JP2735104B2 - Aspherical lens eccentricity measuring apparatus and measuring method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an aspherical lens eccentricity measuring device and a measuring method for measuring the inclination of an aspherical axis in an aspherical lens.

(Prior Art) In manufacturing an aspherical lens, it is necessary to inspect whether or not these manufactured lenses are manufactured according to predetermined design values.

As an apparatus for inspecting such a lens, Japanese Patent Application No. 63-126
No. 866 (Japanese Unexamined Patent Publication No. 1-296132) proposes an aspherical lens eccentricity measuring apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 1-296132. The aspherical lens eccentricity measuring device includes a rotating lens support member having a lens receiving portion for holding a test lens and rotatably driven, and a position of the test lens on the rotary lens support member. A mechanism for adjusting the movement of the support member in the direction perpendicular to the rotation axis, a paraxial eccentricity measurement unit for detecting the amount of eccentricity with respect to the rotation axis of the center of the paraxial curvature of the aspheric surface of the test lens, and An aspherical axis measuring unit for detecting an inclination angle of the aspherical axis with respect to the rotation axis on a lens surface opposite to the lens receiving unit side with an axis other than the axis as a detection axis.

In this configuration, the test lens is supported on the rotation support member and rotated, and the amount of eccentricity of the lens surface of the test lens on the side opposite to the lens receiving portion side with respect to the rotation axis of the paraxial curvature center is set as The center is adjusted by the movement adjusting mechanism of the lens to be inspected so that the amount of eccentricity becomes zero while being detected by the paraxial eccentricity measuring unit. In this state, the inclination angle of the aspherical axis with respect to the rotation axis on the lens surface of the test lens opposite to the lens receiving section is measured by the aspherical axis measuring unit.

(Problem to be Solved by the Invention) In the eccentricity measuring device for an aspherical lens described in the specification of Japanese Patent Application No. 63-126866 (Japanese Patent Application Laid-open No. 1-296132), the lens eccentricity is opposite to the lens receiving portion of the lens to be inspected. The centering work on the rotation axis of the paraxial curvature center of the lens surface on the side requires skill of the operator, and is extremely difficult work because it is necessary to center the eccentricity to at least 1/1000 mm or less. Due to the eccentricity of the paraxial curvature center with respect to the rotation axis, an error occurs in the detection value of the inclination angle of the aspheric axis with respect to the rotation axis by the aspheric axis measurement unit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aspherical lens eccentricity measuring apparatus and a measuring method capable of overcoming the above-mentioned disadvantages of the prior art and measuring the inclination angle of the aspherical axis with higher accuracy.

(Means for Solving the Problems) An aspherical lens eccentricity measuring apparatus of the present invention has a lens receiving portion for holding a lens to be inspected and is configured to be rotatable and rotatable. A mechanism for moving and adjusting the position of the test lens in the direction perpendicular to the rotation axis of the rotating lens support member, and detecting the amount of eccentricity of the aspheric surface of the test lens with respect to the rotation axis of the paraxial center of curvature. The paraxial eccentricity measuring unit, and the tilt angle of the aspherical axis with respect to the rotation axis on the lens surface on the side opposite to the lens receiving unit side with the axis other than the rotation axis as the detection axis on the opposite lens surface. An aspherical axis measuring unit for detecting from a displacement amount of a measuring point, a rotation angle measuring unit for detecting a rotation angle of the rotating shaft, the paraxial eccentricity measuring unit, the aspherical axis measuring unit and the rotation Angle measurement unit It is characterized by comprising a calculation unit for calculating each measured value.

The eccentricity measuring method for an aspherical lens according to the present invention is the eccentricity measuring apparatus for an aspherical lens, wherein the eccentricity of the lens surface of the test lens opposite to the surface on the lens receiving portion side with respect to the rotation axis of the paraxial curvature center is determined. When the center is adjusted by the movement adjusting mechanism of the test lens so as to reduce the amount of eccentricity while detecting by the paraxial eccentricity measuring unit, the amount of eccentricity of the paraxial curvature center that remains slightly is reduced by the aspherical axis. In order to give an error to the detection value of the measuring unit, the amount of eccentricity of the paraxial curvature center detected by the paraxial eccentricity measuring unit is obtained, and the eccentric direction of the paraxial curvature center detected by the rotation angle measuring unit is calculated. A calculating unit for calculating an error amount to the aspherical axis measuring unit due to the eccentricity of the paraxial center of curvature, and correcting a detection value of the aspherical axis measuring unit.

