JP3761693B2 - Reference plane setting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surveying instrument used for surveying work, and more particularly to a reference plane setting device that sets a reference plane with two parallel light bundles.
[0002]
[Prior art]
Conventionally, a leveling device using a leveling instrument and a pole has also been used in recent years with a reference plane setting device.
[0003]
The reference plane setting device is also called a laser planar, but in general, the reference plane setting device main body is placed at a reference location within the measurement range, and the laser beam is rotated around a vertically leveled rotation axis. Used by workers standing near the walls and pillars to be inked, to observe the laser spot on the walls and poles, and to read the measured values of the receiver and set the level. Compared to using a standard and a pole, this system is superior in that it requires only one surveying worker.
[0004]
In addition, the reference plane setting device is mainly used for setting level surfaces on walls, columns, etc. in a building structure or the like, but in recent years, two reference plane setting devices are provided in two directions, upper and lower, perpendicular to the level surface. A reference plane setting device capable of emitting a vertical laser beam and setting a vertical line from the floor to the ceiling has come to be used.
[0005]
The structure of such a conventional reference plane setting device will be briefly described with reference to FIG. 3. The conventional reference plane setting device 200 includes a casing 201. The casing 201 includes a cylinder 203. The cylinder 203 includes a laser diode 205, a first half prism 206, a second half prism 207, a first mirror 208, a half mirror 209, and a second mirror. 210.
[0006]
The laser diode 205 is disposed to irradiate the first half prism with laser light 221, and the first half prism 206, the second half prism 207, and the half mirror 209 are disposed on a rotation axis 202. When the cylinder 203 is rotated around the rotation axis 202 by the motor 204, it is configured to rotate together.
[0007]
When the laser beam 221 is applied to the first half prism 206, half of the laser beam 221 is reflected and becomes a laser beam 222 that is applied to the half mirror 209.
[0008]
The other half passes through the first half prism 206, further passes through the second half prism 207, becomes laser light 223, is irradiated on the first mirror 208, is reflected by the first mirror 208, and Returning to the second half prism 207, at the boundary between the second half prism 207 and the first half prism 206, ½ of the light amount is reflected in the vertically downward direction of the rotation axis 202, and the vertically lower laser beam is reflected. 227 is injected from the window 213 of the casing 201 to the outside of the apparatus.
[0009]
On the other hand, when the laser beam 222 is applied to the half mirror 209, another half (1/4 light amount of the laser beam 221) is further transmitted, and is rotated as the vertically upper laser beam 225 from the window 221 of the casing 201. Irradiated vertically upward along the axis 202.
[0010]
The remaining half (the same ¼ light amount) is reflected by the half mirror 209, further reflected by the second mirror 210, and irradiated as horizontal laser light 226 from the window 211 perpendicular to the rotation axis 202.
[0011]
Since the motor 204 is attached to the cylinder 203, when the rotation axis 202 is leveled vertically by a leveling device (not shown) and the cylinder 203 is rotated around the rotation axis 202, the cylinder 203 is The half prism 209 and the second mirror 210 also rotate about the rotation axis 202, and therefore the horizontal laser beam 226 rotates within one level plane, so that the level plane can be set.
[0012]
At this time, the spot that the vertical upper laser beam 225 hits the ceiling and the spot that the vertical lower laser beam 227 hits the floor are located on the rotation axis 202 and move even when the cylinder 203 rotates. Therefore, a vertical line can be set by connecting the two spots.
[0013]
However, in the reference plane setting device 200 of the prior art, the laser light emitted from the laser diode 205 is divided into two, and one of them is further divided into two to be a horizontal laser beam and a vertically upward laser beam. Therefore, there is only one horizontal laser beam, and there are various problems as follows.
[0014]
That is, if the angular velocity of rotation of the laser beam is constant, the moving speed of the laser spot on the measurement object increases in proportion to the distance to the measurement object. The amount of light is reduced and visibility is deteriorated.
[0015]
Regarding visibility, although there are differences due to differences in individual abilities and proficiency levels depending on the qualities of the observer, when a laser beam with a diameter of 7 mmφ is irradiated at an output intensity of 1 mW, the moving speed of the laser spot is 30 m / Seconds are the observable limit speed, and it is said that it is difficult to perform surveying work at speeds higher than that.
