JPH06137993A - Lens eccentricity measuring device - Google Patents

Abstract

PURPOSE:To measure the eccentricity of a lens to be inspected accurately CONSTITUTION:This device is provided with a master mold support bunch 11 which can be rotated around the Z axis which is the light axis of the flux of light which is projected from a laser light source 1 to a master mold 10, can travel in X and Y axes crossing the Z axis, and can be inclined within XZ surface and the YZ surface and a first displacement measuring machine 12 which can travel in Z-axis direction and can measure the displacement in X direction at the master mold outer diameter part. Then, it is also provided with a bench 13 for supporting a lens to be inspected which rotate around the Z' axis which is the light axis of the flux of light which is projected to the lens 30 to be inspected and at the same time can be inclined within the X'Z' surface and the Y'Z' surface and a second displacement measuring machine 14 which can travel in Z' axis direction and can measure the displacement in X' direction of the outer diameter part of the lens to be inspected. Further, it is also provided with machines 15a and 15b for measuring the amount of travel which measures the amount of travel in X' direction and Y' direction of the 13 for supporting the lens to be inspected and an inclination angle measuring machine 16 for measuring the inclination angle of the X'Z' surface and the Y'Z' surface of the bench 13 for supporting the lens to be inspected, thus achieving an accurate measurement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines the amount of eccentricity of a lens to be measured, that is, the amount of deviation between the optical axis of the lens and the central axis of the lens outer diameter, and the tilt angle between the optical axis of the lens and the central axis of the lens outer diameter. The present invention relates to a lens eccentricity measuring device for measuring.

[0002]

2. Description of the Related Art When measuring the amount of eccentricity of a lens surface, a lens eccentricity measuring device using an interferometer is used. FIG. 6 shows a conventional measuring device described in Japanese Patent Application Laid-Open No. 61-144541. This measuring device captures a reflected image of the laser beam applied to the lens surface 102a of the lens 102 to be measured, which is the object to be measured, with the laser interferometer 101, and the display device 10
3 is displayed. The lens 102 to be inspected is mounted on a sample mounting base 104. The sample mounting base 104 is rotatable about the optical axis of the laser interference device 101, movable in a plane orthogonal to the optical axis, and tiltable. Has become.
Further, a displacement measuring device 1 for measuring the displacement of the lens 102 to be inspected
05 is provided so as to contact the side surface of the lens 102 to be inspected.

In the above structure, the displacement measuring device 105 in contact with the side surface of the lens 102 to be inspected is moved vertically along the optical axis direction of the laser interference device 101 until the displacement amount hardly changes. Sample mount 104
Correct the inclination of. As a result, the central axis of the outer diameter of the lens 102 to be inspected and the optical axis of the laser interference device 101 become parallel. Next, the sample mounting base 104 is rotated, and the sample mounting base 1 is rotated until the scale change of the displacement measuring instrument 105 is minimized.
04 is moved within the plane. As a result, the center axis of the outer diameter of the lens 102 to be inspected and the optical axis of the laser interference device 101 coincide with each other.

Observing the display device 103 in this state,
When the lens surface 102a of the lens 102 to be inspected is decentered, the reflected image of the laser beam applied to the lens surface 102a is
If the center position of the display device 103 does not match, and on the other hand, there is deflection, the interference fringes near the center of the reflected image do not form concentric circles. Therefore, when the sample mounting table 104 is moved so that the reflection image reflected on the display device 103 coincides with the center position of the display device 103, the amount of movement is the amount of eccentricity of the lens surface and the center of the reflection image. When the sample mounting table 104 is tilted so that the interference fringes in the vicinity are concentric circles, the tilt angle can be measured as tilt.

[0005]

In the conventional measuring device,
The amount of eccentricity and deflection is measured by detecting the amount of deviation of the reflected image of the converged laser light projected from the laser interference device and converging on the surface of the lens to be inspected. The deviation of the reflection image is extremely small, so that there is a problem that sensitivity to eccentricity is poor and highly accurate eccentricity measurement cannot be performed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens eccentricity measuring device capable of accurately measuring the amount of eccentricity of the lens surface of the lens under test.

