JP2003172968A - Image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device for simultaneously focusing on the long distance point (outside diameter 15) and the close distance point (inside diameter 13) of an object to be measured 14. <P>SOLUTION: The image pickup device is provided with a 1st optical system 60 arranged between the object to be measured 14 and a 1st image forming surface 28, and a parallel flat plate 16 arranged between the object to be measured 14 and the 1st optical system 60 so as to form the images positioned at the close distance point (inside diameter 13) and the long distance point (outside diameter 15) of the object to be measured 14 on the 1st image forming surface 28 through the optical system 60. By having such the constitution, the optical axis of the emitted light made incident from the long distance point (outside diameter 15) of the object to be measured 14 is deflected by the parallel flat plate 16, and the image positioned at the long distance point (outside diameter 15) is formed on the 1st image forming surface 28 focusing on the close distance point (inside diameter 13). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device. In particular, the present invention relates to an image pickup device that forms an image of the outer peripheral edge and the inner peripheral edge of an object to be measured having an optical distance difference on the same image plane.

[0002]

2. Description of the Related Art Generally, there is known an image pickup apparatus which separately picks up an outer diameter and an inner diameter of a front surface of a ferrule made of ceramics, zirconia, or a nickel material having a tapered outer periphery of a cylindrical object to be measured. There is.

FIG. 10 is a schematic front view of a conventional object to be measured. The ferrule as the object to be measured is placed in contact with the sample installation surface 17 of the holding portion 12 of the glass V groove for measurement. The mounted ferrule was rotated by a roller 86 of an elastic member such as rubber or soft plastic, and the eccentric amount of the ferrule outer diameter 15 was measured by a micrometer 84.

Further, the inner diameter measuring area 80 on the front surface of the ferrule optically located at the near distance point and the outer diameter measuring area 82 on the outer circumference of the ferrule optically located at the far distance point are respectively focused by different image pickup devices. Digital image processing was performed while matching, and the eccentric amounts of the outer diameter 15 and the inner diameter 13 from the rotation center axis of the ferrule were measured.

[0005]

However, as described above, when measuring the amount of eccentricity of the outer diameter 15 of the ferrule, the ferrule is rotated once by the roller 86 to obtain 36
A rotation process of rotating about 0 degrees is required.

Further, when the ferrule as the object to be measured is formed so as to be bent in the direction of the rotation axis, there is a problem that the center axis of the ferrule is eccentric during the rotation process and the measurement reference point is displaced. Was there.

Further, the inner diameter 13 and the outer diameter 15 of the ferrule
If separate image pickup devices for separately picking up and are provided, the mechanism of the ferrule image pickup device becomes complicated, and there is a problem that the manufacturing cost increases.

In view of such a situation, the present invention aims to provide an image pickup apparatus which simultaneously forms an image of the measurement areas optically located at the near distance point and the far distance point from the image pickup surface.

[0009]

In order to achieve the above-mentioned object, an image pickup device according to the first aspect of the present invention, as shown in FIG. 7, is provided between an object to be measured 14 and a first image plane 28. Disposed between the first optical system 60 and the DUT 14 and the first optical system 60, and the near distance point (inner diameter 13) and far distance point (outer diameter 15) of the DUT 14 are measured. ) And the first optical system 60
And the plane-parallel plate 16 for forming an image on the first image plane 28.

With this configuration, the radiation optical axis incident from the far-distance point (outer diameter 15) of the DUT 14 can be deflected by the plane parallel plate 16, and the near-distance point (inner diameter 1
An image of a far point (outer diameter 15) can be formed on the first image forming surface 28 focused on 3).

In order to achieve the above object, the image pickup device according to the invention according to claim 2 is, as shown in FIG.
The first optical system 60 described in 1. has the objective optical system 18 facing the object to be measured 14, and the imaging optical system 24 arranged between the objective optical system 18 and the imaging surface 28. Objective optical system 18
And the imaging optical system 24, and a first beam splitter 22 that splits a light beam incident from the DUT 14.
And a second light flux that is an incident light flux from the DUT 14 and forms an image of the DUT 14 on the second imaging surface 40 in the traveling direction of the light flux split by the first beam splitter 22. Optical system 62 of.

According to this structure, the light beam incident from the DUT 14 is branched and the DIP 1 is formed on the second image plane 40.
The image of 4 can be formed.

