JPH1137738A - Device for measuring shape and eccentricity of aspherical lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve measurement precision and to simplify the configuration of a drive mechanism, by aligning a lens to be inspected, which is aspherical for eccentricity measurement with the optical axis of the lens to be inspected as a reference. SOLUTION: After alignment of a lens to be inspected 1 held by a holding means 2 with an irradiation optical system, an imaging optical system, a gravity position detecting means, etc., measurement is performed two times at an initial position and a position rotated by 90 deg. from the initial position using a measurement means 15 comprising a displacement gauge 16 and a rotation means 3 for rotating the holding means 2, so that a sectional shape data in two directions of the aligned lens to be inspected 1 orthogonal to each other is obtained, and then based on calculation result of the data, measurement of the shape of the lens to be inspected 1 and eccentricity of optical axis reference is performed with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the shape and eccentricity of an aspheric lens used in a camera or the like.

[0002]

2. Description of the Related Art In recent years, aspherical lenses have been widely used in cameras and the like. In this case, it is difficult to create an aspheric surface by polishing the aspheric lens.
Generally, an aspheric surface is created by molding. For this reason, eccentricity of the aspherical surface easily occurs.

The measurement of the eccentricity of an aspherical surface of an aspherical lens is necessary, for example, in product inspection to judge the quality of a product, and the direction of embossing is determined by the eccentricity of a prototyped aspherical lens in the course of manufacture. It is also necessary when adjusting.

Here, only the eccentricity may be measured if only the former is good or bad, but in the latter case the adjustment of the embossing direction is performed not only in the eccentricity but also in the direction of the eccentricity.
That is, it is necessary to measure in which direction the eccentricity occurs.

[0005]

A method for measuring the eccentricity of an aspherical lens is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-37544.
There are techniques disclosed in Japanese Unexamined Patent Publication (Kokai) No. HEI-6-196132 and Japanese Unexamined Patent Application Publication No. 1-296132. However, as disclosed in these publications, usually, the measurement is performed separately from the shape measurement of the aspherical lens. I have.

As a result, there are problems that the configuration of the driving mechanism in the measuring device becomes complicated and that it is difficult to ensure high measurement accuracy.

Therefore, according to the present invention, it is possible to perform eccentricity measurement with reference to the optical axis of the test lens by adjusting the center of the test lens which is an aspherical lens, thereby improving the measurement accuracy and configuring the drive mechanism. It is an object of the present invention to provide an aspherical lens shape and eccentricity measuring device which can simplify the above.

It is another object of the present invention to provide an aspherical lens shape and eccentricity measuring device capable of achieving high accuracy of the alignment.

It is a further object of the present invention to provide an aspherical lens shape and eccentricity measuring device capable of facilitating alignment and achieving high accuracy.

Another object of the present invention is to provide an aspherical lens shape and eccentricity measuring apparatus capable of removing stray light such as reflected light from the back surface of a lens to be measured, which hinders measurement.

[0011]

According to the first aspect of the present invention,
Holding means for holding the aspherical lens as a lens to be tested;
An illumination optical system that includes an illumination light source, and irradiates a light beam emitted from the illumination light source as a convergent light beam or a divergent light beam to a surface to be inspected of the lens to be inspected; a central axis of the holding unit; An optical axis that is set so as to substantially match the optical axis of the system, forms an image of reflected light from the paraxial spherical surface of the surface to be inspected, and forms an image with the imaging optical system. A center-of-gravity position detecting means for detecting the center-of-gravity position of the image, a rotating means for rotating the test lens held by the holding means around the optical axis as a rotation axis, and pressing an outer diameter portion of the test lens. A moving means for moving the test lens in one arbitrary direction in a plane orthogonal to the optical axis; and a displacement meter having a scanning mechanism in one direction with respect to the test lens. Measuring means for measuring the cross-sectional shape;
And an arithmetic processing means for calculating the shape and eccentricity of the lens to be inspected based on the measurement results of the measuring means and the like.