[0007]

To achieve the above object, the lens eccentricity measuring device of the present invention is constructed as shown in FIG. In the present invention, the amount of eccentricity is measured based on the interference between the reflected light from the lens under test and the reflected light from the master mold that serves as the measurement reference. It is used. In FIG. 1, reference numeral 31 denotes a Twyman-Green type interference device, which includes a laser light source 1, a beam expander 2 that expands the light flux of the laser light source 1, a beam splitter 3 that divides the light flux from the beam expander 2 into two. A first objective lens 4 for projecting one of the two light beams split by the beam splitter 3 onto the master mold 10 and the beam splitter 3
The second objective lens 5 for projecting the other divided light flux onto the lens 30 to be inspected, the master mold 10 and the lens 3 to be inspected
A condenser lens 6 for converging the reflected light from 0 through the first objective lens 4 or the second objective lens 5 and the beam splitter 3 to cause interference, and an interference located at the focal plane of the condenser lens 6 A screen 7 for forming stripes and a TV camera 8 for photographing the interference fringes formed on the screen 7.
And a display device 9 for displaying interference fringes photographed by the TV camera 8.

The present invention combines the following elements with respect to such a Twyman-Green type interference device. That is, while holding the master mold 10, when the optical axis direction of the light beam projected on the master mold 10, that is, the optical axis of the first objective lens 4 is the Z axis, the master mold 10 is rotatable about the Z axis. When the two orthogonal axes of the optical axis are the X and Y axes,
A master die support 11 that is movable in these axial directions and that can be tilted in the XZ plane and the YZ plane, and a displacement in the X direction of the outer diameter portion 10b of the master die 10 that is movable in the Z axis direction. Displacement measuring machine 12 for measuring the
0 is supported, and when the optical axis of the light beam projected onto the lens 30 to be inspected is the Z'axis, it can be rotated around the Z'axis, and the two axes orthogonal to the optical axis direction are the X'axis and the Y'axis. When used as the'axis, it can move in the X'axis and Y axis directions, and X'Z '
Lens support base 13 that can be tilted in the plane Y'Z '
And the outer diameter portion 3 of the lens 30 to be inspected that is movable in the Z′-axis direction.
Second displacement measuring machine 14 for measuring the displacement of 0b in the X'direction
And movement amount measuring machines 15a and 15b for measuring the movement amounts of the lens support base 13 in the X'and Y'directions, and the X'Z 'surface and the Y'Z' surface of the lens support base 13. Tilt angle measuring machines 16a and 16b for measuring the tilt angle are arranged. Here, the master mold 10 has a reference surface 10a having a spherical surface or an aspherical surface, which serves as a measurement reference for the measurement surface 30a of the lens 30 to be inspected.

In such a structure, when the first displacement measuring machine 12 is moved up and down along the Z direction, the displacement amount of the first displacement measuring machine 12 is hardly displaced, so that the master die support 1
Correct the inclination of 1. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 become parallel. Next, when the master mold support base 10 is rotated, the master mold support base 11 is moved within the XY plane so that the change of the first displacement measuring machine 12 is minimized. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 coincide with each other. Subsequently, the lens 30 to be inspected is mounted on the lens support base 13 to be inspected, and the same adjustment is performed by using the second displacement measuring machine 14.
The central axis of the outer diameter portion 30b and the optical axis of the objective lens 5 are aligned. Here, the optical axis direction of each of the first objective lens 4 and the second objective lens 5, that is, Z and Z ′.
The positions in the directions are adjusted so that the interference fringes due to the reflected light of the laser light projected on the reference surface 10a of the master mold 10 and the measurement surface 30a of the lens 30 to be inspected can be observed on the display device 9. In this observation, the lens 3 to be inspected
When the optical axis of one surface of 0 does not coincide with the center axis of the outer diameter, there is eccentricity. In this case, the optical axis of the second objective lens 5 also does not coincide with the optical axis of the second objective lens 5. The generated interference fringes are not concentric circles. That is, it is possible to detect that the lens to be inspected is decentered by the interference fringes that are not concentric circles. The sensitivity in this case is 1 / the used wavelength of the laser light.
Since the sensitivity is 10 levels, it becomes 0.1 μm or less,
The sensitivity can be extremely high.