In order to achieve the above object, the image pickup device according to the invention according to claim 3 is the same as that shown in FIG.
A second beam splitter 34 arranged between the second optical system 62 and the second image plane 40 described in 1 above, for splitting the light beam from the first beam splitter 22, and the first beam splitter 22. And a reticle 36 arranged in the traveling direction of the light beam split by the second beam splitter 34. The light from the reticle 36 is reflected by the plane-parallel plate 16 and the The image is formed on the image plane 40.

With this structure, part of the light from the reticle 36 is reflected on the surface of the plane-parallel plate 16 mounted on the angle adjusting mechanism 65 and the surface of the DUT 14 mounted on the position adjusting mechanism 64. An image of the reticle 36 can be formed on the video camera as the second image forming surface 40 by being reflected respectively. The position adjustment mechanism 64 moves the DUT 14 up and down,
It is provided with a position adjustment function of moving it to the left and right and back and forth, and also adjusting the angle with respect to the optical axis of the first optical system.

The plane-parallel plate 16 or the object to be measured 14 is the first
When the central optical axis of the optical system 60 is tilted from the angle of vertical incidence, the image of the reticle 36 is laterally displaced from the central optical axis of the first optical system 60 and serves as the second image plane 40. It is imaged on a video camera. Therefore, it is possible to determine whether the surface of the plane-parallel plate 16 or the object to be measured 14 is vertical or horizontal or the inclination of the installation direction angle based on the position of the reticle image.

In order to achieve the above object, the image pickup device according to the invention according to claim 4 is, as shown in FIG.
The parallel plane plate 16 described in 1 has a first region and a second region, and the first region (peripheral portion) is formed to have an optical distance longer than that of the second region (central portion). The light from the point (outer diameter 15) mainly passes through the first region (peripheral portion), and the light from the short-distance point (inner diameter 13) mainly passes through the second region (center portion). ing.

With this structure, a long distance point (outer diameter 15) passing through the first region (peripheral portion) of the plane-parallel plate 16 is formed.
The light from is imaged on a video camera as a first image plane 28 that focuses light from a near distance point (inner diameter 13) that passes through the second region (center portion) of the plane-parallel plate 16. be able to.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding members are designated by the same reference numerals or similar reference numerals, and redundant description will be omitted.

FIG. 1 is a schematic front view of an optical system of an image pickup apparatus according to the first embodiment of the present invention. The imaging device is
The transillumination device 10 and a sample as the DUT 14,
For example, a ferrule of an optical fiber component and a plane parallel plate 16
Dual focus correction plate as an object, the objective lens 18, and the diaphragm 2
0, an imaging lens 24, a magnification correction lens 26, and a high-resolution video camera as a first imaging surface 28.

In the first optical system 60 arranged between the DUT 14 and the first image plane 28, the plane parallel plate 16 is provided.
A double focus correction plate is arranged as a. This double focus correction plate shifts the focal length of the first optical system so that an image of the inner diameter 13 as the short-distance point and the outer diameter 15 as the far-distance point of the DUT 14 can be obtained by the objective lens 18 and the diaphragm 20. The images of the inner diameter 13 and the outer diameter 15 can be simultaneously formed on the high resolution video camera as the first image forming surface 28 by transmitting them in the order of the image forming lens 24.

The cylindrical object to be measured 14 is placed on the glass V groove holding portion 12 in the lateral and longitudinal direction, and the cylindrical center axis of the object to be measured 14 and the central optical axis of the first optical system 60 are arranged. Arrange to match. Further, the DUT 14 is projected by being irradiated with parallel rays from the transillumination device 10 as a light source from the left side in the drawing in the horizontal direction.

The outer diameter 15 and the inner diameter 1 of the sample as the object to be measured 14 projected by the transillumination device 10 described above.
The edge image of 3 passes through the double focus correction plate as the plane-parallel plate 16 and is refracted by the objective lens 18 to form a parallel light beam through the diaphragm 20 arranged on the focal plane located in the right-hand direction of the objective lens 18. To Penetrate.

The image passing through the optical path splitting half mirror as the beam splitter 22 is corrected to a predetermined magnification by the image forming lens 24 and the magnification correcting lens 26 and is connected to a high resolution video camera as the first image forming surface 28. To be imaged.

