JP5010964B2 - Angle measuring method and apparatus - Google Patents

Description

  The present invention relates to an angle measuring method and an apparatus thereof, and in particular, to a balance between measurement accuracy and operability in measuring an angle between side surfaces of a workpiece.

2. Description of the Related Art Conventionally, angle measuring devices have been used to perform precise measurement of angles such as the apex angle of prisms and the angles formed between polished surfaces of machined parts (for example, Patent Documents 1 to 3).
A conventional angle measuring device includes a rotary table, one optical system, and an angle meter.
In the conventional angle measurement, when the work is placed on the turntable and the turntable is adjusted so that the central axis of the optical system is perpendicular to the first face of the work, the reading of the angle meter is read on the first face. Measured value. Next, the rotation table is rotated, and when the rotation table is adjusted so that the central axis of the optical system is orthogonal to the second surface of the workpiece, the reading of the goniometer is taken as the measurement value of the second surface. Based on the measured value of the first surface and the measured value of the second surface, the angle formed by the first surface and the second surface of the workpiece is obtained.
JP 2006-90950 A JP-A-4-109105 JP 2001-227929 A

However, even in the conventional method, in order to measure the angle formed between the side surfaces of the work, a rotation operation of a rotary table or the like is involved, so that an error of the rotation mechanism is added to the measurement error. In order to measure with high accuracy, it may be possible to prepare a high-accuracy rotation mechanism. However, since the manufacturing cost is high, it has not been adopted as a solution for ensuring accuracy.
Further, since the surface positioning is required at least twice to measure the angle formed between the side surfaces of the workpiece, it takes time and time. In particular, when measuring a plurality of workpieces, the operability problem becomes more serious.
For this reason, regarding the measurement of the angle between the side surfaces of the workpiece, it has been strongly desired to achieve both measurement accuracy and operability. However, conventionally, there has been no appropriate technique that can solve this problem.
The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an angle measuring method and apparatus capable of achieving both measurement accuracy and operability.

<Angle measurement method>
In order to achieve the above object, an angle measuring method according to the present invention includes a first workpiece measuring means and a second angle measuring device, in which an installation angle formed with respect to the mounting table is set in advance. An angle measuring method for measuring an angle formed between the first side surface and the second side surface of the same type of measurement workpiece,
A measurement workpiece installation step, a measurement workpiece measurement step, a comparison step, and a calculation step are provided.

Here, the measurement work installation step includes the measurement of the first side surface of the measurement work by the first angle measurement unit and the measurement of the second side surface of the measurement work by the second angle measurement unit in a fixed state of the installation angle. The measurement workpiece is placed on the above-described table so that the above can be performed simultaneously.
Further, the measurement workpiece measurement step is provided after the measurement workpiece installation step, and the angle information of the first side surface of the measurement workpiece with respect to the central axis of the first angle measurement means is first calculated without operating the measurement workpiece. Obtained as a measurement value, and angle information of the second side surface of the measurement workpiece with respect to the central axis of the second angle measurement means is obtained as a second measurement value.
In the comparison step, a deviation of the first measurement value with respect to the first reference value is obtained as first deviation information, and a deviation of the second measurement value with respect to the second reference value is obtained as second deviation information.
The calculation step includes the first side surface of the measurement workpiece and the second measurement workpiece based on the angle correction value according to the first deviation information and the second deviation information obtained in the comparison step, and the reference angle of the reference workpiece. Find the angle to the side.

The installation angle is obtained by installing the reference workpiece on the platform described above, and measuring the angle of the first side surface of the reference workpiece by the first angle measurement unit and the angle measurement of the second side surface of the reference workpiece by the second angle measurement unit. It was set when the first angle measuring means was opposed to the first side surface of the reference workpiece and the second angle measuring means was opposed to the second side surface of the reference workpiece so that they could be performed simultaneously. .
The reference workpiece is for a workpiece whose reference angle between the first side surface and the second surface measurement is known. Further, the reference workpiece has a central axis of the second angle measuring means with the angle information of the first side surface of the reference workpiece relative to the central axis of the first angle measuring means when the installation angle is set as a first reference value. The angle information of the second side surface of the reference workpiece with respect to is obtained as the second reference value.
When the measurement workpiece is placed on the mounting table, the measurement angle of the first side surface of the measurement workpiece by the first angle measurement means and the measurement workpiece by the second angle measurement means are fixed with the installation angle fixed. The target is to perform angle measurement on two sides simultaneously.

  In the angle measurement method according to the present invention, it is preferable that the measurement workpieces placed on the table are replaced with each other and the plurality of measurement workpieces are sequentially measured.

Moreover, in the angle measuring method according to the present invention, it is preferable to include an installation angle setting step provided in a preceding stage of the measurement work installation step and a reference value acquisition step.
Here, in the installation angle setting step, a reference workpiece having a known reference angle is installed on the object table, and in the installation angle setting step, the first side surface of the reference workpiece with respect to the center axis is set by the first angle measuring means. The first angle measuring means is opposed to the reference work first side so that the angle information of the reference work is measured, and the angle information of the reference work second side with respect to the central axis is measured by the second angle measuring means. Thus, the installation angle is set by making the second angle measuring means face the second side surface of the reference workpiece.
Further, the reference value acquisition step acquires, as the first reference value, angle information of the first side surface of the reference workpiece with respect to the central axis of the first angle measurement means when setting the installation angle, and the second angle measurement means The angle information of the second side surface of the reference workpiece with respect to the central axis is obtained as a second reference value.

