JPH0548169Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The present invention is used to hold an object to be observed in a predetermined position when inspecting the external shape of a relatively small regular part using a microscope. This invention relates to a positioning device using vacuum suction suitable for.

(Prior Art) When inspecting the external shape, shape, etc. of a relatively small precision part using a microscope, it is necessary to hold the object to be observed at a predetermined position.

In such cases, there are four methods:

The first method is to perform autofocus using image processing.

In this method, the distance between the objective lens and the object is measured by image processing based on image data obtained through a microscope. Based on the measured value, a predetermined position (focal position) is determined by moving the object or the objective lens of the microscope.

The second method is to use a distance sensor such as an automatic distance meter. In this method, the distance to the object is detected by the output of a distance sensor and the object lens, etc. is positioned.

The third method incorporates a distance detection mechanism that emits an observation laser on the same axis as the optical axis of the microscope, and performs positioning based on distance detection on the optical axis.

A fourth method is to position the object by pressing it against a stopper provided at a predetermined position.

(Problem that the invention aims to solve) Capturing an enlarged image of the object using a microscope,
When inspecting the external shape, etc., it is necessary to maintain the distance between the object and the microscope objective lens extremely accurately and with high reproducibility, and to position the object quickly.

The first method described above may require a very long positioning time and is not suitable for a large number of processes.

The method using the second distance sensor does not have good reproducibility.

The third method cannot be used, for example, when the portion corresponding to the optical axis of the microscope is deformed, for example, when a through hole is provided.

The fourth method has limitations depending on the structure of the object, and there are many restrictions and the structure may become complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanism for holding an object to be observed in a microscope, in which the object to be observed can be quickly attached to and removed from a focal position by vacuum suction in an apparatus for inspecting the outer shape of an article using a microscope.

(Means for Solving the Problems) In order to achieve the above object, a positioning device using vacuum suction according to the present invention is a positioning device for placing an object at a predetermined position with respect to an objective lens of a microscope. a work holder having a groove for receiving an object so as to guide it in the direction of the optical axis of the microscope, a connection part for connecting to a vacuum device that attracts the object in the direction of the groove, and a work holder that encloses an objective lens barrel of the microscope and faces the work holder. a reference plane, a reference plane forming member having a reference plane, a suction opening surrounding the optical axis and provided on the reference plane, a connection part for connecting the space between the suction opening and the objective lens barrel to a vacuum device; It is comprised of a vacuum device that selectively connects negative pressure, and a distance holding mechanism that adjusts the distance between the work holder and the reference surface forming member in the optical axis direction or maintains the distance at a constant distance.

(Example) Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 1 is a diagram showing an embodiment of a positioning device using vacuum suction according to the present invention.

FIG. 2 is a cross-sectional view showing the relationship between the work holder and the object of the apparatus of the embodiment.

The object 1 to be inspected in this embodiment is a ferrule having a through hole in the center for receiving an optical fiber. This device was developed to measure the inner diameter and eccentricity of a large number of ferrules made of ceramic products.

The work holder 2 has a groove 2b for receiving the object so as to be able to guide it in the direction of the optical axis of the microscope.

And a connection part (hose coupling fitting) connected to the vacuum device 8 that sucks the object 1 in the groove direction 2b.
It has 2c.

The substantially cylindrical reference surface forming member 3 receives an objective lens barrel 6 of a microscope.

An O-ring 4 inserted into an annular groove formed on the inner peripheral surface of the reference surface forming member 3 contacts the outer periphery of the objective lens barrel 6 of the microscope to maintain airtightness. A reference surface 3b is provided on the surface of the reference surface forming member 3 that faces the work holder 2.

A suction opening 3a surrounding the optical axis is provided on the reference surface 3b.

The reference plane forming member 3 is provided with a connecting portion 3c that connects the space 3d between the suction opening 3a and the objective lens barrel 6 to the vacuum device 8.

The vacuum device 8 can selectively connect negative pressure to each of the connection parts 2c and 3c.

The distance between the work holder 2 and the reference plane forming member 3 in the optical axis direction is adjusted or kept at a constant distance by a distance maintaining mechanism 9.

