JPH047165B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a laser surveying machine that performs surveying while scanning a horizontal plane with a laser beam emitted toward a surveying target.

Conventionally, leveling is performed by emitting a laser beam that is scanned in a horizontal plane toward a measurement target, and detecting the height of the position of the laser beam on the measurement target with the naked eye of the surveyor or photoelectrically. A laser surveying machine configured as follows is known.
In this case, the laser beam must always be scanned within a true horizontal plane, so careful adjustments must be made when installing the main body of the machine.

For this reason, a laser surveying machine has been proposed that incorporates an adjustment device that allows the laser beam to be emitted in a fixed direction even when the machine body is tilted.

As one of this type of laser surveying machine, a laser light emitting tube with the laser light emission surface at the bottom end is suspended from the machine body, so that the laser light emission direction is directed vertically, and a rotating reflecting member is installed below. A device configured to scan a horizontal plane is known.

However, with such a configuration, the power supply wire for operating the laser arc tube becomes a hindrance to effective suspension of the laser arc tube, and high precision adjustment cannot be expected.

In addition, as another conventional example, a laser beam is emitted from a semiconductor laser, a projection lens is suspended below the semiconductor laser to convert the emitted laser beam into a parallel beam, and the laser beam from this projection lens is It is known to be configured such that it can be scanned in a horizontal plane by a rotating pentaprism.

However, with such a configuration, the laser beam is emitted downward, so when scanning with a rotating pentaprism, the horizontally directed laser beam is blocked by the frame of the machine body.
There was a risk that surveying accuracy in a particular direction would decrease or surveying would become impossible.

The present invention was made to solve these conventional problems, and it is possible to always scan a laser beam emitted toward a surveying target within a true horizontal plane regardless of the state of the machine body. The purpose of the present invention is to provide a laser surveying machine that can be adjusted as follows.

The present invention will be explained below based on the drawings.

1 and 2 explain the principle of the present invention, in which a Porro prism 4 is fixed to a mounting base 3 suspended from the machine body 1 by four ribbons 2, and the Porro prism 4 is A light source 5 is disposed above the Porro prism 4, and a projection lens 6 having a focal length of f ₀ and converting the light from the light source 5 into a parallel beam is disposed above the Porro prism 4. Here, it is assumed that the length l of the ribbon 2 is set to 1/2 of the focal length f ₀ .

In this way, when the machine body 1 is tilted by an angle θ ₀ with respect to the vertical axis E, the Porro prism 4 is at a distance H ₁ from the optical axis L of the projection lens 6, that is, lθ ₀ = f ₀ θ ₀ /
Move by 2. Note that θ ₀ is a small angle, and θ ₀
It is assumed that ≒tanθ ₀ holds true. On the other hand, since the light source 5 is located on the optical axis L of the projection lens 6, the light beam incident on the Porro prism 4 is reflected four times internally and then separated from the optical axis L by a distance H ₂ , that is, 2lθ ₀ = f ₀ θ ₀ . Orient in the same direction. Therefore, the light flux incident on the projection lens 6 is f ₀ θ ₀ compared to before the machine body 1 is tilted.
will move in parallel. Therefore, the light beam P that has passed through the objective lens 6 is on an axis parallel to the optical axis L.
It is directed in a direction forming an angle θ ₁ with respect to L', and this pointing direction is on the focal point F of the objective lens 6. In other words, the relationship f ₀ θ ₁ =f ₀ θ ₀ always holds true, and even if the machine body 1 is tilted by θ ₀ , the light beam passing through the objective lens 6 is always parallel to the vertical axis E. This phenomenon similarly occurs even when the machine body 1 is tilted in a direction perpendicular to the plane of the paper.