In an aspherical lens eccentricity measuring apparatus 1 according to the present invention shown in FIG. 1, an upper surface (first surface) 2a is used as a lens 2 to be measured.
Is a case where an aspheric lens whose surface is an aspheric surface and whose lower surface (second surface) 2b is a spherical surface is measured. As shown in FIG.
Is a rotary holder 3 for rotatably holding the test lens 2
And a rotation angle detector 9 for detecting the rotation angle of the rotation holder
A paraxial eccentricity measuring unit 5 for detecting the amount of eccentricity of the paraxial curvature center 2c of the first surface 2a with respect to the rotation axis 4, and the inclination angle of the aspherical axis 6 of the first surface 2a with respect to the rotation axis 4. Aspherical axis measuring unit 7 for measuring from the displacement of the measuring point on the first surface 2a
From the rotation angle detecting unit 9, the paraxial eccentricity measuring unit 5, and the aspherical axis measuring unit 7, the paraxial curvature center 2c of the first surface.
Calculation unit 1 for calculating an inclination angle ε _1AS of the aspherical axis 6 with respect to a reference axis 12 which is an axis connecting the center and the paraxial curvature center 2d of the second surface.
It consists of five. Further, a contact portion of the rotary holder 3 with the lens 2 to be inspected is processed concentrically with respect to the rotary shaft 4.

(Operation) In the above configuration, when the test lens 2 is placed on the rotary holder 3, the center of curvature 2 d of the second surface 2 b of the test lens 2 is theoretically always always on the axis of the rotation shaft 4. Further, the amount of eccentricity of the center of paraxial curvature 2c of the first surface 2a with respect to the rotation axis 4 is detected via the paraxial eccentricity measuring unit 5, and the position of the lens 2 to be measured is adjusted so that the amount of eccentricity becomes as small as possible. By doing so, the center of curvature 2c of the first surface 2a can be made substantially coincident with the axis of the rotating shaft 4 like the center of curvature 2d of the second surface 2b. Here, the aspherical axis measuring unit 7 calculates the inclination angle ε ′ _1AS of the aspherical axis 6 of the first surface 2 a with respect to the rotation axis 4 by using the first surface 2
Measure from the displacement at the measurement point on a.

Further, the eccentric direction θ ₁ of the paraxial center of curvature 2 c of the first surface 2 a and the inclination direction θ ₂ of the aspherical axis 6 can be obtained by the rotation angle detecting unit.

Here, when a slight amount of eccentricity of paraxial curvature center 2c of the first surface 2a and [delta] _1, eccentricity [delta] ₁ and its direction theta _1, and aspherical shaft 6 inclination angle epsilon _'1AS and from that direction theta ₂ The calculation unit 15 calculates the inclination angle ε _1AS of the aspherical axis 6 of the first surface 2a with respect to the reference axis 12.

Similarly, when both the first surface 2a and the second surface 2b are aspherical, the inclination of the aspherical axis of the second surface 2b can be measured similarly to the first surface. Also, when the second surface 2b is a flat surface, the first
The inclination ε _1AS can be measured by _using a perpendicular to the second surface passing through the paraxial curvature center 2c of the surface 2a as a reference axis.

(First Embodiment) FIGS. 2 to 4 show a first embodiment of an aspherical lens eccentricity measuring apparatus 1 according to the present invention. FIG. a), (b) and FIG. 4 are explanatory diagrams of the main parts.

As shown in the figure, a measuring device 1 includes a rotation holder 3 for rotatably holding a test lens 2 and a paraxial for detecting the amount of eccentricity of the paraxial curvature center 2c of the first surface 2a with respect to the rotation axis 4. Eccentricity measuring unit 5 and first surface 2a accompanying rotation of test lens 2
And a displacement detector 10 for detecting the displacement amount of the measurement point (1) and measuring the inclination of the aspherical axis with respect to the rotation axis 4.

