JP4751156B2 - Autocollimator and angle measuring device using the same - Google Patents

Description

  The present invention relates to an autocollimator and an angle measuring device using the same, and more particularly to an autocollimator having a wide-range observation optical system.

Conventionally, an angle measuring device (Patent Document 1 and Patent Document 2) has been used to accurately measure angles such as prism angle, machined part flatness, and straightness.
As the angle measuring device, an autocollimator (for example, Patent Documents 3 and 4) is used.

The basic configuration of the autocollimator is shown below.
That is, in the autocollimator, a reticle provided with a crosshair and a focusing plate provided with a graduation line are placed at a conjugate position of the focus of the objective lens via the beam splitter.

  Then, the light emitted from the center of the crosshair of the reticle illuminated by the light emitting means becomes a parallel light flux when passing through the objective lens. When the sample is placed so that the measurement surface is completely perpendicular to this parallel light beam, the light is reflected by the measurement surface and returns to the objective lens along the original path. Focus on the center.

When the sample measurement surface is tilted by a small angle from this state, the return light from the sample measurement surface is tilted, and the light emitted from the center of the reticle crosshair is imaged at a point displaced from the center of the focusing screen.
By reading the amount of displacement of the imaging position from the center of the focusing screen with a micrometer or a photoelectric sensor, the angle of the sample measurement surface can be obtained based on the read amount of displacement and the focal length of the objective lens.
By configuring the autocollimator in this way, precise angle measurement can be performed.

JP-A-6-167325 Japanese Patent Laid-Open No. 11-183148 Special table 2004-317424 gazette JP 2004-219221 A

Incidentally, the autocollimator is required to improve the angular resolution. In order to improve angular resolution, the focal length is usually increased.
As a result, the total length of the objective lens becomes long, and therefore, the total length of the autocollimator becomes long and difficult to handle. Therefore, it is difficult to improve the satisfactory angular resolution.
In addition, in an autocollimator, it is also important to perform the setting before measurement in order to accurately measure the angle.
That is, if a cross-line image from the sample measurement surface is not reliably captured in the setting before measurement, that is, in the field of view of the autocollimator, a measurement error may occur.
Since a general autocollimator has only a measurement optical system, setting before measurement has been performed manually and manually by an operator.
However, the higher the sensitivity of the autocollimator, the more difficult it is to set before measurement, and it takes time to capture the sample measurement surface within the field of view of the autocollimator, leaving room for improvement in operability.

As described above, auto collimators have been desired to simplify the configuration, improve the angular resolution, and improve the operability of the setting before measurement. However, conventionally, there is no appropriate technology that can satisfy these requirements simultaneously. It was.
The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide an autocollimator and an angle measuring device capable of simultaneously simplifying the configuration, improving the angular resolution, and improving the operability. It is to provide.

As a result of studies by the present inventors, a large angle is measured using a collimator optical system, and a small angle is measured using an optical system in which a focal length is extended by providing a concave lens in the collimator optical system. Thus, it has been found that a satisfactory configuration simplification, angle resolution improvement and operability improvement can be achieved simultaneously, and the present invention has been completed.
In order to achieve the above object, an autocollimator according to the present invention includes a light emitting means, a reticle, a measurement optical system, a wide-range observation optical system, and an optical path branching means.
Here, the light emitting means emits light.
Further, the reticle uses the light from the light emitting means as pattern light having a desired pattern.

  The measurement optical system irradiates the sample measurement surface with the pattern light from the reticle as parallel light, converges the reflected pattern light from the sample measurement surface, and converges the reflected pattern light at the measurement imaging point. Assume that measurement is performed based on the imaging position. The measurement optical system includes a teletype optical system and a measurement capturing means. The teletype optical system includes a front lens having a positive power and having a total lens length shorter than the focal length, and a rear lens having a negative power provided on the imaging side of the front lens. The measurement capturing means is provided at the focal point of the teletype optical system which is the measurement imaging point, and determines the imaging position of the reflected pattern light from the sample measurement surface obtained through the measurement optical system. It is meant to be captured.

  The total length of the lens here is designed to be shorter than the focal length, the front lens having a positive power, and the rear lens having a negative power provided on the image forming side of the front lens. This means that the position of the virtual lens when it is replaced with a thin virtual lens is closer to the sample than the front surface of the front lens.

  The wide-range observation optical system irradiates the sample measurement surface with the pattern light from the reticle as parallel light, converges the reflected pattern light from the sample measurement surface, and reflects the reflection pattern at the imaging point for wide-range observation It is intended to perform wide-range observation based on the light imaging position. The wide-range observation optical system includes the front lens of the measurement optical system and a measurement capturing unit. The capturing means for wide-area observation is provided at the focal point of the front lens, which is the imaging point for wide-area observation, and the imaging position of the reflected pattern light from the sample measurement surface obtained through the wide-area observation optical system To capture.

  The optical path branching unit is provided between the front lens and the rear lens, and the optical path of the reflected pattern light from the sample measurement surface obtained by irradiating the sample measurement surface with pattern light is used for the wide-range observation. It is for branching to an optical path of an optical system or an optical path of the optical system for measurement.