Object to be measured 14 used in the above embodiment
Can use a ferrule that is a general sample of optical fiber parts. The outer diameter edge portion of the ferrule is chamfered with a width of about 0.5 millimeters to be a tapered shape, and the inner diameter portion is configured to easily secure a contact surface with the inner diameter portion of another ferrule. Therefore, the plane-parallel plate 16 is required to focus on optically different optical distances when simultaneously imaging the inner diameter edge portion and the outer diameter edge portion of the DUT 14.

The parallel plane plate 16 can correct the optical distance between the outer diameter 15 edge portion and the inner diameter 13 edge portion of the object 14 to be measured by the difference in refractive index. For example, in order to improve the imaging accuracy of the edge portion of the outer diameter 15 without being affected by the chamfered taper shape of the object to be measured 14, the transillumination device 10 is used.
It is advisable to configure the imaging device as a telecentric optical system that shares the central optical axis of the DUT 14 and the high-resolution video camera as the first imaging surface 28.

In the present embodiment, the DUT 14 is a transillumination device 1 having a diffused light source 11 and a condenser lens 9.
0, the objective lens 18, and the diaphragm 20 may be configured by a telecentric optical system. By adopting this telecentric optical system, the focal point of the DUT 14 can be accurately focused without being affected by the change in the taper shape of the DUT 14 with respect to the blur or shift in the focal direction. You can get a video.

Further, in the present embodiment, it is possible to perform imaging with a deep depth of focus, and to provide an image pickup apparatus which is not affected by the chamfer of the DUT 14, the tapered shape, the curved shape, and the like in the visual field direction, and the shift. can do. Further, although the first optical system 60 uses the objective lens and the imaging lens of the lens system, the parallel straight light irradiating the DUT 14 is magnified to a predetermined magnification and the first imaging surface 28 is used. It is also possible to apply a reflection optical system using a concave mirror or a convex mirror as a means for forming an image.

Further, the plane parallel plate 16 is a correction plate for correcting the focal point of the far-distance point (outer diameter 15) of the object 14 to be measured,
A glass plate, an acrylic glass plate, or a quartz glass plate can be used. Further, the image plane 28 is configured to be a flat surface, and for example, a CCD camera such as an area sensor, a MOS
It is possible to capture a two-dimensional image with a sensor.

FIG. 2 is a schematic side view illustrating a telecentric optical system applied to the above embodiment. The transillumination device 10 includes a diffused light source as a light source 11 and a condenser lens 9. The light emitted from the diffused light source is refracted by the lens 9, and along the outer edge portion corresponding to the entire circumference of the sample as the DUT 14. Objective lens 1
8.

The parallel and straight light traveling along the outer diameter edge of the object to be measured 14 is subsequently refracted by the objective lens 18 and then the diaphragm 20.
Will be introduced to. The image of the outer diameter edge portion of the DUT 14 includes the transillumination device 10, the DUT 14, the objective lens 18, and the diaphragm 2.
Each of the 0's is focused on a shared central optical axis. That is,
It is possible to focus parallel straight light traveling along the outer diameter edge portion and the inner diameter edge portion, which represent the characteristics of the cross-sectional shape of the DUT 14, on the central optical axis shared by the first optical system 60.

FIG. 3 is a schematic side view of the plane-parallel plate 16 applied to the above embodiment. The double focus correction plate as the plane-parallel plate 16 is arranged so as to form a plane perpendicular to the central optical axis of the DUT 14. The double focus correction plate is a plane parallel plate having a hollow hole at the center, and the incident light from the inner diameter 13 of the DUT 14 is passed through the hole at the center.

Further, the light incident from the edge portion of the outer diameter 15 of the DUT 14 is transmitted through the flat glass plate surrounding the central hole of the parallel flat plate 16. The light transmitted through the flat glass plate can optically raise the optical path of the image of the DUT 14 in proportion to the thickness of the flat glass plate. For example, when the thickness of the peripheral glass of the plane-parallel plate 16 is d and the refractive index of the peripheral glass is n, the lift amount t is calculated by the following equation.

[0033]

[Equation 1]

The thickness d of the plane-parallel plate 16 can be adjusted so as to raise the focal plane longer than the extension distance of the chamfered taper-shaped inclined portion of the object 14 to be measured. As a means for focusing on the outer diameter 15 of 14, the refractive index n of the flat glass plate may be appropriately selected. The parallel plane plate 16 adjusted or selected in this way can provide an image pickup device for forming an image of the outer diameter 15 and the inner diameter 13 of the DUT 14 on the first image forming surface 28.

