JPS61165611A - Measuring apparatus for change of angle - Google Patents

Abstract

PURPOSE:To measure accurately the change of angle, by measuring interference condition of two diffused waves irradiated from a hologram provided with a function as a double-focus lens. CONSTITUTION:Firstly, by a laser light beam irradiated from a laser beam source 4 a hologram 5 emits No.1 and No.2 diffused waves (a) and (b). On the other hand, an interference condition measuring apparatus 6 is located in a position where each wave interferes mutually by the No.1 and the No.2 diffused moves at a point D and it is installed free to displace along a curve 8 through the same angle as the changed angle beta in the directions of arrows C, C' with the zero point as the center. When the initial angle alpha changed into the angle beta and this angle beta is measured, the apparatus 6 which displaces by the same angle in the direction of the arrow C according to the angle beta, passes through 8a, 8b, 8c where the No.1 and the No.2 waves interfere each other until it arrives at the D' point. The amount of this passage is transmitted into a calculating unit 7 and at the unit 7, the angle beta can be determined by geometrical calculations with this amount as the basis.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a change angle measuring device that uses a hologram to measure the amount of change in angle.

BACKGROUND OF THE INVENTION Hereinafter, a conventional change angle measuring device will be explained with reference to FIG.

In Fig. 4, 1 is a gear installed at the apex of the angle to be measured;
2 is a gear that is brought into proper contact with gear 1, and 3 is a potentiometer connected to gear 2.

In the above configuration, if an angle change occurs by β from the initial angle α (hereinafter referred to as change angle β) and you want to measure this change angle β, rotate gear 1 from point 8 to point 8 in the direction of arrow C. make it move. Along with this rotation, the gear 2 rotates in the direction of arrow C'.

This rotation allows the potentiometer 3 to capture the change angle β as an electrical signal (pulse signal).

Problems to be Solved by the Invention However, in the configuration shown in FIG. Errors caused by angular resolution accuracy when converting to electrical signals, etc.
It has various problems.

In view of the above-mentioned drawbacks, the present invention provides a light-weight, small-sized, and highly accurate changing angle measuring device.

Means for Solving the Problems In order to achieve this object, the present invention provides a light source that emits a highly coherent light beam, and a light beam emitted from the light source that allows the light beams emitted from the light source to emit a first light beam. a hologram that generates a second diffused wave, and a first diffused wave emitted from the hologram. interference state measuring means for measuring the interference state of the second diffused wave while moving according to the change angle to be measured; The variation angle measuring device includes a calculation unit that geometrically calculates the variation angle from the mutual interference state of the second diffused waves.

Effect: With the above-mentioned configuration, the present invention becomes a compact device that can measure the angle of change with high precision, is lightweight, and can be installed freely.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the main structure of a change angle measuring device in an embodiment of the present invention.

In FIG. 1, reference numeral 4 denotes a laser light source that emits a laser beam provided on the line segment OA. 5 is a hologram provided on the extension of the line segment 0m, similar to the laser light source 1, and the laser light emitted from the laser light source 4 causes the first . It functions as a bifocal lens that outputs the second diffused wave. Note that the focus of the first diffused wave is a person, and the focus of the second diffused wave is B. 6 is the first signal sent out from the hologram 5.
゜This is an interference state measuring device that measures the interference state of the second diffused wave.
It is provided so that it can always move equidistantly in the directions of arrows c and c'. In other words, the interference state measuring device 6 is 0.
While moving in the directions of arrows c and c' with the point as the center, select the first point. The amount of interference caused by the second spread waves interfering with each other is measured. Reference numeral 7 denotes a calculation unit that performs geometric calculations based on the amount of interference measured by the interference state measuring device 6 to determine the angle of change β.

The operation of the above configuration will be explained below.