<Measurement>
The measurement here includes, for example, high-sensitivity measurement of the angle of the sample measurement surface, positioning, and the like.
The high-sensitivity measurement of the angle refers to, for example, detecting the inclination of the normal line of the sample measurement surface. The positioning is, for example, determining the relative angle between the autocollimator and the sample measurement surface so that the optical axis of the autocollimator is orthogonal to the sample measurement surface, that is, capturing the center of the pattern light at the center of the field of view of the measurement capturing means. That means.

<Wide area observation>
The wide-area observation mentioned here includes, for example, angle measurement in a wide angle range on the sample measurement surface, aiming, and the like. The aiming means capturing the sample measurement surface within the field of view of the wide range observation capturing means, that is, capturing the reflected pattern light from the sample measurement surface within the field of view of the wide range observation capturing means.

<Light emitting means>
Examples of the light emitting means of the present invention include a light source and an illumination optical system.

<Imaging light capturing means>
Examples of the imaging position capturing means of the present invention include, for example, a focusing screen, a screen, an eyepiece lens, an imaging device, and the like having scale lines. Examples of the image sensor include a CCD and a CMOS.

In the present invention, the optical path branching unit reflects the reflected pattern light from the sample measurement surface obtained by irradiating the sample measurement surface with pattern light and branches it to the optical path of the wide-range observation optical system.
The wide-range observation optical system preferably includes a mirror. Preferably, the mirror is provided between the optical path branching unit and the wide-range observation imaging point, reflects the reflection pattern light from the optical path branching unit, and forms an image on the wide-range observation imaging point. It is.

In the present invention, the reticle is included on the wide-range observation optical system side.
The mirror is a half mirror.
The pattern light from the reticle is preferably transmitted through the mirror of the wide-range observation optical system, reflected by the optical path dividing means, passed through the front lens, and irradiated onto the sample measurement surface.
The half mirror guides the pattern light from the reticle to the optical path branching unit, and guides the optical path of the reflection pattern light branched to the optical path of the wide-range observation optical system by the optical path branching unit. It is preferable to form an image at an imaging point for wide-range observation.

In the present invention, the reticle is included in the wide-range observation optical system side and the measurement optical system side.
The optical path branching unit includes a movable mirror provided so as to be inserted or retracted into an optical path between the front lens and the rear lens.
During the wide-range observation, the movable mirror is inserted into the optical path between the front lens and the rear lens, and the pattern light from the reticle on the wide-range observation optical system side passes through the movable mirror. The sample measurement surface is irradiated, and the reflected pattern light from the sample measurement surface forms an image on the wide-range observation imaging point via the movable mirror.
At the time of measurement, the movable mirror is retracted from the optical path between the front lens and the rear lens, and the pattern light from the reticle on the measurement optical system side does not pass through the movable mirror. It is preferable that the reflected pattern light irradiated from the sample measurement and imaged from the sample measurement surface is imaged on the measurement imaging point without passing through the movable mirror.

Angle measuring device also angle measuring apparatus using such autocollimator to the present invention in order to achieve the object, a specimen mount, the arm, and the rotation means, and a rotation control means, a detector, and calculating means, It is characterized by providing.

Here, the sample stage is fixed to or rotated on the base, and a sample having a first measurement surface and a second measurement surface that constitute an angle to be measured is placed thereon.
In addition, the arm is fixedly or rotatably provided on the base, and holds the autocollimator in a state facing the measurement surface side of the sample on the sample base.
The rotating means rotates the sample table or the arm with respect to the base.
The rotation control means controls rotation of the sample stage or the arm by the rotation means.
The detector detects rotation angle information of the sample table or the arm with respect to the base.
The calculation means includes rotation angle information obtained from the detector when the autocollimator optical axis positioned by the autocollimator is orthogonal to the sample first measurement surface, and the autocollimator optical axis positioned by the autocollimator; Based on the rotation angle information obtained from the detector when orthogonal to the sample second measurement surface, the angle formed by the first measurement surface and the second measurement surface of the sample is obtained.

  According to the autocollimator of the present invention, the measuring optical system includes a front lens having a positive power and a rear lens having a negative power, which is designed to have a total lens length shorter than the focal length, and which is provided at the rear stage of the front lens. System, a wide-range observation optical system including a front stage lens of the measurement optical system, and an optical path branching unit for branching the optical path of the reflected pattern light from the sample measurement surface. , Sufficient angular resolution, and improved operability can be obtained at the same time.

  In the present invention, the wide-range observation optical system includes a mirror that further reflects the reflection pattern light from the optical path branching means, so that the movement of the images of the wide-range observation optical system and the measurement optical system is the same. The operability can be improved more reliably.

  In the present invention, since the reticle is included on the wide-range observation optical system side, the configuration can be simplified more reliably.

  In the present invention, since the reticle is included in the wide-range observation optical system side and the measurement optical system side, and the optical path branching unit includes the movable mirror, sufficient angular resolution or operability is improved. Can be obtained more reliably.