Next, the positioning operation in the optical axis direction of the apparatus according to the embodiment will be explained.

The object 1 is mounted on the work holder 2 in a predetermined posture (parallel to the groove) by an object transport mechanism (not shown).

The vacuum device 8 is operated to supply negative pressure to the work holder 2 side.

The vacuum device 8 is operated to supply negative pressure to the reference surface forming member 3.

The negative pressure supply to the work holder 2 is cut off, and the force for adsorbing the object 1 is weakened. As a result, the object 1 is pulled toward the reference surface forming member 3 by Δx, and the end surface of the object 1 abuts against the reference surface 3b of the reference surface forming member 3.

It is assumed that this reference plane 3b is initially placed at a position -ΔZ from the focal position (measurement position).

Negative pressure is supplied again to the work holder 2 side to adsorb the object.

The negative pressure of the reference surface forming member 3 is cut off.

The distance holding mechanism 9 is operated to move the work holder 2 ΔZ (to the left) from the reference plane 3b and move the object to the focal position of the objective lens.

Note that if the reference plane is held at the focal position by the distance holding mechanism 9, the movement described above is not necessary.

FIG. 3 is a schematic diagram for explaining the principle when the device of the embodiment is applied to measuring the outer diameter of a ferrule.

An image sensor is provided in the microscope objective lens barrel 6, and the data of the hole at the center of the object 1 is taken in and the coordinates of the center on the image sensor are determined.

This moves the work holder 2 to make the center of the object the center of the coordinate system of the measurement system. After that, the distance _l1 from the knife edge 10 at the reference position to the outer diameter is measured by the laser length measuring device. Next, the ferrule is rotated by a ferrule rotation mechanism (not shown) and placed on the work holder 2, and the procedure from the focus positioning is repeated again.
After repeating this process _n times, the eccentricity ε relative to the center of the inner diameter of the ferrule can be calculated as follows: ε＝（ _{lnax -lnio} ）/2 _lnax ＝ _l1 ……maximum value of _{lo lnio ＝ l1} ……minimum value _{of lo}

(Effects of the invention) As explained in detail above, the positioning device using vacuum suction according to the invention uses a work holder and a reference surface forming member to selectively connect negative pressure using a vacuum device to maintain distance. The distance between the work holder and the reference plane forming member in the optical axis direction can be adjusted or maintained at a constant distance by the mechanism.

Therefore, the distance between the object and the microscope objective lens can be maintained extremely accurately and reproducibly, and the position can be quickly determined.

According to the mechanism according to the present invention, a large number of ferrules of a fixed shape can be inspected quickly and accurately.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a positioning device using vacuum suction according to the present invention. FIG. 2 is a cross-sectional view showing the relationship between the work holder and the object of the apparatus of the embodiment. FIG. 3 is a schematic diagram for explaining the principle when the apparatus of the embodiment is applied to measuring the outer diameter of a ferrule. 1...Object (ferrule), 1a...hole in ferrule, 2...work holder, 2b...groove in work holder, 2c...connecting part (coupling metal fitting), 3...
...Reference surface forming member, 3a... Suction opening, 3b...
Optical axis direction position reference surface, 3c...Connection part (coupling metal fitting), 3d...Space, 4...O ring, 6...Microscope objective lens barrel, 8...Vacuum device, 9...Distance holding mechanism, 10...Knife Edge.

Claims (1)

[Scope of utility model registration request] In a positioning device for placing an object at a predetermined position with respect to the objective lens of a microscope, a groove that receives the object so that it can be guided in the direction of the optical axis of the microscope, and is connected to a vacuum device that attracts the object in the direction of the groove. a work holder having a connection portion for connecting the objective lens barrel of the microscope; a reference surface that surrounds the objective lens barrel of the microscope and faces the work holder; a suction opening that surrounds the optical axis and is provided on the reference surface; and a space between the suction opening and the objective lens barrel. a reference plane forming member having a connection part that connects the space to a vacuum device, a vacuum device selectively connecting negative pressure to each of the connection parts, and a distance in the optical axis direction between the work holder and the reference plane forming member. A vacuum suction positioning device consisting of a distance holding mechanism that adjusts or maintains a constant distance.