Therefore, after the alignment of the test lens held by the holding means using the irradiation optical system, the imaging optical system, the center of gravity position detecting means, and the like, the measuring means having the displacement meter,
By using the rotating means for rotating the holding means, it is possible to obtain cross-sectional shape data of the centered test lens in two orthogonal directions, and based on the processing of these data, the shape of the test lens and the optical axis The reference eccentricity measurement can be performed with high accuracy, and the mechanism for that can be simplified.

The invention according to claim 2 includes a holding means for holding the aspherical lens as a lens to be inspected, and an illumination light source, wherein the light emitted from the illumination light source is converted into a convergent light or a divergent light. An irradiation optical system that irradiates the test surface of the test lens, and an optical axis is set so as to substantially match a central axis of the holding unit and an optical axis of the irradiation optical system,
An imaging optical system that forms an image of reflected light from the paraxial spherical surface of the surface to be inspected; a center of gravity position detecting unit that detects a center of gravity of an image formed by the imaging optical system; A displacement unit having a moving unit for pushing an outer diameter part to move the lens to be tested in two directions perpendicular to the optical axis and a scanning mechanism in two directions perpendicular to the lens to be tested; Measuring means for measuring the cross-sectional shape of the lens to be inspected on the basis of the above, and arithmetic processing means for calculating the shape and eccentricity of the lens to be inspected based on the measurement results of the measuring means.

Therefore, after the alignment of the test lens held by the holding means using the irradiation optical system, the imaging optical system, the center of gravity position detecting means, etc., the displacement meter is movable in two orthogonal directions. By using the measuring means having the above, it is possible to obtain the cross-sectional shape data of the centered test lens in two orthogonal directions, and to measure the shape of the test lens and the eccentricity based on the optical axis based on the arithmetic processing of these data. Can be performed with high accuracy,
The mechanism for that is also simple.

According to a third aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the position of the center of gravity detected by the center of gravity position detecting means when the position of the lens to be inspected is adjusted by the moving means. And a feedback control calculating means for calculating an optimum movement amount of the lens to be tested based on the calculated movement amount and performing feedback control on the moving means. Therefore, the alignment of the test lens can be performed with high accuracy when measuring the shape of the test lens and the eccentricity based on the optical axis.

According to a fourth aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the magnification ratio of the imaging optical system is variable. Therefore, by changing the magnification of the imaging optical system, the coarse adjustment can be performed in a wide field of view by reducing the magnification, and the fine adjustment can be performed in a narrow field of view by increasing the magnification. Therefore, the alignment of the test lens can be easily performed, and the alignment can be performed with higher precision as the magnification ratio is increased.

According to a fifth aspect of the present invention, in the aspherical lens shape and eccentricity measuring apparatus according to the first or second aspect, there is provided a branching means for branching the reflected light from the paraxial spherical surface of the surface to be measured into two. An image-forming optical system having a different magnification for each branched reflected light and a center-of-gravity position detecting means are provided. Therefore, the coarse adjustment can be performed in a wide field of view by reducing the magnification of one imaging optical system, and the fine adjustment can be performed in a narrow field of view by increasing the magnification of the other imaging optical system. Therefore, the alignment of the lens to be inspected can be easily performed, and the alignment can be performed with higher precision as the magnification ratio is increased.

According to a sixth aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the irradiation optical system is provided movably in the optical axis direction. Therefore, by moving the optical member in the illumination optical system in the optical axis direction and adjusting the distance between the lens and the test lens, it is possible to cope with a case where the type of the test lens changes.

According to a seventh aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the holding means holding the test lens is provided so as to be movable in the direction of the central axis. . Therefore, when the type of the test lens changes by moving the holding means in the optical axis direction and adjusting the distance between the test lens held by the holding means and the optical member in the illumination optical system. Can also be addressed.

According to an eighth aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the irradiation optical system has a replaceable condenser lens. Therefore,
When the type of the lens to be inspected changes, it is possible to easily cope with the change in the type of the lens to be inspected by replacing the lens with a condenser lens having a curvature corresponding to the lens to be inspected.

According to a ninth aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the irradiation optical system has a light shielding member having a circular opening formed on the optical axis thereof. Therefore, even if reflected light from the back surface of the test lens or the like may be generated as stray light that hinders measurement, the influence of the stray light is removed by shielding the light with the light shielding member having the circular opening. .