  Further, according to the angle measuring apparatus according to the present invention, since the autocollimator according to the present invention is provided, simplification of the configuration, sufficient angular resolution, and improvement in operability can be obtained at the same time.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
Autocollimator <first embodiment>
FIG. 1 shows a schematic configuration of an autocollimator according to a first embodiment of the present invention.
The autocollimator 10 shown in the figure includes a light emitting means 12, a reticle 14, a measurement optical system 16, a wide-range observation optical system 18, and an optical path branching means 20.

Here, the light emitting means 12 includes a light source 22 and an illumination optical system 24, and emits light 26.
The reticle 14 uses the light 26 from the light emitting means 12 as pattern light 28 having a crosshair (a desired pattern).

The measurement optical system 16 irradiates the measurement surface 30a of the sample 30 with the pattern light 28 from the reticle 14 as parallel light, and converges the reflected pattern light 32 from the measurement surface 30a. It is assumed that measurement is performed on the basis of the imaging position of the reflection pattern light 32 with respect to the center (optical axis).
The measurement optical system 16 includes a teletype optical system 34 and a measurement capturing means 36.
The teletype optical system 34 includes a convex lens (a front lens having a positive power) 38 designed to have a total lens length shorter than the focal length, and a concave lens (having a negative power) provided on the imaging side of the convex lens 38. A rear lens) 40.
The measurement capturing means 36 includes a focusing screen having graduation lines, an image sensor (CCD, CMOS), an eyepiece, and the like. For example, as the measurement capturing means 36, an imaging element may be used without using a focusing screen having a graduation line. In addition, when visually confirming, an eyepiece may be used as the measurement capturing means 36. Further, as the measurement capturing means 36, an eyepiece lens and an image pickup device may be used in parallel. When the eyepiece lens is used in this way, a scale plate may be used.
Such a measurement capturing means 36 is provided at a measurement imaging point 42 which is a focal point of the teletype optical system 34, and is reflected pattern light 32 from the measurement surface 30 a obtained via the measurement optical system 16. The imaging position in the direction perpendicular to the optical axis is assumed to be based on the optical axis (center) reference.

The wide-range observation optical system 18 irradiates the sample measurement surface 30 with the pattern light 28 from the reticle 14 as parallel light, converges the reflected pattern light 32 from the measurement surface 30a, and converges at the image point 46 for wide-range observation. Based on the imaging position of the reflection pattern light 32 with respect to the center (optical axis), it is intended to perform wide-range observation.
The wide-area observation optical system 18 includes the convex lens 38 of the measurement optical system 16 and the wide-area observation capturing means 44.
The wide-area observation capturing means 44 includes a focusing plate having graduation lines, such as an image sensor (CCD, CMOS), an eyepiece, etc., and is provided at a wide-area observation imaging point 46 that is the focal point of the convex lens 38. The imaging position in the direction perpendicular to the optical axis of the reflected pattern light 32 from the measurement surface 30a obtained via the optical system 18 is assumed to be taken as the optical axis (center) reference.

  The optical path branching means 20 is provided between the convex lens 38 and the concave lens 40, and the optical path of the reflected pattern light 32 from the measurement surface 30a obtained by irradiating the measurement surface 30a with the pattern light 28 is used as a measurement optical system. It is assumed that 16 optical paths are branched to the optical path of the wide-range observation optical system 18.

  In the present embodiment, a half mirror 48 that reflects the pattern light 28 from the reticle 14 is provided between the concave lens 40 of the measurement optical system 16 and the image forming point 42 for measurement.

The autocollimator 10 according to the present embodiment is configured as described above, and the operation thereof will be described below.
<Wide range observation>
The operation of the wide-range observation optical system 18 will be described below.
That is, the light 26 emitted from the light source 22 passes through the illumination optical system 24 and illuminates the reticle 14.
The light 28 from the reticle 14 is reflected by the beam splitter 48, the light beam diameter is enlarged by the concave lens 40, passes through the beam splitter 20, is emitted as parallel light by the convex lens 38, and is incident on the measurement surface 30 a of the sample 30. The
The reflected pattern light 32 from the measurement surface 30a passes through the convex lens 38 and becomes convergent light. The light is reflected by the beam splitter 20 and imaged on the imaging point 46 for wide range observation.
Here, the aim of the autocollimator 10 can be adjusted to the measurement surface 30a by capturing the imaging position of the reflected pattern light 32 at the imaging point 46 for wide range observation within the field of view of the capturing unit 44 for wide range observation. it can.
As described above, since the wide-range observation optical system 18 uses the convex lens 38 of the measurement optical system 12 as it is, it is possible to realize a short focal length and observe a wide range with a simple configuration.

<During measurement>
Next, the operation of the measurement optical system 16 will be described.
That is, the light 26 emitted from the light source 22 passes through the illumination optical system 24 and illuminates the reticle 14.
The light 28 from the reticle 14 is reflected by the beam splitter 48, the light beam diameter is enlarged by the concave lens 40, passes through the beam splitter 20, and then becomes parallel light by the convex lens 38 and is emitted.
The light 28 from the convex lens 38 is reflected by the measurement surface 30 a and passes through the convex lens 38 and the beam splitter 38 along the same path, and then passes through the concave lens 40 and the beam splitter 48 to form an image on the measurement image point 42.
The imaging position of the reflected pattern light 32 at the measurement imaging point 42 is read by the measurement capturing means 36, so that high-precision positioning, that is, the optical axis of the autocollimator 10 is perpendicular to the measurement surface 30 a of the sample 30. It can be set accurately.
Here, since the measurement optical system 16 uses the teletype optical system 34, the lens barrel length (optical path length) can be shortened compared to the actual focal length.

