JP2735106B2 - Aspherical lens eccentricity measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aspherical lens eccentricity measuring device for measuring the inclination of an aspherical axis of 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 lenses, Japanese Patent Application No.
An eccentricity measuring device for an aspherical lens disclosed in Japanese Patent No. 126866 (JP-A-1-296132) has been proposed. The aspherical lens eccentricity measuring device has a lens receiving portion for holding a test lens, and is configured to be rotatable and rotatable. A rotary lens support member, and the position of the test lens on the rotary lens support member is rotated by the rotation. With respect to the rotation axis of the lens support member,
A mechanism 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 lens to be measured, and a detection axis for axes other than the rotation axis And an aspherical axis measuring unit for detecting an inclination angle of the aspherical axis with respect to the rotation axis on the lens surface opposite to the lens receiving unit side.

In this eccentricity measuring apparatus, the test lens is supported on the rotation support member and rotated, and the eccentricity of the lens surface of the test lens opposite to the lens receiving portion side with respect to the rotation axis of the paraxial curvature center with respect to the rotation axis. Is detected by the paraxial eccentricity measuring unit, and the center is adjusted by the movement adjusting mechanism of the lens to be measured so that the amount of eccentricity becomes zero. In this state, the aspherical axis measuring unit measures the inclination angle of the aspherical axis with respect to the rotation angle on the lens surface of the test lens opposite to the lens receiving unit. In the case where the lens receiving portion is machined axially symmetrically with respect to the rotation axis of the rotating lens support member, the first adjustment of the lens to be inspected is performed by the center adjustment.
The axis connecting the paraxial curvature centers of the surface and the second surface completely coincides with the rotation axis of the rotating lens support member. Therefore, the inclination angle of the aspherical axis can be measured based on the axis connecting the paraxial curvature centers of the first surface and the second surface of the aspherical lens by the measurement by the aspherical axis measuring unit.

[Problems to be Solved by the Invention] By the way, generally, an aspherical lens is generally used by being incorporated in a form inserted into a lens frame.
It is necessary to inspect the inclination angle of the aspherical axis with respect to the center axis of the lens frame and the amount of lateral displacement when the lens is inserted into the lens frame.
Here, the posture of the aspherical lens when inserted into the lens frame is determined by the outer diameter ridge 2d of the aspherical lens 2 and the lens receiving surface 2b 'as shown in FIG. That is, the inclination angle ε _1A s of the aspherical axis 6 of the aspherical surface 2a of the aspherical lens 2 with respect to the central axis 4 ′ determined by the outer diameter ridge 2d of the aspherical lens 2 and the lens receiving surface 2b ′ and The lateral shift amount δ of the aspheric lens 2 from the center axis 4 on the aspheric surface 2a may be inspected.

However, in the aspherical lens eccentricity measuring device described in the specification of Japanese Patent Application No. 63-126866, since the amount of runout of the outer diameter portion of the aspherical lens cannot be measured, the lens outer diameter ridge and the lens receiving surface cannot be measured. It is not possible to measure the amount of lateral displacement of the aspherical axis and the inclination angle of the aspherical axis with reference to the determined central axis.

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 the aspherical lens, so that the center determined by the outer diameter ridge of the lens and the lens receiving surface of the lens. An apparatus for measuring a lateral shift amount of an aspherical axis and an inclination angle of the aspherical axis with reference to the axis is provided.

[Means for Solving the Problems] An aspherical lens eccentricity measuring apparatus according to the present invention has a lens receiving portion for holding a test lens and is configured to be rotatable and rotatable, and a rotary lens supporting member is provided. A mechanism for moving and adjusting the position of the test lens on the member in a direction orthogonal to the rotation axis on the rotating lens support member,
A paraxial eccentricity measuring unit for detecting the amount of eccentricity of the paraxial curvature center of the aspheric surface with respect to the rotation axis in the test lens, and a lens on the side opposite to the lens receiving unit side with an axis other than the rotation axis as a detection axis An aspherical axis measuring unit for detecting a tilt angle of the aspherical axis with respect to the rotation axis on the surface, and a detection axis orthogonal to a plane including the rotation axis, and an outer diameter of the lens to be measured with respect to the rotation axis; An outer diameter runout measuring unit for detecting a runout amount, 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 outer diameter runout measurement And a calculation unit for calculating the measured values of the rotation angle measurement unit.