A specific example of the Porro prism 4 is shown in FIG. 3, and the light emitted from the first light source 5' is directed upward by the condensing lens 7 and passes through the first to fourth reflecting surfaces R ₁ , It is reflected at R ₂ , R ₃ , and R ₄ and emitted upward. This emission direction S
coincides with the optical axis direction of the light (directed upward by the condenser lens 7') from the second light source 5'' provided below the fourth reflective surface _R4.In other words, the same output Two different light beams can be superimposed in the direction S.If the first light source 5' is a semiconductor laser that emits infrared light and the second light source 5'' is a visible light source, the reflecting surface _R3 is If it is formed on a reflective surface that has a wavelength selection characteristic of infrared reflection and visible light transmission, it is possible to project two beams of infrared light and visible light without causing a loss of light quantity.

FIG. 4 shows an example of another erecting normal image Porro prism 4', in which the light beam from the light source 5A is
to fourth reflecting surfaces r ₁ , r ₂ , r ₃ , and r ₄ , respectively. It is configured such that the incident optical axis and the output optical axis coincide.

FIG. 5 shows a laser surveying machine constructed on the basis of the above-mentioned principle. The machine main body 11 is installed on an adjustable base 12, and a holder 13 is fixed to the bottom center of the machine main body 11, and a semiconductor laser 14 as a laser light emitting unit is mounted at the bottom of the holder 13. A projection lens 15 is also arranged above it. Note that the visible light source explained in FIG. 3 is omitted in the drawing. Further, above the projection lens 15, an erected normal image Porro prism 16 constituting an erected normal image reflecting member is fixed to a suspension table 17, and this suspension table 17 is connected to the machine body 11.
A ribbon 19 is attached to the top plate of the holding frame 18 that constitutes the
It is suspended by a suspension wire consisting of. The ribbon 19 has a length that is approximately half the focal length f ₀ of the projection lens 15 and has a length that is approximately half the focal length f 0 of the projection lens 15 .
It is made up of four plastic strings placed at targeted locations.

Therefore, since the erect image Porro prism 16 is suspended by the ribbon 19, the configuration can be simplified, and the surveying machine can be made smaller and lighter.

In addition, since the erect image Porro prism 16 does not change the direction of output of the reflected light even if the erect image Porro prism 16 is tilted forward, backward, left, or right to some extent, mounting accuracy is not required, and the installation work is simple. Become something.

Further, another holding frame 20 is attached below the top plate of the holding frame 18, and a parallel plane glass 21 for adjustment is attached to this holding frame 20.

A lens holder 2 is mounted on the top plate of the holding frame 18.
2 is attached, and this lens holder 2
A projection lens 23 consisting of two groups of lenses 23 ₁ and 23 ₂ is fixed to the lens 2 . These two groups of lenses 2
3 ₁ and 23 ₂ can be moved and adjusted as one unit, and lens 2
It is configured such that the distance between the lenses 3 ₁ and 23 ₂ can be variably adjusted.

In this way, the laser light emitted from the semiconductor laser 14 passes through the condenser lens 15, the Porro prism 16, the parallel plane glass 21, and the projection lens 23, and is emitted upward.

At this time, the Porro prism 16 reflects the laser light upward and always directs the optical axis of the reflected light in the vertical direction as an erect image. Further, the projection lens 23 converts the laser beam reflected upward by the Porro prism 16 into a substantially parallel beam and projects it.

On the other hand, a bearing 24 is provided at the upper part of the machine body 1, and a rotating shaft 26 to which a pulley 25 is attached is attached to the bearing 24.
A belt 30, which is wound around a pulley 29 that is pivotally attached to a motor 28, is wound around the pulley 25, so that the rotating shaft 26 is rotationally driven. Further, a pentagonal prism 3 constituting a rotational reflection member is provided at the upper end of the rotation shaft 26.
An entrance window 32A is provided on the incident light side of the pentagonal prism 31, and an adjustment prism 33 is provided on the exit light side of the pentaprism 31. The prism house 32 can be easily attached to and detached from the machine body 1 using simple attachment means such as fastening screws. That is, when the prism house 32 is removed, it functions as a device that projects laser light vertically upward. The emitted light reflected by the pentaprism 31 is emitted toward a survey point, which is a survey target, and is scanned over the survey target by rotation of the rotation shaft 26.