Thus, in the present embodiment, the wide-area observation optical system 18 including the measurement optical system 16 including the convex lens 38 and the concave lens 40 designed so that the total lens length is shorter than the focal length, and the convex lens 38 of the measurement optical system 16. And optical path branching means 20 for branching the optical path of the reflection pattern light 32 from the measurement surface 30a into the optical path of the wide-range observation optical system 18 and the optical path of the measurement optical system 16.
As a result, in the present embodiment, simplification of configuration, sufficient angular resolution, and improvement in operability can be obtained at the same time.

  That is, in this embodiment, it is possible to realize a measurement optical system (long focal length collimator lens) and a wide range observation optical system (short focal length collimator lens) with a single unit. Since the measurement optical system becomes a long focal length collimator lens, it can be used for highly accurate angle measurement and positioning. Further, since the wide-range observation optical system becomes a short focal length collimator lens, it can be used as an angle measurement or a sighting optical system in a wide angle range.

  In this embodiment, since the image in the wide-range observation optical system 18 is opposite to the movement of the image in the measurement optical system 16, it is basically an optical system dedicated to positioning. Then, further simplification is achieved by further simplifying the optical system. The reason why such further downsizing can be achieved is considered to be because the measurement optical system and the wide-range optical system share a main optical system and thus have a large effect.

Incidentally, the autocollimator is required to have high resolution. In order to increase the resolution, the focal length is usually increased.
Then, the total length of the objective lens becomes long, and therefore, the total length of the autocollimator becomes long and difficult to handle, so that it is difficult to achieve satisfactory high resolution.

In addition, in an autocollimator, it is also important to perform the setting before measurement in order to accurately measure the angle.
However, the higher the autocollimator, the more difficult it is to set before measurement. That is, the angle sensitivity of the autocollimator is determined by the difference in magnification depending on the focal length of the lens used. For this reason, a lens having a longer focal length is used for a highly sensitive collimator, but the field of view (range of measurable angles) that can be observed as a negative effect is narrowed. For this reason, it is difficult to capture the reflected pattern light within the field of view, and setting takes time.

  As described above, the autocollimator has been desired to simplify the configuration, to provide sufficient angular resolution, and to improve the operability of the setting before measurement. However, conventionally, there has been no appropriate technique for obtaining these simultaneously. .

  Therefore, various types of autocollimators exist. In the present invention, a teletype optical system is selected in order to simplify the configuration and obtain sufficient angular resolution at the same time. Furthermore, there are various types of wide-range observation methods, but in the present invention, in order to obtain sufficient angular resolution and operability improvement of setting before measurement, an optical path branching means is provided in the teletype optical system. A method of selecting a wide-range observation optical system that combines a teletype optical system convex lens and realizes a shorter focal length than the measurement optical system is selected.

<Teletype optical system>
Next, a characteristic measurement optical system in the present invention will be described.
In the measurement optical system of the present embodiment, as shown in FIG. 2, in order to reduce the length of the long-focus lens, in particular, a concave lens system (concave lens 40) is arranged in the rear group away from the convex system (convex lens 38) of the front group. And the lens is designed so that the total lens length A is shorter than the focal length B.
As a result, in the measurement optical system of the present embodiment, when the convex lens 38 and the concave lens 40 are replaced with one thin virtual lens, the position C of the virtual lens is closer to the sample 30 than the front surface of the convex lens 38.
Therefore, in a general lens, the total length of the lens is longer than the focal length of the lens, whereas in the measurement optical system of the present embodiment, the focal length B is longer than the total lens length A.
As a result, in the measurement optical system of the present embodiment, a single unit can achieve a more compact configuration (shorter lens barrel length) and improved angular resolution (sufficient angular resolution) compared to a general lens. It can be obtained at the same time.

<Second embodiment>
In the present embodiment, it is also preferable to use the following in order to improve accuracy.
FIG. 3 shows a schematic configuration of an autocollimator according to the second embodiment of the present invention.
The parts corresponding to those in FIG.

In the autocollimator 110 shown in the figure, since the beam splitter 120 reflects the reflected pattern light 132 from the measurement surface 130a and enters the optical path of the wide-range observation optical system 118, the wide-range observation optical system 118 further includes: It is preferred to include a mirror 150.
The mirror 150 is provided between the beam splitter 120 and the wide-range observation imaging point 146, and further reflects the reflected pattern light 132 from the beam splitter 120 to form an image on the wide-range observation imaging point 146.
The autocollimator 110 according to the present embodiment is configured as described above, and the operation thereof will be described below.