FIG. 1 shows a conceptual diagram of an aspherical lens eccentricity measuring apparatus 1 according to the present invention. As a lens 2 to be detected, an upper surface (first surface) 2a is an aspherical surface, and a lower surface (second surface) 2b is a spherical surface. The case where a certain aspherical lens is measured is illustrated.

The eccentricity measuring device 1 includes a rotation holder (lens support member) 3 for rotatably holding the lens 2 to be measured, a rotation angle measurement unit 9 for detecting a rotation angle of the rotation holder 3, and a first surface 2a. A paraxial eccentricity measuring unit 5 for detecting the amount of eccentricity of the paraxial curvature center 2c with respect to the rotation axis 4 and an aspheric axis measurement for measuring the inclination angle of the aspherical axis 6 of the first surface 2a with respect to the rotation axis 4 An outer diameter fluctuation measuring unit 70 for detecting a vibration amount of the outer diameter ridge 2d of the lens 2 to be measured with respect to the rotation axis 4; a rotation angle detecting unit 9; a paraxial eccentricity measuring unit 5; The inclination angle ε _1A s of the aspherical axis 6 with respect to the central axis 4 ′ determined by the outer diameter ridge 2 d of the lens and the lens receiving surface 2 b ′, and the aspherical surface It comprises an operation unit 15 for calculating the amount of shaft lateral deviation δ.
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 lens receiving surface 2 b ′ of the test lens 2 is perpendicular to the rotation axis 4 of the rotary holder 3 as shown in FIG. Becomes 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 measuring unit 5, and the position of the lens 2 to be measured is adjusted so that this amount of eccentricity becomes zero. 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. Here, the inclination angle ε _1A s of the aspherical axis 6 of the first surface 2 a with respect to the rotation axis 4 is measured by the aspherical axis measurement section 7, and the lens outer diameter ridge 2 d with respect to the rotation axis 4 is measured by the outer diameter fluctuation measurement section 70. Is measured.

Further, the inclination direction θ ₁ of the aspherical shaft 6 and the deflection direction θ ₂ of the lens outer diameter ridge ₂ d can be obtained by the rotation angle measuring unit 9.

Thus, the amount of lateral shift δ of the aspherical axis with respect to the central axis 4 ′
Is determined by the following equation.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

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

The eccentricity measuring device 1 of this embodiment includes a rotating lens support member 3, a paraxial eccentricity measuring unit 5, an aspherical axis measuring unit 7, an outer diameter runout measuring unit 70, a rotation angle measuring unit 9, and a calculating unit 15. .

Among them, the paraxial eccentricity measuring unit 5 is mounted on the XY stage 71 so that the optical axis of the paraxial eccentricity measuring unit 5 can coincide with the rotating axis 4 of the rotating lens support member 3. The paraxial eccentricity measuring unit 5 projects light to be focused on the paraxial center of curvature 2c of the first surface 2a of the lens 2 to be inspected, and calculates the paraxial center of curvature with respect to the rotation axis 4 from the reflected light on the first surface 2a. and it has a function of obtaining the eccentricity [delta] ₁ of 2c.

The aspherical axis measuring unit 7 includes two one-axis moving stages 72 and 74.
Is mounted on the rotary stage 73. The aspherical axis measurement unit 7 can be set at an arbitrary measurement point P on the first surface 2a of the lens 2 to be measured. The aspherical axis measurement unit 7 includes an optical system for observing the measurement point P and a measurement point P
Having both the function of detecting the displacement amount delta ₁ due to the rotation. The optical axis of the optical system of the aspherical axis measurement unit 7 and the rotation axis 4
Is defined as θ ₀ .

The outer diameter runout measuring unit 70 is mounted on two uniaxial movement stages 75 and 76 that can move in directions perpendicular to each other, and is set with respect to an arbitrary measurement point Q on the outer diameter ridge 2d of the lens 2 to be measured. It is possible to The outer diameter runout measurement unit 70
Has a function of detecting an amount of displacement 2δ 'due to the rotation of.

FIG. 5 shows a specific configuration of the outer diameter runout measuring device 70.