A battery box 35 for storing a battery 34 as a power source is provided on the side of the machine body 1, and the electric system is activated by turning on a switch 36.

As mentioned above, the laser surveying machine shown in FIG. 5 is constructed based on the principle shown in FIGS. Even if a deviation occurs, the optical axis of the laser beam emitted from the Porro prism 16 is directed vertically because the length of the ribbon 19 is set to half the focal length of the projection lens 23. be done. Therefore,
The light flux emitted from the pentaprism 31 toward the surveying object is always scanned in a horizontal plane.

Note that the laser light emitted from the semiconductor laser 14 generally uses infrared light, which is invisible light.
Horizontal surveying is carried out by installing a detector that photoelectrically detects infrared laser light so that it can be moved up and down. For this reason, since it is often difficult to easily determine the position of the laser beam incident on the detector before surveying, a visible light source is used to make it easier to detect the approximate position. In other words,
The first light source 5' shown in FIG. 3 may be a semiconductor laser, and the second light source 5'' may be used as a lamp for emitting visible light.

Furthermore, the projection lens 23, which is composed of two groups of lenses, can be moved as a unit to convert the incident laser beam into a parallel beam of light, and the focal length can be changed by changing the distance between both lens groups. Adjustment is also possible. Further, the parallel plane glass 21 is tiltable, so that the direction of emission of the incident laser beam can be adjusted. Porro prism 16 which is an erect normal image reflecting member
may be an erect image prism, or a combination of a plurality of rectangular prisms as shown in FIG. 3 or a combination of a roof prism and a trapezoidal prism as shown in FIG. 4.

As explained above, according to the present invention, the laser light from the laser light emitting section is made to enter from below the erecting normal image reflecting member, and the light emitted from the erecting normal image reflecting member can always be directed in the vertical direction. The optical path of the light beam passing through the erect image reflecting member is changed horizontally by the rotating reflecting member so that it can be scanned, so scanning can always be performed in a horizontal plane regardless of the inclination of the machine body. Since constant light is always available in all directions without being obstructed by the frame of the main body, surveying accuracy can be maintained at a constant and high level.

Furthermore, the mounting accuracy of the erecting normal image reflecting member is not required, and the mounting work becomes simple. Furthermore, since the erect image reflecting member is suspended by a suspension wire, the structure can be simplified, and the surveying machine can be made smaller and lighter.

[Brief explanation of drawings]

Figures 1 and 2 are schematic configuration diagrams of an optical system to explain the principle of this invention. Figure 1 shows a case where the machine body is not tilted, and Figure 2 shows a case where the machine body is tilted. , FIG. 3 is a perspective view illustrating a Porro prism, FIG. 4 is a perspective view illustrating another Porro prism, and FIG. 5 is a longitudinal cross-sectional view illustrating an embodiment of a laser surveying machine according to the present invention. . 11... Machine body, 14... Semiconductor laser (laser light emitting part), {16... Porro prism,
17... Hanging base, 19... Ribbon} Erect normal image reflecting member, 23... Projection lens, 31... Pentaprism (rotating reflecting member).

Claims (1)

[Claims] 1. A laser light emitting section, and an erecting normal image reflection device that reflects the laser light emitted from the laser light emitting section upward and always directs the optical axis of the reflected light in the vertical direction as an erected normal image. a suspension wire for suspending the erecting normal image reflecting member; a projection lens system for projecting the laser beam reflected upward by the erecting normal image reflecting member into a substantially parallel beam; and this projection lens. A laser surveying machine having a rotary reflecting member rotatably arranged to change the optical path of a parallel light beam obtained from the system by approximately 90 degrees and scan the object to be surveyed with the parallel light beam in a horizontal plane. 2. The laser surveying machine according to claim 1, wherein the erect image reflecting member is a Porro prism. 3. The laser surveying machine according to claim 1, wherein the length of the suspension wire is set to approximately half the focal length of the projection lens system. 4. The laser surveying machine according to claim 1, wherein the erect normal image reflecting member is suspended by four suspension wires.