<Wide range observation>
The operation of the wide range observation optical system 118 will be described below.
That is, in the wide range observation optical system 118, the reflected pattern light 132 from the measurement surface 130a passes through the convex lens 138 and becomes convergent light. The light is reflected by the beam splitter 120, bent by the mirror 150, and then imaged at the wide-range observation imaging point 146.
As described above, the wide-range observation optical system 118 is a short focal length collimator lens as in the first embodiment, and also serves as the convex lens 138 of the measurement optical system 116, thereby realizing a short focal length and a wide range. An angular range can be observed.
In the wide-area observation optical system 118 of this embodiment, the reflection pattern light 132 from the measurement surface 130 a is reflected by the even number of times until reaching the wide-range observation image formation point 146, that is, reflected by the beam splitter 120 and the mirror 150. Therefore, the movement of the image in the measurement optical system 116 is the same.

<During measurement>
Next, the operation of the measurement optical system 116 will be described.
That is, since the measurement optical system 116 is a long focal length collimator lens, the change in the angle of the measurement surface 130a is obtained by reading the image formation position of the crosshair at the measurement image formation point 142 with the measurement acquisition means 136. (Fluctuation) can be read accurately.
Here, since the measurement optical system 116 employs the teletype optical system 134 as in the first embodiment, the lens barrel length (optical path length) can be shortened compared to the actual focal length.

  As described above, the autocollimator according to this embodiment includes the measurement optical system 116 including the teletype optical system 134, the wide-range observation optical system 118, and the beam splitter 120, as in the first embodiment. With one unit, simplification of the configuration, sufficient angular resolution, and improved operability can be obtained at the same time.

  Furthermore, in this embodiment, since the mirror is provided in the wide-range observation optical system, the movement of the image is the same as that of the measurement optical system in the wide-range observation optical system. For this reason, this embodiment can perform the pre-measurement setting with the wide-range observation optical system with higher accuracy than the first embodiment. In addition, angle measurement in a wide angle range can be performed with higher accuracy.

<Third embodiment>
In this embodiment, it is also important to simplify the optical system in order to reduce the size, and in order to simplify the optical system, it is also preferable to use the following.
FIG. 4 shows a schematic configuration of an autocollimator according to the third embodiment of the present invention.
The parts corresponding to those in FIG.

The autocollimator 210 shown in the figure includes the reticle 214 of the present invention on the wide-range observation optical system 218 side.
The mirror 250 is a half mirror (hereinafter referred to as a half mirror 250).
Then, the pattern light 228 from the reticle 214 passes through the half mirror 250 of the wide-range observation optical system 218 and is irradiated onto the measurement surface 230a. The reflected pattern light 232 from the measurement surface 230 a is preferably reflected by the beam splitter 220, further reflected by the half mirror 250 of the wide-range observation optical system 218, and imaged on the wide-range observation imaging point 246.

The autocollimator 210 according to the present embodiment is configured as described above, and the operation thereof will be described more specifically below.
<Wide range observation>
The operation of the wide-range observation optical system 218 will be described below.
That is, in the wide-range observation optical system 218, the light 226 emitted from the light source 222 passes through the illumination optical system 224 and illuminates the reticle 214.
Pattern light 228 from reticle 214 passes through half mirror 250, is reflected by beam splitter 220, and is emitted as parallel light by convex lens 238.
Pattern light 228 from the convex lens 238 is applied to the measurement surface 230. The reflected pattern light 232 from the measurement surface 230a passes through the convex lens 238 along the same path and becomes convergent light. The light is reflected by the beam splitter 220, bent by the half mirror 250, and then focused on the wide-range observation imaging point 246.
By capturing the imaging position of the crosshair (reflection pattern light 232) at the imaging point 246 for wide-area observation within the field of view of the capturing means 244 for wide-area observation, the aim of the autocollimator 210 is adjusted to the measurement surface 230a. Can do.
As described above, since the wide-range observation optical system 218 also serves as the convex lens 238 of the measurement optical system 216 as in the first embodiment, a short focal length can be realized and a wide angle range can be observed.

<During measurement>
Next, the operation of the measurement optical system 216 will be described.
That is, in the measurement optical system 216, the light 226 emitted from the light source 222 passes through the illumination optical system 224 and illuminates the reticle 214.
Pattern light 228 from reticle 214 passes through half mirror 250, is reflected by beam splitter 220, and is emitted as parallel light by convex lens 238.
The pattern light 228 from the convex lens 238 is reflected by the measurement surface 230a, passes through the convex lens 238 and the beam splitter 220 through the same path, and then forms an image on the concave lens 240 and the measurement imaging point 242.
By reading the imaging position of the crosshair (reflection pattern light 232) at the measurement imaging point 242 with the measurement capturing means 236, the angle of the measurement surface 230a of the sample 230 can be accurately measured and positioned. .
Here, since the measurement optical system 216 uses the teletype optical system 234, the lens barrel length (optical path length) can be shortened compared to the actual focal length.

  As described above, the autocollimator 210 according to the present embodiment includes the measurement optical system 216 including the teletype optical system 234, the wide-range observation optical system 218, and the beam splitter 220, as in the first embodiment. With a single unit, simplification of configuration, sufficient angular resolution, and improved operability can be obtained at the same time.

  Furthermore, in this embodiment, since the reticle 214 is provided on the wide-range observation optical system 218 side, one mirror (for example, the half mirror 148 in FIG. 3) is deleted as compared with the second embodiment. Therefore, simplification of the optical system can be achieved more reliably.