The apparatus includes a light source 81 for projecting the outer diameter of the lens 2 to be measured, a collimating lens 82 for collimating light from the light source, a light receiving element 84 for receiving the light beam of the light source, the light source 81 and the light receiving element 84. And the light receiving element 84
An amplifier 85 converts the amount of received light into a voltage, and a display 86 displays the output voltage of the amplifier 84.

With the above configuration and arrangement, a shadow of the lens outer diameter portion is formed on the slit 83 as shown in FIG. Therefore, when the central axis of the outer diameter of the test lens 2 is eccentric with respect to the rotation axis of the rotating lens support member 3, rotating the rotating lens support member 3 causes 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 changes accordingly.
The amount of change in the outer diameter of the lens 2 to be measured is determined from the 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 _1A s of the aspherical axis are obtained from the output values from the outer diameter fluctuation measuring unit 70 and the rotation angle measuring unit 9 in the rotation driving unit.

Next, a description will be given of an operation until the lateral deviation amount δ and the inclination angle ε _{1As of the} aspherical axis are obtained based on the above configuration.

First, when the annular mark 2j of the test lens 2 is not provided, the paraxial eccentricity measuring unit 5 determines the center of the paraxial curvature of the first surface 2a.
The amount of eccentricity of the 2c with respect to the rotating shaft 4 is detected, and the center is adjusted so that the amount of eccentricity becomes zero.

In this state, as shown in FIG. 4, the X coordinate (distance) of one displacement peak point P _{1 from} the rotation axis 4 at the measurement point P is Xp ₁ , and the symmetrical point of the other peak point P ₂ with respect to the rotation axis 4. Xp ₁ ′, the intersection point between the first surface 2a and the rotation axis 4 is X ₀ , and the inclination between the aspherical axis 30 and the rotation axis 4 of the first surface 2a is ε _1A
s, 4 single formula analytic geometry over Next the value detected by the aspherical axis measuring section 7 (displacement amount) and delta ₁ is satisfied.

_{tan (ε 1A s + θ 0} ) = f 1 '(Xp 1) (3) tan (ε 1A s-θ 0) = f 1' (Xp 1 ') (4) tanε 1A s = f 1' (X 0) (5) [｛f ₁ (Xp ₁ ′) −f ₁ (Xp ₁ )｝ cosε _1A s− (Xp ₁ ′ −Xp ₁ ) sinε _1A s] ² + [(Xp ₁ ′ −Xp ₁ −2X ₀ ) the _{cosε 1A s + {f 1 (} Xp 1 ') + f (Xp 1) -2f 1 (X 0)} sinε 1A s] 2 = Δ 1 2 (6) Xp 1 from equation (3), (4) more Xp ₁ ', and (5) can be expressed since the X ₀ as a function of each epsilon _1A s by formula, epsilon _1A s is determined by substituting to the equation (6).

Further, by measuring the shake amount 2δ ′ of the lens outer diameter ridge 2d with respect to the rotating shaft 4 by the outer diameter swing measuring unit 70, the lateral shift amount δ of the aspherical axis is obtained as described above.

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

If the aspherical axis measuring unit 7 is configured as described above, the inclination angle ε _{1As of the} aspherical axis and the lateral shift amount δ are obtained by the present apparatus 1.

That is, as shown in FIG.
When the surface 2a is provided with a concentric annular mark 2j centered on the aspherical axis 30 of the first surface 2a, the inclination angle ε _1A s of the aspherical axis 30 with respect to the central axis 4 ′ is as follows. In addition, the lateral shift amount δ of the aspherical axis can be obtained.

As shown in FIG. 8, the test lens 2 is
, And detects the amount of shake Δ of the orbicular mark 2j due to rotation via the aspherical axis measuring unit 7 and adjusts the position of the lens 2 so that the amount of shake becomes zero. By
The intersection 2h between the first surface 1a of the test lens 2 and the aspherical axis can be made substantially coincident with the axis of the rotating shaft 4. Here, the paraxial eccentricity measuring unit 5 measures the amount of eccentricity δ ₁ of the paraxial curvature center 2 c of the first surface 2 a with respect to the rotation axis 4, and the outer diameter fluctuation measuring unit 70 measures the lens outer diameter ridge 2 d with respect to the rotation axis 4. Is measured.

