JP3336584B2 - Tilt angle measuring method and measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring an inclination angle, and more particularly, to a method for evaluating a transmission apparatus using an optical waveguide.

[0002]

2. Description of the Related Art A conventional measurement of a tilt angle of a mirror provided at an end of a three-dimensional optical waveguide will be described with reference to FIGS. As shown in FIG. 6, a mirror 53 is provided at an end of an optical waveguide 52 which is a light beam transmitting body provided on a substrate 51 having conductor wiring such as a silicon substrate. The substrate 51 is cut along the longitudinal direction of the optical waveguide 52, as shown in FIG. 7, was measured by observing the inclination angle theta _a formed between the surface and the mirror 53 of the substrate 51 is an optical microscope 21 .

[0003]

In the measurement of the inclination angle as described above, the substrate 51 must be cut before the measurement, which is troublesome and inefficient. In addition, since the substrate 51 is destructively treated, what is used for measurement cannot be actually used, not only increasing waste and increasing costs, but also using the measured sample for actual use. It must infer tilt angle theta _a things, although actually used to determine the inclination angle theta _a high precision has been very difficult.

[0004]

[0005]

[Means for Solving the Problems ] To solve the above-mentioned problems.
Therefore, the present invention is to irradiate a light beam to the measured object through the light beam transmission body, in a predetermined direction of the first radiated light having the maximum radiation intensity among the radiated light of the light beam emitted from the measured object obtains a first radiation angle theta _r1, obtains a first provisional inclined angle theta _x1 of the measured object with respect to a predetermined direction on the basis of the theta _r1 in formula (1) shown below, the value of the theta _x1 is below If it is shown smaller than the value of the critical reflection angle theta _c of the measured object obtained from the formula (2), or, the theta value of _x1 is greater than the value of the theta _c and the first emitted light the light beam when traveling to the upstream side, the value of the theta _x1 and the inclination angle theta _a of the measured object with respect to a predetermined direction, the theta _x1
Is larger than the value of θ _c and the first radiation light travels to the downstream side of the light ray, the second direction of the object to be measured in a predetermined direction based on the following equation (3). seeking temporary inclination angle theta _x2, wherein if larger than the predetermined range for values of theta _x2 the value of the theta _c to the value of the theta _x2 and the theta _a, the value of the theta _x2 said theta _If the value of _c is included within a predetermined range, a second radiation angle θ _r2 with respect to a predetermined direction of the second radiation having the radiation intensity next to the first radiation is obtained, and the following θ _r2 is obtained from the θ _r2: The third temporary inclination angle θ _r3 and the fourth temporary inclination angle θ _r4 of the measured object with respect to a predetermined direction based on Expressions (4) and (5) shown in
Is calculated, and an exponent value P is calculated from θ _x1 , θ _x2 , θ _x3 , and θ _x4 based on the following equation (6). When the value of P is a positive value, the following equation ( the theta _a based on 7)
Look, when the value of the P becomes a negative value by obtaining the theta _a according to equation (8) shown below, it was constituted the inclination angle measuring methods.

_Equation 3 θ _x1 = {cos ⁻¹ (sin θ _r1 / N)} / 2 (1) θ _c = cos ⁻¹ (1 / N) (2) θ _x2 = tan ⁻¹ (N−sin θ _r1 ) / (Cos θ _r1 ) (3) θ _x3 = {cos ⁻¹ (sin θ _r2 / N)} / 2 (4) θ _x4 = tan ⁻¹ (N−sin θ _r2 ) / (cos θ _r2 ) (5) ) P = | θ _x1 −θ _x4 | − | θ _x2 −θ _x3 | (6) θ _a = (θ _x2 + θ _x3 ) / 2 (7) θ _a = (θ _x1 + θ _x4 ) / 2 (( 8) where N is the refractive index of the light transmitting body

[0006] Here, the a measured object is a mirror, may the light is a laser beam.