In order to achieve the above object, the angle measuring device according to the present invention includes a first angle measuring unit and a second angle measuring unit that set in advance an installation angle formed with respect to the mounting table. An angle measuring device for measuring an angle formed by a first side and a second side of a measurement workpiece of the same type as a reference workpiece,
Moreover, a comparison means and a calculation means are provided.
Here, in the present invention, in the fixed state of the installation angle, the first angle measurement means acquires angle information of the first side surface of the measurement workpiece with respect to the central axis as the first measurement value, and the second angle measurement. The angle information of the second side surface of the measurement workpiece with respect to the central axis is acquired as a second measurement value by the means.
Further, the comparison means obtains a deviation of the first measurement value with respect to the first reference value as first deviation information, and obtains a deviation of the second measurement value with respect to the second reference value as second deviation information.
The calculation means obtains an angle formed between the first side surface and the second side surface of the measurement workpiece based on an angle correction value corresponding to the first deviation information and the second deviation information and a reference angle of the reference workpiece.

The installation angle is obtained by installing the reference workpiece on the platform described above, and measuring the angle of the first side surface of the reference workpiece by the first angle measurement unit and the angle measurement of the second side surface of the reference workpiece by the second angle measurement unit. It was set when the first angle measuring means was opposed to the first side surface of the reference workpiece and the second angle measuring means was opposed to the second side surface of the reference workpiece so that they could be performed simultaneously. .
The reference workpiece is intended for a known reference angle formed by the first side surface and the second measurement surface, and the reference workpiece is the first angle measuring means when the installation angle is set. The angle information of the first side surface of the reference workpiece with respect to the central axis of the first angle is used as the first reference value, and the angle information of the second side surface of the reference workpiece with respect to the central axis of the second angle measuring means is obtained as the second reference value It is said.
The measurement workpiece is configured so that the angle measurement of the first side surface of the measurement workpiece by the first angle measurement unit and the angle measurement of the second side surface of the measurement workpiece by the second angle measurement unit can be performed simultaneously with the installation angle fixed. Intended for those installed on the above-mentioned table.

The first angle measuring means and the second angle measuring means of the present invention are those including at least two angle measuring means. That is, the present invention uses the angle measuring means as many as the number of surfaces to be measured. For example, if the number of measured surfaces is three, three angle measuring means are used, and if the number of measured surfaces is four, four angle measuring means are used.
As the angle measurement means of the present invention, for example, an interferometer, an autocollimator or the like can be used.
When an interferometer is used, an interference optical system and a capturing unit (for example, a screen or an imaging unit) are provided, and interference fringe information on the capturing unit can be used as angle information.
When an autocollimator is used, it has an autocollimator optical system and a capturing means (for example, a focusing screen, an eyepiece lens, and an imaging means), and captures a reflected image obtained by projecting a reticle light pattern onto the measurement surface. Captured above, the horizontal position of the observed image can be used as angle information.

<Remarks of the present invention>
The following measures may be taken to improve measurement accuracy. However, it has been difficult to achieve both measurement accuracy and operability in measuring the angle between the side surfaces of the workpiece.
(1) When the angle is measured by rotating the workpiece, it is conceivable to measure the rotation error of the rotating mechanism and correct the measurement result. However, satisfactory measurement accuracy could not be obtained.
(2) On the other hand, it is conceivable that the workpiece is fixed without rotating and the relative measurement with respect to the reference workpiece is performed, but there remains room for improvement in terms of operability.
That is, in order to perform relative measurement, as shown in FIG. 7A, a fixing jig 90, a mirror 92, and an optical system 22 such as an interferometer are provided. A reference workpiece is previously placed on the fixing jig 90, and the measurement angle is determined. Then, the angle of the measurement workpiece 12 is measured by placing the measurement workpiece 12 on the same fixing jig 90 and measuring the amount of deviation from the reference workpiece.
However, in this case, a seating error of the workpiece on the jig occurs, so the jig accuracy and the shape and fixing method of the workpiece that do not pinch dust are required, and satisfactory operability cannot be obtained. It was. Moreover, in order to ensure accuracy, a highly accurate jig is required. In particular, when the workpiece has an irregular shape as shown in FIG. 5B, the shape of the jig becomes very complicated. Furthermore, a jig adapted to each shape of the workpiece is required. Further, since the reference workpiece is also a reference in a state where it is seated on a jig, a workpiece having almost the same shape as the workpiece is required. For this reason, it did not come to employ | adopt as a solution means for ensuring precision.

On the other hand, as a result of repeated studies on the above problems, the present inventor has found the following points and completed the present invention.
That is, a plurality of angle measuring means corresponding to the number of measured surfaces of the workpiece are prepared. Using a reference workpiece with a known reference angle, an installation angle formed between the angle measuring means is set in advance. Further, when setting the installation angle, the reference value of the reference workpiece is measured by the angle measuring means.
Instead of the standard workpiece, the same type of measurement workpiece is installed on the mounting table of the angle measurement device equipped with a plurality of angle measurement means, where the installation angles are set in advance, and each side of the measurement workpiece is measured simultaneously To do. By adding or subtracting the angle correction value according to the deviation of the measured value from the reference value to the reference angle of the reference workpiece to obtain the angle between the sides of the measured workpiece, the angle between the side surfaces of the workpiece, which has been extremely difficult in the past. In measurement, both measurement accuracy and operability can be achieved.