[0016]
When this moving speed is converted into a distance, for example, if the angular speed at which the laser beam rotates is 360 degrees / second, this corresponds to the case where the distance between the measurement object and the reference plane setting device is 4.8 m.
[0017]
Therefore, it is necessary to ensure the visibility of a measurement object longer than this distance by adjusting any of the output intensity, angular velocity, and beam diameter of the laser beam.
[0018]
In order to ensure the visibility by adjusting the output intensity of the laser beam, the output intensity must be increased according to the distance. However, for safety standards, a limit value is set for the output intensity per unit area of the laser beam, and there is a certain limit to improving the visibility. In particular, in the conventional reference plane setting apparatus as described above, when the light intensity of the horizontal laser light emitted from the laser diode 105 is 1, the light intensity of the vertically lower laser light is ½. The vertical upper laser beam and the horizontal laser beam become 1/4 each, the light intensity of the horizontal laser light that must reach far is weak, and it is only possible to increase the light intensity of the horizontal laser light Impossible.
[0019]
In order to improve visibility by adjusting the angular velocity of rotation of the laser beam to keep the moving speed of the laser spot constant, the angular velocity must be reduced in proportion to the length of the distance. However, if the angular velocity is reduced, the period in which the laser spot can be observed becomes longer.
[0020]
In general, due to measurement accuracy and work requirements, the observer observes and confirms the laser spot on the object to be measured multiple times and performs the reference plane setting work. The workability of the plane setting work is significantly reduced.
[0021]
When the diameter of the laser beam is increased, it becomes easier to see, but it is easy for the observer to determine which point in the laser spot is the reference plane, and even if a receiver is used, the light receiving surface is Since it becomes large, there exists a possibility that the setting precision of a reference plane may fall. Therefore, simply increasing the diameter of the irradiation light such as laser light is not a practical solution.
[0022]
Therefore, the applicant has proposed a reference plane setting device as described in Japanese Patent Application No. 5-104510.
[0023]
4A is a side view of the optical system of the reference plane setting device, and FIG. 4B is a top view. 4 (a) and 4 (b), the reference plane setting device 101 includes a light emitting means 109 and a disk 102. The disk 102 has a rotational axis 108 by a rotating means having a motor (not shown). Rotated to the center. The light emitting means 109 is disposed on the rotation axis 108, and the optical axis of the laser beam 131 emitted from the light emitting means 109 is made to coincide with the rotation axis 108.
[0024]
A hole 103 that intersects the rotational axis 108 is formed in the disk 102, a first beam splitter 141 is disposed on the hole 103, and a second beam splitter 142 is disposed on the side thereof.
[0025]
The first beam splitter 141 is composed of a half prism, and the second beam splitter 142 is composed of three triangular prisms.
[0026]
When the laser beam 131 is applied to the first beam splitter 141 through the hole 103, ½ light amount of the laser beam 131 is reflected and becomes the laser beam 134 ₀ and applied to the second beam splitter. The remaining half (1/2 light amount) is transmitted and becomes vertical laser light 132 and irradiated upward along the rotation axis 108.
[0027]
When the laser beam 134 ₀ is irradiated to the second beam splitter 142, half (the 1/4 amount) is a first horizontal laser beam 134 ₁ is transmitted through the second beam splitter 142, It is emitted from the window 112 _1. The other half is a second horizontal laser beam 134 ₂ is reflected by the second beam splitter 142, through the windows 112 ₂ and ₁ the first laser beam 134 is emitted in the opposite direction.
[0028]
When the disc 102 is rotated around the rotational axis 108, the disc 102 wherein arranged on the first beam splitter 141 a second beam splitter 142 is also rotated, ₁ and the first horizontal laser beam 134 Since the second horizontal laser beam 134 ₂ also rotates around the rotation axis 108, if the rotation axis 108 is leveled vertically, the two laser beams 134 ₁ and 134 ₂ are equal to each other. Two levels can be set.
[0029]
As shown in the figure, when the two laser beams 134 ₁ and 134 ₂ are used, the light amount per unit time of the irradiation light incident on the same measurement point can be increased.