[0007]

On the other hand, the present invention provides a light beam
Means and the light beam from the light beam oscillating means to the object to be measured.
A light beam transmitting body to be transmitted via a light beam transmitting body,
Radiation intensity of the light emitted from the light beam and the radiation
Measuring means for measuring the radiation angle of a predetermined direction of light
A predetermined emission of the emitted light measured by the measurement means.
And selecting the radiation angle of the radiation having the radiation intensity
Based on the selected radiation angle,
Calculating means for calculating the inclination angle of the object to be measured;
Display means for displaying a calculation result of the means, wherein the calculation means calculates a radiation angle θ _{r1 with} respect to a predetermined direction of the first radiation light having the maximum radiation intensity among the radiation lights measured by the measurement means. Calculating a first temporary inclination angle θ _x1 of the measured object with respect to a predetermined direction based on the following equation (1);
When the value of the θ _x1 is smaller than the value of the critical reflection angle θ _c of the object to be measured determined by the following equation (2), or the value of the θ _x1 is larger than the value of the θ _c and When the first emitted light travels upstream of the light beam,
The value of θ _x1 is determined to be the inclination angle θ _{a of the} measured object with respect to a predetermined direction, the value of θ _x1 is larger than the value of θ _c and the first radiation light is downstream of the light beam. In the case of proceeding, the second provisional inclination angle θ _x2 of the measured object with respect to a predetermined direction is calculated based on the following equation (3), and the value of θ _x2 is predetermined with respect to the value of θ _c. If more than a large range to determine the value of the theta _x2 and the theta _a, the theta
below the second radiating angle theta _r2 for a given direction of the second emitted light having a radiation intensity behind the first emitted light when the value of _x2 is included within a predetermined range with respect to the value of the theta _c calculating a third provisional inclined angle theta _x3 and the fourth tentative inclination angle theta _x4 of the measured object with respect to a predetermined direction based on the equations (4) and (5) shown in the θ _x1, θ _x2, θ _An index value P is calculated from _x3 and _θx4 based on the following equation (6).
When the value of P is a positive value, the θ _a is calculated based on the following equation (7). When the value of P is a negative value, the θ _a is calculated based on the following equation (8). with processor to calculate the theta _a Te, structure the inclination angle measuring device
It was done .

_Equation 4 θ _x1 = {cos ⁻¹ (sin θ _r1 / N)} / 2 (1) θ _c = cos ⁻¹ (1 / N) (2) θ _x2 = tan ⁻¹ (N−sin θ _r1 ) / (Cos θ _r1 ) (3) θ _x3 = {cos ⁻¹ (sin θ _r2 / N)} / 2 (4) θ _x4 = tan ⁻¹ (N−sin θ _r2 ) / (cos θ _r2 ) (5) ) P = | θ _x1 −θ _x4 | − | θ _x2 −θ _x3 | (6) θ _a = (θ _x2 + θ _x3 ) / 2 (7) θ _a = (θ _x1 + θ _x4 ) / 2 (( 8) where N is the refractive index of the light transmitting body

It is preferable that the light beam oscillating means is a laser diode device, the light beam transmitter is a single mode optical fiber, and the object to be measured is a mirror.

[0010]

In the tilt angle measuring method according to the above-described configuration, the object to be measured is irradiated with a light beam, and the emission angle of the light having a predetermined radiation intensity with respect to a predetermined direction among the light emitted from the object to be measured. Is obtained, and the inclination angle of the object to be measured with respect to a predetermined direction is obtained based on the radiation angle. Therefore, the inclination angle of the object to be measured can be obtained nondestructively.

Further, if the inclination angle of the object to be measured is obtained based on each of the above conditions, the angle of inclination of the object to be measured can be obtained more accurately.

Here, when the object to be measured is a mirror and the light beam is a laser beam, the tilt angle of the mirror can be obtained with higher accuracy.

On the other hand, in the tilt angle measuring device having the above-described configuration, when the light beam oscillated by the light beam oscillating means is sent to the measured object by the light beam transmitting body via the light beam transmitting body, the measuring means is radiated from the measured object. The radiation intensity and the radiation angle of the light beam are measured, and the calculation means selects the radiation angle of the radiation light having the predetermined radiation intensity from the radiation light measured by the measurement means, and the radiation angle with respect to the predetermined direction based on the selected radiation angle. The tilt angle of the measured object is calculated, and the display means displays the calculation result of the calculating means, so that the measured angle of the measured object is nondestructively measured.