The invention according to claim 10 is the first or second invention.
In the shape and eccentricity measuring device of the described aspheric lens,
The irradiation optical system has a stop member whose aperture diameter is variable on the optical axis. Therefore, even if the reflected light from the back surface of the test lens or the like is generated as stray light that hinders the measurement, the influence of the stray light is removed by shielding the light with the aperture member. In particular, by changing the aperture diameter of the diaphragm member,
Even when the type of the lens to be inspected changes, it can be easily dealt with.

[0023]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a schematic front view showing a basic configuration of an optical system in the measuring apparatus according to the present embodiment. First, a holding unit 2 for holding an aspheric lens as the lens 1 to be measured is provided. The holding means 2 has a spherical portion 1b on the surface of the lens 1 opposite to the surface 1a to be measured.
Basically, the lens is held such that the center of curvature of the paraxial spherical portion of the lens 1 to be measured is on the optical axis φ.
The holding means 2 is mounted on the rotating means 3. The rotating means 3 rotates the lens 1 to be measured held by the holding means 2 by rotating the holding means 2 with its central axis (optical axis) φ as a rotation axis.

On the other hand, an irradiation optical system 4 is provided on the test surface 1a side of the test lens 1. The irradiating optical system 4 includes an illuminating light source 5 such as a laser light source, and irradiates a light beam emitted from the illuminating light source 5 to the surface to be measured 1a as a convergent light beam (or a divergent light beam). In this embodiment, the objective lens 6, the collimator lens 7, and the condenser lens 8 are provided in this order. Here, the optical axis of the irradiation optical system 4 is set so as to substantially coincide with the central axis φ of the holding means 2. Further, an image forming optical system 10 is provided on the optical axis branched by the light branching means 9 such as a half mirror interposed in the irradiation optical system 4. The imaging optical system 10 forms an image on a light receiving element after the reflected light reflected from the surface 1a to be detected passes through the condenser lens 8, the collimating lens 7, and the light splitting means 9. It is composed of a combination of a lens and a light receiving element. This imaging optical system 1
The optical axis of 0 is also set to substantially coincide with the central axis φ of the holding means 2. That is, in the present embodiment, it is assumed that the central axis φ of the holding means 2 substantially matches the optical axes of the optical systems 4 and 10. A center-of-gravity position detecting means 11 for receiving an output from a light receiving element in the image forming optical system 10 detects a center of gravity position of a spot image of reflected light formed by the image forming optical system 10 through a monitor 12.

With such a basic configuration, the light beam emitted from the illumination light source 5 is irradiated on the surface 1a of the lens 1 to be measured held by the holding means 2 by the irradiation optical system 4. . Then, the reflected light from the test surface 1a passes through the same optical path and is deflected to the imaging optical system 10 side by the light splitting means 9, and a spot image of the reflected light is formed by the imaging optical system 10. The center of gravity of the spot image is detected by the center of gravity position detecting means 11.

Here, the optical positional relationship and the like in the vicinity of the test lens 1 will be described with reference to FIG. Holding means 2
The lens 1 is held by the condenser lens 8
Is set at a position where light is condensed at the curvature center point 1a 'of the paraxial spherical portion of the lens 1 to be measured. In this case, the test lens 1
Is equal to the radius of curvature R ₀ of the paraxial spherical portion of the lens 1 to be measured. Therefore, the reflected light from the paraxial spherical portion of the test surface 1a becomes parallel light again by the condenser lens 8, so that the image forming optical system 10
After that, the reflected light becomes a spot image.

In the present embodiment, as shown in FIG. 3, the outer diameter of the lens 1 to be inspected is adjusted to adjust the position (centering) of the lens 1 to be inspected held by the holding means 2. Pressing means 13 for moving the lens 1 to be tested in only one arbitrary direction in a plane orthogonal to the optical axis φ.
Is provided. Therefore, first, while rotating the test lens 1 around the optical axis φ by the rotating means 3 while holding the test lens 1 by the holding means 2, the spot of the reflected light from the paraxial spherical portion of the test lens 1 The center of gravity position of the image is detected by the center of gravity position detecting means 11. At this time, if the optical axis of the test lens 1 is deviated from the optical axis φ of the optical system as shown in FIG. 1, the position of the center of gravity of the spot image of the reflected light becomes the rotation locus as shown in FIG. 14 is detected. Therefore, when there is a deviation, the test lens 1 is moved to the optical axis φ.
The position of the test lens 1 is adjusted by the moving means 13 that moves in an arbitrary direction in an orthogonal plane perpendicular to the direction of the lens 1 so that the rotation locus 14 becomes zero. When such adjustment is completed, the optical axis of the lens 1 to be inspected coincides with the optical axis φ of the optical systems 4 and 10.