<Fourth embodiment>
In the present embodiment, it is also important to reduce the loss of light quantity in order to achieve high accuracy, and it is also preferable to use the following.
5 and 6 show a schematic configuration of an autocollimator according to a fourth embodiment of the present invention.
FIG. 5 shows the state of the autocollimator during wide-range observation, and FIG. 6 shows the state of the autocollimator during measurement.
The parts corresponding to those in FIG.

In the autocollimator 310 shown in the figure, the reticle of the present invention is included in the wide-range observation optical system side and the measurement optical system side.
That is, the wide-area observation optical system 318 side includes a reticle similar to the reticle shown in FIGS. 1 to 4 (hereinafter referred to as a reticle 314a) as the reticle of the present invention.
The measurement optical system 316 side includes a reticle similar to the reticle shown in FIGS. 1 to 4 (hereinafter referred to as a reticle 314b) as the reticle of the present invention.

  Further, the optical path branching means includes a movable mirror provided in the optical path between the convex lens 338 and the concave lens 340 in place of the beam splitter (hereinafter referred to as a movable mirror 360).

Further, the autocollimator 310 shown in the figure includes mirror movable means 362 and mirror control means 364.
The mirror movable means 362 inserts or retracts the movable mirror 360 in the optical path between the convex lens 338 and the concave lens 340.
The mirror control means 364 includes a movable mirror 360 inserted in the optical path between the convex lens 338 and the concave lens 340 during wide-range observation, and the movable mirror 360 from the optical path between the convex lens 338 and the concave lens 340 during measurement. The movement of the movable mirror 360 by the mirror moving means 362 is controlled so as to be retracted.

  The autocollimator 310 according to the present embodiment is configured as described above, and the operation thereof will be described more specifically below.

<Wide range observation>
As shown in FIG. 5, when the wide-range observation optical system 318 is used, a movable mirror 360 is inserted in the optical path between the convex lens 338 and the concave lens 340.
Then, the pattern light 328 a from the reticle 314 a passes through the half mirror 350 of the wide-range observation optical system 318, is reflected by the movable mirror 360, and is irradiated onto the measurement surface 330 a through the convex lens 338. The reflected pattern light 332a from the measurement surface 330a passes through the convex lens 338, is reflected by the movable mirror 360, is reflected by the half mirror 350 of the wide-area observation optical system 318, and forms an image at the wide-area observation imaging point 346.

<During measurement>
On the other hand, as shown in FIG. 6, when the measurement optical system 316 is used, the movable mirror 360 is retracted from the optical path between the convex lens 338 and the concave lens 340.
Then, the pattern light 328b from the reticle 314b is reflected by the mirror 348 of the measurement optical system 312 and irradiates the measurement surface 330a through the concave lens 340 and the convex lens 338 in this order. The reflected pattern light 332b from the measurement surface 330a passes through the mirror 348 of the measurement optical system via the convex lens 338 and the concave lens 340 in this order, and forms an image on the measurement image point 342.

  As described above, the autocollimator 310 according to the present embodiment is similar to the first embodiment in the measurement optical system 318 including the teletype optical system 334, the wide-range observation optical system 318, and the movable type optical path branching unit. Since the mirror 360 is provided, it is possible to obtain a simplified configuration, sufficient angular resolution, and improved operability at the same time with a single unit.

  Furthermore, in this embodiment, reticles 314a and 314b are respectively provided on both the wide-range observation optical system 318 and the measurement optical system 316 side, and are used alternately with movable mirrors that are optical path branching means. Compared with the embodiment, it is possible to reduce the loss of light amount.

Angle Measuring Device FIG. 7 shows a schematic configuration of an angle measuring device using the autocollimator according to the present embodiment.
FIG. 3A is a view of the angle measuring device according to the present embodiment as viewed from above, and FIG. 4B is a view of the angle measuring device as viewed from the side.
Portions corresponding to those in the first embodiment are indicated by the reference numeral 400 and description thereof is omitted.

  The angle measuring device 470 shown in the figure includes an autocollimator (hereinafter referred to as autocollimator 410) described in any of FIGS. 1 to 6, a sample stage 472, an arm 474, a rotating means 476, and a rotation control means. 478, a rotary encoder (detector) 480, and a calculation means 482.

Here, the sample stage 472 has a first measurement surface 430 a and a second measurement surface 430 b that are provided so as to be rotatable with respect to the base 484 and constitute the apex angle (angle to be measured) of the prism (sample) 430. A sample 430 is placed.
The arm 474 is provided on the base 484 and holds the autocollimator 410 while facing the measurement surface side of the prism 430 on the sample base 472.
The rotating means 476 rotates the sample table 472 with respect to the base 484.
The rotation control unit 478 controls the rotation of the sample stage 472 by the rotation unit 476.
The rotary encoder 480 detects the rotation angle of the sample table 472 with respect to the base 484.
The computing means 482 is positioned by the autocollimator 410 and the rotation angle information α of the sample table 472 obtained from the rotary encoder 480 when the autocollimator optical axis positioned by the autocollimator 410 is orthogonal to the first measurement surface 430a. The angle formed by the first measurement surface 430a and the second measurement surface 430b of the prism 430 based on the rotation angle information β of the sample table 472 obtained from the rotary encoder 480 when the autocollimator optical axis is orthogonal to the second measurement surface 430b. Find θ.