Next, so that the interference fringes are concentric,
The lens support base 13 to be tested is adjusted. When the measurement surface 30a of the lens 30 to be inspected is a spherical surface, the interference fringes become concentric circles by moving the lens support 13 to be inspected in the X'Y 'plane. The movement amount of the lens support base 13 to be tested is measured by the movement amount measuring machines 15a and 15b. Then, as shown in FIG. 2, the root mean square of both movement amounts is the outer diameter portion 30b of the lens 30 to be inspected.
Center of curvature 30c of the spherical portion 30a with respect to the central axis 30d of
Deviation amount δ. On the other hand, the measurement surface 30 of the lens 30 to be inspected
When a is an aspherical surface, the test lens support 13 is moved in the X'Y 'plane and tilted in the X'Z' plane / Y'Z 'plane to form concentric interference fringes. Then, as shown in FIG. 2, the lens 3 to be inspected is based on the root mean square of both movement amounts measured by the movement amount measuring machines 15a and 15b.
Aspherical surface 30a with respect to the central axis 30d of the outer diameter portion 30b of 0
The shift amount δ of the aspherical surface axis 30d can be obtained. Further, based on the root mean square of both tilt amounts displayed on the tilt angle measuring machines 16a and 16b, the aspherical surface axis 30c of the aspherical surface portion 30a with respect to the central axis 30d of the outer diameter portion 30b of the lens 30 to be tested.
The inclination amount ε of can be obtained. From the above, the amount of eccentricity of the lens surface can be measured with high accuracy.

[0011]

[Embodiment 1] FIG. 3 shows Embodiment 1 of the present invention, in which the same elements as in FIG. In FIG. 3, reference numeral 31 denotes a Twyman-Green type interference device, which divides a laser light source 1, a beam expander 2 for expanding the light beam of the laser light source 1, and a light beam from the beam expander 2 into two. The beam splitter 3, the first objective lens 4 that projects one of the light fluxes split by the beam splitter 3 onto the master mold 10, and the other light flux that is split by the beam splitter 3 into the test lens 30 Condensing the reflected light from the second objective lens 5 and the master mold 10 and the lens 30 to be examined through the first objective lens 4 or the second objective lens 5 and the beam splitter 3 to cause interference. A lens 6 and a screen 7 positioned on the focal plane of the condenser lens 6 to form interference fringes
And a TV camera 8 for photographing the interference fringes formed on the screen 7, and a display device 9 for displaying the interference fringes photographed by the TV camera 8.

In contrast to such a Twyman-Green type interference device, the master mold 1 is provided on the side of the first objective lens 4 thereof.
The master die support 11 for supporting 0 is arranged,
On the side of the objective lens 5 of the above, a lens support base 13 for mounting a lens 30 for inspection is arranged. Master mold support 11
Is a spindle 11a rotatable around the Z axis and two axes orthogonal to the optical axis direction of the light flux projected on the master mold 10, that is, when the optical axis of the first objective lens 4 is the Z axis. Where X is the X-axis / Y-axis, the movable stage 11b is movable in the X-axis / Y-axis directions, and the tilt stage 11c is tiltable in the XZ plane and the YZ plane. Further, with respect to the master die 10, the outer diameter portion 10b of the master die 10 is mounted on the stage 17a movable in the Z direction.
And a first pick tester 17b for measuring the displacement of the outer diameter portion 10b of the master die 10 in the X direction.

On the other hand, when the optical axis of the light beam projected on the lens 30 to be inspected is the Z'axis, the lens support base 13 to be inspected Z '
When a rotary spindle 13a rotatable about an axis and two orthogonal axes in the optical axis (Z'-axis) direction are X'-axis / Y'-axis, a movable stage movable in the X'-axis / Y'-axis direction. Thirteen
b, and a tilt stage 13c capable of tilting in the X'Z 'plane and the Y'Z' plane. Also, the lens 30 to be inspected
On the other hand, it is mounted on the stage 18a movable in the Z ′ direction and contacts the outer diameter portion 30b of the lens 30 to be measured, and the displacement of the outer diameter portion 30b of the lens 30 to be measured in the X ′ direction is measured. The pick tester 18b of FIG. Further, on the lens support base 13 to be inspected, the moving stage 1 of the support base 13 is attached.
3b, the first and second micrometers 19a and 19b for reading the movement amount of the stage 13b in the X'and Y'directions, and the tilt stage 13c, the X'Z 'surface of the stage 13c. And Y'Z '
Third and fourth micrometers 20a and 20b for detecting the tilt angle by reading the tilt movement amount of the surface are provided. Here, the master mold 10 has a reference surface 10a having a spherical surface or an aspherical surface, which serves as a measurement reference for the measurement surface 30a of the lens 30 to be inspected.