Further, as shown in FIG. 4, there is provided a measuring means 15 which is used after the lens 1 to be measured is held on the holding means 2 and the alignment thereof is performed as described above. The measuring means 15 has a scanning mechanism (not shown) which is movable only in one arbitrary direction A in a plane orthogonal to the optical axis φ with respect to the surface 1a of the lens 1 to be measured. Test surface 1
a is provided with a displacement gauge 16 which comes into contact with (or does not contact) a. Although not particularly shown, an arithmetic processing unit for calculating the shape and the amount of eccentricity of the test lens 1 based on the cross-sectional shape of the test lens 1 measured by the displacement meter 16 is provided.

In such a configuration, after the lens 1 to be measured is held on the holding means 2 and its alignment is performed, the sectional shape thereof is measured using the measuring means 15. That is, by moving the displacement meter 16 in one direction A in a plane orthogonal to the optical axis φ while scanning the surface 1a to be measured, the one direction A
Is measured (first time). Thereafter, the test lens 1 is rotated by 90 ° together with the holding means 2 by the rotating means 3 and stopped, and at that position,
Again, the displacement gauge 16 is moved in one direction A in an orthogonal plane orthogonal to the optical axis φ.
The cross-sectional shape of the test lens 1 in the one direction A is measured by scanning the test surface 1a while moving to the second position (second time). Here, the cross-sectional shape of the test lens 1 at a position different by 90 ° between the first time and the second time results in two directions orthogonal to the test lens 1 (X direction, Y direction).
Is measured. Therefore, for example, as shown in FIGS. 5A and 5B, these two in the X and Y directions
If the inclination angles of the axes in the respective directions are calculated based on the two cross-sectional shape data, the inclination (thick line) of the aspherical axis of the test lens 1 (test surface 1a) is obtained from the coordinate relationship shown in FIG. Can be The inclination angle θ of the aspherical axis at this time is the amount of eccentricity with respect to the optical axis of the test lens 1. At this time, it is also possible to calculate the eccentric direction with reference to an arbitrary direction A while the test lens 1 is held.

Therefore, according to the present embodiment, it is possible to adjust the position of the lens 1 to be inspected. After the installation and adjustment of the position of the lens 1 to be inspected, the measuring means provided with the displacement meter 16 15 and the rotating means 3 rotates the test lens 1 by 90 °, so that cross-sectional shape data in two orthogonal directions can be obtained, and the shape and the shape of the test lens 1 The eccentricity measurement based on the optical axis can be performed.

In the present embodiment, the magnification of the imaging optical system 10 is variable. As a method of changing the magnification, for example, a zoom lens may be used, or a lens constituting the imaging optical system 10 may be exchangeable or position-changeable by a revolver method. If the magnification of the imaging optical system 10 is made variable as described above, for example, the coarse adjustment is performed in a wide field of view with a small magnification, and the fine adjustment is performed in a narrow field of view with a large magnification. Alignment of the test lens 1 can be easily performed. Further, the centering can be performed with higher accuracy as the enlargement ratio is increased.

In this embodiment, the condenser lens 8 in the irradiation optical system 4 is provided so as to be movable and adjustable in the direction of the optical axis φ. As a result, as shown in FIG.
The distance Z between (focal length f ₁ ) and the test surface 1 a of the test lens 1 is adjustable. If the type of the test lens 1 changes, the curvature of the paraxial spherical portion changes,
The distance Z between the test lens 1 and the condenser lens 8 is adjusted accordingly.
Is changed, the curvature of the light applied to the test lens 1 changes, so that even if the type of the test lens 1 changes, it is possible to cope with the change. That is, the distance Z may be adjusted according to the curvature of the paraxial spherical portion of the lens 1 to be measured.