The autocollimator 410 includes a measurement camera (measurement capturing unit) 436, a wide range observation camera (wide range observation capture unit) 444, and a computer 486.
Here, the measurement camera 436 is provided at the measurement imaging point of the autocollimator 410 and photoelectrically reads the imaging position of the crosshair (reflection pattern light). The measurement camera 436 is connected to a computer 486, and image data read by the measurement camera 436 is taken into the computer 486.
The wide-range observation camera 444 is provided at the wide-range observation imaging point of the autocollimator 410 and photoelectrically reads the imaging position of the crosshair (reflection pattern light). The wide range observation camera 444 is connected to a computer 486, and image data read by the wide range observation camera 444 is taken into the computer 486.

The computer 486 includes a wide-range observation data processing unit 488, a measurement data processing unit 490, and a calculation unit 482, and also includes a monitor 492.
Here, the wide-area observation data processing means 488 processes the image data from the wide-area observation camera 444 and displays it on the monitor 492.
The wide-area observation data processing means 488 instructs the rotation control means 478 to adjust the rotation angle of the sample stage 472 so that a crosshair can be captured within the field of view of the wide-area observation camera 444.

The measurement data processing means 490 processes image data from the measurement camera 436 and displays it on the monitor 492.
The measurement data processing means 490 monitors the cross lines and scale lines in the field of view of the measurement camera 436 and displays them on the monitor 492. Then, the rotation control means 478 is instructed to adjust the rotation angle of the sample stage 472 so that the center of the cross line and the center of the scale line coincide with each other. In addition, the measurement data processing unit 490 instructs to take in rotation angle information from the rotary encoder 480 when the center of the cross line coincides with the center of the scale line.

  In the present embodiment, a transmission deflection angle collimator 494 is provided to measure the polarization angle of the prism by passing the prism 430 through the prism 430 with the prism 430 interposed therebetween.

The angle measuring device 470 according to the present embodiment is configured as described above, and the operation thereof will be described below.
Since the angle measuring apparatus 470 according to the present embodiment uses the autocollimator 410 according to the present embodiment, a single unit simultaneously simplifies the configuration, increases the resolution of the angle, and improves the operability of the setting before measurement. be able to.

<First setting process>
In the first setting step, for example, the prism is slightly rotated together with the sample stage, and the rotation angle of the prism is adjusted so that the crosshair (first measurement surface) is captured in the field of view of the wide range observation camera.
Here, in the first setting step, the operability of the setting before measurement can be improved by using a cross-hair image obtained via the wide-range observation optical system (short focal length collimator lens) of the autocollimator 410. it can.

<First measurement process>
After the completion of the first setting process, the first measurement process is performed.
That is, in the first measurement step, the prism is rotated together with the sample stage until the center of the cross line (first measurement surface) and the center of the scale line coincide with each other. The rotation angle α from the autocollimator when the center of the cross line (first measurement surface) and the center of the scale line coincide is read.
Here, in the first measurement process, by using the crosshair image obtained through the measurement optical system (long focal length collimator lens) of the autocollimator 410, high resolution of the angle can be achieved with a compact configuration. Can be planned.

<Second setting process>
In the second setting step, for example, the prism is slightly rotated together with the sample stage, and the rotation angle of the prism is adjusted so that the crosshair (second measurement surface) is captured in the field of view of the wide range observation camera.
Here, in the second setting step, as in the first setting step, the operability of the setting before measurement is improved by using an image obtained through the wide-range observation optical system (short focal length collimator lens) of the autocollimator 410. Can be achieved.

<Second measurement process>
After the completion of the second setting, the second measurement process is performed in the same manner as the first measurement process.
That is, in the second measurement step, the prism is rotated together with the sample stage until the center of the crosshair (second measurement surface) coincides with the center of the scale line. The rotation angle β from the autocollimator when the center of the cross line and the center of the scale line coincide is read.
Here, in the second measurement step, as in the first measurement step, by using an image obtained through the measurement optical system (long focal length collimator lens) of the autocollimator 410, the angle can be reduced with a compact configuration. High resolution can be achieved.

<Angle calculation>
Based on the rotation angle α ° obtained in the first measurement step and the rotation angle β ° obtained in the second measurement step, an angle θ ° formed by the first measurement surface 430a and the second measurement surface 430b of the prism 430 is obtained. be able to.
θ ° = 180 ° − | α ° −β ° |

As described above, the angle measuring device 470 according to the present embodiment uses the autocollimator 410 according to the present embodiment, that is, adopts a teletype optical system including a lens having a positive power and a lens having a negative power. By simply branching the optical path of the reflected pattern light from the measurement surface by the optical path branching means, both the wide-range observation optical system (short focal length collimator lens) and the measurement optical system (long focal length collimator lens) can be used. Can be realized.
As a result, the angle measuring device according to the present embodiment can be made compact, highly accurate, and improved in operability at the same time.