The contact portion of the rotary holder 3 with the lens 2 to be inspected is formed concentrically with respect to the rotary shaft 4, and the rotary holder 3 is configured to be rotationally driven via a rotary drive unit (not shown).

The paraxial eccentricity measuring device 5 has an optical system 1 as shown in FIG.
2, amplifier 13, switching unit 14 for alignment mode and measurement mode, calculation unit 15, display unit 16, and lens data input unit
It consists of 17.

To explain the configuration of the optical system 12, a semiconductor laser 18 is shown. The laser light from the semiconductor laser 18 is converted into parallel light through a collimator lens 19, and the polarized light
It is configured to be incident on 20. The transmitted light from the polarizing prism 20 is configured to enter the first condenser lens 22 via the quarter-wave plate 21. Condensing lens 22
Is focused at the focal position of the first condenser lens 22. Therefore, the paraxial center of curvature 2c of the first surface 2a of the test lens 2 is When set at the focal position, the light beam incident on the first surface 2a is the first surface 2a
Is set so that the light is reflected by and incident on the polarizing prism 20. Then, the reflected light from the test lens 2 that has entered the polarizing prism 20 is reflected by the polarization plane, enters the second condenser lens 23, and is condensed at a fixed position. Reference numeral 24 denotes a magnifying lens for magnifying the point image formed by the second condenser lens 23. Light emitted from the magnifying lens 24 is a light position detection for detecting the center of gravity of the magnified image. It is set so that light is condensed on the element 25.

The optical position detecting element 25 is connected to the amplifier 13 and a signal (voltage signal) corresponding to the optical position detected by the optical position detecting element 25
Are amplified by the amplifier 13. The output signal from the amplifier 13 is set so as to be input to the display unit 16 via the switching unit (switching between the alignment mode and the measurement mode) 14. In this case, when the alignment mode is switched, the signal 26 is output. It is directly input to the display unit 16, and when the measurement mode is switched, the calculation unit
It is set so as to be input to the display unit 16 via 15. The display unit 16 is set so that the detection value in each mode, that is, the detection value in the alignment mode and the detection value (final measurement value) in the measurement mode are switched and displayed.

The lens data input unit 17 is for inputting in advance the shape, refractive index, and the like of the measurement surface of the lens 2 to be measured at the time of measurement. shape Z = f ₁ spherical) 2a (x), the second surface (aspherical) 2b of the shape Z = f ₂ (x) (where, Z, x is Z-axis aspheric axis, the aspherical surface apex As a variable of a two-dimensional coordinate system with the axis orthogonal to the Z axis as the x axis), the surface distance d, the refractive index n, the distance h ₁ of the reference measurement point P of the first surface 2a from the rotation axis, the rotation holder It is set so as to be able to enter the third radius h _2.

The displacement detection unit 10 is provided with a first surface 2a associated with the rotation of the lens 2 to be inspected.
Intended (the intersection between the displacement detection axis 28 between the first surface 2a) measuring point for detecting the displacement detection axis 28 direction of displacement delta ₁ of P, the detected value is input to the arithmetic unit 15 the arithmetic unit At 15, the inclination between the aspherical axis and the rotation axis 4 is calculated. The arithmetic processing configuration in the arithmetic unit 15 will be described in the operation description for convenience of explanation.

The display means in the display unit 16 is a so-called x-
Means for directly displaying the coordinate values in the x and y directions of the y coordinate may be used, but it is preferable to use means for displaying the coordinate values together with the coordinate axes. Also, a better convenient if to display the rotation radius h _1.

Next, the operation of detecting and measuring the inclination of the aspherical axes 30, 31 in the lens 2 to be inspected having the aspherical surfaces 2a, 2b based on the above configuration will be described.

 First, the switching unit 14 is set to the alignment mode.

