JPH0666515A - Interferometer apparatus - Google Patents

Abstract

PURPOSE:To fix a mount part for setting an object of inspection to be inspected by an interferometer, by regulating the position of the side of the main body of the interferometer provided with a reference lens, even when the kind of the object changes. CONSTITUTION:A fixed board 21 is fitted on the upper part of a main body frame 20 and an X-Y stage 24 constituting a mechanism for regulating a position in the direction intersecting an optical axis perpendicularly is provided on the lower side of the fixed board 21. Moreover, an optical-axis direction position regulating mechanism 29 is provided on this X-Y stage 24 and the main body 1 of an interferometer is fitted to a Z-axis guide 31 of this optical-axis direction position regulating mechanism 29. An X-axis table 26 and a Y-axis table 28 of the X-Y stage 24 are driven by a stepping motor 35 respectively and, besides, the main body 1 of the interferometer is driven to move up and down by a stepping motor 35. A lens mount part 45 on which a lens 8 to be inspected is set is fitted in a fixed manner on the upper side of the fixed board 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interferometer device for inspecting the surface condition of precision optical products such as lenses using a laser interferometer.

[0002]

2. Description of the Related Art As a precision optical product, for example, a structure in which a laser interferometer is used to inspect the finishing accuracy of a lens is known. That is, a reference lens that serves as a reference for the lens is provided in the optical path of the laser light from the laser light source, and a lens to be inspected is provided on the extension line of the reference lens in this optical path, and the reflected light from the reference surface of the reference lens is provided. The surface state of this lens is inspected by measuring the number of interference fringes (normally called Newton's number) generated between the reflected light from the surface to be inspected of the lens to be inspected. As described above, when the laser interferometer is used, the lens to be inspected can be inspected in a non-contact manner, so that the reference lens and the lens to be inspected can be precisely inspected without damage, which is extremely convenient.

[0003]

In order to accurately inspect the lens to be inspected, it is necessary to adjust the relative position between the reference lens of the interferometer body and the lens to be inspected. This position adjustment is performed by matching the optical axes of the two and changing the distance between the test lens and the reference lens according to the type of the test lens. In the prior art, as the position adjusting mechanism, at least one of the position adjustment in the optical axis direction or the direction orthogonal to the optical axis is performed on the side of the mount portion on which the lens to be inspected is set. However, when the mount side is moved in this way, the position where the lens to be inspected is set is not constant, which changes the position where the lens to be inspected is set.

In recent years, there has been a strong demand for automation of inspection using an interferometer. However, as described above, when the position of the mount part on which the test object is set changes, it is necessary to adjust the setting of the test object to the mount part and the taking-out position from the mount object each time, and this test object is Adjusting this position is very cumbersome because it must be positioned strictly. It is also possible to attach a sensor or the like to a member that handles the object to be inspected, and then to set the object to be inspected after confirming the position of the mount section with this sensor, but the configuration of the handling member is extremely complicated. In addition, there is a problem in that high speed operation cannot be ensured and there is a risk of malfunction. For this reason, conventionally, it has been difficult to automate the work of setting and removing the object to be inspected.

The present invention has been made in view of the above points, and it is an object of the present invention to mount a mount portion of an object to be inspected in adjusting the position between the reference lens and the object to be inspected. To avoid having to move.

[0006]

In order to achieve the above-mentioned object, the present invention generates an interference fringe between the reflected light from the reference lens in the interferometer body and the reflected light from the object to be inspected. The optical axis direction position adjusting mechanism for adjusting the position of the interferometer body in the direction in which the reference lens approaches and separates from the object to be inspected, It is characterized in that it is provided so as to be supported by an adjusting means consisting of an optical axis deviation adjusting mechanism for performing position adjustment in a direction orthogonal to the above, and a mount portion for setting an object to be inspected is fixedly installed. is there.

[0007]

As described above, the position adjustment between the reference lens and the object to be inspected is performed in the optical axis direction and in the direction orthogonal to the optical axis on the side of the interferometer body on which the reference lens is mounted. By doing so, the position of the mount portion on which the object to be inspected is set can be fixed. Therefore, the position where the object to be inspected is set or removed is always constant, and the automation of this work can be smoothly and easily achieved, and the entire process of inspecting the object to be inspected can be automated.