According to the angle measurement method according to the present invention, since the measurement workpiece installation step, the measurement workpiece measurement step, the comparison step, and the calculation step are provided, in the angle measurement between the side surfaces of the workpiece, Both measurement accuracy and operability can be achieved.
According to the angle measuring method according to the present invention, the angle is set on the mounting table of the angle measuring apparatus provided with the first angle measuring means and the second angle measuring means in which the setting angle is set in advance using the reference workpiece. By exchanging the measurement workpiece and sequentially measuring the plurality of measurement workpieces, it is possible to more reliably realize both the measurement accuracy and the operability.
According to the angle measurement method according to the present invention, by providing the installation angle setting step and the reference value acquisition step, it is possible to more reliably realize both the measurement accuracy and the operability.

  In addition, according to the angle measuring device according to the present invention, since the angle measuring unit, the comparing unit, and the calculating unit are provided, the measurement accuracy and operability in the angle measurement between the side surfaces of the workpiece are obtained. Can be compatible.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of an angle measuring apparatus according to an embodiment of the present invention. In addition, the figure (A) is the figure which looked at the principal part of the angle measurement apparatus from the upper part, and the figure (B) is the figure which looked at the principal part of the angle measurement apparatus from the side. In the present embodiment, an example will be described in which a prism is assumed as a workpiece, and an apex angle between side surfaces of the prism is measured using an autocollimator as an angle measurement unit.
The angle measuring device 10 shown in the figure obtains an angle θ ₁ formed by the first side surface 12a and the second side surface 12b of the measurement workpiece 12.
For this purpose, the angle measuring device 10 includes a base 14, a mounting table 16, and a first angle measuring means 18 a and a second angle that are set in advance with an installation angle θ _L formed around the mounting table 16. An angle measuring means 18b and a computer 20 are provided.

Here, the stage 16 is provided on the base 12, and the measurement workpiece 12 or the reference workpiece is installed.
The first angle measuring unit 18a includes a first measuring optical system 22a and a first capturing unit 24a. The second angle measuring unit 18b includes a second measuring optical system 22b and a second capturing unit 24b. The first measurement optical system 22a and the second measurement optical system 22b are made of an autocollimator. The first capturing unit 24a and the second capturing unit 24b are made of an image sensor such as a CCD.

The computer 20 includes a memory 26, a comparison unit 28, a calculation unit 30, an input unit 32, and a monitor 34.
The memory 26 stores image data from the first capturing unit 24a and the second capturing unit 24b. The memory 26 also includes a reference angle θ ₀ formed by the first side surface and the second side surface of the reference workpiece 21, a first reference value and a second reference value, a first measurement value and a second measurement value, and first deviation information. In addition, an angle correction value or the like corresponding to the second deviation information is stored.
The computer 20 performs image processing such as edge detection on the image data from the first capturing unit 24a and the second capturing unit 24b, thereby observing the capturing units 24a and 24b in the visual fields R ₁ and R ₂ . The horizontal position of the image is obtained on the basis of the center position (position when the center axis line and the line perpendicular to the side face coincide).

Comparison means 28 for setting a first reference value acquired in advance at the time of installation angle theta _L, the displacement of the first measurement value determined as the first shift information, and pre-acquired by the set time of the installation angle theta _L The deviation of the second measurement value with respect to the second reference value is obtained as second deviation information.
The calculation means 30 adds or subtracts an angle correction value Δθ corresponding to the difference between the first deviation information and the second deviation information with respect to the reference angle θ ₀ of the reference workpiece 21, and the first side surface 12 a and the second side of the measurement workpiece 12. An angle θ ₁ formed with the side surface 12b is obtained.

In the present embodiment, the computer 20 further includes an input unit 32 and a monitor 34.
The input means 32 inputs the reference angle θ ₀ of the reference workpiece 21 to the computer 20.
The monitor 34 displays, for example, image data from the first capturing unit 24a and the second capturing unit 24b.

In the present embodiment, the angle measuring device 10 includes the adjusting mechanism 40 in order to perform the installation angle setting process of the present invention.
Here, the adjustment mechanism 40, when setting the installation angle theta _L only, the first angle measuring means 18a and rotatable relative to the base 14, also a second angle measuring means 18b as rotatable relative to the base 14 Yes.
On the other hand, adjustment mechanism 40, when determining the installation angle theta _L, to fix the angular position of the first angle measuring means 18a with respect to the base 14, and by fixing the angular position of the second angle measuring means 18b against the base 14 Yes.

  In this embodiment, in order to measure the angle, two angle measuring means for capturing each surface are provided. Of the two angle measuring means, one or more angle measuring means are configured to be rotatable with respect to the base. Moreover, when the angle measuring means which can be rotated is set to one, the stage is configured to be rotatable with respect to the base.

The angle measuring device 10 according to the present embodiment is configured as described above, and the operation thereof will be described below.
In the present embodiment, by using a first angle measuring means 18a and the second angle measuring means 18b which has been previously set the installation angle theta _L using the reference workpiece, the reference work the same kind of measuring the workpiece 12 first The angle θ ₁ formed by the one side surface 12a and the second side surface 12b can be measured while achieving both measurement accuracy and operability.