Needless to say, the condenser lens 8 side may be fixed, and the test lens 1 side may be movable and adjustable in the optical axis φ direction together with the holding means 2. Further, the condenser lens 8 itself may be exchangeable, and as a countermeasure in the case where the test lens 1 changes, the condenser lens 8 may be replaced with a condenser lens 8 having a curvature corresponding to the test lens 1.

A second embodiment of the present invention will be described with reference to FIG. The same parts as those described in the above embodiments are denoted by the same reference numerals, and description thereof is omitted (the same applies to each of the following embodiments). In the present embodiment, a feedback control calculating means 17 connected to the center-of-gravity position detecting means 11 and performing feedback control of the moving means 13 is added. The feedback control calculating means 17 calculates an optimum amount of movement of the lens 1 to be measured based on the position of the center of gravity detected by the center-of-gravity position detecting means 11 at the time of adjusting the position of the lens 1 to be measured by the moving means 13 and performs the movement. Means 1
3 is feedback-controlled. More specifically, the amount of deviation from the optical axis φ of the test lens 1 based on the diameter of the rotation locus 14 of the reflected spot image obtained when the position of the test lens 1 is adjusted, that is, the movement of the test lens 1 The optimal movement amount by the means 13 is calculated. Therefore, according to the present embodiment,
When measuring the shape of the test lens 1 and the amount of eccentricity based on the optical axis, the position of the test lens 1 can be adjusted with high accuracy.

A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, on the optical axis of the reflected light from the paraxial spherical surface of the test surface 1a, there is provided a branching means 18 for branching the reflected light into two, and an image forming optical system is provided on one of the branched optical axes. A system 10 is provided, and an imaging optical system 19 is also provided on the other branch optical axis. These imaging optical systems 10 and 19
Are configured to have different magnifications. For example, the imaging optical system 10 having a large magnification is used for fine adjustment, and the imaging optical system 19 having a small magnification is used for coarse adjustment. The output side of these imaging optical systems 10 and 19 is a center-of-gravity position detecting means 1.
It is connected to one side.

Therefore, according to the present embodiment, at the time of centering of the lens 1 to be inspected, first, as a rough adjustment, the imaging optical system 19 having a small enlargement ratio and the center-of-gravity position detecting means 11 are used in a wide visual field state. The fine adjustment can be performed in a narrow visual field state by using the imaging optical system 10 having a large enlargement ratio and the center-of-gravity position detecting means 11, and the alignment of the test lens 1 can be easily performed. In addition, the higher the magnification on the imaging optical system 10 side, the more accurate the alignment can be.

A fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a light-shielding member 20 having a circular opening 20a formed on the optical axis φ in front of the light splitting means 9 in the irradiation optical system 6 is interposed.

With the interposition of the light shielding member 20, a specific portion of the light to be irradiated on the lens 1 to be inspected by the irradiation optical system 6 is shielded. Depending on the type of the lens 1 to be inspected, for example, the reflected light from the back side is the surface to be inspected (front surface) 1.
It may return to the imaging optical system 10 through substantially the same optical path as that of the circular aperture 2a.
If 0a is formed in a size corresponding to the lens 1 to be inspected, the light reflected by the back surface side (stray light) can be appropriately removed by the light shielding by the light shielding member 20 having the circular opening 20a.

In this embodiment, the light shielding member 2
If a stop member that can change the size of the circular opening 20a is used as 0, it is possible to easily cope with a case where the type of the lens 1 to be measured is changed.

A fifth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, first,
In the basic configuration corresponding to FIG. 1, the rotation unit 3 is omitted as shown in FIG. FIG.
As shown in FIG. 1, the lens 1 to be inspected held by the holding means 2 is orthogonal to the lens 1 in an orthogonal plane orthogonal to the optical axis φ.
Two moving means 13x and 13y for moving in the directions are provided. Thus, the center-of-gravity position of the spot image of the reflected light from the paraxial spherical portion of the lens 1 to be detected is detected by the center-of-gravity position detecting means 11 while the lens 1 to be measured is held by the holding means 2. At this time, when the optical axis of the test lens 1 is shifted from the optical axis φ of the optical system, the test lens 1 is moved to the optical axis φ.
The position of the lens 1 to be measured is adjusted by the moving means 13x and 13y moving in two directions orthogonal to each other in the orthogonal plane orthogonal to the position of the lens 1 to be measured. When such adjustment is completed, the optical axis of the lens 1 to be inspected coincides with the optical axis φ of the optical systems 4 and 10.

