JPH03115944A - Eccentricity measuring instrument for aspherical lens - Google Patents

Abstract

PURPOSE:To measure the lateral shift quantity and tilt angle of an aspherical surface axis by providing a rotary lens supporting member, a paraxial eccentricity measurement part, an aspherical surface axis measurement part, an external diameter deflection measurement part, and a rotational angle measurement part. CONSTITUTION:A lens 2 to be inspected is mounted on a rotary holder 3 and the quantity of eccentricity of a 1st surface 2a with the rotary axis 4 of the center 2c of paraxial curvature is detected through the paraxial eccentricity measurement part 5; and the position of the lens 2 to be inspected is so adjusted as to eliminate the quantity of the quantity of eccentricity, and thus the center 2c of curvature of a 1st surface 2a can be coincident almost with the axis of the rotary axis 4. Then the aspherical surface axis measurement part 7 measures the tilt angle epsilon1AS of the aspherical surface axis 6 of the 1st surface 2a to the rotary axis 4 and the external diameter deflection measurement part 70 measures the quantity of deflection of the external diameter ridge 3d of the lens from the rotary axis 4. The rotational angle measurement part 9 can find the tilt direction of the aspherical surface axis 6 and the deflection direction of the lens external diameter ridge 2d. Consequently, the tilt angle epsilon1AS and lateral shift quantity of the axis 6 of the aspherical surface can accurately be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aspheric lens eccentricity measuring device for measuring the inclination of an aspheric axis in an aspheric lens.

[Prior Art] When manufacturing aspherical lenses, it is necessary to inspect whether the manufactured lenses are manufactured according to predetermined design values.

As a device for inspecting such lenses, Japanese Patent Application No. 611
An apparatus for measuring eccentricity of an aspherical lens is disclosed in Japanese Patent No. 26866. This aspherical lens eccentricity measuring device has a lens receiving part for holding a test lens, and a rotary lens support member configured to be rotatably driven;
a mechanism for adjusting the position of the test lens on the rotary lens support member in a direction perpendicular to the rotation axis of the rotary lens support member; a paraxial eccentricity measurement unit for detecting the amount of eccentricity, and a detection axis for detecting an inclination angle of an aspherical axis with respect to the rotational axis on the lens surface on the opposite side to the lens receiving portion side, using an axis other than the rotational axis as the detection axis. It consists of an aspherical axis measuring section.

In this eccentricity measuring device, the test lens is supported on the rotation support member and rotated, and the eccentricity of the paraxial curvature center of the lens surface on the opposite side to the lens receiving part side of the test lens with respect to the rotation axis is measured. is detected by the paraxial eccentricity measurement section, and the center of the lens to be tested is adjusted by the movement adjustment mechanism section so that the amount of eccentricity becomes O. In this state, the inclination angle with respect to the rotation angle of the aspherical axis on the lens surface on the opposite side of the lens receiving part of the test lens is measured by the aspherical axis measuring section. When the lens receiving portion is machined axially symmetrically with respect to the rotation axis of the rotary lens support member, the center adjustment allows the axis connecting the paraxial curvature centers of the first and second surfaces of the test lens to be aligned. completely coincides with the rotation axis of the rotating lens support member. Therefore, the inclination angle of the aspherical axis can be measured with reference to the axis connecting the paraxial curvature centers of the first surface and the second surface of the aspherical lens, respectively, by the measurement by the aspherical axis measuring section.

[Problems to be Solved by the Invention] Generally, an aspherical lens is used by being inserted into a lens frame. It is necessary to inspect the inclination angle and lateral deviation of the aspherical axis with respect to the central axis. Here, the attitude of the aspherical lens when inserted into the lens frame is determined by the outer diameter portion 2d of the aspherical lens 2 and the lens receiving surface 2b', as shown in FIG. That is, the inclination angle ε, As, and , the central axis 4 of the aspherical surface 2a of the aspherical lens 2;
What is necessary is to inspect the amount of lateral deviation δ from .