Thus, the inclination angle ε _{1A of the} aspherical axis with respect to the central axis 4 ′
s is obtained by the following equation.

According to the present embodiment, even if the orbicular mark 2j is provided by the same apparatus or not, it is possible to extremely accurately measure the inclination angle and the lateral shift amount of the aspherical axis in the aspherical lens. it can.

As described above, the invention made by the inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and it can be said that various modifications can be made without departing from the gist of the invention. Not even.

[Effects of the Invention] An aspherical lens eccentricity measuring apparatus according to the present invention includes a rotating lens support member having a lens receiving portion for holding a test lens and configured to be rotatable and rotatable. A mechanism for moving and adjusting the position of the inspection lens in a direction orthogonal to the rotation axis on the rotation lens support member,
A paraxial eccentricity measuring unit for detecting the amount of eccentricity of the paraxial curvature center of the aspheric surface with respect to the rotation axis in the test lens, and a lens on the side opposite to the lens receiving unit side with an axis other than the rotation axis as a detection axis An aspherical axis measuring unit for detecting a tilt angle of the aspherical axis with respect to the rotation axis on the surface, and a detection axis orthogonal to a plane including the rotation axis, and an outer diameter of the lens to be measured with respect to the rotation axis; An outer diameter runout measuring unit for detecting a runout amount, 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 outer diameter runout measurement Unit, and a calculation unit for calculating the respective measurement values of the rotation angle measurement unit, so that the lens receiving surface of the test lens is supported on the rotating member, and rotated, and the lens in the test lens is rotated. Near the lens surface opposite to the lens receiving surface While the amount of eccentricity of the center of curvature with respect to the rotation axis is detected by the paraxial eccentricity measuring unit, the center adjustment is performed by the movement adjusting mechanism of the lens to be measured so that the amount of eccentricity becomes zero. The inclination angle of the aspherical axis on the side opposite to the lens receiving section is measured by an aspherical axis measuring section, and the amount of deflection of the outer diameter of the test lens is measured by an outer diameter deflection amount measuring section. From the above, the amount of lateral displacement of the aspherical axis and the inclination angle of the aspherical surface can be obtained by calculation with reference to the center axis determined by the outer diameter ridge of the lens and the lens receiving surface, and the inclination of the aspherical axis in the aspherical lens can be obtained. The angle and the amount of lateral displacement can be measured very accurately.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an aspherical surface measuring apparatus according to the present invention, FIG. 2 is a partial view for explaining the principle of the present invention, FIG. The figure 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 fluctuation measuring device, and FIG. 6 is the operation of the slit incorporated in the outer diameter fluctuation measuring device. FIG. 7 (a) is a plan view of an aspherical lens having an annular mark, FIG. 7 (b) is a side view of an aspherical lens having an annular mark, and FIG. 8 is an annular shape. FIG. 5 is a partial view for explaining the principle of aspheric measurement in the case of an aspheric lens having a mark. DESCRIPTION OF SYMBOLS 1 ... Eccentricity measuring device 2 ... Aspherical lens 2c ... Center of curvature 3 ... Rotating lens support member 4 ... Rotating axis 5 ... Paraxial eccentricity measuring unit 6 ... Aspherical axis 7 ... Aspherical axis measurement Unit 9: Rotation angle measurement unit 15: Calculation unit 70: Outer diameter runout measurement unit

Claims (1)

(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 is determined by rotating the rotating lens supporting member. A mechanism for adjusting the movement in a direction perpendicular to the axis, a paraxial eccentricity measuring unit for detecting the amount of eccentricity of the aspherical center of curvature of the aspherical surface of the test lens with respect to the rotation axis, and a unit other than the rotation axis. An aspherical axis measuring unit for detecting the inclination 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 as a detection axis, and orthogonal to the plane including the rotation axis Having a detection axis, an outer diameter fluctuation measuring unit for detecting a fluctuation amount of the outer diameter of the lens to be inspected with respect to the rotation axis, a rotation angle measuring unit for detecting a rotation angle of the rotation axis, and the paraxial; Eccentricity measuring unit,
An aspherical lens eccentricity measuring device, comprising: the aspherical axis measuring unit, the outer diameter runout measuring unit, and a calculating unit that calculates respective measured values of the rotation angle measuring unit.