The plane-parallel plate 16 has its focal points at the far distance point and the near distance point shifted based on the refractive index n of the glass flat plate as described above. It is also possible to arrange a glass substrate having a small size in the center and surround the center with a glass substrate having a large refractive index. Further, the central portion of the parallel flat plate 16 having the refractive index n may be thin and the peripheral portion may be thick. Further, the plane-parallel plate 16 can use quartz glass to reduce the thermal expansion. Furthermore, it is also possible to simultaneously form the first region (for the peripheral portion) and the second region (for the central portion) having different optical distances by injection molding using acrylic glass.

The resolution of the high-resolution video camera as the first image plane 28 is determined by the field of view and the magnification of the camera. When the resolution of the camera is effectively used, the magnification correction lens 26 is used. , The outer diameter 1 of the DUT 1
5 may be appropriately selected so that it falls within about 95% of the field of view of the camera.

As shown in FIG. 1, the image pickup apparatus according to the second embodiment of the present invention has an objective lens as an objective optical system 18 and an image forming lens as an image forming optical system 24. The first optical system 60, the optical path splitting half mirror as the first beam splitter 22 arranged between the objective optical system 18 and the imaging optical system 24, and the progress of the light flux incident from the DUT 14 are measured. Optical path changing mirror 32 to be changed
And a second optical system 62 for forming an image of the DUT 14 on a video camera as the second image forming surface 40.

The first optical system 60 irradiates the object 14 to be measured with parallel light rays by the transillumination device 10 and corrects the images of the outer diameter 15 and the inner diameter 13 of the object 14 to be measured as a parallel plane plate 16 for double focus correction. An image having an outer diameter 15 and an inner diameter 13 is made incident on the objective optical system 18 facing the object to be measured 14 through the plate.

Between the objective optical system 18 and the image forming surface 28, a diaphragm 20, an optical path splitting half mirror as the first beam splitter 22, and an image forming lens as the image forming optical system 24 are provided. A magnification correction lens 26 is arranged. This optical path splitting half mirror is configured so that one of the incident light beams is transmitted inside and the other light beam is reflected on the incident surface. However, as means for branching the optical path, another prism is used. The incident light flux may be branched from the radiation side surface side.

Further, the second optical system 62 is used for the object to be measured 1
4, a parallel light beam of the light beam split by the optical path splitting half mirror as the first beam splitter 22 splitting the light beam entering from the optical path 4 is split as an optical path as the collimator correction lens 30, the optical path changing mirror 32, and the second beam splitter 34. An image of the DUT 14 is formed on a video camera as a second image forming surface 40 arranged in the traveling direction via the half mirror.

According to the above-described embodiment, the light flux incident from the DUT 14 is branched and guided to the second optical system 62, and the outer diameter 15 and the inner diameter of the DUT 14 are formed on the second image plane 40. 13 images can be formed at the same time. Further, the collimator correction lens 30 is a collimator lens that can add a function as a collimator auxiliary lens for adjusting the focal length of the reticle image, in addition to a function as a correction lens for adjusting the size of the reticle image described later. is there.

FIG. 4 is a schematic side view of the plane parallel plate 16. The plane-parallel plate 16 is installed so as to form a plane perpendicular to the incident optical axis 50 so as to focus on two points of the outer diameter 15 and the inner diameter 13 of the DUT 14 as described above. In some cases, the incident optical axis 50 is arranged at an angle that does not vertically enter the plane-parallel plate 16 and the image is captured as it is.

For example, when the contact point on the incident surface side of the vertical axis of the plane parallel plate 16 and the incident optical axis 50 is the vertex B1 and the contact point of the emission optical axis 52 on the emitting surface side is the hypotenuse vertex B2, the vertex B1
The base D-B2 of the right triangle is determined by the angle of the hypotenuse vertex B2. The angle of the hypotenuse B2 is equal to that of the plane-parallel plate 1.
It is determined by the refractive index n of 6. Therefore, the incident optical axis 50
From the displacement angle i1 with respect to the vertical axis of the plane-parallel plate 16, the internal refraction angle i2 of the emission optical axis 52 can be obtained from the refractive index of the plane-parallel plate 16. In this embodiment, the outer diameter is 15
It was revealed that the image of (1) produces a lateral shift corresponding to the distance of the base D-B2 of the right triangle formed in the plane-parallel plate 16.