First, a laser beam emitted from the laser light source 4 causes the hologram 5 to be moved to the first hologram. A second diffused wave is output. On the other hand, the interference state measuring device 6 uses the first. Due to the second diffused wave, it is installed at a place where the waves interfere with each other at the point shown in FIG. 2, and it is movable along the curve 8, that is, the arrow c , c' and by the same angle as the change angle β.

Now, when the initial angle α changes and a change angle β occurs, and it is desired to measure this change angle β, the interference state measuring device 6 moves by the same angle in the direction of arrow C according to this change angle β and reaches point D/. Until then, the first and second waves pass between sa, sb, and ac, which interfere with each other. This amount of passage is sent to the calculation section 7. The calculation unit 7 can also calculate the change angle β by geometric calculation based on this amount of passage.

Hereinafter, the calculation by the calculation unit 7 will be explained with reference to FIG.

In FIG. 3, M and B are the first . It is assumed for convenience that, in particular, the mermaid is located at the origin of the XY coordinates at the focal point of the second diffused wave. 0
The angle (α' + θ) with the point as the apex is the initial angle, the angle β is the change angle, D is the point where the interference state measuring means 6 was installed, and D/ is because the interference state measuring device 6 measures the change angle β. This is the point where it moved to . y is the y coordinate at 8 points.

The first beam emitted from the hologram 5. Assuming that the second diffused wave is a spherical wave, the equivalent phase surface of the diffused wave from the human point (however,
At a certain time t=t0, the phase is O) is x 2 +y 2 =t1rλ (where 10=0.1
．． 2...N...(1) Also, the equivalent phase surface of the diffused wave from point B is x2+ (y y, >2 = nλ (where n==o, 1, 2... )・・・・・・
・(2) becomes.

From the first and second equations above, the coordinates of the intersection (the point where the 1st and 2nd diffused waves interfere with each other) are 2 y, 2
,! /.

(However, m=1.2.3-..., ni=nm).

On the other hand, D of the interference state measuring device 6 caused by the change angle β
' point is xI) t = 3:0 + on cos (α + β - θ)...
・・・乍)yDt = y0+OD 5in(α+β
-θ>-...-<e>.

Points that simultaneously satisfy Equations 3.4 and 5.6 become interference fringes measured by the interference state measuring device 6. That is, 2y.

There are many points, and the interference state measuring device 6
A large number of points satisfying Equation 8 are measured as interference.

On the other hand, since the calculation unit 7 simulates in advance the interference state in which the interference state measuring device 6 rotates, it calculates the angle of change geometrically from the value (interference fringes) measured by the interference state measuring device 6. β can be found.

In addition, the focus person or B of the first or second diffused wave is made to match the zero point by selecting the hologram,
If the rotation trajectory of the interference state measuring device 6 is configured to match one of the waves, the measurement accuracy will be further improved.

Effects of the Invention As described above, the present invention can accurately measure the angle of change by simply measuring the interference state of the first and second diffused waves emitted from the hologram that functions as a bifocal lens. It is possible to provide a compact device that is lightweight and can be installed freely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a change angle measuring device according to an embodiment of the present invention, and FIG. A conceptual diagram showing the interference state of the second diffused wave, Figures 3a and 3b are geometric diagrams showing the measurement positional relationship of the device, and Figure 4 is a block diagram of the main parts of a conventional change angle measuring device. It is. 4... Laser light S, S old... hologram, 6
. . . Interference state measuring device, 7 . . . Calculation unit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3

Claims (3)

[Claims] (1) A light source that emits a highly coherent light beam, a hologram that generates first and second diffused waves using the light beam emitted from the light source, and first and second diffused waves that are emitted from the hologram. interference state measuring means for measuring the interference state of the first and second diffused waves while moving according to the change angle to be measured; A calculation unit that calculates the angle of change according to the angle of change. (2) The change angle measuring device according to claim 1, wherein the interference state measuring means rotates at an equal distance around the change angle point to be measured. (3) The interference state measuring means is installed at one end of the arm, and the other end of the arm is rotatably provided at a change angle point to be measured. Change angle measuring device.