Further, in the present embodiment, FIG.
As shown in FIG.
Measuring means 15 is provided which is used after being held above and centered. The measuring means 15 has a scanning mechanism (not shown) movable in two directions A and A ′ perpendicular to the surface 1a of the lens 1 to be measured in a plane perpendicular to the optical axis φ. And a displacement gauge 21 for measuring the cross-sectional shape of the surface 1a by contacting (or non-contacting) the surface 1a. Although not particularly shown, an arithmetic processing unit is provided for calculating the shape and the amount of eccentricity of the lens 1 to be measured based on the cross-sectional shape of the lens 1 to be measured in the two orthogonal directions measured by the displacement meter 21.

In such a configuration, after the test lens 1 is held on the holding means 2 and its alignment is performed, the cross-sectional shape is measured using the measuring means 15. That is, by moving the displacement meter 21 in one direction A in an orthogonal plane perpendicular to the optical axis φ, the object 1a is scanned in the one direction A.
Is measured (first time). Then, by moving the displacement gauge 21 in a direction A 'orthogonal to the direction A in a direction orthogonal to the optical axis φ, the surface 1a is scanned while scanning in the direction A'. The cross-sectional shape of the lens 1 is measured (second time). Here, since the cross-sectional shape of the test lens 1 at a position different by 90 ° between the first time and the second time, as a result,
This means that the cross-sectional shape of the test lens 1 in two orthogonal directions (X direction, Y direction) has been measured. Therefore, for example, FIG.
If the inclination angle of the axis in each direction is calculated based on these two cross-sectional shape data in the X and Y directions as shown in (b), the lens to be inspected can be obtained from the coordinate relationship shown in FIG. 1
The inclination (thick line) of the aspherical axis of (test surface 1a) is obtained.
The inclination angle θ of the aspherical axis at this time is the amount of eccentricity with respect to the optical axis of the test lens 1.

Therefore, according to the present embodiment, the position of the test lens 1 can be adjusted. After the test lens 1 is installed and its position is adjusted, the test lens 1 can be moved in two orthogonal directions. By using the measuring means 15 having the displacement meter 21, the cross-sectional shape data in two orthogonal directions can be obtained without using the rotating means 3, and the shape and the shape of the lens 1 to be inspected can be obtained based on the arithmetic processing of these data. The eccentricity measurement based on the optical axis can be performed.

Although not particularly shown, the present embodiment can be applied to the systems of the above-described second to fourth embodiments and the modified examples similarly to the case of the first embodiment. .

[0045]

According to the first aspect of the present invention, since the configuration is as described above, the alignment of the test lens held by the holding means is adjusted by the irradiation optical system, the imaging optical system, the center of gravity position detecting means, etc. After performing by using, measuring means having a displacement meter,
By using the rotating means for rotating the holding means, it is possible to obtain the cross-sectional shape data of the centered test lens in two orthogonal directions. Therefore, the shape of the aspherical lens and the light The eccentricity measurement based on the axis can be performed with high accuracy, and the mechanism for that can be simplified.

According to the second aspect of the present invention, since the configuration described above is used, the alignment of the test lens held by the holding means is determined by using the irradiation optical system, the imaging optical system, the center of gravity position detecting means, and the like. After that, the cross-sectional shape data of the centered test lens in the two orthogonal directions can be obtained by using a measuring unit having a displacement meter movable in two orthogonal directions,
The eccentricity measurement based on the shape of the aspherical lens and the optical axis can be performed with high accuracy based on the arithmetic processing of these data, and the mechanism therefor can be simplified.

According to the third aspect of the present invention, in the apparatus for measuring the shape and eccentricity of the aspherical lens according to the first or second aspect, the center of gravity detected by the center of gravity position detecting means when the position of the lens to be inspected is adjusted by the moving means. Since there is provided a feedback control operation means for calculating an optimal movement amount of the test lens based on the position and performing feedback control of the movement means,
The alignment of the test lens can be performed with high accuracy when measuring the shape of the aspheric lens and the eccentricity based on the optical axis.

