JPH0738806Y2 - Interferometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an interferometer used for measuring the flatness of a surface of a subject to be examined.

[Conventional technology]

Generally, even on the surface of a product that looks flat, if it is enlarged, it has fine irregularities, so it is necessary to measure this in order to obtain a flat surface with a high degree of flatness. Conventionally, in order to measure the flatness of the surface of a product, as shown in FIGS. 2 and 3, laser light is irradiated onto a test surface 86'a of a test object 86 'to test the test object 86'. An interferometer for measuring the flatness of the test surface 86'a of the test object 86 'by forming interference fringes between the reflected light from the reference standard 82'b and the reflected light from the reference surface 82'b of the standard prototype 82' is used. ing.

[Problems to be solved by the device]

However, the conventional interferometer X'shown in FIGS. 2 and 3 includes a laser oscillator 90 'and a laser light 90' in a housing 40 'supported by four columns established on a base 10'. Optical system 50 ', an interference fringe image forming optical system 60' and an image pickup unit 70 'are built in, and a laser beam is passed through a collimator lens 81' and a reference prototype 82 'to the lower part of the housing 40'. Subject 86 ′
The laser beam emitting cylindrical body 80 'for irradiating the laser is fixed, and since the laser oscillator 90' is long, the housing 40 'inevitably becomes large.
The interferometer X'has a large installation area and is inconvenient, and the four struts supporting the housing 40 'interfere with the insertion and removal of the subject 86', resulting in poor operability.

The present invention has been made in view of the above circumstances,
The object is to provide a desk-top type interferometer with a small installation area and good operability.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the interferometer of the present invention is configured such that a tubular base of an arm-supported column is externally fitted to a cylindrical column that is established on a base, and is vertically moved along the tubular column, and On the free end side of the arm of the column with the arm that can be fixed, a laser light optical system and an imaging system are vertically installed from a housing, and the laser light is passed through a collimator lens and a reference prototype to be examined. While fixing the laser light emitting cylinder for irradiating to the inside, inside the cylindrical support, a laser oscillator for laser light oscillation to the laser light optical system of the housing is mounted. To do.

[Action]

In the interferometer according to the present invention, the cylindrical base of the arm-supported column is externally fitted to the cylindrical column that is established on the base so that the arm can be moved vertically along the cylindrical column. The laser light emitting housing fixed to the free end side can be moved up and down to adjust the distance to the subject to a desired distance.

The laser oscillator is vertical because it is installed inside the cylindrical column that is established on the base, and the installation area of the interferometer can be reduced. Further, since there is no obstacle below the laser beam emitting cylinder for taking in and out the subject, it is possible to improve the operability of the interferometer.

〔Example〕

Hereinafter, embodiments of the interferometer of the present invention will be described in detail with reference to the drawings.

In FIG. 1, X is an interferometer, and the interferometer X is
Interference fringe image forming optical system 60, light spot image forming optical system 63, and image capturing unit 70 which form a base 10, a cylindrical column 20, an arm column 30, a housing 40, a laser beam optical system 50, and an image capturing system. It mainly comprises a cylinder 80 for emitting laser light, a laser oscillator 90, and an object mounting base 100.

By the way, the bottom surface of the base 10 has rubber feet 11, 11, ...
... is attached, and a mounting portion 12 for mounting the cylindrical column 20 is formed on the upper surface, and the cylindrical column 20 is established on this mounting portion 12. Then, a square screw 21 is engraved on the outer side of the lower portion of the cylindrical column 20, and a nut 22 is screwed into the square screw 21,
As will be described later, a column with an arm that is fitted onto the cylindrical column 20
It is adapted to support the cylindrical base 31 of 30. Although not shown, a guide groove is formed along the axial direction on the outer peripheral surface of the cylindrical column 20, and a push screw screwed into the cylindrical base 31 in the guide groove. By engaging the distal end portion of 35, the arm-supported column 30 is prevented from rotating around the tubular column 20.

The arm-supported column 30 is a housing in which a base portion of the arm body is provided with a tubular base portion 31 having a split groove portion 32 provided with an opening / closing handle 33, and a free end side thereof is inserted with a laser light emitting tubular body 80 described later. Support tubes 34 supporting 40 are respectively formed, and the cylindrical base portion 31 is externally fitted to the cylindrical support 20, is supported by the nut 22, and is opened and closed by the opening / closing handle 33. When the groove portion 32 is opened, the inner diameter of the tubular base portion 31 becomes large, and the tubular base portion 31 can be moved in the vertical direction along the tubular strut 20, and when the split groove portion 32 is closed by the opening / closing handle 33, the inner diameter of the tubular base portion 31 becomes smaller. It is made smaller so that it can be fixed to the cylindrical column 20. Further, the support tube 34 is divided into two for convenience of assembly, and is joined by a bolt 36 so that the laser light emitting tube 80 does not rotate in the support tube 34. The arm-supported column 30 may have an inclined shape or an orthogonal shape. Since an air gap is generated between the upper end of the arm-supported column 30 and the laser oscillator mounting portion 47, which will be described later, it is possible to put a hand between them and the laser oscillator 90 can be easily replaced.