Here, if the arithmetic means is an arithmetic processing device as described above, the inclination angle of the measured object can be measured more accurately.

If the light beam oscillating means is a laser diode device, the light beam transmitter is a single mode optical fiber, and the object to be measured is a mirror, the mirror tilt angle can be measured with higher accuracy. You.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic principle of the tilt angle measuring method and measuring apparatus according to the present invention will be described with reference to FIG. In addition, FIG.
It is a schematic diagram showing the basic principle.

As shown in FIG. 5, the light beam 101 is transmitted from the other end of the light beam transmitting member 42, that is, from the left side in FIG.
When irradiated in parallel to the substrate 41 toward
A substrate 41 in accordance with the form inclination angle theta _a between the measurement object 43, the reflected or transmitted through, the emitted light 1 from the measurement object 43
Emitted as 02. The emitted light 102, the inclination angle theta _a is in the case of below the critical reflection angle theta _c of the measurement object 43 (A), is reflected to the downstream side of the beam 101 (a), the inclination angle theta _a critical reflection angle In the case of _θc or more (B), ray 1
The light beam 101 is reflected upstream (b) and transmitted downstream of the light beam 101 (c). Mixed ratio of reflection and transmission of not less than the critical reflection angle theta _c depends on the inclination angle theta _a.

Therefore, the radiation direction of the radiation 114 and the substrate 1
By measuring the formed radiation angle theta _r a direction perpendicular to 11, according to Snell's law, it is possible to obtain the inclination angle theta _a. That is, when the radiated light 102 is reflected light, the inclination angle θ _a is obtained based on the following equation (11). When the radiated light 102 is transmitted light, the inclination angle θ _a is calculated by the following equation (12). the inclination angle theta _a is being asked based. However, the radiation angle θ _r is a deviation angle with respect to a direction perpendicular to the substrate 41, the downstream side of the light beam 101 is positive, and the upstream side of the light beam 101 is negative. Incidentally, the critical reflection angle theta _c described above can be determined based on equation (13) shown below.

Θ _a = {cos ⁻¹ (sin θ _r / N)} / 2 (11) θ _a = tan ⁻¹ (N−sin θ _r ) / (cos θ _r ) (12) θ _c = cos ^{− 1} (1 / N) (13) where N is the refractive index of the light transmitting body

An embodiment of a method and an apparatus for measuring an inclination angle according to the present invention, to which such a basic principle is applied, will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of the inclination angle measuring device.

As shown in FIG. 1, a laser beam 1
An input of a laser attenuator 2 for attenuating a laser beam is connected to an output of a laser diode device 1 as a light beam oscillating means for oscillating 11 via a single mode optical fiber 3 as a light beam transmitter. One end of an optical waveguide 52 which is a light beam transmitting body provided on a substrate 51 having a conductor wiring such as a silicon substrate is connected to an output portion of the attenuator 2 via a single mode optical fiber 4. Optical waveguide 52
On the other end side, a mirror 53 as an object to be measured is erected so as to be inclined with respect to the surface of the substrate 101.

Accordingly, the laser diode device 1 is operated to transmit the laser beam 111 to the single mode optical fibers 3 and 4.
The mirror 53 is irradiated with the laser beam 111 by sending the light from the one end of the optical waveguide 52 to the inside of the optical waveguide 52 via the attenuator 2. Thereby, the mirror 5
3, according to the size of the inclination angle theta _a formed between the substrate 51,
The laser beam 111 is emitted as the radiated light 112 so that the laser beam 111 is reflected or transmitted.

In the vicinity of the mirror 53, there is provided a measuring device 5 which is a measuring means for measuring a radiation angle and a radiation intensity of the radiation 112 from the mirror 53. The measuring device 5 is electrically connected to an arithmetic processing device 6 which is a calculating means for calculating an inclination angle between the substrate 51 and the mirror 53 based on a signal from the measuring device 5.

