JPH0875597A - Non-spherical surface eccentricity measuring machine - Google Patents

Abstract

PURPOSE: To provide a non-spherical surface eccentricity measuring machine which can measure the eccentricity of a non-spherical surface lens with a flange surface and can easily measure the eccentricity of the non-spherical surface lens in a complex configuration in reference to the flange surface. CONSTITUTION: This measuring machine is provided with a lens pad 2 for horizontally retaining a flange surface c-d of the reverse side of a non-spherical surface lens 1 to be inspected with a flange surface, a scanning-type-shaped measuring machine 3 for obtaining a shape by scanning the surface of the non-spherical surface lens 1 to be inspected, and a means for obtaining an inclination angle θof a flange surface a-b on the surface from the obtained shape, thus obtaining the amount of eccentricity from the above inclination angle. Therefore, the eccentricity of the non-spherical surface lens to be inspected is defined in reference to the flange surface which is the mounting reference of the non-spherical surface lens with the flange surface, is measured, and is analyzed, thus performing an evaluation (inspection) matched for product performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aspherical surface eccentricity measuring device used for measuring the eccentricity of an aspherical optical element, and more particularly to an aspherical lens for a camera, an aspherical lens for an optical pickup, etc. The present invention relates to an aspherical surface eccentricity measuring machine used for measuring and inspecting eccentricity of an optical element to be assembled on its edge surface.

[0002]

2. Description of the Related Art Conventionally, the eccentricity measurement of an aspherical lens is performed by rotating the displacement of the lens surface (aspherical surface) with a line connecting the paraxial curvature centers of the front and back surfaces as a reference axis. A common method is to calculate the amount of eccentricity from the amount of displacement.
Further, as an aspherical lens eccentricity measuring device using the method, there is provided a rotary lens supporting member which has a lens receiving portion for holding a lens to be tested and is rotatably driven, and a lens to be tested on the rotary lens supporting member. A mechanism part for moving and adjusting the position of, a paraxial eccentricity measuring part for detecting the amount of eccentricity with respect to the rotation axis of the paraxial curvature center of the aspherical surface of the lens to be measured, and a shaft other than the rotation shaft As one of the proposals, there is proposed a structure comprising an aspherical surface axis measuring portion for detecting an inclination angle of an aspherical surface axis with respect to a rotation axis on a lens surface opposite to the surface on the lens receiving portion side (JP-A-1- Two
96132).

[0003]

However, the conventional aspherical lens eccentricity measuring device has a problem that the structure is complicated and the measurement cannot be easily performed. The present invention has been made in view of the above circumstances, and an aspherical lens having an edge surface is an object to be measured, and the decentering of the aspherical lens having the edge surface can be measured by a single lens, thereby providing a complicated configuration. SUMMARY OF THE INVENTION It is an object of the present invention to provide an aspherical surface eccentricity measuring device in which the eccentricity of an aspherical lens can be easily measured with reference to the edge surface.

[0004]

In order to achieve the above object, the aspherical surface eccentricity measuring machine according to claim 1 has means for horizontally holding the edge surface of the back surface of the aspherical lens under test having an edge surface. It is characterized in that it is provided with a means for obtaining a shape by scanning the surface of the aspherical lens to be inspected and a means for obtaining an inclination angle of the edge surface of the surface from the obtained shape.

An aspherical surface eccentricity measuring device according to a second aspect of the present invention comprises means for horizontally holding the edge surface of the back surface of the aspherical lens under test having the edge surface, and the surface of the aspherical lens under test for passing the optical axis. It is characterized in that it is provided with a means for obtaining a shape by scanning in and a means for obtaining an inclination angle of the surface from the aspherical shape of the lens surface.