Next, the measurement according to this embodiment will be described. First
The stage 17a equipped with the pick tester 17b of
The tilt stage 11c of the master mold support 11 is adjusted so that the displacement amount of the first pick tester 17b is hardly displaced when vertically moved along the direction. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 become parallel. Next, when the rotary spindle 11a of the master mold support base 10 is rotated, the moving stage 11b of the master mold support base 11 is moved so as to minimize the change of the first pick tester 17b.
Move in Y plane. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 coincide with each other. The optical axis of the spherical (or aspherical) portion of the master die 10 is pre-coaxially cut with the outer diameter portion and the spherical (or aspherical) portion so that the optical axis thereof coincides with the optical axis of the first objective lens 4.

Subsequently, the lens 30 to be inspected is mounted on the lens support base 13 to be inspected, and the same adjustment is performed by using the second pick tester 18b, so that the center axis of the outer diameter portion 30b of the lens 30 to be inspected and the second The optical axis of the objective lens 5 of is matched. Here, the positions of the first objective lens 4 and the second objective lens 5 are adjusted in the optical axis direction, that is, in the Z and Z ′ directions, respectively, and the reference surface 1 of the master mold 10 is adjusted.
0a and the interference fringes due to the reflected light of the laser light projected on the measurement surface 30a of the lens 30 to be inspected can be observed on the display device 9. In this case, when the optical axis of one surface of the lens 30 to be inspected does not coincide with the central axis of the outer diameter, that is, when there is eccentricity, it does not coincide with the optical axis of the second objective lens 6 either. The interference fringes observed are not concentric. That is, the eccentricity of the lens under test can be detected by the interference fringes that are not concentric circles.

Next, so that the interference fringes are concentric,
Adjustment is performed using the moving stage 13b of the lens support base 13 and the tilt stage 13c. Here, when the measurement surface 30a of the lens 30 to be measured is a spherical surface, the interference fringes become concentric circles by moving the moving stage 13b of the lens support base 13 to be tested on the X'Y 'plane. This moving amount is measured by the first and second micrometers 19a and 19b mounted on the moving stage 13b, and the root mean square of both moving amounts is calculated. This calculated value is the outer diameter portion 3 of the lens 30 to be inspected.
The center of curvature 3 of the spherical surface portion 30a with respect to the central axis 30d of 0b
The shift amount δ is 0c. On the other hand, when the measurement surface 30a of the lens 30 to be inspected is an aspherical surface, the moving stage 13b of the lens support 13 to be inspected is moved in the X'Y 'plane, and the tilt stage 13c is used to move in the X'Z' plane and Y'Z 'plane. A concentric interference fringe is formed by inclining in the ′ plane. At this time, these are measured by the first and second micrometers 19a and 19b mounted on the moving stage 13b. The mean square of these movement amounts is the shift amount δ of the aspherical surface axis 30c of the aspherical surface portion 30a with respect to the central axis 30d of the outer diameter portion 30b of the lens 30 to be tested. Further, the root mean square of both tilt amounts is calculated from the tilt amounts measured by the third and fourth micrometers 20a and 20b mounted on the tilt stage 13c. This is the inclination amount ε of the aspherical surface axis 30c of the aspherical surface portion 30a with respect to the central axis 30d of the outer diameter portion 30b of the lens 30 to be tested.

According to the present embodiment as described above, the amount of eccentricity of the lens can be measured with high accuracy. In particular, in this embodiment, the first and second micrometers 19a and 19b for moving the moving stage 13b of the lens support base 13 also have a function as a movement amount measuring machine, and the tilt of the lens support base 13 is also measured. Third and fourth tilting stage 13c
Since the micrometers 20a and 220b also have a function as a tilt angle measuring machine, there is no need to separately add a movement amount measuring machine and a tilt angle measuring machine, and the configuration is simple and the operation is easy.