In this embodiment, by using the following workpiece, it is possible to achieve both measurement accuracy and operability in measuring the angle between the side surfaces of the workpiece.
That is, the reference workpiece is intended for a workpiece whose reference angle between the first side surface and the second surface measurement is known. Further, this reference work is the time of setting the eggplant installation angle theta _L between the first angle measuring means 18a and the second angle measuring means 18b, reference work first side with respect to the center axis L ₁ of the first angle measuring means 18a the angle information as a first reference value, the reference work angle information of the second side surface with respect to the center axis L ₂ of the second angle measuring means 18b as the second reference value, are directed to those which had been obtained in advance.
Measurements workpiece 12, when installed in the mount base 16, in a fixed state of the installation angle theta _L that is set in advance by using a reference work, the measured workpiece first side 12a by the first angle measurement means 18a It is intended for those capable of simultaneously performing angle measurement and angle measurement of the measurement work second side surface 12b by the second angle measurement means 18b.

In the present embodiment, by performing the following settings in advance, it is possible to achieve both measurement accuracy and operability at the measurement angle between the side surfaces of the workpiece.
That forms installation angle theta _L between the center axis L ₂ of the first angle measuring means 18a central axis L ₁ of the second angle measuring means 18b has established a reference workpiece mount base 16, a first angle measuring means The first angle measuring unit 18a is opposed to the first side surface of the reference workpiece so that the angle measurement of the first side surface of the reference workpiece by 12a and the angle measurement of the second side surface of the reference workpiece by the second angle measuring unit 18b can be performed simultaneously. And it was set when the 2nd angle measurement means 18b was made to oppose the 2nd side surface of a reference | standard workpiece.
As described above, in the present embodiment, two angle measuring means corresponding to the number of measured surfaces are provided, and the installation angle between each angle measuring means is set in advance using the reference workpiece. Also, obtain a reference value when setting the installation angle.

Then, in the present embodiment, a plurality of angle measuring means preset the installation angle theta _L, and the angle information of the first side surface 12a of the measurement work 12 with respect to the center axis L _1, the central axis L for ₂ and angle information of the second measurement Hakamen 12b are simultaneously measured. The angle between the side surfaces 12a and 12b of the measurement workpiece 12 can be obtained by adding or subtracting an angle correction value corresponding to the deviation of the measurement value from the reference value to the reference angle of the reference workpiece.
As a result, in the present embodiment, the first side surface and the second side surface can be measured simultaneously without rotating the measurement workpiece. In the measurement of the first side surface and the second side surface of the measurement workpiece, no mechanical error occurs because there is no rotational motion. Even if the position of the measurement workpiece is slightly deviated from the reference workpiece, no error occurs because each surface is captured and added / subtracted by the two optical systems. Therefore, it is possible to accurately measure with a simple fixing jig. Further, even if dust or the like adheres to the fixing jig and seating accuracy is somewhat deteriorated, measurement can be performed with the same accuracy. Thereby, a measurement error can be reduced significantly.
In addition, in the present embodiment, since the angle measurement of the first side surface and the angle measurement of the second side surface of the measurement work are simultaneously performed, the measurement time and labor associated with a general rotation operation can be reduced. Thereby, operability is improved.

Hereinafter, the operation will be described more specifically with reference to FIGS.
<Setting the installation angle>
This embodiment includes an installation angle setting step (S10) as shown in FIG.
Installation angle setting step (S10) is to set up the reference work 21 to mount base 16, setting the forming installation angle theta _L between the first angle measuring means 18a and the second angle measuring means 18b.
For this purpose, the installation angle setting step (S10) includes a first angle measurement means adjustment step (S12) shown in FIG. 2 (A) and a second angle measurement means adjustment step (S14) shown in FIG. 2 (B). And a reference value acquisition step (S16) shown in FIG.

<First angle measurement means adjustment>
In the first angle measurement means adjustment step (S12) shown in FIG. 2A, the reference workpiece 21 is installed on the stage 16. Then, by rotating the mount base 16 or the first angle measuring means 18a, in the field of view R ₁ of the first locking means 24a, capturing the first reference reflection images A ₁ from the reference work first side 21a.
As a result, as the first angle measuring means adjusting step (S12), angle information of the reference work first side 21a with respect to the center axis L ₁ is measured by the first angle measurement means 18a, a first side surface of the reference work 21 The first angle measuring means 18a can be opposed to 21a.

<Second angle measurement means adjustment>
Next, the second angle measuring means adjusting step (S14) shown in FIG. 2 (B), rotates the second angle measuring means 18b, in the field of view R ₂ of the second locking means 24b, reference work second side captures a second reference reflected image _{a 2} from 21b.
As a result, as the angle information of the second angle measuring means adjusting step in (S14), with respect to the center axis L _2, reference work the second side surface 21b is measured at a second angle measuring means 18b, a second reference work 21 The second angle measuring means 18b can be opposed to the side surface 21b.

<Acquiring reference values>
In the reference value acquisition step (S16) shown in FIG. 2C, the reference value is acquired and the installation angle is fixed.
That is, when setting the installation angle theta _L, the first angle measuring means 18a, a horizontal angle information of the reference workpiece first side 21a with respect to the center axis L _1, to obtain a first reference value. Therefore, in this embodiment, when the first reference reflection images A ₁ from the reference work first side 21a captured in the first field R ₁ of the first locking means 24a, the first reference reflected image A ₁ Is read as a first reference value for the reference work first side surface 21a.
Further, by the second angle measurement means 18b, the horizontal angle information of the reference workpiece second side 21b with respect to the center axis L _2, we obtain a second reference value. Therefore, in this embodiment, when the second reference reflected image A ₂ from the reference work second side 21b captured in the second field R ₂ of the second locking means 24b, the second reference reflected image A ₂ Is read as a second reference value for the reference workpiece second side surface 21b.