When setting an object to be inspected by an automatic machine, it is most rational to arrange the mount portion in the horizontal direction and place the object to be inspected thereon. For this purpose, the surface plate is arranged in the horizontal direction, the mount portion is provided on the upper surface side of the surface plate, and the adjusting means is attached to the lower surface.
The interferometer body is attached to the adjusting means, and the position of the interferometer body is adjusted in the optical axis direction, that is, the vertical direction, and the direction orthogonal to the optical axis, that is, the horizontal direction. As a result, when the handling means for the object to be inspected takes out the object to be inspected from the loader part, moves it horizontally, displaces it to the upper position of the mount part, and then lowers it, this object to be inspected of the mount part. Can be located on top. In this state, if the handling of the test object by the handling means is released, the test object is set accurately on the mount portion. Further, it is possible to easily remove the object to be inspected from the mount portion after the inspection.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, in FIG. 1, reference numeral 1 denotes an interferometer body, and the casing of the interferometer body 1 is a body casing 1.
The main body casing 1a has a cylindrical body portion 1b provided upright on the upper surface of the main body casing 1a. The body casing 1a has a cylindrical body portion 1b.
A laser oscillator 2 made of a He-Ne laser or the like is attached in parallel with. Body housing 1a
A laser light guiding optical system 4 including a reflection mirror 3 and an expander, a diver, and the like is provided therein.
The laser light from the laser oscillator 2 is bent by 90 ° by the reflection mirror 3 and is reflected by the beam splitter 5 while expanding the spot diameter through the optical system 4 for guiding the laser light and again in the 90 ° direction. Convert
The collimator lens 6 travels in the direction opposite to the emission direction from the laser oscillator 2 along the axial direction of the cylindrical body portion 1b.
Is made into parallel light by and is incident on the reference lens 7 provided in front of it.

The reference lens 7 has a reference surface 7b opposite to the incident surface 7a, and the incident surface 7a is provided with an antireflection coating. A part of the laser light incident on the reference lens 7 is reflected by the reference surface 7b, and most of the laser light is transmitted through the reference lens 7 and a laser beam of a lens 8 to be inspected as an object to be inspected is set at the front position thereof. It is incident on the surface 8a to be inspected, and a part thereof is reflected by the surface 8a to be inspected. And
The reflected light from the surface 8a to be inspected and the reference surface 7 of the reference lens 7
The reflected light from b interferes with each other to form an interference fringe. Thus, the reflected light having the interference fringes passes through the collimator lens 6 and the beam splitter 5, and enters the image pickup means 11 via the screen 9 and the interference fringe image forming lens 10.
An image of the interference fringe is taken by the image pickup means 11, and the image can be displayed on a monitor device (not shown).

Next, in FIG. 2, reference numeral 20 denotes a main body frame of the interferometer device, and a surface plate 21 is provided above the main body frame 20.
A vibration-proof member 22 is interposed between the surface plate 21 and the main body machine frame 20. And the platen 21
An adjusting means 23 is vertically provided on the lower surface of the. The interferometer body 1 is mounted on the adjusting means 23 so as to be able to move up and down. The adjusting means 23 is for adjusting the position of the reference lens 7 of the interferometer body 1 with respect to the lens 8 to be inspected. This position adjustment is performed in the optical axis direction and the direction orthogonal to the optical axis.

As is apparent from FIG. 3, a plate 21a is fixed to the lower surface of the surface plate 21 by means of bolts or the like, and the interferometer body 1 is orthogonal to the optical axis on this plate 21a. XY stage 2 that constitutes a position adjustment mechanism in the direction
4 are provided. In the XY stage 24, an X-axis table 26 is slidably connected to a pair of X-axis guides 25 extending in the X-axis direction on the lower surface of the plate 21a, and the X-axis table 26 is extended in the Y-axis direction. A Y-axis table 28 is slidably connected to a pair of Y-axis guides 27 provided in the table. The Y-axis table 28 has an optical axis direction position adjusting mechanism 2 for displacing the interferometer body 1 in the optical axis direction.
9 is provided. This optical axis direction position adjusting mechanism 29
Is provided with a Z-axis guide 31 on a support member 30 vertically provided on the Y-axis table 28.
The two are slidably connected. The interferometer body 1 is attached to the lifting block 32.

As described above, the XY stage 24 which connects the interferometer main body 1 to the optical axis direction position adjusting mechanism 29 and constitutes the position adjusting mechanism of the optical axis direction position adjusting mechanism 29 in the direction orthogonal to the optical axis. The interferometer body 1 can be positionally adjusted in the direction of the optical axis as well as in the direction orthogonal to the optical axis. Moreover, this position adjustment is configured to be automatically performed. Therefore, as the mechanism for displacing the X-axis table 26 and the Y-axis table 28, the one having the configuration shown in FIG. 4 is used. Note that X
Since the displacement mechanism of the shaft table 26 and the displacement mechanism of the Y-axis table 28 have substantially the same configuration, X in the drawing shows
The displacement mechanism of the shaft table 26 is shown, and the displacement mechanism of the Y-axis table 28 is not shown and described.