However, in the aspheric lens eccentricity measuring device disclosed in the specification of Japanese Patent Application No. 63-126866, iJ
Since it is not possible to measure the amount of deflection of the outer diameter of the aspherical lens, the amount of lateral deviation of the aspherical axis and the inclination angle of the aspherical axis are calculated based on the central axis determined by the outer diameter of the lens and the lens receiving surface. cannot be measured.

The present invention overcomes the above-mentioned drawbacks of the prior art and makes it possible to measure the amount of deflection of the outer diameter of an aspherical lens. The present invention provides a device that measures the amount of lateral deviation of an aspherical axis and the inclination angle of the aspherical axis with the axis as a reference.

[Means for Solving the Problems] The aspheric lens eccentricity measuring device of the present invention includes a rotating lens support member having a lens receiving portion for holding a test lens and configured to be rotatably driven, and this rotating lens support. A mechanism section for moving and adjusting the position of the test lens on the member in a direction perpendicular to the rotation axis on the rotating lens support member, and an eccentricity of the center of paraxial curvature of the aspheric surface of the test lens with respect to the rotation axis. a paraxial eccentricity measurement unit for detecting, and an aspheric surface for detecting the inclination angle of the aspheric axis with respect to the rotation axis on the lens surface on the opposite side to the lens receiver side, with an axis other than the rotation axis as the detection axis. an axis measuring section; an outer diameter deflection measuring section having a detection axis orthogonal to a plane including the rotation axis and for detecting the amount of deflection of the outer diameter of the lens to be tested with respect to the rotation axis; a rotation angle measuring section for detecting a rotation angle, the paraxial eccentricity measuring section, the aspherical axis measuring section, the outer diameter runout measuring section, and a calculation section calculating the measured values of the rotation angle measuring section, respectively. It is made up of.

FIG. 1 shows a conceptual diagram of an aspheric lens eccentricity measuring device 1 according to the present invention, in which the upper surface (first
A case is illustrated in which an aspherical lens in which the surface 2a is an aspherical surface and the lower surface (second surface) 2b is a spherical surface is measured.

This eccentricity measuring device 1 includes a rotary holder (lens support member) 3 for rotatably holding a test lens 2, a rotation angle measuring section 9 for detecting the rotation angle of the rotary holder 3, and a first
A paraxial eccentricity measuring section 5 for detecting the amount of eccentricity of the paraxial center of curvature 2C of the surface 2a with respect to the rotation axis 4; a spherical axis measuring section 7; and an outer diameter deflection measuring section 70 for detecting the amount of deflection of the outer diameter 2d of the lens 2 to be tested relative to the rotation axis 4.
is determined by the rotation angle detection section 9, the paraxial eccentricity measurement section 5, the aspherical axis measurement section 7, and the outer diameter runout measurement section 7o from the outer diameter portion 2d of the lens and the lens receiving surface 2b'. It is comprised of a calculation unit 15 for calculating the inclination angle ε1^S of the aspherical axis 6 with respect to the central axis 4' and the lateral deviation amount δ of the aspherical axis. Further, the contact portion of the rotating holder 3 with the lens 2 to be tested is machined to be concentric with the rotating shaft 4.

[Function] In the configuration described in section 2, when the test lens 2 is placed on the rotary holder 3, the lens receiving surface 2b' of the test lens 2 is aligned with the rotation axis 4 of the rotary holder 3, as shown in FIG. It is perpendicular to the opposite direction. Here, the amount of eccentricity of the paraxial center of curvature 2c of the first surface 2a with respect to the rotation axis 4 is detected via the paraxial eccentricity measurement unit 5, and the position of the lens 2 to be tested is adjusted so that this amount of eccentricity becomes O. By doing so, the center of curvature 2c of the first surface 2a can be substantially aligned with the axis of the rotating shaft 4. Here, the inclination angle ε, AS of the aspherical axis 6 of the first surface 2a with respect to the rotational axis 4 is measured by the aspherical axis measurement unit 7, and the lens outer diameter portion 2d with respect to the rotational axis 4 is measured by the outer diameter runout measurement unit 70. Runout amount 2
Measure 6'.