[0018]

Embodiment 2 FIG. 4 shows Embodiment 2 of the present invention, and Embodiment 1
The same elements as are designated by the same reference numerals. In the second embodiment, it is mounted on a stage 21a movable in the Z direction and comes into contact with the outer diameter portion 10b of the master die 10 to measure the displacement of the outer diameter portion 10b of the master die 10 in the X direction. The electric displacement meter 21b and the first display unit 21c for displaying the displacement amount measured by the first displacement electric meter 21b constitute a first displacement measuring machine.
Further, the lens to be measured 3 is mounted on the stage 22a movable in the Z'direction and comes into contact with the outer diameter portion 30b of the lens 30 to be measured.
A second electric micrometer 22b that measures the displacement of the outer diameter portion 30b of 0 in the X'direction, and a second display unit 22 that displays the amount of displacement measured by the second electric micrometer 22b.
A second displacement measuring machine is constituted by c and c. Further, the third and fourth electric micrometers 23a and 23b for reading the amount of movement in the X'direction and the Y'direction by contacting the moving stage 13b of the lens support base 13 and the electric micrometers 23a and 23b. A moving amount measuring machine is constituted by the third display portion 23c which displays the root mean square value of both measured moving amounts, and contacts the tilt stage 13c of the lens support base 13 to be tested, and the X'Z 'plane and Based on the fifth and sixth electric micrometers 24a and 24b for reading the tilt amount tilted in the Y'Z 'plane, and the tilt amounts measured by the electric micrometers 24a and 24b, the tilt stage 13
A tilt angle measuring machine is configured by the fourth display unit 24c that calculates and displays the tilt angle of c.

In such a structure, when the stage 21a on which the first electric micrometer 21b is mounted is moved up and down in the Z direction, the first electric micrometer 21b read by the first display device 21c. The tilt stage 11c of the master die support 11 is adjusted so that the displacement amount is hardly displaced. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 become parallel. Next, when the rotary spindle 11a of the master mold support 10 is rotated, the moving stage 11b of the master mold support 11 is moved in the XY plane so that the change of the first electric micrometer 21b is minimized. To move. Thereby, the outer diameter portion 10b of the master die 10
The central axis of and the optical axis of the first objective lens 4 coincide with each other. The optical axis of the spherical (or aspherical) portion of the master die 10 is pre-coaxially cut with the outer diameter portion and the spherical (or aspherical) portion so that the optical axis thereof coincides with the optical axis of the first objective lens 4.

Subsequently, the lens 30 to be inspected is mounted on the lens support base 13 to be inspected, and the same adjustment is performed by using the second electric micrometer 22b and the second display portion 22c, and the outside of the lens 30 to be inspected. The central axis of the diameter portion 30b and the optical axis of the second objective lens 5 are aligned. Here, the first objective lens 4
And the second objective lens 5 are respectively adjusted in the optical axis direction, that is, in the Z and Z'directions, and the reflection of the laser light projected on the reference surface 10a of the master mold 10 and the measurement surface 30a of the lens 30 to be inspected, respectively. The interference fringes caused by light are made visible on the display device 9.

Next, so that the interference fringes are concentric,
Adjustment is performed using the moving stage 13b of the lens support base 13 and the tilt stage 13c. Here, when the measurement surface 30a of the lens 30 to be tested is a spherical surface, the lens support base 1 to be tested 1
By moving the third moving stage 13b in the X'Y 'plane, concentric interference fringes are obtained, and the moving amount of the third and fourth electric micrometers 23a and 23b in contact with the moving stage 13b is obtained. Measured at, 2 of both movement
The third display device 23c displays the weighted average. This displayed value is the shift amount δ of the center of curvature 30c of the spherical surface portion 30a with respect to the central axis 30d of the outer diameter portion 30b of the lens 30 to be tested. On the other hand, when the measurement surface 30a of the lens 30 to be inspected is an aspherical surface, the moving stage 13b of the lens support base 13 to be inspected is moved in the X'Y 'plane and X'Z' in the tilt stage 13c.
By tilting in the plane and the Y'Z 'plane,
Concentric interference fringes. At this time, the moving stage 13
The mean square of both movement amounts obtained by the first and second electric micrometers 23a and 23b in contact with b is displayed on the third display device 23c, and this display value is displayed outside the lens 30 to be inspected. The displacement amount δ of the aspherical surface axis 30d of the aspherical surface portion 30a with respect to the central axis 30d of the diameter portion 30b is obtained. Also,
The tilt amount obtained from the moving amount measured by the fifth and sixth electric micrometers 24a and 24b in contact with the tilt stage 13c is displayed on the fourth display device 24c, and this display value is displayed on the lens 30 to be tested. Outer diameter part 30b
Of the aspherical surface portion 30a with respect to the central axis 30d of the
The inclination amount ε of d is obtained.