Here, the arithmetic processing function of the arithmetic processing unit 6 will be described with reference to FIGS. FIG. 2 is a flow chart, and FIG. 3 is a graph showing an example of data measured by a measuring instrument.

As shown in FIG. 2, the arithmetic processing unit 6 is arranged such that, in FIG. 3, the first radiation light 113 having the maximum radiation intensity of the radiation light 112 measured by the measuring instrument 5 and the direction perpendicular to the substrate 51 DOO seek a first radiation angle theta _r1 formed (S1).

That is, the actual radiation angle measurement data includes:
Many high-order mode peaks that cannot be assumed to be parallel to the substrate 51 exist. However, if the optical waveguide 52 is excited in a steady state, the peak intensity of the measured higher-order mode becomes smaller. Therefore, as shown in FIG. 3, the radiation angle of the peak having the large radiation intensity may be obtained.

As shown in FIG. 2, the arithmetic processing unit 61 comprises:
Based on the following equation (1), a first provisional tilt angle θ _x1 formed by the substrate 51 and the mirror 53 is calculated from the first radiation angle θ _r1 and the previously input refractive index N of the optical waveguide 52 (S
2).

_Equation 6 θ _x1 = {cos ⁻¹ (sin θ _r1 / N)} / 2 (1)

The arithmetic processing unit 6 calculates the critical reflection angle theta _c of the mirror 53 based on the equation (2) shown below, comparing the first temporary tilt angle theta _x1 and the critical reflection angle theta _c. When first temporary tilt angle theta _x1 is smaller than the critical reflecting angle theta _c is emitted light 112 are the reflected light, the arithmetic processing unit 6, a first temporary tilt angle theta _x1 and the substrate 51 a mirror 53 it is determined that the tilt angle theta _a to preparative forms (S11).

Equation 7 θ _c = cos ⁻¹ (1 / N) (2)

On the other hand, when the first provisional inclination angle θ _x1 is larger than the critical reflection angle θ _c , the emitted light 112 is reflected light or transmitted light, and the arithmetic processing unit 6 sets the first emission angle θ _It is determined whether _r1 is positive or negative (S3).

When the first radiation angle θ _r1 is negative, the radiated light 112 is radiated to the upstream side in the incident direction of the laser light 111, so that it is determined that the radiated light is reflected light.
It is determined that the first temporary tilt angle θ _x1 is the tilt angle θ _a of the mirror 53 (S12).

On the other hand, when the first radiation angle θ _r1 is positive,
Since the emitted light 112 is emitted to the downstream side in the incident direction of the laser beam 111, it is determined that the emitted light 112 is transmitted light or reflected light, and the arithmetic processing unit 6 assumes that the emitted light 112 is transmitted light, and The second provisional inclination angle θ _x2 is calculated based on Expression (3) shown in (4) (S4).

[Equation 8] θ _x2 = tan ⁻¹ (N−sin θ _r1 ) / (cos θ _r1 ) (3)

The arithmetic processing unit 6, a predetermined range for the critical reflection angle theta _c, i.e., the second temporary tilt angle within the error range of the instrument such as the instrument 5 for the critical reflection angle theta _c (approximately 5%) It is determined whether or not θ _x2 is included.

If the second provisional inclination angle θ _x2 is out of the above range, the emitted light 112 is determined to be transmitted light, and the processing unit 6 determines that the second provisional inclination angle θ _x2 is it is determined that the tilt angle θ _a (S13).

On the other hand, when the second provisional inclination angle θ _x2 is within the above range, the radiated light 112 has a large radiant intensity in both the transmitted light and the reflected light. For this reason, in FIG. 3, the arithmetic processing device 6 sets the second radiation 114 having the radiation intensity next to the first radiation 113 in the radiation 112 measured by the measuring device 5 in the direction perpendicular to the substrate 51. A second radiation angle θ _r2 is determined (S5).

As shown in FIG. 2, the arithmetic processing unit 6 calculates the third temporary angle from the second radiation angle θ _r2 and the refractive index N of the optical waveguide 52 based on the following equations (4) and (5). The inclination angle θ _x3 and the fourth provisional inclination angle θ _x4 are calculated (S6).