The relationship between the incident optical axis 50 and the emission optical axis 52 of the plane-parallel plate 16 is the glass thickness d of the double-focus correction plate as the plane-parallel plate 16 and the glass refractive index n of the double-focus correction plate. In this case, it can be expressed by the following equation.

[0045]

[Equation 2]

FIG. 5 is a side cross-sectional view of a supporting portion applied to the image pickup apparatus according to the embodiment of the present invention. The holder 12 includes a sample setting surface 17 on which the object 14 to be measured is placed, a glass V groove holder 12 and a collimator light reflecting surface 19.

The collimator light reflecting surface 19 is preferably arranged perpendicularly to the central optical axis of the first optical system 60 and has a high surface flatness. Further, the angle formed by the intersection of the extension line extending in the horizontal direction of the sample installation surface of the glass V groove holding portion 12 and the extension line of the collimator light reflection surface 19 is formed to be 90 degrees, and its accuracy is (plus or minus ) It is better to create with an error of ± 1 second.

The object to be measured 14 is the holding portion 12 of the glass V groove.
The sample is placed on the sample setting surface 17 in the horizontal and longitudinal directions. The front surface of the mounted object 14 to be measured and the collimator light reflecting surface 19 are located in parallel to each other, and both of them form a plane perpendicular to the central optical axis of the first optical system 60. This optical system has a collimator function and can guarantee the parallelism of the double focus correction plate.

The image pickup apparatus according to the third embodiment of the present invention, as shown in FIG. 1, is the second optical system 62.
And a video camera serving as the second imaging surface 40, and an optical path splitting half mirror serving as a second beam splitter 34 that splits a light beam from the first beam splitter 22 reflected by the optical path changing mirror 32. And a reticle 36 arranged in the traveling direction of the light beam split by the second beam splitter 34.

The light from the reticle 36 serves as a second beam splitter 34, an optical path splitting half mirror, an optical path changing mirror 32, a collimator correction lens 30, and a first beam splitter 34.
It is reflected by the plane-parallel plate 16 via the beam splitter 22, the diaphragm 20, and the objective lens 18.

The reflected light from the reticle passes through the objective lens 18, the diaphragm 20, the first beam splitter 22, the collimator correction lens 30, the second beam splitter 34, and the second image plane 40. Is imaged on a video camera as.

That is, a part of the light from the reticle 36 is reflected on the surface of the plane-parallel plate 16 mounted on the angle adjusting mechanism 65 and the surface of the DUT 14 mounted on the position adjusting mechanism 64, respectively. An image of the reticle 36 can be formed on a video camera as the second image forming surface 40.

The image of the reticle and the light beam having the outer diameter 15 as the far point of the object to be measured 14 are laterally displaced because the plane-parallel plate 16 has an oblique angle with respect to the central optical axis of the first optical system 60. It is when they are placed. In the state where the image of the outer diameter 15 and the image of the inner diameter 13 as the short-distance point are not formed on the same axis, the image is taken by the video camera as the second image forming surface 40 for forming the light flux reflected from the plane-parallel plate 16. The inclination of the plane-parallel plate 16 may be adjusted by the angle adjusting mechanism 65 so that the deviation of the optical axis of the reticle image to be corrected is corrected to the direction of the reference mark that is zero or minimized.

When the surface to be imaged, which is the front surface of the object to be measured 14, is tilted, the image of the outer diameter 15 as the far-distance point is deviated obliquely and the outer diameter 15 can be accurately imaged. Can not. Therefore, in order to correct the deviation of the optical axis of the reticle image projected on the video camera as the second image forming surface 40 for forming an image of the light beam reflected from the DUT 14 toward the reference mark direction which becomes zero or minimum, It is advisable to provide a position adjusting mechanism 64 for adjusting the inclination of the DUT 14 or for adjusting the inclination of the holding unit 12 on which the DUT 14 is placed.

The position adjusting mechanism 64 and the angle adjusting mechanism 65.
By manually or automatically performing the alignment operation, the plane to be imaged of the plane-parallel plate 16 or the object to be measured 14 can be set perpendicular to the central optical axis of the first optical system 60.

The illumination light source 38 illuminates the reticle 36. The divergent light transmitted through the reticle 36 is reflected by the optical path splitting half mirror as the second beam splitter 34, and is collimated by the optical path changing mirror 30.
Be led to.