Next, the first surface of the test lens 2 is input to the lens data input unit 17.
2a and the shape of the second surface 2b Z = f ₁ (x), Z = f ₂ (x), both distance d, refractive index n, reference measurement point of the first surface 2a (for example, P
Distance h ₁ from the rotation axis 4 of the point), radius h _{2 of the} rotation holder 3
Enter

Next, the test lens 2 set on the rotary holder 3 is irradiated with laser light from the semiconductor laser 18 to start measurement. In this case, the laser light from the semiconductor laser 18 becomes parallel light via the collimator lens 19, and this parallel light is incident on the first condenser lens 22 via the polarizing prism 20 and the / 4 wavelength plate 21. Then, the light emitted from the first condenser lens 22 is adjusted such that the paraxial center of curvature 2c of the first surface 2a of the first condenser lens 2 becomes the focal position of the first condenser lens 22.
In other words, the light emitted from the first condenser lens 22 is directed to the first surface
First focusing lens to focus on paraxial curvature center 2c of 2a
If the apparatus 22 or the whole apparatus is moved up and down, the condensed light beam from the first condensing lens 22 is reflected by the first surface 2a, reverses the incident optical path, and enters the polarizing prism 20 again. Then, the reflected light incident on the polarizing prism 20 is reflected by the polarization plane,
The light is condensed at a fixed position through the condensing lens 23. in this case,
The reflected light from the first surface 2a is
By the action of 0, almost 100% is incident on the second condenser lens 23, and the point image condensed to a fixed point by the second condenser lens 23 is enlarged by the magnifying lens 24. The enlarged point image is condensed on the light position detecting element 25. The light position detecting element 25 outputs a voltage signal corresponding to the light position of the point image converged on the element as an output signal, and this output signal is amplified by the amplifier 13. Here, the switching unit
17 is set to alignment mode, so amplifier
The output signal from 13 is input to the display unit 16 as it is, and the detected value corresponding to the detected signal is displayed.

Here, an operation of centering the paraxial center of curvature 2c of the first surface 2a of the test lens 2 on the rotation axis 4 will be described. That is, generally, only by placing the test lens 2 on the rotary holder 3, the paraxial centers of curvature 2c and 2d of the first surface 2a and the second surface 2b.
Is generally not present on both rotation axes 4 as shown in FIG. Therefore, in this state, if the test lens 2 is rotated via the rotary holder 3, the paraxial center of curvature 2c of the first surface 2a rotates around the rotation axis 4, and the rotation radius is determined by the auto-collimation method. Display unit based on the principle of
Appears on 16. The measurement of the radius of gyration can be performed as follows. That is, assuming that paraxial curvatures of the first surface 2a and the second surface 2b are C ₁ and C ₂ respectively, In expressed, therefore, if one paraxial curvature center 2c of the first surface 2a is located downward by S ₁ from the reference plane L of the rotary holder _{3, S 1 = (1 /} C 1) -f 2 (h ₂ ) -d (3) Accordingly, the optical system of the paraxial eccentric measuring unit 5 as the light flux from the first focusing lens 22 is focused on the position of the S ₁ 12
Is adjusted in the axial direction of the rotation shaft 4 to measure the rotation radius. Therefore, the lens 2 to be measured is slid on the rotating holder 3 by a moving mechanism (not shown) while confirming the turning radius displayed on the display unit 16, and the position is adjusted so that the turning radius becomes as small as possible. I do. According to the above procedure, the paraxial center of curvature 2c of the first surface 2a is substantially located on the rotating shaft 4 as shown in FIG.

Next, the switching unit 14 is switched to the measurement mode, and the displacement detecting unit is switched.
10, the measurement point P of the first surface 2a accompanying the rotation of the lens 2 to be inspected
Detecting the amount of displacement delta _1. During this detection, the displacement detection axis
28 is preferably at right angles to the measuring plane and the distance
In order to detect in terms of h ₁ is determined by the following equation (4) from the reference plane L of the rotary holder 3 downward on the rotary shaft 4 Z ₀
And a displacement detection axis 28 having a slope of θ ₀ obtained from the following equation (5) with respect to the rotation axis 4 needs to be disposed. Here, Z ₀ and θ ₀ can be obtained by the following equations.

Z ₀ = f ₁ (h ₁ ) + h / [f ₁ ′ (h ₁ ) −f ₂ (h ₂ ) −d (4) θ ₀ = tan ⁻¹ {f ₁ ′ (h ₁ )}. (5) now, as shown in FIG. 3 (a), x coordinate (distance) from the rotation axis 4 of the one displacement peak point P ₁ at the measurement point P
XP ₁ , the x coordinate of the symmetric point of the other peak point P ₂ with respect to the rotation axis 4 is xP ₁ ′, the intersection of the first surface 2 a and the rotation axis 4 is x ₀ , and the aspherical axis 30 of the first surface 2 a is Assuming that the inclination from the rotation axis 4 is ε ₁ as ′ and the detection value (displacement amount) by the displacement detection unit 10 is Δ ′ ₁ ,
The following five equations hold in analytical geometry.