In this embodiment as well, the eccentricity amount can be measured with high accuracy, but δ can be directly read from the value of the third display device 23c, and ε can be directly read from the fourth display device 24c. Can be read, which has the advantage of improving workability.

[0023]

[Third Embodiment] FIG. 5 shows a third embodiment of the present invention.
The same elements as 2 and 2 are associated with the same reference numerals.
In the third embodiment, the displacement of the outer diameter portion 10b of the master die 10 in the X direction is measured without being in contact with the outer diameter portion 10b of the master die 10 by being mounted on the stage 25a movable in the Z direction. The optical displacement meter 25b and the first display unit 25c for displaying the displacement amount measured by the first optical displacement meter 25b constitute a first displacement measuring machine, which is movable in the Z'direction. The lens to be inspected 3 mounted on the stage 26a
The second optical displacement meter 26b for measuring the displacement in the X'direction of the outer diameter portion 30b of the lens 30 to be measured in a non-contact state with the outer diameter portion 30b of 0 and the second optical displacement meter 26b. The second display unit 26c that displays the amount of displacement constitutes a second displacement measuring machine. Further, the third and fourth optical displacement meters 2 for reading the movement amounts of the moving stage 13b of the lens support base 13 in the X'direction and the Y'direction in a non-contact state.
7a and 27b, and both optical displacement meters 27a and 27
3rd which displays the root mean square value of both movement amount which is read with b
The display unit 27c and the display unit 27c constitute a movement amount measuring device, and a photoelectric autocollimator 28a for reading the tilt angle of the tilt stage 13c of the lens support base 13 to be measured, and a tilt of the tilt stage 13c read by the photoelectric autocollimator 28a. A tilt angle measuring machine is configured with the fourth display unit 28c that displays the angle.

In the above structure, the first optical displacement meter 2
When the stage 25a on which the 5b is mounted is moved up and down along the Z direction, the first display device 25c reads the first image.
The tilting stage 11c of the master die support 11 is adjusted so that the displacement amount of the optical displacement meter 25b is hardly displaced. Thereby, the outer diameter portion 10 of the master mold 10
The central axis of b and the optical axis of the first objective lens 1 are parallel to each other. Next, the rotary spindle 1 of the master mold support 10
When 1a is rotated, the moving stage 11b of the master mold support 11 is moved within the XY plane so that the change of the first optical displacement meter 25b is minimized. As a result, the central axis of the outer diameter portion 10b of the master mold 10 and the optical axis of the first objective lens 4 coincide with each other. In the master mold 10, the outer diameter portion and the spherical surface (or aspherical surface) are coaxially cut in advance so that the optical axis of the spherical surface (or aspherical surface) is first.
Coincides with the optical axis of the objective lens 4.

Subsequently, the lens 30 to be inspected is mounted on the lens support base 13 to be inspected, and the second optical displacement meter 26b and the second optical displacement meter 26b are mounted.
The same adjustment is performed by using the display section 26c of (1) to align the central axis of the outer diameter portion 30b of the lens 30 to be tested with the optical axis of the second objective lens 5. Here, each of the first objective lens 4 and the second objective lens 5 is set in the optical axis direction, that is, Z.
And the position of the Z'direction are adjusted, and the reference surface 10a of the master mold 10 and the measurement surface 3 of the lens 30 to be measured are respectively adjusted.
The interference fringes due to the reflected light of the laser light projected on 0a are made visible on the display device 9.