The collimator correction lens 30 forms the image of the reticle 36 reflected by the shunt branching half mirror as the first beam splitter 22 at the position of the diaphragm 20. That is, this image formation position corresponds to the rear focus position of the objective lens 18. The formed light flux is transmitted and refracted by the objective lens 18 to become parallel light, which is radiated to the double focus correction plate as the plane-parallel plate 16.

The light flux of the reticle image reflected by the plane-parallel plate 16 is imaged at the position of the diaphragm 20 by transmitting and refracting the objective lens 18. The imaged luminous flux is subsequently branched by the optical path branching half mirror serving as the first beam splitter 22, and enters the collimator correction lens 30.

The light flux of the reticle image that has entered the collimator correction lens 30 changes its traveling direction by the optical path changing mirror 32, passes through the optical path splitting half mirror as the second beam splitter 34, and then the second image forming surface 40. As an image on a video camera.

As described above, the objective lens 18, the diaphragm 20, the optical path splitting half mirror as the first beam splitter 22, the collimator correction lens 30, the optical path changing mirror 32, and the optical path splitting half as the second beam splitter 34. The optical system including the mirror, the reticle 36, the illumination light source 38, and the video camera as the second image plane 40 has a central optical axis of the first optical system 60 and a central light of the second optical system 62. The auto-collimator function of automatically compensating the arrangement angle of the double focus correction plate as the plane-parallel plate 16 having the same axis can be achieved, and the object 14 to be measured can be imaged with higher accuracy.

In order to improve the imaging accuracy, the DUT 1
The precision of the holding part 12 on which the 4 is placed is not a little involved. That is, it is desirable that the angle between the sample installation surface 17 of the glass V groove and the collimator light reflection surface is 90 degrees, and it is created with an error of several seconds.

Then, in the same manner as the method of compensating the parallelism of the double focus correction plate described above, the illumination light source 38 is controlled by the reticle 3.
The divergent light that illuminates 6 and passes through the reticle 36 is reflected by the optical path splitting half mirror as the second beam splitter 34, and is guided to the collimator correction lens 30 by the optical path changing mirror 32.

By the collimator correction lens 30, the image of the reticle 36 is formed at the position of the diaphragm 20 by the optical path splitting half mirror as the second beam splitter. That is, an image is formed at the rear focus position of the objective lens 18. The light flux of the formed reticle image is transmitted and refracted through the objective lens 18 to become parallel light, which is radiated to the holding portion 12 of the glass V groove.

The light flux reflected from the glass V groove holding portion 12 is transmitted through the objective lens 18 and refracted to form the diaphragm 2.
The light flux of the reticle image is formed at the position of 0. The formed light flux is split by the optical path splitting half mirror as the first beam splitter 22, and the collimator correction lens 3
It is incident on 0.

The light beam incident on the collimator correction lens 30 passes through an optical path changing mirror 32 and an optical path splitting half mirror serving as a second beam splitter 34 to form a reticle image on a video camera serving as a second image forming surface 40. Form an image. In addition, the illumination light source 38 arranged in the second optical system 62
Is used for the collimator function, and DUT 1
When the outer diameter 15 and the inner diameter 13 of 4 are imaged and observed, they may be appropriately turned off.

The objective lens 18, the diaphragm 20, the optical path splitting half mirror as the first beam splitter 22,
Collimator correction lens 30, optical path changing mirror 32, second
The optical path splitting half mirror serving as the beam splitter 34, the reticle 36, the illumination light source 38, and the video camera serving as the second image forming surface 40 include the central optical axis of the first optical system 60 and the second optical system 62. Since the central optical axis is common, the error of the installation angle of the holding part 12 of the glass V groove can be compensated and the installation angle of the DUT 14 placed on the holding part 12 can also be compensated. It is possible to achieve the collimator function and further improve the imaging accuracy of the DUT 14.

The above-mentioned image pickup device, for example, clearly picks up the outer diameter 15 and the inner diameter 13 of the ferrule, and visually or image-processes the eccentricity of each of the outer diameter 15 and the inner diameter 13 with respect to the center axis of the ferrule to perform high precision. Can be observed or measured. The glass V groove holding portion 12 is not limited to glass, and other transparent transparent plastic or acrylic can be used.
It is also possible to use heat-resistant non-transparent metals such as copper and aluminum.

FIG. 7 is a schematic side view of the image pickup device according to the first to third embodiments of the present invention. The imaging device is
The transillumination device 10, the position adjusting mechanism 64, the angle adjusting mechanism 65, the plane-parallel plate 16, the objective lens 18, and the first
And an optical resolution video camera as the first image plane 28.