_{tan (ε 1AS '+ θ 0} ) = f 1' (x P1) ...... (6) tan (ε 1AS -θ 0) = f 1 '(x P1') ...... (7) tanε 1AS '= f 1' (X ₀ )… (8) [｛f ₁ (x _P1 ′) −f ₁ (x _P1 )｝ cosε _1AS ′ − (x _P1 ′ −x
_{P1) sinε 1AS} '] ² + _{[(x P1' -x P1 -2x 0} ) cos
ε _1AS '+ ｛f ₁ (x _P1 ') + f ₁ (x _P1 ) -2f ₁ (x ₀ ) sin
ε _1AS '] ² = Δ ₁ ² …… (9) Here, δ ₁ is the amount of eccentricity of the paraxial curvature center 2c of the first surface 2a, R ₁
Indicates a paraxial radius of curvature of the first surface 2a.

The second to fourth terms of equation (10), in order paraxial curvature center 2c of the first surface 2a exists eccentricity [delta] ₁ slightly after adjustment position, values detected by the displacement detector 10 (Displacement), which is a correction term for this.

X _P1 can be expressed by the above equation (6), x _P1 'can be expressed by the equation (7), and x ₀ can be expressed as a function of ε _1AS ' by the equation (8). By substituting these into the equation (9), ε _1AS ′ can be expressed as a function of Δ ₁ . That is, ε _1AS ′ = g ₁ (Δ ₁ , θ ₀ ) (11) Accordingly, the inclination ε _1AS ′ between the aspherical axis 30 of the first surface 2 a and the rotation axis 4 is obtained by the equation (10). Can be.

Next, similarly to the detection of the radius of rotation (the amount of eccentricity) of the paraxial curvature center 2c of the first surface 2a, the rotation axis 4 of the paraxial curvature center 2d of the second surface 2b is measured using the paraxial eccentricity measuring unit 5. Turning radius δ ₂
(See FIGS. 3A and 3B). in this case,
It is necessary to adjust the optical system 12 of the paraxial eccentricity measuring unit 5 in the axial direction of the rotating shaft 4 so that the light beam from the first condenser lens 22 is focused on a specific point on the rotating shaft 4. Now, the focal point, if some only S ₂ below the reference plane L of the rotary holder 3, S ₂ by the paraxial theory is given by the following equation.

Then, the lateral magnification of the detection optical system is β, and the paraxial eccentricity measurement unit 5
In turning radius [delta] ₂ of the paraxial curvature center 2d of the rotating radius of the detection value delta ₂ Tosureba second surface 2b of the reflected image to be measured is given by the following equation.

Here, equation (13) the first term in the square root of the adjusted paraxial curvature center 2c position of the first surface 2a is also slightly, to eccentricity [delta] ₁ is present, paraxial eccentricity determination unit Second surface by 5
Detected value Δ of the radius of gyration about the axis of rotation of paraxial center of curvature 2d of 2b
₂ , which is a correction term for this.

Next, a method for determining the angle from the obtained [delta] ₂ values, aspherical axis 31 of the second surface 2b and the rotary shaft 4 (13).