In the present embodiment, when obtaining the reference value, for mount base 16, by fixing the angular position of the first angle measuring means 18a and the second angle measuring means 18b, a fixed installation angle theta _L went ing.
As a result, in the present embodiment, it is possible to set up angle theta _L settings, and the acquisition of the reference values conducted.

<Installation and measurement of measurement workpiece>
The present embodiment includes a measurement work installation step (S20), a measurement work measurement step (S22), a comparison step (S24), and a calculation step (S26) as shown in FIG.
That is, in the measurement work installation step (S20) as shown in FIG. 5A, the measurement work 12 is installed at substantially the same position as the reference work installation on the mounting table 16. That is, the measurement workpiece 12 is placed on the stage 16 so that the angle measurement of the measurement workpiece first side surface 12a by the first angle measurement means 18a and the angle measurement of the measurement workpiece second side surface 12b by the second angle measurement means 18b can be performed simultaneously. Is installed.
After the measurement workpiece 12 is installed, the measurement workpiece measurement step (S22) is performed.
That is, the measuring work measuring step (S22), by the first angle measurement means 18a, obtains for the center axis L _1, the angle information of the measurement work first side 12a as a first measurement value, and the second angle measuring means by 18b, obtains the angle information of the measurement work second side 12b with respect to the center axis L ₂ as the second measured value.

<Comparison process>
In the comparison step (S24), the deviation of the first measurement value with respect to the first reference value is obtained as first deviation information, and the deviation of the second measurement value with respect to the second reference value is obtained as second deviation information.
In the present embodiment, in the comparison step (S24), as shown in FIG. 3B, the reflected images A ₁ and A ₂ when the reference workpiece is installed, and the reflected images B ₁ and B ₂ when the measurement workpiece is installed, by comparing the deviation, and the angle correction value [Delta] [theta], i.e. the deviation from the reference angle theta ₀ of the angle theta ₁ between the first side surface 12a and second side 12b of the measurement work 12 determined.
That is, when capturing the first measurement reflected image B ₁ from the measuring work first side 12a in the first field R ₁ of the first locking means 24a, the reading of the horizontal position of the first measurement reflector image B _1, Acquired as the first measurement value for the measurement work first side surface 12a.
At the same time when capturing the second measurement reflected image B ₂ from measuring the workpiece second side 12b in the second field R ₂ of the second locking means 24b, the reading of the horizontal position of the second measuring reflection image B _2, measured Obtained as the second measurement value for the workpiece second side surface 12b.
The comparison in step (S24), obtains a first measurement horizontal position displacement of the reflected image B ₁ with respect to the first reference reflection images A ₁ as the first shift information. Moreover, obtaining a second horizontal positional deviation of the measured reflection image B ₂ with respect to the second reference reflected image A ₂ as the second shift information.
As a result, in the comparison step (S24), the angle θ formed by the first side surface 12a and the second side surface 12b of the measurement workpiece 12 based on the difference (shift direction, shift amount) between the first shift information and the second shift information. _1, it is possible to obtain the deviation Δθ from the reference angle theta _0.

<Calculation process>
In calculation step (S26), according to the deviation Δθ from the first side surface 12a and the angle between the second side 12b, the reference angle theta ₀ of the reference work 21 of the measurement work 12 as shown in FIG. 3 (C) The obtained angle correction value Δθ is added to or subtracted from the reference angle θ ₀ of the reference workpiece 21.
As a result, the calculation step (S26), it is possible to obtain the angle theta ₁ between the first side surface 12a and second side 12b of the measurement work 12.

As described above, in the present embodiment, the deviation of the first measurement value with respect to the first reference value is the horizontal position of the first measurement reflected image when the measurement workpiece is installed with respect to the horizontal position of the first reference reflection image when the reference workpiece is installed. It can be obtained from the deviation. The deviation of the second measurement value with respect to the second reference value can be obtained from the deviation of the horizontal position of the second measurement reflected image when the measurement workpiece is installed with respect to the horizontal position of the second reference reflection image when the reference workpiece is installed.
Here, the horizontal position of the reflected image with respect to the center position in the field of view of the capturing means is when the central axis of the angle measuring means coincides with a line perpendicular to the side surface of the workpiece (the side surface is orthogonal to the central axis). To the angle change of the side surface. For this reason, the amount of change in the angle between the first side surface and the second side surface of the measurement workpiece from the reference angle of the reference workpiece can be obtained from the difference between the first deviation information and the second deviation information.
Therefore, the angle between the side surfaces of the measurement workpiece can be obtained by adding / subtracting the angle change amount obtained as described above to / from the reference angle of the reference workpiece.

<Measurement of multiple workpieces>
Thereafter, only the measurement workpiece 12 is exchanged, and measurement of a plurality of measurement workpieces 12 (FIGS. 3A to 3C) can be performed.
That is, in the present embodiment, the measurement workpiece 12 is a workpiece of the same type as the reference workpiece 21.
For this reason, in this embodiment, a several measurement workpiece | work can be measured sequentially only by installing in the mounting base 16. FIG.

As described above, according to the present embodiment, it is possible to achieve both improvement in measurement accuracy and operability in measuring the angle between the side surfaces of the workpiece.
Specifically, it is as follows.
(1) Although it depends on the accuracy of the reference workpiece, high-accuracy measurement can be performed.
(2) Since it is not necessary to make the side surface to be measured completely orthogonal to the central axis of the angle measuring means, it is easy to set the workpiece.
(3) Since it is a polygon simultaneous measurement, the measurement time is shortened and high-speed measurement can be performed.
(4) The mechanism can be simplified.
(5) simplified near jig is achieved.
(6) Standard work creation becomes easy.