  In the configuration described above, an example in which a camera is provided at each imaging point of the autocollimator and the imaging position of the crosshair (or other pattern) is optically read has been described. It is also preferable that the measurement person reads the imaging position of the crosshair (or other pattern) by visual observation.

  Moreover, although the example which rotates a sample stand was demonstrated in the said structure, it is also preferable to rotate an arm.

It is explanatory drawing of schematic structure of the autocollimator concerning 1st embodiment of this invention. It is explanatory drawing of the optical system for measurement characteristic in the autocollimator concerning this embodiment. It is explanatory drawing of schematic structure of the autocollimator concerning 2nd embodiment of this invention. It is explanatory drawing of schematic structure of the autocollimator concerning 3rd embodiment of this invention. It is explanatory drawing at the time of wide range observation of the autocollimator concerning 4th embodiment of this invention. It is explanatory drawing at the time of measurement of the autocollimator concerning 4th embodiment of this invention. It is explanatory drawing of schematic structure of the angle measuring apparatus using the autocollimator concerning this embodiment.

Explanation of symbols

10, 110, 210, 310, 410 Autocollimator 12, 112, 212, 312 Light emitting means 14, 114, 214, 314 Reticle 16, 116, 216, 316 Measuring optical system 18, 118, 218, 318 For wide-range observation Optical system 20, 120, 220, 320 Optical path branching means 34, 134, 234, 334 Teletype optical system 38, 138, 238, 338 Convex lens (front lens having positive power)
40,140,240,340 Concave lens (back lens with negative power)
470 Angle measurement device

Claims (3)

Light emitting means for emitting light;
A reticle that makes the light from the light emitting means a pattern light having a desired pattern;
The pattern light from the reticle is irradiated onto the sample measurement surface as parallel light, the reflected pattern light from the sample measurement surface is converged, and measurement is performed based on the imaging position of the reflection pattern light at the measurement imaging point. Measuring optical system for
Irradiating the specimen measuring Teimen pattern light from said reticle as parallel light, converges the reflected light pattern from the specimen measuring Teimen, imaging of the reflected pattern light in a wide range observation image point A wide-range observation optical system for performing wide-range observation based on the position;
With
The measuring optical system includes a teletype optical system including a front lens having a positive power and a rear lens having a negative power provided on the image forming side of the front lens, the total lens length being designed to be shorter than the focal length. When,
Wherein provided on the focus of the teletype optical system is a measuring imaging point, capture measurement for capturing an imaging position of the reflected light pattern from the sample measuring surface obtained through the measuring optical system Means,
Including
The wide-range observation optical system includes the front lens of the measurement optical system,
Provided at the focal point of the front lens wherein a wide observation image point, capture measurement for capturing an imaging position of the reflected light pattern from the sample measuring surface obtained through the widespread observation optical system Means,
Including
Furthermore, the optical path of the reflected pattern light from the sample measurement surface, which is provided between the front lens and the rear lens and is obtained by irradiating the sample measurement surface with pattern light, An optical path branching means for branching into an optical path or an optical path of the measuring optical system;
Provided between the light emitting means and the optical path branching means, and between the optical path branching means and the wide-range observation imaging point, and guides pattern light from the reticle to the optical path branching means, A half mirror that guides the optical path of the reflected pattern light branched to the optical path of the wide-range observation optical system by the optical path branching means and forms an image on the wide-area observation imaging point;
An autocollimator characterized by comprising The autocollimator according to claim 1, wherein
The reticle is included in the wide-range observation optical system side and the measurement optical system side,
The optical path branching unit includes a movable mirror provided to be inserted or retracted into an optical path between the front lens and the rear lens,
During the wide-range observation, the movable mirror is inserted into the optical path between the front lens and the rear lens, and the pattern light from the reticle on the wide-range observation optical system side passes through the movable mirror. The sample measurement surface is irradiated, and the reflected pattern light from the sample measurement surface forms an image at the imaging point for wide-area observation through the movable mirror,
During the measurement, the movable mirror is withdrawn from the optical path between the front lens and the rear lens, and the pattern light from the reticle on the measurement optical system side does not pass through the movable mirror. An autocollimator characterized in that a reflected pattern light irradiated from a measurement surface is imaged on the measurement imaging point without passing through the movable mirror. In the angle measuring device using the autocollimator according to claim 1 or 2,
A sample stage on which a sample having a first measurement surface and a second measurement surface, which are fixed or rotatable on the base and constitute an angle to be measured, is placed;
An arm for holding the autocollimator provided in a fixed or rotatable manner on the base and facing the measurement surface side of the sample on the sample base;
Rotating means for rotating the sample table or the arm with respect to the base;
Rotation control means for controlling rotation of the sample stage or the arm by the rotation means;
A detector for detecting a rotation angle of the sample table or the arm with respect to the base;
When the autocollimator optical axis positioned by the autocollimator is orthogonal to the sample first measurement surface, the rotation angle information of the sample stage or the arm obtained from the detector, and the autocollimator positioned by the autocollimator when orthogonal to the optical axis and the sample second measuring surface, the angle between the basis of the rotation angle information of the sample stage to the arm obtained from the detector, the first measuring surface of the sample and the second measuring surface Computing means for obtaining
An angle measuring device comprising:

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