Further, the inclination direction θ1 of the aspherical shaft 6 and the deflection direction θ of the lens outer diameter portion 2d can be determined by the rotation angle measurement unit 9.

As a result, the amount of lateral deviation δ of the aspherical axis with respect to the central axis 4' can be determined by the following equation.

δ= −R, s+nε, A S COS θ, −θ
, +R, sin εAS (1) [Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIGS. 3 and 4 show an embodiment of an aspheric lens eccentricity measuring device 1 according to the present invention.

=7= The eccentricity measuring device 1 of this embodiment has a rotary lens support member 3
, a paraxial eccentricity measurement section 5, an aspherical axis measurement section 7, an outer diameter runout measurement section 7o, a rotation angle measurement section 9, and a calculation section 15.

Of these, the paraxial eccentricity measuring section 5 is mounted on the XY stage 71 so that its optical axis can coincide with the rotation axis 4 of the rotary lens support member 3. This paraxial eccentricity measurement unit 5 projects light to be focused on the paraxial curvature center 2c of the first surface 2a of the lens 2 to be tested, and determines the paraxial curvature center relative to the rotation axis 4 from the reflected light on the first surface 2a. It has a function of determining the amount of eccentricity δ of 2c.

The aspherical axis measuring section 7 includes two uniaxial movement stages 72.7.
4 and is mounted on a rotation stage 73. This aspherical axis measuring section 7 can be set at any measurement point P on the first surface 2a of the lens 2 to be tested. Note that the aspherical axis measuring section 7 has both an optical system for observing the measurement point P and a function of detecting the displacement amount Δ1 accompanying the rotation of the measurement point P.

- The outer diameter runout measuring unit 70 is mounted on two l-axis moving stages 75 and 76 that are movable in two directions orthogonal to each other, and measures any measurement point Q on the outer diameter portion 2d of the lens 2 to be tested.
It is possible to set The outer diameter runout measuring section 70 is
It has a function of detecting the amount of displacement 26' accompanying the rotation of the measurement point Q.

A specific configuration of this outer diameter runout measuring device 70 is shown in FIG.

This device includes a light source 81 that projects the outer diameter portion of the lens 2 to be tested, a collimating lens 82 that converts the light from the light source into parallel light, a light receiving element 84 that receives the light beam from the light source, and the light [8].
and a slit 83 located between the light-receiving element 84 and an amplifier 85 that converts the amount of light received by the light-receiving element 84 into a voltage.
and a display 86 that displays the output voltage of the amplifier 84.

With the above configuration and arrangement, a shadow of the outer diameter portion of the lens is formed above the slit 83, as shown in FIG.

Therefore, if the central axis of the outer diameter of the test lens 2 is eccentric with respect to the rotation axis of the rotary lens support member 3, rotating the rotary lens support member 3 will cause the shadow of the lens to move left and right. Become. As a result, the amount of light received by the light-receiving element changes, and the output voltage of the amplifier 85 also changes accordingly, so the amount of outer diameter deflection of the lens 2 to be tested can be determined from this amount of change.

The calculation unit 15 includes a paraxial eccentricity measurement unit 5, an aspherical axis measurement unit 7,
The lateral deviation amount δ and the inclination angle ε, As of the aspherical axis are determined from the output values from the outer diameter runout measurement unit 70 and the rotation angle measurement unit 9 in the rotation drive unit.

Next, based on the configuration shown in FIG. 3, the operation until the amount of lateral deviation δ and the angle of inclination ε and As of the aspherical axis are determined will be explained.