In addition, this invention is not limited to the said structure, A various deformation | transformation is possible if it is in the range of the summary of invention.
For example, the standard workpiece can be replaced with an actual product that exhibits performance as a product.
Moreover, since this embodiment is comparative measurement with a reference | standard workpiece, after a rotation mechanism determines an installation angle, it should just be able to fix. Therefore, manufacture is easy and cost reduction can be achieved.
Furthermore, if only a fixed angle is measured, the rotation mechanism itself is unnecessary, and all can be manufactured with a fixing mechanism, so that further cost reduction is possible.

It is also preferable to apply the following reading mechanism, composite type angle measuring device, multi-optical system type angle measuring device, or measuring optical system.
<Reading angle information>
The image to be projected may be an arbitrary image whose position is easy to read.
The reflected image can be read by any method such as a scaled eyepiece or edge detection by image processing.
The pyramidal error can also be measured by reading the vertical direction of the observation image.
When an interferometer is used in the optical system, it is not necessary to project an image because measurement is performed using interference fringes.

As means for capturing the imaged light, there are an ocular lens, an image sensor, and the like. It is also preferable to perform image processing on image data captured from the image sensor and to automate reading.
That is, in this embodiment, it is also preferable to perform image processing in order to obtain the angle between the two side surfaces.
When image processing is performed, it is also preferable to take in a plurality of images to a computer and perform calculations.
When performing image processing, it is also preferable to create an in-screen calibration work.
It is also preferable to create a reference workpiece.

<Composite angle measuring device>
It is also preferable to constitute the following composite type as the angle measuring device.
FIG. 4 shows a schematic configuration when the angle measuring apparatus of the present embodiment is a composite type. Portions corresponding to those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
In the figure, the stage 16 is configured to be rotatable with respect to the base 14. An angle meter 50 is incorporated in such a table 16. And it is also possible to implement | achieve the measuring method shown by said FIG. 3 (A)-(C), and the measuring method shown by the following FIG. 4 with one angle measuring device.

That is, the measurement workpiece 12 as shown in Fig (A) placed on Nobutsu base 16, so that the center axis L ₁ of the first angle measuring means 18a is completely perpendicular to the first side surface 12a of the measurement work 12 The reading of the goniometer 50 when the stage 16 is adjusted to the measurement value of the measurement work first side surface 12a.
Then, by rotating the mount base 16, the angle at the time of adjusting the Nobutsu table 16 as the center axis L ₁ of the first angle measuring means 18a is completely perpendicular to the second side 12b of the measurement work 12 meter 50 Is the measured value of the measurement work second side surface 12b.
Based on the first measurement value and the second measurement value thus obtained, the angle θ ₁ formed by the first side surface 12a and the second side surface 12b of the measurement workpiece 12 is obtained.
As a result, the measurement method shown in FIG. 4 is used for measurement of a prism of an arbitrary angle created on a trial basis, and the measurement method shown in FIG. 3 is used for mass production. Is possible.

<Multi-optical system angle measuring device>
In the above configuration, an example using two angle measuring means has been described. However, the present invention is not limited to this, and it is also possible to provide, for example, three or more units according to the number of measured surfaces. preferable.
FIG. 5 shows a schematic configuration when the angle measuring apparatus of the present embodiment is a multi-optical system type. In addition, the figure (A) shows the mode of an installation angle setting process, and the figure (B) shows the state of a measurement work installation process and a measurement work measurement process. Portions corresponding to those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
In the drawing, three side surfaces of the measurement workpiece 12, that is, a first side surface 12a, a second side surface 12b, and a third side surface 12c are measured surfaces. The first angle measuring unit 18a, the second angle measuring unit 18b, and the third angle measuring unit 18c are opposed to the first side surface 12a, the second side surface 12b, and the third side surface 12c of the measurement workpiece 12, respectively.
Then, the measurement of the angle information of the first side surface 12a by the first angle measurement unit 18a, the measurement of the angle information of the second side surface 12b by the second angle measurement unit 18b, and the third side surface 12c by the third angle measurement unit 18c. Simultaneously measure angle information.

That is, in FIG. 2A, the reference workpiece 21 is installed, the first side surface 21a is captured by the first angle measuring means 18a, the second side surface 21b is captured by the second angle measuring means 18b, and the third side as a side 21c is captured by the third angle measuring means 18c, eggplant installation angle between the center axis L ₂ of the central axis of the first angle measuring means 18a L ₁ and the second angle measuring means 18b, a second angle measuring means 18b installation formed by the center axis L ₂ forms installation angle between the central axis line L ₃ of the third angle measuring means 18c, the center axis L ₁ of the third angle and measuring means 18c center axis L ₃ of the first angle measuring means 18a of The corner is set.
In the figure, the reference workpiece 21 has a known first reference angle formed by the first side surface 21a and the second side surface 21b, a second reference angle formed by the second side surface 21b and the third side surface 21c, and a third side surface. It is assumed that the third reference angle formed by 21c and the first side surface 21a is known.