[0030]
However, the reference plane setting apparatus 101 as described above requires two beam splitters, the first beam splitter 141 and the second beam splitter 142, in order to form two laser beams traveling in opposite directions.
[0031]
In addition, since the second beam splitter 142 cannot be disposed on the rotation axis 108, the center of gravity is not located on the rotation axis, and the weight balance is poor, so that smooth rotation cannot be obtained. For this reason, a weight balancer is fixed on the disk 102 to adjust the weight balance, but this adjustment work is complicated.
[0032]
Further, since the disk 102 needs to be large enough to arrange at least two beam splitters, there has been a certain limit to downsizing the apparatus.
[0033]
[Problems to be solved by the invention]
The present invention was created in view of the above disadvantages of the prior art, and an object of the present invention is to provide a small reference plane setting device capable of emitting two parallel light beams.
[0034]
[Means for Solving the Problems]
In order to solve the above problems, the present invention emits a first parallel light beam and a second parallel light beam that are parallel to a plane perpendicular to one straight line, and the first parallel light beam and the second parallel light beam. A reference plane setting device for setting a reference plane by rotating a bundle with the one straight line as a rotation axis, a light emitting means for generating a primary parallel ray bundle, and the primary parallel ray bundle as the first parallel ray bundle. And a beam splitting means for splitting into the second parallel light flux, and a rotating means for synchronously rotating the light emitting means and the beam splitting means about the rotation axis, the light emitting means and the beam splitting And the first parallel light beam is linearly polarized light, and the beam splitting means has a polarization beam splitting surface, a quarter wavelength plate, and a reflection mirror. The beam split Is arranged so that the primary parallel light beam is incident on the beam splitting surface at an angle of 45 ° with respect to the plane of polarization of the primary parallel light beam. The main axis is disposed so as to form 45 ° with respect to the polarization plane of the linearly polarized light transmitted through the beam split plane, and the reflection mirror reflects the light transmitted through the quarter-wave plate to It is arranged so as to return to the four-wave plate.
[0035]
Two parallel ray bundles having the same optical axis are emitted in parallel to a plane perpendicular to the rotation axis, leveled so that the rotation axis is vertical, and the two parallel ray bundles are centered on the rotation axis. Is rotated, one reference plane can be stretched with the two parallel beam bundles.
[0036]
If the light emitting means and the beam splitting means are arranged on the rotation axis, the center of gravity is located on the rotation axis, so that the rotation can be performed smoothly.
[0037]
Further, linearly polarized light is used for the primary parallel beam bundle, and the beam splitting means is provided with a polarization beam split surface, a quarter wavelength plate, and a reflection mirror, and the principal axis of the beam split surface is the primary parallel beam. The 1/4 wave plate is arranged so as to form 45 ° with respect to the polarization plane of the light beam and so that the primary parallel light beam is incident on the beam split surface at an angle of 45 °. The four-wave plate is arranged so that the principal axis of the four-wave plate forms an angle of 45 ° with respect to the polarization plane of the linearly polarized light transmitted through the beam split plane, and the reflection mirror reflects the light transmitted through the quarter-wave plate. If it arrange | positions so that it may return to this quarter wave plate, the said 2 parallel light beam can be made with few optical components.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0039]
Referring to FIG. 1, reference numeral 2 denotes a reference plane setting device, in which a light emitting means 5 is provided in a bottomed cylinder 6, and a beam split means 16 is provided in an opening 10 of the bottomed cylinder 6. . The bottomed cylinder 6 is rotatably supported by a housing 8 via a bearing 7 and is configured to be able to rotate with the center axis of the bottomed cylinder 6 as a rotation axis 9 by a motor (not shown).
[0040]
The light emitting means 5 comprises a laser light emitting diode 3 and a collimation lens 4, and the laser light emitting diode 3 is fixed at a position intersecting the rotation axis 9 at the bottom of the bottomed cylinder 6, and the collimation lens 4 is disposed between the laser light emitting diode 3 and the beam splitting means 16 in the bottomed cylinder 6.