Next, so that the interference fringes are concentric,
Adjustment is performed using the moving stage 13b of the lens support base 13 and the tilt stage 13c. Here, when the measurement surface 30a of the lens 30 to be tested is a spherical surface, the lens support base 1 to be tested 1
By moving the moving stage 13b of No. 3 in the X'Y 'plane, concentric interference fringes are obtained, and the moving amount is measured by the third and fourth optical displacement gauges 27a and 27b.
The third display device 27c displays the root mean square of the two movement amounts. This root mean square value is the outer diameter portion 30b of the lens 30 to be inspected.
The deviation amount δ of the center of curvature 30c of the spherical surface portion 30a with respect to the central axis 30 of On the other hand, the measurement surface 30a of the lens 30 to be inspected
Is an aspherical surface, the moving stage 13b of the lens support base 13 is moved in the X'Y 'plane, and the tilting stage 13c is tilted in the X'Z' and Y'Z 'planes to form concentric circles. Interference fringes. At this time, the first and second optical displacement meters 27a and 27
The mean square of the two movement amounts obtained in step b is used for the third display device 2
7c is displayed, and the displayed value is the outer diameter portion 3 of the lens 30 to be measured.
The deviation amount δ of the aspherical surface axis 30c of the aspherical surface portion 30a with respect to the central axis 30d of 0b. Further, the fourth display device 28b displays the amount of inclination measured by the photoelectric autocollimator 28, and this display value is the aspherical surface axis 30c of the aspherical surface portion 30a with respect to the central axis 30d of the outer diameter portion 30b of the lens 30 to be measured. The inclination amount is ε.

According to the present embodiment as described above, the eccentricity of the lens can be measured with high accuracy, and moreover, the outer diameter portion 1 of the master mold 10 can be measured.
0b and the first and second optical displacement gauges 25b and 26 for measuring the displacement of the outer diameter portion 30b of the lens 30 to be tested.
Since b is non-contact, damage is not generated due to contact with the outer diameter portion 10b of the master mold 10 and the outer diameter portion 30b of the lens 30 to be inspected, and maintenance is easy.

[0028]

As described above, according to the present invention, the eccentricity of the lens to be inspected can be detected with extremely high sensitivity by observing the interference fringes due to the reflected light from the master die and the lens to be inspected. Good eccentricity measurement is possible.

[Brief description of drawings]

FIG. 1 is a side view showing a basic configuration of the present invention.

FIG. 2 is a side view showing an example of a lens to be inspected.

FIG. 3 is a side view showing the configuration of the first embodiment of the present invention.

FIG. 4 is a side view showing the configuration of the second embodiment of the present invention.

FIG. 5 is a side view showing a configuration of a third embodiment of the present invention.

FIG. 6 is a side view of a conventional device.

[Explanation of symbols]

 10 master mold 11 master mold support 12 first displacement measuring machine 13 lens support base 14 second displacement measuring machine 15a moving amount measuring machine 15b moving amount measuring machine 16a tilt angle measuring machine 16b tilt angle measuring machine 30 test lens

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeya Sugada 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Nobuyoshi Iwasaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Inventor Mitsuo Goto 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Ryusuke Nozawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical industry Co., Ltd. (72) Inventor Ken Kawamata 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An apparatus for measuring the amount of eccentricity of a lens surface by causing the reflected light from a lens under test and the reflected light from a master mold, which is a measurement reference, to interfere with each other. With the optical axis as the Z axis,
A master mold support base that is rotatable about its axis, movable in the X-axis and Y-axis directions orthogonal to the Z-axis, and tiltable in the XZ plane and YZ; Can be moved to the X of the outer diameter part of the master mold
A first displacement measuring device for measuring displacement in a direction, and an optical axis of a light beam projected on the lens to be inspected as a Z'axis,
A member that is rotatable about that axis, is movable in the X'axis and Y'axis directions orthogonal to the Z'axis, and is tiltable in the X'Z 'and Y'Z' planes. An inspection lens support base, a second displacement measuring device which is movable in the Z'-axis direction and measures a displacement in the X'direction of the outer diameter portion of the lens to be inspected, and an X'direction of the inspection lens support base and A movement amount measuring device for measuring a movement amount in the Y'direction; and an inclination angle measuring device for measuring an inclination angle of the X'Z 'surface and the Y'Z' surface of the lens support to be tested. Characteristic lens eccentricity measuring device.