Next, in FIG. 4B, a measurement workpiece 12 is installed instead of the reference workpiece 21. That is, the first side surface 12a of the measurement workpiece 12 is captured by the first angle measurement unit 18a, the second side surface 12b is captured by the second angle measurement unit 18b, and the third side surface 12c is captured by the third angle measurement unit 18c. As shown, the measurement workpiece 12 is arranged.
And the angle information of the 1st side surface 12a of the measurement workpiece | work 12 is acquired as a 1st measured value by the 1st angle measurement means 18a. The angle information of the second side surface 12b of the measurement workpiece 12 is acquired as the second measurement value by the second angle measurement means 18b. The third angle measurement means 18c acquires the angle information of the third side surface 12c of the measurement workpiece 12 as a third measurement value.

Then, an angle correction value corresponding to the deviation of the first measurement value and the second measurement value with respect to the first reference value and the second reference value is added to or subtracted from the first reference angle, The angle formed with the second side surface 12b is obtained. An angle correction value corresponding to the deviation of the second measurement value and the third measurement value with respect to the second reference value and the third reference value is added to or subtracted from the second reference angle, and the second side surface 12b of the measurement workpiece 12 and the third correction value are added. The angle formed with the side surface 12c is obtained. An angle correction value corresponding to the deviation of the third measurement value and the first measurement value with respect to the third reference value and the first reference value is added to or subtracted from the third reference angle, and the third side surface 12c of the measurement workpiece 12 and the first correction value The angle formed with the side surface 12a is obtained.
Examples of the work include a polygonal prism (including a triangular prism), a polygon mirror, and the like. Further, in the angle measuring apparatus shown in the figure, an angle meter can be incorporated as in the angle measuring apparatus shown in FIG.

<Measurement optical system>
A general interferometer or autocollimator can also be used as the angle measurement means of the present embodiment.
However, in order to achieve better balance between measurement accuracy and operability, it is also very important to quickly capture the target within the field of view of the angle measuring means.
Therefore, in the present embodiment, it is particularly preferable to use the following autocollimator as the angle measuring means, that is, as the measurement optical system.

FIG. 6 shows a schematic configuration of an autocollimator suitable as a measurement optical system of the present embodiment. In the figure, one measurement optical system among a plurality of measurement optical systems will be described as an example, but the other measurement optical systems have the same configuration. Hereinafter, the measurement optical system is referred to as an autocollimator 22.
What is characteristic in the figure is that a single autocollimator 22 realizes both a high-magnification collimator and a low-magnification collimator. For this purpose, the autocollimator 22 shown in the figure includes a light emitting means 60, a reticle 62, a long focal length collimating lens 64, a short focal length collimating lens 66, and an optical path branching means 68.
The long focal length collimator lens 64 includes the teletype optical system 70 and the capturing means 24 provided at the focal point 72 of the teletype optical system 70. The teletype optical system 70 includes a convex lens 74 and a concave lens 76 provided on the image forming side of the convex lens 74, the total lens length of which is designed to be shorter than the focal length.
The short focal length collimator lens 66 includes a convex lens 74 of the long focal length collimator lens 64 and a capturing means 24 ′ provided at the focal point 78 of the convex lens 74.

Then, the light 80 from the light emitting means 60 illuminates the reticle 62, and the pattern light 82 having a cross line is emitted from the reticle 62.
The pattern light 82 from the reticle 62 is reflected by the beam splitter 84, the light beam diameter is enlarged by the concave lens 76, passes through the beam splitter 68, becomes parallel light by the convex lens 74, and enters the side surface 12 a of the workpiece 12. The reflected pattern light 86 from the side surface 12a passes through the convex lens 74 and becomes convergent light.

  The optical path branching unit 68 uses the optical path of the reflected pattern light 86 from the side surface 12 a obtained by irradiating the pattern light 82 on the side surface 12 a as the optical path of the long focal length collimator lens 64 and the optical path of the short focal length collimator lens 66. Divide.

That is, the reflection pattern light 86 from the convex lens 74 forms an image at the focal point 78 when reflected by the beam splitter 68. By capturing the imaging position of the reflected pattern light (observation image) 86 at the focal point 78 within the visual field of the capturing unit 24 ′, the autocollimator 22 is aimed at the side surface 12 a.
Further, when the reflected pattern light 28 from the convex lens 74 passes through the beam splitter 68, it forms an image at the focal point 72 through the concave lens 76 and the beam splitter 84. The capturing unit 24 reads the imaging position of the reflected pattern light 86 at the focal point 72.

  By configuring the autocollimator 22 in this manner, a long focal length collimator lens and a short focal length collimator lens can be realized by a single unit. That is, the long focal length collimator lens can be used for obtaining highly accurate angle information. On the other hand, the short focal length collimator lens can be used when capturing the side surface in the field of view of the capturing means.

It is explanatory drawing of schematic structure of the angle measuring device concerning one Embodiment of this invention. It is explanatory drawing which shows the process sequence of the installation angle setting process characteristic in the angle measuring method concerning one Embodiment of this invention. It is explanatory drawing which shows the process sequence of the measurement workpiece | work installation process-calculation process characteristic in the angle measuring method concerning one Embodiment of this invention. It is explanatory drawing of schematic structure of the composite type angle measuring apparatus which is a modification of the angle measuring apparatus shown in FIG. It is explanatory drawing of schematic structure of the multi-optical type angle measuring device which is a modification of the angle measuring device shown in FIG. It is explanatory drawing of schematic structure of the measurement optical system suitable in this embodiment. It is explanatory drawing of the general angle measuring method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Angle measuring device 14 Base 16 Mounting base 18a First angle measuring means 18b Second angle measuring means 22a First measuring optical system (first angle measuring means)
22b Second measuring optical system (second angle measuring means)
24a First capturing means (first angle measuring means)
24b Second capturing means (second angle measuring means)
28 Comparison means 30 Calculation means