According to the fourth aspect of the present invention, in the aspheric lens shape and eccentricity measuring device according to the first or second aspect, the magnification of the imaging optical system is variable, so that By changing the magnification, coarse adjustment can be performed in a wide field of view with a small magnification, and fine adjustment can be performed in a narrow field of view with a large magnification. In addition to being able to easily perform the centering, the centering can be performed with higher precision as the enlargement ratio is increased.

According to the fifth aspect of the present invention, in the aspherical lens shape and eccentricity measuring apparatus according to the first or second aspect, the branching means for branching the reflected light from the paraxial spherical surface of the surface to be tested into two. The imaging optical system and the center-of-gravity position detection means having different magnifications for each of the branched reflected lights are provided, so that the magnification is reduced for one of the imaging optical systems and coarse adjustment is performed in a wide field of view. The fine adjustment can be performed in a narrow field of view by increasing the magnification of the other image forming optical system. The mind can be performed with high precision.

According to the sixth aspect of the present invention, in the aspherical lens shape and eccentricity measuring apparatus according to the first or second aspect, the illumination optical system is provided so as to be movable in the optical axis direction, so that the illumination optical system is provided. By moving the optical member in the system in the optical axis direction to adjust the distance between the lens and the test lens, it is possible to cope with a case where the type of the test lens changes.

According to the seventh aspect of the present invention, in the aspherical lens shape and eccentricity measuring device according to the first or second aspect, the holding means for holding the lens to be measured is provided movably in the central axis direction. Moving the holding means in the direction of the optical axis to adjust the distance between the test lens held by the holding means and the optical member in the illumination optical system, thereby changing the type of the test lens. Can also be dealt with.

According to the eighth aspect of the present invention, in the aspherical lens shape and eccentricity measuring apparatus according to the first or second aspect, the irradiation optical system has an exchangeable condenser lens. When the type of the lens changes, it is possible to easily cope with the change in the type of the lens to be inspected by replacing the lens with a condenser lens having a curvature corresponding to the lens to be inspected.

According to the ninth aspect of the present invention, in the aspherical lens shape and eccentricity measuring apparatus according to the first or second aspect, the irradiation optical system includes a light shielding member having a circular opening formed on an optical axis thereof. Even if reflected light from the back surface of the test lens or the like may be generated as stray light that hinders measurement, the light is shielded by the light-blocking member having the circular opening, so that the influence of the stray light is reduced. Is removed.

According to the tenth aspect, according to the first aspect,
Or in the aspherical lens shape and eccentricity measuring device according to 2, since the irradiation optical system has a stop member with a variable aperture diameter on its optical axis, reflected light from the back surface of the lens to be inspected or the like. Even if it occurs as stray light that hinders measurement, it is possible to remove the effect of stray light by blocking light with a diaphragm member.In particular, by changing the aperture diameter of the diaphragm member, the type of lens to be inspected can be changed. You can easily deal with changes.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a basic configuration of a first embodiment of the present invention.

FIG. 2 is an enlarged front view showing the vicinity of the holding means.

FIG. 3 is an enlarged plan view showing the vicinity of a test lens.

FIGS. 4A and 4B show main parts, wherein FIG. 4A is an enlarged front view showing the vicinity of a holding means, and FIG. 4B is a plan view thereof.

FIG. 5 is a characteristic diagram showing cross-sectional shape data.

FIG. 6 is a characteristic diagram showing a tilt angle in a three-dimensional coordinate system.

FIG. 7 is a schematic front view showing the configuration of the second embodiment of the present invention.

FIG. 8 is a schematic front view showing the configuration of the third embodiment of the present invention.

FIG. 9 is a schematic front view showing the configuration of the fourth embodiment of the present invention.

FIG. 10 is a schematic front view showing the configuration of a fifth embodiment of the present invention.

FIG. 11 is an enlarged plan view showing the vicinity of a test lens.