[0041]
The beam splitting means 16 comprises a polarizing beam splitter 12, a quarter wavelength plate 13, and a reflection mirror 14. The collimation lens 4 converts the laser light L ′ emitted from the laser diode 3 into parallel light. And the polarization beam splitter 12 is irradiated as a primary parallel light beam L ₀ .
[0042]
The collimation lens 4 centered in the center of the light emitting surface of the laser light emitting diode 3, since it is arranged so as to be located on the rotation axis 9, an optical axis 11 of the primary parallel beam bundle L ₀ is the rotation It coincides with the axis 9. Further, since the laser beam L ′ is linearly polarized light, the primary parallel light beam L ₀ is also linearly polarized light and has a certain plane of polarization.
[0043]
The beam splitter 12 has a beam splitting surface 15, and the beam splitting surface 15 is arranged so that the primary parallel light beam L ₀ is incident at an angle of 45 ° as shown in FIG. Has been placed. The principal axis of the beam splitting surface 15 is arranged to form an angle of 45 ° with the polarization plane of the primary parallel light beam L ₀ , and when the primary parallel light beam L ₀ is irradiated onto the beam split surface 15. , Half is reflected to become the first parallel light beam L ₁ , and the other half is transmitted to become the beam split surface transmitted light M ₁ .
[0044]
When the primary parallel light beam L ₀ is reflected by the beam split surface 15, the polarization plane is inclined 45 °, so that the polarization surface of the first parallel light beam L ₁ is perpendicular to the principal axis of the beam split surface 15. Become. Further, when the primary parallel light beam L ₀ is transmitted, the polarization plane is inclined 45 ° in the opposite direction to the first parallel light beam, so that the polarization plane of the beam split surface transmitted light M ₁ is the beam It is parallel to the main axis of the split surface 15. Accordingly, when the polarization plane is viewed with reference to the traveling direction of light, the polarization plane of the first parallel light beam L _{1 and} the polarization plane of the beam split plane transmitted light M ₁ form an angle of 90 ° with each other. Become.
[0045]
Moreover, the beam on the splitting surface transmitted light M ₁ of the optical path, since the quarter-wave plate 13 and the reflective mirror 14 are disposed in this order, said beam splitting surface transmitted light M ₁ is the quarter wavelength The light is applied to the plate 13, passes through the quarter-wave plate 13, becomes a quarter-wave plate transmitted light M _2, and is applied to the reflection mirror 14 to become reflected light M ₃ . Since the beam split plane transmitted light M ₁ is linearly polarized light, the quarter-wave plate transmitted light M ₂ and the reflected light M ₃ are circularly polarized light.
[0046]
Instead of the reflecting mirror 14, a triangular prism 18 can be used as shown in FIG.
[0047]
When the reflected light M ₃ is applied to the back surface of the quarter-wave plate 13, it passes through the quarter-wave plate 13 and becomes a quarter-wave plate retransmitted light M ₄ . Since the reflected light M ₃ is circularly polarized light, the quarter-wave plate retransmitted light M ₄ is linearly polarized light. The main axis of the ¼ wavelength plate 13 is arranged to form 45 ° with respect to the polarization plane of the beam split plane transmission light M ₁ , and the beam split plane transmission light M ₁ is the 1 / Irradiated to the four-wave plate 13 and transmitted through the quarter-wave plate 13 twice from the front and back to become the quarter-wave plate retransmitted light M _4. The polarization plane of the light M ₄ is inclined 90 ° from the polarization plane of the beam split plane transmitted light M ₁ . In this case, since the polarization plane of the beam split plane transmitted light M ₁ is parallel to the principal axis of the beam split plane, the polarization plane of the quarter-wave plate retransmitted light M ₄ is that of the beam split plane 15. The quarter-wave plate retransmitted light M ₄ is perpendicular to the main axis and is totally reflected by the beam splitting surface 15 to become a second parallel light beam L ₂ . Accordingly, the light amounts of the first parallel light beam L ₁ and the second parallel light beam L ₂ are substantially equal. The polarization plane of the second parallel light beam L ₂ is parallel to the polarization plane of the first parallel light beam L ₁ .