Claims (4)

The angle formed between the first side and the second side of the same kind of measurement workpiece as the reference workpiece by the first angle measurement means and the second angle measurement means that have been set in advance with respect to the mounting table. An angle measurement method for measuring
The installation angle is obtained by installing the reference workpiece on the platform described above, and measuring the angle of the first side surface of the reference workpiece by the first angle measurement unit and the angle measurement of the second side surface of the reference workpiece by the second angle measurement unit. It was set when the first angle measuring means was opposed to the first side surface of the reference workpiece and the second angle measuring means was opposed to the second side surface of the reference workpiece so that they could be performed simultaneously. ,
The reference workpiece is intended for a known reference angle formed by the first side surface and the second measurement surface, and the reference workpiece is the first angle measuring means when the installation angle is set. The angle information of the first side surface of the reference workpiece with respect to the central axis of the first angle is used as the first reference value, and the angle information of the second side surface of the reference workpiece with respect to the central axis of the second angle measuring means is obtained as the second reference value. And
When the measurement workpiece is placed on the mounting table, the measurement angle of the first side surface of the measurement workpiece by the first angle measurement means and the measurement workpiece by the second angle measurement means are fixed with the installation angle fixed. Targeting those that can measure the angle of two sides simultaneously,
The work table described above, so that the angle measurement of the first side surface of the measurement workpiece by the first angle measurement unit and the angle measurement of the second side surface of the measurement workpiece by the second angle measurement unit can be simultaneously performed in the fixed state of the installation angle. And a measurement work installation step for installing the measurement work,
Provided in the subsequent stage of the measurement workpiece installation step, without operating the measurement workpiece, to obtain angle information of the measurement workpiece first side surface with respect to the central axis of the first angle measurement means as a first measurement value, and the first A measurement workpiece measurement step of obtaining angle information of the measurement workpiece second side surface with respect to the central axis of the two-angle measurement means as a second measurement value;
A comparison step for obtaining a deviation of the first measurement value with respect to the first reference value as first deviation information, and obtaining a deviation of the second measurement value with respect to the second reference value as second deviation information;
An angle formed between the first side surface of the measurement workpiece and the second side surface of the measurement workpiece based on the angle correction value according to the first deviation information and the second deviation information obtained in the comparison step, and the reference angle of the reference workpiece. A calculation step for obtaining
An angle measuring method comprising: The angle measuring method according to claim 1,
An angle measuring method, comprising: exchanging a measuring work set on the table and measuring a plurality of the measuring works sequentially. In the angle measuring method according to claim 1 or 2,
An installation angle setting step provided in the previous stage of the measurement work installation step, and a reference value acquisition step,
In the installation angle setting step, the reference workpiece having the known reference angle is placed on the object table, and the first angle measuring means measures the angle information of the first side surface of the reference workpiece with respect to the central axis. The reference workpiece second side surface is arranged so that the first angle measurement means faces the reference workpiece first side surface and the second angle measurement means measures angle information of the reference workpiece second side surface with respect to the central axis. By setting the second angle measuring means to face each other, the installation angle is set,
In the reference value acquisition step, when setting the installation angle, the angle information of the first side surface of the reference workpiece with respect to the central axis of the first angle measurement unit is acquired as a first reference value, and the center of the second angle measurement unit An angle measurement method characterized in that angle information of a second side surface of a reference workpiece with respect to an axis is acquired as a second reference value. A first angle measuring means and a second angle measuring means, in which the installation angles formed with respect to the mounting table in advance are set in advance, are formed between the first side surface and the second side surface of the same type of measuring workpiece as the reference workpiece. An angle measuring device for measuring an angle,
The installation angle is obtained by installing the reference workpiece on the platform described above, and measuring the angle of the first side surface of the reference workpiece by the first angle measurement unit and the angle measurement of the second side surface of the reference workpiece by the second angle measurement unit. It was set when the first angle measuring means was opposed to the first side surface of the reference workpiece and the second angle measuring means was opposed to the second side surface of the reference workpiece so that they could be performed simultaneously. ,
The reference workpiece is intended for a known reference angle formed by the first side surface and the second measurement surface, and the reference workpiece is the first angle measuring means when the installation angle is set. The angle information of the first side surface of the reference workpiece with respect to the central axis of the first angle is used as the first reference value, and the angle information of the second side surface of the reference workpiece with respect to the central axis of the second angle measuring means is obtained as the second reference value. And
The measurement workpiece is configured so that the angle measurement of the first side surface of the measurement workpiece by the first angle measurement unit and the angle measurement of the second side surface of the measurement workpiece by the second angle measurement unit can be performed simultaneously with the installation angle fixed. , Intended for those installed on the table above,
In the fixed state of the installation angle, the first angle measurement means acquires the angle information of the first side surface of the measurement work relative to the center axis as the first measurement value, and the second angle measurement means measures the measurement work for the center axis. Obtain the angle information of the second side as the second measurement value,
Further, a comparison means for obtaining a deviation of the first measurement value with respect to the first reference value as first deviation information, and obtaining a deviation of the second measurement value with respect to the second reference value as second deviation information;
Calculation means for obtaining an angle formed between the first side surface and the second side surface of the measurement workpiece based on the angle correction value according to the first deviation information and the second deviation information, and the reference angle of the reference workpiece;
An angle measuring device comprising:

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