Θ _x3 = {cos ⁻¹ (sin θ _r2 / N)} / 2 (4) θ _x4 = tan ⁻¹ (N−sin θ _r2 ) / (cos θ _r2 ) (5)

The arithmetic processing unit 6 determines the reflection / transmission of the first radiation light 113 and the second radiation light 114 based on the following equation (6). An index value P is calculated from the fourth temporary inclination angles θ _x1 , θ _x2 , θ _x3 , θ _x4 (S7).

P = | θ _x1 −θ _x4 | − | θ _x2 −θ _x3 | (6)

When the exponent value P becomes a positive value, the arithmetic processing unit 6 calculates the mirror 53 from the second and third temporary inclination angles θ _x2 and θ _x3 based on the following equation (7). Tilt angle θ _a
Is calculated (S8).

Equation 11 θ _a = (θ _x2 + θ _x3 ) / 2 (7)

On the other hand, when the exponent value P is a negative value,
The arithmetic processing unit 6 calculates the first value based on the following equation (8).
First, fourth temporary inclination angle θ_x1, Θ_x4From the mirror 53
Degree θ _aIs calculated (S9).

[Expression 12] θ _a = (θ _x1 + θ _x4 ) / 2 (8)

That is, in steps S5 to S9,
If the reflection / transmission of the first radiated light 113 and the second radiated light 114 is properly determined, the tilt angle θ _{a of the} mirror 53 is determined regardless of whether the first radiated light 113 or the second radiated light 114 is used. Coincide with each other, the deviation in the absolute value shown in the above equation (6) approaches 0 within the error range. Therefore, using towards deviations in the absolute value is smaller, is set to ask the inclination angle theta _a mirror 53.

Accordingly, the arithmetic processing unit 7 determines the reflection and transmission of the radiation 112 from the mirror 53 and
Calculating a tilt angle theta _a.

As shown in FIG. 1, the arithmetic processing unit 6 includes:
A display 7 which is a display means for displaying a result calculated by the arithmetic processing unit 6 is electrically connected.

Accordingly, when the radiation 112 emitted by the mirror 53 is measured by the measuring device 5, the arithmetic processing unit 6 determines the inclination angle θ _a between the substrate 51 and the mirror 53 based on the signal from the measuring device 5. The calculation is performed, and the result is displayed on the display 7.

In order to determine the measurement accuracy of such an inclination angle measuring device, an inclination angle was determined using an obliquely polished optical fiber having _a known inclination angle θa. FIG. 4 shows the results. FIG. 4 is a graph showing the result. Here, the horizontal axis represents the actual inclination angle, and the vertical axis represents the error rate of the measured inclination angle with respect to the actual inclination angle.

As is apparent from FIG. 4, it was found that the error range of the inclination angle measuring device as described above was within ± 3%. Therefore, the present device can be used without any problem.

[0044] In the embodiment described above, was measured tilt angle theta _a mirror 53, for example, it is also possible to measure the tilt angle, such as a mirror prism like or obliquely polished fiber. In addition, after performing measurement by this method,
Using the measurement sample for which the mirror tilt angle and mirror surface accuracy were determined by destruction as a standard sample, the radiation beam profile from the mirror provided at the end of the optical waveguide, which is another sample, and the book determined before destruction measurement It is also possible to examine the inclination angle of the measurement sample and the mirror surface accuracy by comparing the measurement results with the method.

[0045]

According to the tilt angle measuring method of the present invention, the object to be measured is irradiated with a light beam, the emission angle of the light emitted from the object to be measured is determined, and the measurement angle of the object to be measured is determined based on the emission angle. Since the inclination angle of the object to be measured is obtained non-destructively by obtaining the inclination angle, the pre-processing of the object to be measured is not required, and the labor is greatly saved and the efficiency is improved. In addition, since the sample used for the measurement can be actually used, the cost is reduced, and the actually used sample can be directly measured, so that an accurate tilt angle can be obtained.