The x-coordinates of two contact points between the rotation axis 4, the rotation holder 3 in the section including the aspherical axis 31 of the second surface 2 b, and the second surface 2 b are represented by x _P2 and x _P2 ′ (where x _P2 <x _P2 '), second surface
If the x coordinate of the intersection of the rotation axis 4 and the rotation axis 4 is x ₀ ′ and the angle between the aspherical axis 31 of the second surface 2 b and the rotation axis 4 is ε _2AS ′, the following 4 One of formula holds _{x P2 '-x P2 = 2h 2} cosε 2AS' ...... (15) x P2 + x P2 '= 2 ^{_{[x P2 sin 2 ε 2AS' +}} x 0 'cos 2 ε 2AS' +
｛F ₂ (x ₀ ′) −f ₂ (x _P2 )｝ sinε _2AS ′ cosε _2AS ′]…
… (16) x _P2 + x _P2 ′ = 2 [x _P2 ′ sin ² ε _2AS ′ + x ₀ ′ cos ² ε _2AS ′
+ ｛F ₂ (x ₀ ′) −f ₂ (x ₂ ′)｝ sin ε _2AS ′ cos _{ε 2AS} ′] (17) δ ₂ = | [1 + f ₂ ′ (x ₀ ′) ² ] / [f ₂ ″ (X ₀ ')]
_{{F 2 '(x 0)} · cosε 2AS' -sinε 2AS '} | ...... (18) Thus, (15), x _P2 by (16) and (17)
And x _P2 ′ are eliminated, x ₀ ′ is obtained, and δ _{2 is} obtained by substituting this value into equation (18). Conversely, δ ₂ is (13)
If it can be calculated by the equation, ε _2AS ′ can be obtained. That is, ε _2AS ′ can be expressed by the following equation.

ε _2AS ′ = g ₂ (δ ₂ , h ₂ ) (19) Here, a straight line connecting the two paraxial curvature centers 2c and 2d of the first surface 2a and the second surface 2b is _defined as an aspheric lens 2. Of the reference axis 40 relative to the rotation axis 4.
The inclination epsilon ₀ can be obtained by the following expression.

Therefore, the inclinations ε _1AS and ε _2AS of the aspherical axes 30 and 31 of the first surface 2a and the second surface 2b with respect to the reference axis 40 can be obtained by the following equations.

Where (21) of alpha ₁ are aspherical eccentric orientation of the first surface 2a with respect to the reference axis 40 (22) of alpha ₂ are aspherical eccentric orientation of the second surface 2b with respect to the reference axis 40. α ₁ and α ₂ are obtained by the following equations.

α ₁ = θ ₁ −tan ⁻¹ ｛(δ ₂ sin θ ₂ −δ ₁ sin θ ₁ ) /
(Δ ₂ · cos θ ₂ −δ ₁ cos θ ₂ )｝ (23) α ₂ = θ ₂ -tan ^-1 ｛(δ ₂ sin θ ₂ -δ ₁ sin θ ₁ ) /
(Δ ₂ · cos θ ₂ −δ ₁ cos θ ₂ ｝) (24) All of these calculations are performed by the calculation unit 15.

As described above, according to the present embodiment, even if the paraxial center of curvature 2c of the first surface 2a does not completely coincide with the rotation axis 4, the inclination ε _{1AS of the} aspherical axes 30, 31 can be extremely accurately _determined. And ε _2AS can be measured.

In the above embodiment, the measurement example of the test lens 2 having both aspheric surfaces has been described. However, the present invention is not limited to this. inclination (epsilon _1AS, epsilon either _2AS) can measure the inclination of the aspheric axis since only the same manner as above aspherical side is detected as zero.

(Second Embodiment) FIGS. 5 (a) and 5 (b) and FIGS. 6 (a) and 6 (b) show a second embodiment of the present invention. The feature of this embodiment is that a concentric annular mark 2j centered on the aspherical axis 30 of the first surface 2a is provided on the first surface 2a of the lens 2 to be inspected.
The shake amount Δ3 ′ (corresponding to the displacement amount) due to the rotation of the object is detected by the objective lens 60, the television camera 61, and the image processing unit 62, and the detection result is processed by the calculation unit 15 to obtain The configuration is such that the inclination of the aspherical axes 30 and 31 of the lens 2 can be measured. The ring-shaped mark 2j is the first surface 2a
Because it is easy to mold with the same mold, it is also possible to position the center of the annular mark 2j on the aspherical axis 30,
Easy. In this embodiment, attention is paid to this fact, and the inaccuracy of the measurement of an aspherical surface close to a spherical surface is intended to be improved by detecting the center of the annular mark 2j.

Deflection amount Δ of orbicular mark 2j due to rotation of lens 2 to be inspected
3 ′ is an objective lens 60, a television camera 61, and an image processing unit 62.
Is detected by The illumination method at this time may be either external illumination or epi-illumination usually used with a microscope. In the second embodiment, it is calculated by the following equation.

