making it even easier to align the tip 24 with the measurement point.

[0115] Figure 20 shows an eleventh modification. The eleventh modification shown in Figure 20 corresponds to the second modification in Figure 10, in which the incident optical axis 3 is deflected twice by the mirrors 5, 5a, the distance between the reflection position R and the virtual image O' is increased, and the length of the probe 25 is also increased, improving the workability when aligning the tip 24 with the measurement point.

[0116] Figure 21 shows the twelfth modified example. In Figure 21, components equivalent to those shown in Figure 19 are given the same reference numerals, and their explanations are omitted.

[0117] In the twelfth modification shown in Figure 21, the deflection optical elements, mirrors 5 and 5a, in the tenth modification shown in Figure 19 are replaced with a reflecting prism 41.

[0118] The reflecting prism 41, acting as a deflecting optical element, has two orthogonal reflecting surfaces 31a and 31b. These reflecting surfaces 31a and 31b reflect the incident measurement light twice, deflecting the incident optical axis 3 twice. In the illustration, the apex angle of the reflecting prism 41 is shown as 90°, but it is not limited to 90° and may be appropriately changed according to the manufacturing conditions of the target device 21.

[0119] Figure 22 shows the 13th modified example. In Figure 22, components equivalent to those shown in Figure 20 are given the same reference numerals, and their explanations are omitted.

[0120] In the 13th modified example shown in Figure 22, the deflection optical elements, mirrors 5 and 5a, in the 11th modified example in Figure 20 are replaced with a reflecting prism 41.

[0121] In addition, in the 12th and 13th modified examples shown in Figures 21 and 22, the reflective prism 41 and the corner cube prism 6 are separated, but they may be in close contact or joined together.

[0122] Figure 23 shows the 14th modified example. In Figure 23, the housing 4 is omitted, and only the optical components are shown.

[0123] In the 14th modified example, the deflection optical element consists of a mirror 5 and a reflective triangular prism 18, and the deflection optical element deflects the incident optical axis 3 twice. The first deflection is performed by the mirror 5, and the second deflection is performed by the reflective triangular prism 18.

[0124] Figure 24 shows the 15th modified example.

[0125] In the 15th modification, similar to the 14th modification, the deflection optical element consists of a mirror 5 and a reflective triangular prism 18, and the deflection optical element deflects the incident optical axis 3 twice. The first deflection is performed by the reflective triangular prism 18, and the second deflection is performed by the mirror 5.

[0126] Figures 25(A) and 25(B) show the 16th modified example.

[0127] The 16th modification is such that the deflection optical member is composed of a single deflection prism 42, the deflection prism 42 having two opposing reflective surfaces 42a and 42b, and the incident optical axis 3 is deflected twice by the reflective surfaces 42a and 42b. The reflective surface 42b is configured to deflect the optical axis in a direction perpendicular to the plane containing the reflected optical axis 3' deflected by the reflective surface 42a and the incident optical axis 3.

[0128] The 14th, 15th, and 16th variations described above can be miniaturized and widened, respectively.

[0129] Figure 26 shows the 17th example of modification.

[0130] In the 17th modification example, a mirror 46 is used as the deflection optical element, and the corner cube prism 6 is positioned directly in front of the center of the reflective surface 46a of the mirror 46.

[0131] In the 17th modified example, the incident optical axis 3 is obliquely incident on the mirror 46 from the side of the corner cube prism 6, and the corner cube prism 6 is positioned on the reflected optical axis 3' deflected by the mirror 46.

[0132] The virtual image O' of the optical center O of the corner cube prism 6 is located on the extension of the incident optical axis 3 and is formed in a position symmetrical with respect to the reflective surface of the mirror 46.

[0133] Measurement light, centered on the virtual image O' and incident on both sides of the corner cube prism 6 within an angle range of α, is incident on the corner cube prism 6 and retroreflected.

[0134] In the 17th example of the modification, retroreflection of measurement light is possible with a wide field of view.

[0135] Figure 27 shows the 18th example of modification.

[0136] The 18th modification example uses a mirrored parallel plate 47 as the deflection optical element.

[0137] The back surface 47a of the mirrored parallel plane plate 47 is a reflective surface, and a corner cube prism 6 is provided on the surface of the mirrored parallel plane plate 47. In this modified example, the optical function is the same as in the 17th modified example, and the configuration is compact because the corner cube prism 6 is provided on the mirrored parallel plane plate 47. [Explanation of Symbols]

[0138] 1. Target device 2 reflectors 3 Incident optical axis 4 Housing 5 Mirror 6 Corner Cube Prism 8 poles 9. Butt cap 18 Reflecting triangular prism 24 Tip 25 probes 26 Pole Holder 28 probes 29 Pole Holder 30 Reflector Modules 31 Pole Holder 41 Reflecting prism 42 Deflection Prism 46 Mirror 47 Parallel flat plate with mirror

Claims

1. A reflector comprising a deflection optical member provided on the incident optical axis of the measurement light and reflecting the measurement light at least once, and a retroreflector that retroreflects the measurement light on the reflected optical axis of the deflection optical member, wherein a virtual image of the optical center of the retroreflector is formed on the extension of the incident optical axis.

2. The reflector according to claim 1, comprising the deflection optical member and a housing for housing the retroreflector, wherein a window glass is provided on the incident surface of the housing.

3. The reflector according to claim 1, wherein the retroreflector is a prism having retroreflective properties.

4. The reflector according to claim 1, wherein the retroreflector is composed of three mirrors so as to have retroreflective properties.

5. The reflector according to claim 1, wherein the deflection optical member is a mirror.

6. The reflector according to claim 1, wherein the deflection optical member is a reflective prism.

7. The reflector according to claim 1, wherein the deflection optical member includes a mirror and a reflective prism, and is configured to reflect and deflect the measurement light at least twice.

8. The reflector according to claim 6, wherein the reflective prism has at least two reflective surfaces and is configured to reflect and deflect the measurement light at least twice by the at least two reflective surfaces.

9. A target device comprising a reflector according to any of claims 1 to 8 and a pole holding the reflector, wherein the pole has a ferrule at its tip, and the virtual image is configured to be located on the axis of the pole.

10. The target device according to claim 9, wherein the reflector is movably mounted relative to the pole.

11. A target device comprising a reflector according to any one of claims 3 to 8 and a housing for housing the reflector, wherein an indicator portion is provided on the rear wall of the housing, and the indicator portion has a tip that indicates the position of the virtual image.

12. A target device comprising a reflector according to any one of claims 3 to 8, a housing for housing the reflector, and a pole having a ferrule at its tip, wherein an engaging projection is formed on the rear wall of the housing, a recess is formed in the pole, the recess and the engaging projection are fitted together, and the reflector is supported by the pole by the fitting of the recess and the engaging projection, and the virtual image of the reflector is positioned on the axis of the pole.

Images