In FIG. 4, reference numeral 33 denotes an advancing / retreating shaft, and this advancing / retreating shaft 33 is a mounting plate 3 provided on the plate 21a.
4 is rotatably inserted. The tip end of the advancing / retreating shaft 33 is in contact with the X-axis table 26, and the X-axis table 26 is biased in a direction in which it is in contact with the advancing / retreating shaft 33 by a biasing means such as a spring (not shown). Also, advance / retreat axis 3
Reference numeral 3 is rotated by a stepping motor 35. For this reason, the forward / backward shaft 33 has a head portion 33a formed in contact with the X-axis table 26 at the tip, a screw portion 33b screwed into the mounting plate 34 in the middle portion, and a base end side portion. It is a spline portion 33c. The pulley 36 is fitted to the spline portion 33c so as to be displaceable in the axial direction thereof, and the output shaft 35a of the stepping motor 35 is also attached with a pulley 37 so that a timing belt is provided between the pulleys 36 and 37. 38 is wound and provided. Therefore, when the stepping motor 35 is driven, the pulley 36 rotates and the advancing / retreating shaft 32 moves.
Is moved back and forth, and the X-axis table 26 moves the X-axis guide 2
It is made to slide along 5.

Next, a screw shaft 39 is provided as a drive mechanism of the optical axis direction position adjusting mechanism 29, and the screw shaft 39 is provided between the support plates 30a and 30b provided above and below the support member 30. . The nut member 4 is attached to the screw shaft 39.
0 is fitted, and the nut member 40 is connected to the elevating block 32. A pulley 41 is connected to the lower end of the screw shaft 39, and the supporting member 3
0 has a stepping motor 42 installed, and an output shaft 42 a of the stepping motor 42 has a pulley 43.
Is attached, and a timing belt 44 is wound around the pulley 43 and the pulley 41 of the screw shaft 39. Therefore, by rotating the stepping motor 42 forward and backward, the interferometer main body 1 is driven up and down.

On the other hand, on the upper surface of the surface plate 21, the lens 8 to be inspected
Is provided with a lens mount portion 45, and a projection 46 for positioning the lens 8 to be inspected is provided on the upper surface of the lens mount portion 45.
Here, when the lens 8 to be inspected is a spherical lens, the protrusions 46 are provided at three positions every 120 °. Also, surface plate 2
1 is provided with a light guiding through hole 21b for securing an optical path between the interferometer body 1 and the lens 8 to be inspected.

Here, by the adjusting means 23 including the XY stage 24 and the optical axis direction position adjusting mechanism 29 described above,
The position of the optical path of the interferometer main body 1 can be adjusted in the direction orthogonal to the optical axis and in the direction of the optical axis, but no tilt adjustment mechanism for the optical axis is provided. Lens to be inspected 8
It is necessary to adjust the position in the optical axis direction between the reference lens 7 and the lens 8 to be inspected and the direction orthogonal to the optical axis according to the type of the above, but if the tilt direction is initially adjusted, If the optical axis does not tilt when the interferometer body 1 is moved, this tilt adjustment is not particularly necessary. Therefore,
As described above, since the adjusting means 23 and the lens mount portion 45 on which the lens 8 to be inspected are set are also attached to the surface plate 21, the plate 21a is mounted in a state strictly parallel to the surface plate 21. Further, if the Z-axis guide 31 is assembled to the surface plate 21 so as to be correctly in the vertical state, even if the position of the interferometer body 1 is adjusted, the optical axis will not be tilted.

The interferometer device is constructed as described above, and by using this interferometer device, it can be used as a device for measuring the number of Newtons of the lens 8 to be inspected. It is possible to perform an inspection of finishing accuracy of 8. Moreover, as shown in FIG. 5, many test lenses 8 are arranged in the loader section L,
The lenses 8 to be inspected are taken out one by one from the loader L by the handling member H, and the lens mount 45
, The inspection lens 8 is inspected, and when the inspection is completed, the inspection lens 8 is moved to the unloader unit U, and in this unloader unit U, the state is classified based on the inspection result. It is supposed to be housed.

Then, first, the reference lens 7 having an F value suitable for measuring the number of Newtons of the lens 8 to be inspected is attached to the interferometer main body 1, and the lens mount portion 45 is attached to the lens 8 to be inspected. According to the outer diameter dimension, the one having the optimum dimension for supporting the outer peripheral edge portion is attached to the surface plate 21.
Therefore, a Newton gauge is set on the lens mount portion 45. Here, the Newton gauge is the lens 8 to be inspected.
The surface 8a to be inspected has an ideal shape. However, the material is not necessarily the same as that of the lens 8 to be inspected.

In this state, the positional relationship between the interferometer main body 1 and the Newton gauge is adjusted so as to be the optimum relative positional relationship for measuring the number of Newtons when the lens 8 to be inspected is set. The adjustment means 23 adjusts the relative positional relationship. That is, in order to adjust the distance between the reference lens 7 and the lens 8 to be inspected in the interferometer body 1, that is, the position in the optical axis direction, by operating the stepping motor 42 that constitutes the optical axis direction position adjusting mechanism 29,
This can be done by moving the elevating block 32 up and down. The position adjustment in the direction orthogonal to the optical axis can be performed by moving the X-axis table 26 and the Y-axis table 28 of the XY stage 24. Here, the X-axis table 26 and the Y-axis table 28 are operated by operating the stepping motors 35 provided respectively.