Further, if the inclination angle of the object to be measured is obtained based on each of the above conditions, the inclination angle of the object to be measured can be obtained more accurately.

If the tilt angle of the mirror is measured using laser light, the tilt angle of the mirror can be determined with higher accuracy.

In the tilt angle measuring apparatus according to the present invention, the light beam oscillated by the light beam oscillating means is sent to the object to be measured, the measuring means measures the radiation intensity and the radiating angle of the light beam radiated from the object to be measured, and the calculating means The tilt angle of the measured object is calculated based on the radiation angle of the radiation measured by the measuring means, and the display means displays the calculation result of the calculating means, thereby non-destructively measuring the tilt angle of the measured object. This eliminates the need for pretreatment of the object to be measured, greatly reducing labor and improving efficiency. In addition, since the sample used for the measurement can be actually used, the cost is reduced, and the actually used sample can be directly measured, so that an accurate tilt angle can be obtained.

Further, by using the above-mentioned arithmetic processing unit, the inclination angle of the measured object can be measured more accurately.

If the laser beam is irradiated from the laser diode device to the mirror with a single mode optical fiber, the mirror tilt angle can be measured with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of one embodiment of a tilt angle measuring device according to the present invention.

FIG. 2 is a flowchart of an arithmetic processing function of the arithmetic processing device according to the embodiment;

FIG. 3 is a graph showing an example of data measured by the measuring instrument of the embodiment.

FIG. 4 is a graph showing the accuracy of the measurement result of the example.

FIG. 5 is a schematic explanatory view showing a basic principle of a tilt angle measuring method and a measuring device according to the present invention.

FIG. 6 is an external view in which a part of the three-dimensional optical waveguide is omitted.

FIG. 7 is a schematic explanatory view of a conventional inclination angle measuring method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser diode device 3, 4 Single mode optical fiber 5 Measuring instrument 6 Arithmetic processing unit 7 Display 51 Substrate 52 Optical waveguide 53 Mirror 111 Laser light 112 Emitted light

Continuation of the front page (56) References Japanese Utility Model 1-70111 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01B 11/00-11/30 G01M 11/00

Claims (4)