However (25) of the theta ₃ is a maximum deflection direction of the annular mark 2j. Here, delta ₃ in order to influence the deflection of delta _{3 'due} to the presence of eccentricity [delta] ₁ while paraxial curvature center 2c is slightly adjusted position of the first surface 2a, annular after correction This is the amount of eccentricity of the mark 2j with respect to the rotation axis 4.

Therefore, the swing amount Δ of the annular mark 2j on the first surface 2a
3 ′, the eccentricity δ ₂ of the paraxial center of curvature 2d of the second surface 2b with respect to the rotation axis 4 after the adjustment, the eccentric azimuth difference α in both detections, and the shape data f ₁ (x), f ₂ ( x)
At 15, the angles ε _1AS and ε _2AS formed by the aspherical axes 30 and 31 with respect to the reference axis 40 of each surface are calculated in the same manner as in the first embodiment, and are displayed.
At 16 these values are displayed. The display unit 16 also serves to display the amount of eccentricity of the paraxial center of curvature 2c of the first surface 2a for alignment with respect to the rotation axis 4.

According to the present embodiment, the shake amount Δ3 ′ of the annular mark 2j is detected, and the angle ε between the aspherical axes 30 and 31 with respect to the reference axis 40 is formed.
_{Since 1AS} and _ε2AS are detected and measured, there is an advantage that measurement with higher accuracy is possible as compared with the first embodiment.

(Effect of the Invention) As described above, according to the present invention, the inclination and eccentricity of the aspherical axis of the aspherical lens can be detected extremely accurately and highly accurately.
It can be measured.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of an eccentricity measuring device for an aspherical lens of the present invention, FIG. 2 is an explanatory diagram showing a configuration of an eccentricity measuring device for an aspherical lens of the present invention, FIG. , (B) and FIG. 4 are explanatory diagrams each showing a main part thereof, and FIGS. 5 (a) and (b) and FIGS. 6 (a) and (b) are decentering measuring apparatuses for the aspheric lens of the present invention. It is explanatory drawing which respectively shows the structure of another Example. 2 ... lens to be inspected, 2a ... first surface 2b ... second surface 3, ... rotating holder 4 ... rotating shaft 5, ... paraxial eccentricity measuring unit 6 ... aspherical shaft, 7 ... non- Spherical axis measurement unit 9: rotation angle detection unit, 15: calculation unit

Claims (2)

(57) [Claims] A rotating lens supporting member having a lens receiving portion for holding the lens to be inspected and rotatably driven; and a position of the lens to be inspected on the rotating lens supporting member, the rotation axis of the rotating lens supporting member. A mechanism unit for adjusting the movement in the vertical direction, a paraxial eccentricity measuring unit for detecting the amount of eccentricity with respect to the rotation axis of the paraxial curvature center of the aspheric surface in the test lens, and an axis other than the rotation axis. An aspherical axis for detecting a tilt angle of the aspherical axis with respect to the rotation axis on a lens surface opposite to the lens receiving portion side as a detection axis from a displacement amount of a measurement point on the opposite lens surface; A measurement unit, a rotation angle measurement unit for detecting a rotation angle of the rotation shaft, and a calculation unit that calculates respective measurement values of the paraxial eccentricity measurement unit, the aspherical axis measurement unit, and the rotation angle measurement unit. It is special that Eccentricity measuring apparatus of the aspherical lens to. 2. The eccentricity measuring apparatus for an aspherical lens according to claim 1, wherein an eccentricity of a center of paraxial curvature of a lens surface of the test lens opposite to a surface on the lens receiving portion side with respect to a rotation axis. When the center is adjusted by the movement adjusting mechanism of the test lens so as to reduce the amount of eccentricity while detecting by the paraxial eccentricity measuring unit, the amount of eccentricity of the paraxial curvature center that remains slightly is reduced by the aspherical axis. In order to give an error to the detection value of the measuring unit, the amount of eccentricity of the paraxial curvature center detected by the paraxial eccentricity measuring unit is obtained, and the eccentric direction of the paraxial curvature center detected by the rotation angle measuring unit is calculated. An eccentricity of the center of paraxial curvature caused by the eccentricity of the center of the paraxial curvature to the aspherical axis measuring unit, and correcting a detection value of the aspherical axis measuring unit.