First, if the lens 2 to be tested is not provided with the annular marks 2 and j, the paraxial eccentricity measurement unit 5 detects the eccentricity of the paraxial center of curvature 2C of the first surface 2a with respect to the rotation axis 4, and Center adjustment is performed so that the amount of eccentricity becomes O.

In this state, as shown in FIG. The X coordinate is Xp, and the intersection of the first surface 2a and the rotation axis 4 is X. , the inclination of the aspherical axis 30 of the first surface 2a and the rotating axis 4 is ε, As is the detected value (displacement amount) by the aspherical axis measuring section 7 is △, then the following four equations hold true in terms of analytical geometry. .

tan(ε, As+L) =f,'(Xp,)
(3) tan(ε, AS-0,) =f,'
(Xp,') (4) tan ε, A
s=f,' (X,) (5)
[(r+ (xp+')-fl (XI)l))CO
8εl A 5−(Xp+' −Xp+ ) sinεl
A S]”+[(Xp+ 'Xf)+2X
e ) cos εl A S +(fl (xp+ '
) 10F(Xp+)−2f, (X,))sinε,
As]'=△," (6) (3) above
xp from equation (4), Xp from equation (4), and (5)
X by the formula. can be expressed as functions of ε and As, respectively, and by substituting these into equation (6), ε and 8 can be obtained.

Furthermore, by measuring the deflection amount 26' of the lens outer diameter edge 2d with respect to the rotation axis 4 in the outer diameter deflection measuring section 70, the lateral shift amount δ of the aspherical axis is determined as described above.

i Note that the first surface 2a as shown in FIGS. 7(a) and (b)
As shown in FIG. 8, an aspherical axis measuring section 7 is provided so as to be applicable to an aspherical lens having a concentric annular mark 2j centered on the aspherical axis 30 of the first surface 2a. ,
It may be configured by an objective lens 60, a television camera 61, and an image processing section 62 for detecting the shake amount Δ due to the rotation of the annular mark 2j on the test lens 2.

By configuring the aspherical axis measuring section 7 in this way, the apparatus 1 can determine the inclination angle ε, AS, and the lateral deviation amount δ of the aspherical axis.

That is, when 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 tested as shown in FIG. The inclination angle ε and As of the aspherical axis 6 with respect to the central axis 4' and the lateral deviation amount δ of the aspherical axis can be determined.

As shown in FIG. 8, the lens 2 to be tested is placed on the second part of the rotating holder 3, and the amount of deflection △ of the annular mark 2j due to rotation is detected via the aspherical axis measuring unit 7. By adjusting the position of the lens 2 to be tested so that the amount of shake is O, the intersection 2h of the first surface 1a of the lens 2 to be tested and the aspherical axis can be made to approximately coincide with the axis of the rotation axis 4. can. Here, the paraxial eccentricity measurement unit 5 determines the eccentricity δ1 of the paraxial curvature center 2C of the first surface 2a with respect to the rotation axis 4.
In addition, the amount of deflection 2δ of the lens outer diameter edge 2d with respect to the rotating shaft 4 is measured by the outer diameter deflection measuring section 70.

From this, the inclination angle ε of the aspherical axis with respect to the central axis 4', A
s is determined by the following formula.

δ.

ε, As:=stn −== (2) According to this embodiment, the inclination of the aspherical axis of the aspherical lens is determined regardless of whether or not the annular mark 2J is provided in the same device. Angles and lateral deviations can be measured very accurately.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the above Examples, and it should be noted that various changes can be made without departing from the gist of the invention. Not even.