As described above, since the interferometer body 1 is moved when the position is adjusted in the optical axis direction of the interferometer body 1 and in the direction orthogonal to the optical axis, the lens mount portion 45 is fixed. Can be held in a fixed state, and therefore the lens 8 to be inspected
The position to set is always constant.

When the position adjustment of the interferometer body 1 is completed in this way, the Newton gauge is moved to the lens mount portion 4.
5, the handling means H is operated, and one lens 8 to be inspected is taken out from the loader section L and set on the lens mount section 45. Then, the laser light emitted from the laser oscillator 2 is partially reflected by the reference surface 7b of the reference lens 7, and a part of the transmitted light is reflected by the surface 8a of the lens 8 to be inspected so that both reflected light beams are reflected. The interference fringes generated between the two are imaged on the image pickup means 11. Then, the signal from the image pickup means 11 is transmitted to the monitor device, the interference fringe image is displayed on the monitor device, and the number of the interference fringes is automatically measured based on the image processing. When the inspection of the lens 8 to be inspected is finished in this way, the lens 8 to be inspected, which has been measured by the handling means H, is taken out from the lens mount part 45 and sent to the unloader part U, based on the measurement result of the interference fringes. Be classified.

As described above, in performing automatic measurement of the lens 8 to be inspected, how accurately the lens 8 to be inspected is set on the lens mount 45 is extremely important. Is always held constant, the teaching of the handling means H can be carried out once at the beginning, and it is not necessary to readjust again every time the type of the lens 8 to be inspected changes, and it is smooth and reliable. To
Moreover, the lens 8 to be inspected can be set in a state where the lens 8 is strictly positioned.

In the above-described embodiment, the lens 8 to be inspected is set by the automatic machine, but it is not always necessary to use the automatic machine, and the lens 8 is manually set. Even when performing, the work efficiency can be improved if the lens mount portion 45 is fixed.

[0025]

As described above, according to the present invention, an optical axis direction position adjusting mechanism for adjusting the position of the interferometer main body in the direction in which the reference lens approaches and separates from the object to be inspected, and the optical axis orthogonal to the optical axis. It is provided by being supported by an adjusting means consisting of an optical axis shift adjusting mechanism for adjusting the position in the direction of, and the mount part for setting the object to be inspected is fixedly installed.
The position where the object to be inspected is set is always constant, and it is extremely easy and accurate to set and remove the object to be inspected, and the attachment / detachment of the object to be inspected is automated. There are various effects such as possible.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the configuration of a laser interferometer.

FIG. 2 is a cross-sectional view showing the overall configuration of the interferometer device of the present invention.

FIG. 3 is an external perspective view of adjusting means.

FIG. 4 is a structural explanatory view of a drive portion of an optical axis shift adjusting mechanism.

FIG. 5 is a structural explanatory view of an inspection mechanism of a lens to be inspected using an automatic machine.

[Explanation of symbols]

 1 Interferometer Main Body 2 Laser Oscillator 7 Reference Lens 7b Reference Surface 8 Test Lens 8a Test Surface 20 Main Machine Frame 21 Surface Plate 21a Opening 22 Vibration Isolator 23 Adjusting Means 24 XY Stage 26 X Axis Table 28 Y Axis Table 29 Optical Axial adjustment mechanism 32 Lifting block 35, 42 Stepping motor 45 Lens mount part 46 Protrusion L Loader part H Handling means U Unloader part

Claims (3)

[Claims] 1. An apparatus for inspecting a surface state of an object to be inspected by generating interference fringes between reflected light from a reference lens in an interferometer main body and light reflected from the object to be inspected. Adjustment with an optical axis direction position adjustment mechanism that adjusts the position of the main body of the meter in the direction in which the reference lens approaches and separates from the object to be inspected, and an optical axis deviation adjustment mechanism that adjusts the position in the direction orthogonal to the optical axis. An interferometer device characterized in that it is provided so as to be supported by a means, and a mount portion for setting an object to be inspected is fixedly installed. 2. A structure in which the mount portion is installed on an upper surface of a surface plate provided in a horizontal direction, an opening for guiding a laser beam is formed in the surface plate, and the adjusting means is mounted on a lower surface of the surface plate. The interferometer device according to claim 1, wherein 3. The interferometer apparatus according to claim 1, wherein the optical axis direction position adjusting mechanism and the optical axis shift adjusting mechanism of the adjusting means are each driven by a driving means such as a motor.