The aspherical surface eccentricity measuring machine according to a third aspect of the present invention comprises means for horizontally holding the edge surface of the back surface of the aspherical lens to be tested having the edge surface, and the central axis of the holding portion as a rotation axis. Rotation mechanism integrated with the section, a means for obtaining the displacement of the edge surface of the surface at any point while rotating the aspherical lens under test, and the inclination angle of the edge surface of the aspherical lens surface under test from the displacement It is characterized by having means for obtaining.

An aspherical surface eccentricity measuring device according to a fourth aspect of the present invention comprises means for holding an aspherical lens to be inspected having an edge surface by the edge surface, and scanning the surface of the aspherical lens to be inspected so as to pass through the optical axis. To obtain the inclination angle of the edge surface of the obtained cross-sectional shape, and to obtain the inclination angle of the optical axis from the aspherical shape of the lens surface. It is characterized by having a means for comparing two inclination angles.

An aspherical surface eccentricity measuring machine according to a fifth aspect is the first aspect.
Alternatively, by the means according to claim 3, a means for obtaining a relative inclination angle between the edge surface of the surface and the back surface of the aspherical lens under test,
The surface of the aspherical lens to be tested by the means according to claim 4,
It is characterized in that it is provided with a means for obtaining the inclination angle of the lens surface with respect to each edge surface of the back surface.

An aspherical surface eccentricity measuring machine according to a sixth aspect of the present invention comprises means for horizontally holding the edge surface of the back surface of the aspherical lens under test having the edge surface, a rotating mechanism integrated with the holding portion, Means for matching the outer cylinder axis of the aspherical lens to be detected with the rotation axis of the rotating mechanism, an auto-collimating mechanism for obtaining reflected light from the vicinity of the paraxial of the aspherical lens to be detected, and detecting the reflected light, It is characterized in that a means for detecting the amount of deviation from the rotating shaft is provided.

[0010]

In the aspherical surface eccentricity measuring machine of the present invention, an aspherical lens having an edge surface is measured, and the eccentricity (back surface side edge surface) of the aspherical lens to be inspected is based on the edge surface which is the mounting reference of the lens. The inclination of the front side edge surface, the inclination of the lens surface with respect to the edge surface, the inclination of the optical axis with respect to the front and back edge surfaces respectively, and the lateral deviation of the optical axis with respect to the outer cylinder axis (center axis of the outer cylinder part) Etc.), and measurement and analysis make it possible to perform evaluation (inspection) suitable for product performance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of the present invention will be described below with reference to the drawings. First, FIG. 1 shows an example of an aspherical lens having an edge surface, which is an object of measurement in claims 1, 2, and 3 of the present invention.
Shown in In this aspherical lens 1, the optical axis r _A of the lens surface A on the front surface side is orthogonal to the edge surface a-b, and the optical axis r _B of the lens surface B on the back surface side is also orthogonal to the edge surface cd. ing.

Next, FIG. 2 shows an example of the configuration and operation of the aspherical surface eccentricity measuring machine of claim 1. In FIG. 2A, reference numeral 2 is a lens receiver for holding the edge surface cd of the back surface of the aspherical lens 1 under test horizontally, and 3 is a shape obtained by scanning the surface of the aspherical lens 1 under test. The scanning type profiler for obtaining is shown, and the aspherical lens 1 to be tested is held by the lens receiver 2 so that the holding surface cd and the scanning axis of the scanning type profiler 3 are parallel to each other. Adjust the angle of the lens receiver 2. And
A cross-sectional shape 4 passing through the optical axis of the surface of the aspherical lens 1 to be tested is obtained by the scanning shape measuring machine 3 (FIG. 2B). Then, an inclination angle θ with respect to a horizontal plane (parallel to the back side edge surface) of the edge surfaces a-b on the surface of the cross-sectional shape 4 is obtained and used as an eccentric amount of this lens.