The object to be measured 14 is the transillumination device 1 from the rear.
It receives the irradiation of parallel straight light of zero. Inner diameter 1 of DUT 14
3 and parallel straight rays along the edge of the outer diameter 15 are parallel plane plates 1
It is incident on 6. Due to the difference in the refractive index of the plane-parallel plate 16, the contours of the inner diameter 13 and the outer diameter 15 of the DUT 14 can be imaged on the same central optical axis, and the objective lens 18 and the first optical system 60 can be used to To the optical resolution video camera as the imaging surface 40 of No. 1, the inner diameter 13 and the outer diameter 15 of the DUT 14
Can be imaged.

FIG. 8 is a front view of the DUT 14 imaged by the video camera in this embodiment. The sample as the object 14 to be measured placed on the holding portion 12 of the glass V groove in the horizontal and longitudinal directions so as to come into contact with the sample setting surface 17 has an edge portion having an inner diameter 13 and an edge portion having an outer diameter 15. The contour is imaged on the first image plane 40. The contour of the DUT 14 imaged by the high-resolution video camera can be determined from the brightness of light, the illuminance, and the brightness.

For example, the first image plane 28 formed by a two-dimensional sensor such as a CCD camera or a MOS sensor is
It is possible to determine the boundary between the DUT 14 and the background by converting the illuminance of incident light into a charge amount. That is, the first image plane 28 having a resolution of 2,048 × 2,048 pixels of an image sensor of 1 pixel 7.4 × 7.4 μm has an outer diameter 15 of 2.5 mm and an inner diameter 13 of 1. 0.25m
The imaging range of the DUT 14 which is m is 95% of the camera visual field.
The predetermined magnification of the objective lens 18 is set to 7.
It can be multiplied by 76.

An image can be picked up with an accuracy of approximately 15,000 from the pixel arrangement dimension of the first image plane 28, and the inside diameter 13 and the outside diameter 15 of the object 14 to be measured and from the central axis are measured. An eccentricity error between the outer diameter 15 and the inner diameter 13 can be imaged with an error within 0.2 micrometer.

FIG. 9 is a schematic side view showing the arrangement of the plane-parallel plate 16 and the illuminating device 70 of another embodiment. A plurality of illuminating devices 70, which share the central optical axis of the device under test 14 and the central optical axis of the plane-parallel plate 16, are arranged between the device under test 14 and the plane-parallel plate 16.

The central area of the plane-parallel plate 16 can mainly pass the image of the inner diameter 13 of the object 14 to be measured and guide the light beam to the objective lens 18. The peripheral area of the plane-parallel plate 16 is mainly measured. An image of the outer diameter 15 of the object 14 can be transmitted.

In this case, the image of the outer diameter 15 located deeper than the inner diameter 13 is shifted by the chamfered tapered shape on the outer circumference of the tip of the object to be measured 14 so that the image of the inner diameter 13 is formed on the central optical axis. Since the light can be deflected, the images of the inner diameter 13 and the outer diameter 15 can be simultaneously formed on the first image forming surface 28. Similarly, in the collimator mechanism, the images of the inner diameter 13 and the outer diameter 15 can be formed on the second image forming surface 40 at the same time.

As described above, the image pickup apparatus described in the embodiments of the present invention can accurately image the outer diameter value, the inner diameter value, and the eccentricity amount from the central axis of the ferrule as the object to be measured 14. . Further, since the tip portion of the object to be measured 14 can be imaged without rotating the object to be measured 14, an error caused by the rotation is unlikely to occur, and an accurate eccentricity amount can be imaged.

Further, since it is possible to simultaneously image the inner diameter 13 and the outer diameter 15 of the object to be measured 14 with a single image forming surface 28, digital signal processing is applied to the output signal of the high resolution video camera. It is possible to image the object to be measured 14 or measure the eccentricity of the inner diameter 13 and the outer diameter 15 in 1 to 2 seconds.

Furthermore, when the collimator function is exerted, the tilt angle between the inner diameter 13 and the outer diameter 15 that occurs when the object 14 to be measured is replaced can be automatically compensated by the position adjusting mechanism 64. It is possible to improve workability when the imaging device is diverted to the measuring device.