[0048]
Further, since the quarter-wave plate 13 and the reflection mirror 14 are arranged so as to be perpendicular to the optical axis 11 of the primary parallel light beam L ₀ , the beam split surface transmitted light M ₁ The optical axes of the 1/4 wavelength plate transmitted light M ₂ , the reflected light M _3, and the 1/4 wavelength plate retransmitted light M ₄ coincide with the optical axis 11 of the primary parallel light beam L 0.
[0049]
Further, since the beam splitting surface 15 is arranged so that the primary parallel light beam L ₀ is incident at an angle of 45 °, the quarter-wave plate retransmitted light M ₄ is transmitted to the beam splitting surface 15. Is incident on the back surface at an angle of 45 °. Accordingly, the optical axes of the first parallel light beam L ₁ and the second parallel light beam L ₂ are the same, and both intersect perpendicularly with the optical axis 11 (rotation axis 9) of the primary parallel light beam L ₀ .
[0050]
Accordingly, if the reference plane setting device 2 is leveled so that the rotation axis 9 is vertical and the bottomed cylinder 6 is rotated around the rotation axis 9, the first parallel light beam L ₁ and the first in a second parallel light beam L _2, it is possible to put a single level surface.
[0051]
At this time, since the optical axis 17 of the first parallel light beam L ₁ and the second parallel light beam L ₂ intersects the rotation axis 9 at a right angle, the bottomed cylinder 6 is rotated at a constant speed. Then, a laser spot is created at a fixed period at the measurement point.
[0052]
Further, since the light emitting means 5 and the beam splitting means 16 are located on the rotation axis 9, the center of gravity exists on the rotation axis 9, and the bottomed cylinder 6 rotates smoothly.
[0053]
However, the light emitting means 5 and the beam splitting means 16 do not necessarily have to be arranged on the rotation axis 9 in order to allow the parallel light flux to enter the measurement point at a constant period, and the first parallel is not necessarily required. It is only necessary that the optical axes of the light beam L ₁ and the second parallel light beam L ₂ intersect the rotation axis.
[0054]
【The invention's effect】
Compared to a reference plane setting device that uses only one parallel light beam, the number of times the parallel light beam is irradiated onto the measurement object per unit time is doubled, and the efficiency of the surveying work is improved.
[0055]
In addition, since the center of gravity can be positioned on the rotation axis, the rotational movement becomes smooth, and the apparatus can be configured with a small number of optical components.
[Brief description of the drawings]
FIG. 1 is an example of the device of the present invention. FIG. 2 is a diagram for explaining the optical principle. FIG. 3 is a sectional view of a conventional reference plane setting device. Figure showing symbols [Explanation of symbols]
2 ...... reference plane setting device 5 ...... emitting means 9 ...... rotational axis 13 ...... 1/4-wavelength plate 14 ...... reflecting mirror 15 ...... polarizing beam splitting surface 16 ...... beam splitting means L ₀ ...... primary parallel beam Bundle L ₁ …… First parallel beam L ₂ …… Second parallel beam

Claims (1)

Emitting a first parallel beam bundle and a second parallel beam bundle parallel to a plane perpendicular to one straight line;
A reference plane setting device for setting a reference plane by rotating the first parallel light beam and the second parallel light beam with the one straight line as a rotation axis;
A light emitting means for generating a primary parallel light flux;
Beam splitting means for splitting the primary parallel light flux into the first parallel light flux and the second parallel light flux;
In what comprises the rotating means for synchronously rotating the light emitting means and the beam splitting means about the rotation axis,
The light emitting means and the beam splitting means are disposed on the rotation axis,
The primary parallel light flux is linearly polarized light,
The beam splitting means has a polarization beam splitting surface, a quarter wave plate, and a reflection mirror,
The main axis of the beam splitting plane forms 45 ° with respect to the polarization plane of the primary parallel light flux, and the primary parallel light flux is arranged to enter the beam splitting surface at an angle of 45 °.
The main axis of the quarter-wave plate is arranged to form 45 ° with respect to the polarization plane of the linearly polarized light transmitted through the beam split plane,
The reference plane setting device, wherein the reflection mirror is arranged so as to reflect the light transmitted through the quarter-wave plate and return it to the quarter-wave plate.

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