In the housing 40, a laser light optical system 50, an interference fringe image forming optical system 60, a light spot image forming optical system 63, and a television camera 70 as an image pickup unit are built in. system
50 is a reflection mirror 51, a beam diverger 52, and a pinhole
53 and a beam splitter 54, the interference fringe image forming optical system 60 includes an interference fringe image forming lens 61 and a screen 62, and the light spot image forming optical system 63 forms an interference fringe image. It is designed to be switched to the lens 61 for use. And the housing
The bottom plates 41 of 40 are the same shape that can be separated.
43, and through holes 44 and 45 are formed on the bottom plate 41 at positions corresponding to the reflection mirror 51 and the beam splitter 54,
A light amount adjusting filter 91 is attached to the through hole 44 of the upper bottom plate 42, and a laser oscillator attaching portion 47 having a laser oscillator attaching hole 46 communicating with the through hole 44 is attached to the lower bottom plate 43.
And a through hole 45 is formed in the laser beam emitting cylinder 80 described later.
The upper end of the lens barrel 83 constituting the above is connected.

The laser light emitting cylinder 80 is the support column 30 with the arm.
The collimator lens 81 is mounted and fixed to the lower end of the lens barrel 83 which is fitted into the support tube 34 on the free end side and is supported via the lower bottom plate 43, and the reference prototype 82 can be finely adjusted under the collimator lens 81. It is attached to the.

The laser oscillator 90 is inserted into the cylindrical column 20, the upper end portion thereof is inserted into the laser oscillator mounting hole 46 of the laser oscillator mounting portion 47, and the set screw 48 screwed into the mounting portion 47. It is fixed so that it can be removed.

The housing 40 may be provided integrally with the laser light emitting cylinder 80 without being separated by the bottom plate 41.

Then, when exchanging the laser oscillator 90, the procedure is as follows.

First, the push screw 48 is loosened to lower the laser oscillator 90 and separate it from the mounting portion 47.

Next, the bolt 36 is loosened to form a gap between the laser light emitting cylinder 80 and the support cylinder 34, and the laser light emitting cylinder 80 provided integrally with the housing 40 is attached to the optical axis of the collimator lens 81. A cylinder for laser light emission that is not rotatable about
Rotate the mounting part 47 provided integrally with 80 to the side away from the axial direction of the laser oscillator 90, pull out the laser oscillator 90 upward, replace it with another laser oscillator, and then return to the original state. Excuse me.

As laser light oscillated by the laser oscillator 90, lasers of various wavelengths can be used, and for example, He—Ne laser, Ar laser, semiconductor laser, etc. are used.

The subject mounting table 100 includes the laser light emitting cylinder 80.
Below the reference standard 82, it is attached to the upper surface of the base 10 so as to be finely adjustable by a fine adjustment tool.

In measuring the flatness of the test surface 86a of the test object 86 with the interferometer X configured as described above, the laser oscillator 90
When the laser beam oscillated from the laser beam is applied to the test surface 86a of the subject 86 through the laser light optical system 50 and the laser light emitting cylinder 80, the reflected light is emitted from the reference surface 82b of the standard prototype 82. The interference fringes are imaged on the image pickup section 70 by the interference fringes imaging optical system 60 that interferes with the reflected light of the beam splitter 54. It should be noted that the surface of the subject 86 to be inspected is read by reading the number of interference fringes projected on a television monitor (not shown).
The flatness of 86a is measured. Further, when the interference fringe image forming lens 61 in the interference fringe image forming optical system 60 is switched to the light spot image forming optical system 63, focusing can be performed.

[Effect of device]

As is clear from the above description, the interferometer of the present invention has a small laser oscillator, so that the installation area is small, and the object to be taken in and out is obstructed below the laser beam emitting cylinder. Therefore, it is possible to obtain practically excellent effects such as good operability.

[Brief description of drawings]

FIG. 1 is a front view showing a part of an interferometer according to the present invention in a cutaway view, FIG. 2 is a plan view showing the interior of a conventional interferometer with a top plate removed, and FIG. It is a front view which cuts and shows a part of interferometer. X: Interferometer 10: Base 20: Cylindrical support 30: Support with arm 40: Enclosure 50: Laser light optical system 60: Interference fringe imaging optical system 70: Imaging unit 80: Laser light emitting cylinder 86 : Subject 90: Laser oscillator

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An arm of a column with an arm, wherein the tubular base of the column with an arm is externally fitted to a tubular column established on a base so that the column can move vertically along the tubular column and be fixed. On the free end side, a laser light optical system and an imaging system are vertically installed from a housing that is built in, and a laser light emitting cylinder that irradiates the subject with laser light through a collimator lens and a reference prototype is fixed. On the other hand, an interferometer characterized in that a laser oscillator for oscillating laser light to the optical system for laser light of the housing is installed inside the cylindrical support.