FIGS. 12A and 12B show main parts, wherein FIG. 12A is an enlarged front view showing the vicinity of the holding means, and FIG. 12B is a plan view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test lens 1a Test surface 2 Holding means 3 Rotating means 4 Irradiation optical system 5 Illumination light source 8 Condensing lens 10 Imaging optical system 11 Center of gravity position detecting means 13, 13x, 13y Moving means 15 Measuring means 16 Displacement meter 17 Feedback control calculation means 18 Branching means 19 Imaging optical system 20 Light shielding member 20a Circular aperture 21 Displacement meter φ Optical axis, central axis

Claims (10)

[Claims] An illumination light source, comprising: a holding unit for holding an aspheric lens as a lens to be inspected; and a light beam emitted from the illumination light source as a convergent light beam or a divergent light beam. An irradiation optical system for irradiating a surface, an optical axis is set so as to substantially coincide with a central axis of the holding unit and an optical axis of the irradiation optical system, and the reflection from the paraxial spherical surface of the surface to be measured is performed. An imaging optical system that forms light, a center-of-gravity position detecting unit that detects a center-of-gravity position of an image formed by the imaging optical system, and the optical axis of the test lens held by the holding unit. Rotating means for rotating as a rotation axis; moving means for pushing an outer diameter portion of the test lens to move the test lens in any one direction within an orthogonal plane orthogonal to the optical axis; On the other hand, based on a displacement meter with a scanning mechanism in one direction Measuring means for measuring the cross-sectional shape of the test lens; and arithmetic processing means for calculating the shape and eccentricity of the test lens based on the measurement results of the measuring means and the like. Lens shape and eccentricity measuring device. 2. An inspection apparatus comprising: a holding means for holding an aspheric lens as a lens to be inspected; and a light source for illumination, wherein a light beam emitted from the light source for illumination is detected as a convergent light beam or a divergent light beam. An irradiation optical system for irradiating a surface, an optical axis is set so as to substantially coincide with a central axis of the holding unit and an optical axis of the irradiation optical system, and the reflection from the paraxial spherical surface of the surface to be measured is performed. An imaging optical system that forms light, a center-of-gravity position detection unit that detects a center-of-gravity position of an image formed by the imaging optical system, and an orthogonal diameter to the optical axis by pushing an outer diameter portion of the test lens. A cross-sectional shape of the lens to be measured is measured based on a displacement unit having a moving unit for moving the lens to be tested in two directions perpendicular to each other in a perpendicular plane, and a displacement meter having a scanning mechanism in two directions perpendicular to the lens to be tested. Measuring means for measuring Arithmetic processing means for calculating the shape and eccentricity of the lens to be inspected based on the data. 3. A feedback control operation for calculating an optimum amount of movement of the lens to be measured based on the position of the center of gravity detected by the center-of-gravity position detecting means when the position of the lens to be inspected is adjusted by the moving means, and performing feedback control of the moving means. 3. An apparatus for measuring the shape and eccentricity of an aspheric lens according to claim 1, further comprising means. 4. The apparatus for measuring the shape and decentering of an aspheric lens according to claim 1, wherein the magnification ratio of the imaging optical system is variable. 5. A splitting means for splitting reflected light from a paraxial spherical surface of a test surface into two, an imaging optical system having a different magnification for each split reflected light, and a center of gravity position detecting means. The apparatus for measuring the shape and eccentricity of an aspheric lens according to claim 1 or 2, wherein: 6. An apparatus for measuring the shape and eccentricity of an aspheric lens according to claim 1, wherein the irradiation optical system is provided so as to be movable in the optical axis direction. 7. The apparatus for measuring the shape and eccentricity of an aspheric lens according to claim 1, wherein the holding means for holding the test lens is provided so as to be movable in the central axis direction. 8. An apparatus for measuring the shape and decentering of an aspheric lens according to claim 1, wherein the irradiation optical system has an exchangeable condenser lens. 9. The illumination optical system according to claim 1, further comprising a light-shielding member having a circular opening formed on an optical axis thereof.
Or an apparatus for measuring the shape and eccentricity of the aspherical lens according to 2. 10. The aspherical lens shape and eccentricity measuring apparatus according to claim 1, wherein the irradiation optical system has a stop member having a variable aperture diameter on an optical axis thereof.