Next, the structure of the aspherical surface eccentricity measuring device of claim 2 is the same as that of FIG. 2, and the cross-sectional shape of the surface of the aspherical lens 1 to be tested passing through the optical axis is the same as the operation of claim 1. 5 (FIG. 3). Then, as shown in FIG. 3, from the aspherical shape of the lens surface A having the sectional shape 5 to the inclination angle of the surface (the lens surface A on the front surface side with respect to the axis orthogonal to the scanning axis (horizontal plane)).
The angle of inclination of the optical axis r _A ) θ is obtained, and this is taken as the decentering amount of this lens.

Next, FIG. 4 shows an example of the construction and operation of the aspherical surface eccentricity measuring machine according to the third aspect. In FIG. 4, reference numeral 2 is a lens receiver for horizontally holding the edge surfaces cd of the back surface of the aspherical lens 1 to be tested, and 6 is a holding shaft (lens receiver 2) having a central axis as a rotation axis and holding the same. A rotation mechanism (spindle) integrated with the unit, 7 is a displacement meter (electric micro, optical micro, etc.) for obtaining the displacement of the edge surface a-b of the surface at an arbitrary point while rotating the aspherical lens 1 to be tested. First, the aspherical lens 1 to be tested is held by the lens receiver 2, and the spindle 6 having the central axis of the lens receiver 2 as the rotation axis,
The aspherical lens 1 and the lens receiver 2 to be tested are rotated. Then, a displacement meter 7 such as an electric micro or an optical micro is brought into contact with the edge surface of the aspherical lens 1 to be tested to obtain the displacement amount of the edge surface. For example, when the displacement meter 7 is first in contact, it is set to 0 °, the displacement amount at that time is set to α, and 1 from that position.
When the displacement amount when rotated by 80 ° is β, the eccentricity amount θ of the lens is obtained by the equation (1). θ = tan ~ ¹ {(α-β) / L} (1) where L is the distance from the rotation axis to the contact point of the displacement gauge, which is 2
Double.

Next, in the aspherical surface eccentricity measuring machine of claim 4,
As shown in FIG. 5, the measurement target is an aspherical lens in which the optical axis r _A of the lens surface A on the front surface side and the edge surface ab are not orthogonal to each other. FIG. 6 shows an example of the configuration and operation of the aspherical surface eccentricity measuring machine of claim 4. In FIG. 6 (a), reference numeral 2 is a lens receiver for horizontally holding the edge surface cd of the back surface of the aspherical lens 1 to be tested, and 3 is a shape obtained by scanning the surface of the aspherical lens 1 to be tested. 1 shows a scanning shape measuring instrument for obtaining the aspherical lens 1 to be inspected, which is held by a lens receiver 2 and has a sectional shape 8 including the edge surface and passing through the optical axis of the surface of the aspherical lens 1 to be inspected.
(FIG. 6B) is obtained by the scanning shape measuring machine 3. From the obtained sectional shape 8, the tilt angles of the lens surface A and the edge surface a-b from the scanning axis of the shape measuring machine 3 are obtained. That is, FIG.
As shown in (b), the scanning axis (horizontal plane) of the edge surface a-b
If the inclination angle θ1 with respect to the angle θ2 and the inclination angle θ2 with respect to the axis orthogonal to the scanning axis of the optical axis r _A of the lens surface A are obtained, the difference θ ′ is obtained.
(= Θ1−θ2) is the amount of eccentricity with reference to the edge surface ab of the lens surface A.

Next, in the aspherical surface eccentricity measuring machine of claim 5,
By the method of claim 1 (FIG. 2) or claim 3 (FIG. 4), the angle θ formed by the edge surface of the aspherical lens 1 to be tested is obtained, and the method of claim 4 (FIG. 6) described above. Due to
The eccentricity amount θA ′ of the front surface side lens surface A and the edge surface reference eccentricity θB ′ of the back surface side lens surface B are obtained.
That is, the inclination angle θ of the front side edge surface a-b with respect to the back side edge surface cd (horizontal plane) is measured, and as shown in FIG. The tilt angle θA ′ of the optical axis r _A of _A and the back surface side edge surface cd
Angle θ of the optical axis r _B of the lens surface B with respect to the axis orthogonal to
B'is measured to obtain the amount of eccentricity. From these θ, θA ′, θB ′, both surfaces are aspherical surfaces, and both surfaces have optical axes r _A , r _B and edge surfaces ab, c−.
It is possible to obtain the decentering amount corresponding to the aspherical lens in which d is not orthogonal.