(57) [Claims] 1. An object to be measured is irradiated with a light beam via a light beam transmitting body.
Shines, most of the emitted light of the light beam emitted from the measurement object
The first radiation having a high radiation intensity has a
One radiation angle θ _r1 is determined, and a predetermined direction is determined from θ _r1 based on the following equation (1).
The first provisional inclination angle θ _x1 of the measured object with respect to is obtained, and the value of the θ _x1 is obtained by the following equation (2).
If less than the value of the critical reflection angle theta _c of the measurement object, or
_{Alternatively,} the value of the θ _x1 is larger than the value of the θ _c and
When the first emitted light travels upstream of the light beam,
The value of the θ _x1 is determined by tilting the measured object with respect to a predetermined direction.
And the angle theta _a, greater than the value of the value of the theta _x1 said theta _c and the first
If the emitted light travels downstream of the ray,
The object to be measured in a predetermined direction based on equation (3)
The second provisional inclination angle θ _x2 is obtained, and the value of θ _x2 is not less than a predetermined range with respect to the value of θ _c.
If larger, the value of θ _x2 is defined as θ _a, and the value of θ _x2 is within a predetermined range with respect to the value of θ _c.
If included, has radiation intensity next to the first radiation
The second radiation angle θ _r2 with respect to the predetermined direction of the second radiation
And _calculated from θ _r2 based on the following equations (4) and (5).
And the third temporary inclination angle θ of the measured object with respect to a predetermined direction.
_r3 and the fourth provisional inclination angle θ _r4 are obtained, and from the above θ _x1 , θ _x2 , θ _x3 , and θ _x4 , the following equation (6) is obtained.
An exponent value P is obtained based on the above. If the value of P is a positive value, the following equation (7) is obtained.
Obtains the theta _a based on, shown below when the value of the P becomes a negative value (8)
Tilt angle and obtaining the theta _a based on the
Measuring method. _Equation 1 θ _x1 = {cos ⁻¹ (sin θ _r1 / N)} / 2 (1) θ _c = cos ⁻¹ (1 / N) (2) θ _x2 = tan ⁻¹ (N−sin θ _r1 ) / ( Cos θ _r1 ) (3) θ _x3 = {cos ⁻¹ (sin θ _r2 / N)} / 2 (4) θ _x4 = tan ⁻¹ (N−sin θ _r2 ) / (cos θ _r2 ) (5) ) P = | θ _x1 −θ _x4 | − | θ _x2 −θ _x3 | (6) θ _a = (θ _x2 + θ _x3 ) / 2 (7) θ _a = (θ _x1 + θ _x4 ) / 2 (( 8) where N is the refractive index of the light beam transmitting body Wherein said measured object is a mirror, to claim 1, wherein said light beam is a laser beam
The described tilt angle measuring method. 3. A light beam oscillating means for oscillating a light beam, and a light beam transmitted from the light beam oscillating means to an object to be measured.
A light beam transmitting body that transmits through a body, and an emission intensity of the light beam emitted from the object to be measured.
Measures the radiation angle and the radiation angle of the radiation with respect to the specified direction
Measuring means, and a predetermined radiant intensity of the radiated light measured by the measuring means.
The radiation angle of the radiation having the degree
Based on the selected radiation angle,
A calculating means for calculating an inclination angle of the measuring object; and a display means for displaying a calculation result of the calculating means , wherein the calculating means measures the radiation beam measured by the measuring means.
In the given direction of the first radiation having the maximum radiation intensity
From the radiation angle θ _r1 based on the following equation (1).
Calculate the first temporary tilt angle theta _x1 of the measured object with respect to the direction of
And the value of θ _x1 is determined by the following equation (2).
If less than the value of the critical reflection angle theta _c of the measurement object, or
_{Alternatively,} the value of the θ _x1 is larger than the value of the θ _c and
When the first emitted light travels upstream of the light beam,
The value of the θ _x1 is determined by tilting the measured object with respect to a predetermined direction.
Determines that the angle theta _a, greater than the value of the value of the theta _x1 said theta _c and the first
If the emitted light travels downstream of the ray,
The object to be measured in a predetermined direction based on equation (3)
The second provisional tilt angle θ _x2 is calculated, and the value of θ _x2 is not less than a predetermined range with respect to the value of θ _c.
The value of the theta _x2 is determined that the theta _a to greater, within a predetermined range with respect to values of said theta _c of the theta _x2
If included, has radiation intensity next to the first radiation
Second radiating angle theta _r2 or for a given direction of the second emitted light that
A predetermined one based on the following equations (4) and (5)
The third temporary inclination angle θ _x3 and the fourth
The temporary inclination angle θ _x4 is calculated, and from the above θ _x1 , θ _r2 , θ _x3 , θ _r4 , the following equation (6) is obtained.
An exponent value P is calculated based on the following equation. If the value of P is a positive value, the following equation (7) is used.
Calculates the theta _a based on, shown below when the value of the P becomes a negative value (8)
It is an arithmetic processing unit for calculating the theta _a based on the
A tilt angle measuring device. (2) θ _x1 = {cos ⁻¹ (sin θ _r1 / N)} / 2 (1) θ _c = cos ⁻¹ (1 / N) (2) θ _x2 = tan ⁻¹ (N−sin θ _r1 ) / ( Cos θ _r1 ) (3) θ _x3 = {cos ⁻¹ (sin θ _r2 / N)} / 2 (4) θ _x4 = tan ⁻¹ (N−sin θ _r2 ) / (cos θ _r2 ) (5) ) P = | θ _x1 −θ _x4 | − | θ _x2 −θ _x3 | (6) θ _a = (θ _x2 + θ _x3 ) / 2 (7) θ _a = (θ _x1 + θ _x4 ) / 2 (( 8) where N is the refractive index of the light beam transmitting body 4. The apparatus according to claim 1, wherein said light beam oscillating means includes a laser diode.
4. The apparatus according to claim 3 , wherein the light beam transmitter is a single mode optical fiber, and the object to be measured is a mirror.
The inclination angle measuring device according to 1.