As an example of means for applying the image pickup apparatus according to the embodiment of the present invention to a measuring apparatus, the measuring apparatus includes a transillumination device 10, a sample as a DUT 14, for example, a ferrule of an optical fiber component, and a parallel device. A double focus correction plate as the plane plate 16, an objective lens 18, a diaphragm 20, an imaging lens 24, a magnification correction lens 26, and a first imaging surface 28.
As a high resolution video camera. According to this structure, the double focus correction plate as the plane parallel plate 16 is arranged in the first optical system 60 arranged between the DUT 14 and the first image plane 28. The focal length of the optical system 1 is shifted, and the images of the inner diameter 13 as the near distance point and the outer diameter 15 as the far distance point of the DUT 14 are transferred in the order of the objective lens 18, the diaphragm 20, and the imaging lens 24. The high resolution video camera as the first image plane 28 is made transparent and has an inner diameter of 1
A two-dimensional pixel image composed of 3 and the outer diameter 15 can be formed at the same time.

The image pickup apparatus of the present invention is not limited to the above-mentioned illustrated examples, and it goes without saying that various modifications can be made without departing from the scope of the present invention. For example, when imaging, the plane-parallel plate 16 and the DUT 14 are
When the surface to be imaged is fixed perpendicularly to the central optical axis of the first optical system 60, it is possible to configure an imaging device in which the second optical system 62 is omitted.

[0081]

As described above, the first aspect of the present invention is as described above.
According to the image pickup apparatus described in any one of 5 to 5, the following excellent effects can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic front view of an optical system of an image pickup apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side view illustrating an optical system according to an embodiment of the present invention.

FIG. 3 is a schematic side view of a plane-parallel plate applied to the embodiment of the present invention.

FIG. 4 is a schematic side view of a plane-parallel plate applied to the embodiment of the present invention.

FIG. 5 is a side sectional view of a holding unit applied to the image pickup apparatus according to the embodiment of the present invention.

FIG. 6 is a plan view of the image pickup apparatus according to the image pickup apparatus according to the embodiment of the present invention.

FIG. 7 is a side view of the image pickup apparatus according to the image pickup apparatus of the embodiment of the present invention.

FIG. 8 is a front view of the DUT imaged by the imaging device according to the embodiment of the present invention.

FIG. 9 is a schematic side view showing an illumination device according to another embodiment of the present invention.

FIG. 10 is a schematic front view of an object to be measured by a conventional imaging method.

[Explanation of symbols]

10 Transillumination device 11 light source 12 Holder 13 inner diameter 14 DUT 15 outer diameter 16 Parallel plane plate 17 Sample installation surface 18 Objective lens 19 Collimator light reflection surface 22 Beam splitter 24 Imaging optical system 26 Magnification correction lens 28 Image plane 30 Collimator correction lens 32 Optical path changing mirror 34 Beam splitter 36 reticle 36 above reticle 38 Illumination light source 40 Image plane 50 incident optical axis 52 Radiation optical axis 60 First optical system 62 Second optical system 64 Position adjustment mechanism 65 Angle adjustment mechanism 70 Lighting device 80 Inner diameter measurement area 82 Outer diameter measurement area 84 micrometers 86 Laura

Claims (4)

[Claims] 1. A first optical system arranged between an object to be measured and a first imaging plane; and a first optical system arranged between the object to be measured and the first optical system, An image pickup apparatus, comprising: a plane-parallel plate for forming an image of a near distance point and a far distance point of an object on the first image forming surface by the first optical system; 2. The first optical system has an objective optical system facing the object to be measured, and an imaging optical system arranged between the objective optical system and the imaging plane. A first beam splitter disposed between the objective optical system and the imaging optical system for branching a light beam incident from the object to be measured; The image pickup apparatus according to claim 1, further comprising: a second optical system that forms an image of the object to be measured on a second image formation surface in a traveling direction of the light beam split by the beam splitter. 3. A second beam splitter disposed between the second optical system and the second image plane to split a light beam from the first beam splitter; the first beam splitter.
And a reticle arranged in the traveling direction of the light beam split by the second beam splitter, the light from the reticle being reflected by the plane-parallel plate, The imaging device according to claim 2, wherein the imaging device is configured to form an image on two imaging planes. 4. The plane-parallel plate has a first area and a second area, and the first area is formed to have an optical distance longer than that of the second area. The light according to any one of claims 1 to 3, wherein light mainly passes through the first region and light from the short-distance point mainly passes through the second region. Imaging device.