Next, FIG. 8 shows an example of the configuration and operation of the aspherical surface eccentricity measuring machine according to the sixth aspect. In FIG. 8, reference numeral 1 is an aspherical lens to be inspected, 2 is a lens receiver for horizontally holding the edge surface of the back surface of the aspherical lens to be inspected 1, and 6 is a rotation mechanism (spindle) integrated with the lens receiver. , 7 is a displacement meter, 9 is a light source, 10 is a beam splitter, 11 is a collimator lens, 12 is an objective lens, 13 is a chart, and 14 is a CCD.
Shows the camera.

In this aspherical surface eccentricity measuring device, the aspherical lens 1 to be tested is held by a lens receiver 2, and the spindle 6 with the central axis of the lens receiver 2 as a rotation axis is used to test the aspherical lens 1 and the lens to be tested. Rotate the receiver 2. Then, a displacement meter 7 such as an electric micro or an optical micro is brought into contact with the outer cylindrical surface of the aspherical lens 1 to be inspected, and the aspherical lens 1 to be inspected is laterally moved and adjusted so that the displacement becomes constant. . Further, the light emitted from the light source (laser or the like) 9 is reflected by the beam splitter 10, becomes a parallel light by the collimator lens 11, and the objective lens 12 makes A of the aspherical lens 1 to be tested.
The light is focused so as to focus on the paraxial curvature center A0 of the surface. Then, the reflected light from the surface A of the aspherical lens 1 to be tested is the objective lens 12, the collimator lens 11, and the beam splitter 1.
A reflection spot image is projected on the chart 13 through 0. The reflected image is observed by the CCD camera 14. At this time, since the reflected image draws a circle on the chart 13 as the aspherical lens 1 to be tested rotates, the CCD camera 14 detects the radius of gyration of the circle. This radius of gyration is the amount of lateral deviation (shift eccentricity) of the optical axis with reference to the outer cylinder axis (center axis of the outer cylinder portion) of the aspherical lens 1 to be tested.

[0019]

As described above, in the aspherical surface eccentricity measuring device of the present invention, an aspherical lens having an edge surface is used as the object of measurement, and the edge surface, which is the mounting reference for the aspherical lens, is used as the reference. Eccentricity of aspherical lens (tilt of front side edge surface with respect to back side edge surface, inclination of lens surface with respect to edge surface, inclination of optical axis with respect to front and back edge surfaces respectively, outer cylinder axis (center axis of outer cylinder part) ) Is defined as a reference, and the measurement and analysis can be performed to perform an evaluation (inspection) suitable for product performance. Further, the test aspherical lens to be measured can be either aspherical on one side or aspherical on both sides. Further, by using a scanning shape measuring instrument as a means for obtaining the shape by scanning the surface of the aspherical lens to be inspected, both the aspherical shape error and the eccentricity can be measured (inspected) at one time. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an aspherical lens to be measured by the aspherical surface eccentricity measuring device according to any one of claims 1 to 3.

2A and 2B are diagrams showing a configuration and an operation example of the aspherical surface eccentricity measuring machine according to claim 1, wherein FIG. 2A is a schematic configuration diagram of the aspherical surface eccentricity measuring machine, and FIG. It is a figure which shows the cross-sectional shape which passes along the optical axis of the obtained aspherical lens surface under test.

FIG. 3 is a diagram showing an operation example of claim 2, wherein FIG.
It is a figure which shows the cross-sectional shape which passes along the optical axis of the to-be-tested aspherical lens surface obtained by the measuring machine of the structure similar to (a).