[Effects of the Invention] The aspheric lens eccentricity measuring device of the present invention includes a rotary lens support member having a lens receiving portion for holding a test lens and configured to be rotatably driven, and a cover on the rotary lens support member. A mechanism unit for moving and adjusting the position of the test lens in a direction perpendicular to the rotation axis on the rotating lens support member, and a mechanism unit for detecting the eccentricity of the center of paraxial curvature of the aspheric surface of the test lens with respect to the rotation axis. a paraxial eccentricity measuring section; and an aspherical axis measuring section for detecting an inclination angle of an aspherical axis with respect to the rotational axis on a lens surface on the opposite side to the lens receiving section, using an axis other than the rotational axis as a detection axis. , an outer diameter runout measurement unit having a detection axis orthogonal to a plane including the rotation axis, and for detecting the amount of runout of the outer diameter of the tested lens with respect to the rotation axis; and a rotation angle of the rotation axis. the paraxial eccentricity measurement section, the aspherical axis measurement section, the outer diameter runout measurement section, and a calculation section that calculates the respective measurement values of the rotation angle measurement section. Therefore, the lens receiving surface of the test lens is supported by the rotating member and rotated to determine the eccentricity of the center of paraxial curvature of the lens surface on the opposite side to the lens receiving surface of the test lens with respect to the rotation axis. While detecting the amount with the paraxial eccentricity measuring section, adjust the center of the test lens by the movement adjustment mechanism section so that the amount of eccentricity becomes O, and in this state, the lens receiving section of the test lens The inclination angle of the aspherical axis on the opposite side is measured by the aspherical axis measuring section, and the amount of deflection of the outer diameter of the test lens is measured by the outer diameter deflection measuring section, and from these measured values,
The amount of lateral deviation of the aspherical axis and the inclination angle of the aspherical surface can be calculated based on the central axis determined by the outer edge of the lens and the lens receiving surface, and the inclination angle of the aspherical axis of the aspherical lens and the inclination angle of the aspherical surface can be calculated. The amount of lateral shift can be measured extremely accurately.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of an aspherical surface measuring device according to the present invention, Fig. 2 is a partial diagram for explaining the principle of the present invention, and Fig. 3 is a schematic configuration diagram of an aspherical surface measuring device according to an embodiment. , Fig. 4 is a partially enlarged view for explaining the operation of the aspherical surface measuring device of the embodiment, Fig. 5 is a configuration diagram of the outer diameter runout measuring device, and Fig. 6 is a slit incorporated in the outer diameter runout measuring device. Figure 7(a) is a top view of an aspherical lens with an annular mark; FIG. 7(b) is a side view of an aspherical lens with an annular mark; The figure is a partial diagram for explaining the principle of aspheric surface measurement in the case of an aspheric lens having an annular mark. ] ... Eccentricity measuring device 2 ... Aspherical lens 2C ... Center of curvature 3 ... Rotating lens support member 4 ... Rotating axis 5 ... Paraxial eccentricity measuring section 6 ... Aspherical axis 7 ... Aspherical axis measuring section 9 ... Rotation angle measuring section 15 ... Calculating section 70 ... Outer diameter runout measuring section

Claims (1)

[Claims] A rotary lens support member having a lens holder for holding a test lens and configured to be rotatably driven, and a position of the test lens on the rotary lens support member perpendicular to the rotation axis of the rotary lens support member. a mechanism unit for adjusting the movement in the direction; a paraxial eccentricity measurement unit for detecting the amount of eccentricity of the center of paraxial curvature of the aspheric surface in the test lens with respect to the rotation axis; and an axis other than the rotation axis as a detection axis. an aspherical axis measuring unit for detecting an inclination angle of an aspherical axis with respect to a rotational axis on a lens surface opposite to the lens receiving portion side; and a detection axis perpendicular to a plane including the rotational axis. , an outer diameter deflection measurement section for detecting the deflection amount of the outer diameter of the test lens with respect to the rotation axis; a rotation angle measurement section for detecting the rotation angle of the rotation axis; the paraxial eccentricity measurement section; 1. An aspherical lens eccentricity measuring device comprising an aspherical axis measuring section, an outer diameter runout measuring section, and a calculating section that calculates respective measurement values of the rotational angle measuring section.