FIG. 4 is a schematic configuration diagram showing an example of an aspherical surface eccentricity measuring machine according to claim 3.

FIG. 5 is a sectional view of an essential part showing an example of an aspherical lens which is an object to be measured by the aspherical surface eccentricity measuring device of claim 4;

6A and 6B are diagrams showing a configuration and an operation example of the aspherical surface eccentricity measuring machine according to claim 4, wherein FIG. 6A is a schematic configuration diagram of the aspherical surface eccentricity measuring machine, and FIG. It is a figure which shows the cross-sectional shape which passes along the optical axis of the obtained aspherical lens surface under test.

FIG. 7 is a cross-sectional view showing an example of an aspherical lens to be measured by the aspherical surface eccentricity measuring machine according to claim 5;

FIG. 8 is a schematic configuration diagram showing an example of an aspherical surface eccentricity measuring machine according to claim 6;

[Explanation of symbols]

1: Aspherical lens to be inspected 2: Lens receiver 3: Scanning shape measuring instrument 4, 5, 8: Measurement sectional shape 6: Spindle (rotating mechanism) 7: Displacement meter (electrical micro, optical micro, etc.) 9: Light source 10 : Beam splitter 11: Collimator lens 12: Objective lens 13: Chart 14: CCD camera A: Surface side lens surface of aspherical lens to be tested B: Backside lens surface of aspherical lens to be tested ab: Aspherical surface to be tested Front-side edge surface of lens cd: Back-side edge surface of aspherical lens to be tested r _A : Optical axis of lens surface A r _B : Optical axis of lens surface B

Claims (6)

[Claims] 1. A means for horizontally holding an edge surface of a back surface of an aspherical lens to be inspected having an edge surface; a means for obtaining a shape by scanning the surface of the aspherical lens to be inspected; An aspherical surface eccentricity measuring machine comprising means for obtaining the inclination angle of the edge surface. 2. A means for horizontally holding the edge surface of the back surface of the aspherical lens to be inspected having the edge surface, and a means for obtaining a shape by scanning the surface of the aspherical lens to be inspected so as to pass through the optical axis. An aspherical surface eccentricity measuring device comprising means for obtaining the inclination angle of the lens surface from the aspherical surface shape. 3. A means for horizontally holding an edge surface of a back surface of an aspherical lens to be tested having an edge surface, and a rotating mechanism which has a central axis of the holding portion as a rotation axis and is integrated with the holding portion. A means for obtaining the displacement of the edge surface of the surface at an arbitrary point while rotating the aspherical lens to be inspected, and a means for obtaining the inclination angle of the edge surface of the aspherical lens surface to be inspected from the displacement. And aspherical eccentricity measuring machine. 4. A means for holding an inspected aspherical lens having an edge surface by the edge surface, and a means for obtaining a shape by scanning the surface of the inspected aspherical lens so as to pass through the optical axis. Of the sectional shape, a means for obtaining the inclination angle of the edge surface portion, a means for obtaining the inclination angle of the optical axis from the aspherical shape of the lens surface, and a means for comparing the two obtained inclination angles are provided. An aspherical surface eccentricity measuring machine characterized by that. 5. A means for obtaining a relative inclination angle between an edge surface of a front surface and a back surface of an aspherical lens to be tested by the means according to claim 1 or 3, and a means to be tested by the means according to claim 4. An aspherical surface eccentricity measuring device comprising means for obtaining a tilt angle of a lens surface with reference to respective edge surfaces of the aspherical lens. 6. A means for horizontally holding an edge surface of a back surface of an aspherical lens to be inspected having an edge surface, a rotation mechanism integrated with the holding portion, and an outer cylinder shaft of the aspherical lens to be inspected. A means for matching the rotation axis of the rotation mechanism, an auto-collimation mechanism for obtaining reflected light from the paraxial vicinity of the aspherical lens under test, and detecting the reflected light to detect the amount of deviation from the rotation axis. An aspherical surface eccentricity measuring machine comprising: