JP2000186976A - Eccentricity measuring method and eccentricity measuring device for optical lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and simply measure eccentricity and simply by providing a positioning stopper, and using a jig kept in peripheral contact with one face of the curved face section of a lens and a jig rotating the lens, while it is kept in contact with the other outer periphery. SOLUTION: A measuring device for eccentricity after the centering machining or connecting machining of an optical lens is provided with a lens-holding rotary unit, having a fitting base 81a with a hole through which a laser beam is passed at the center, for example. The fitting base 81a has a cylindrical member with a step section in the vertical direction, and a measuring lens 5 is inserted into the step section with one curved face kept in contact with the outer periphery. Two prescribed missing sections are provided on the fitting base 81a, and the edge of one missing section serves as the positioning stopper of the lens 5. The other missing section is arranged so that a rotating jig 81d butts against the outer periphery of the lens 5 so as to apply force in the slant direction, and the lens 5 is rotated when the rotating jig 81d is moved. A rubber member, for example, is used for the contact section with the lens 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical lens eccentricity measuring method and an eccentricity measuring apparatus.

[0002]

2. Description of the Related Art Lenses for precision optical instruments such as cameras are
In order to form a subject image, a plurality of lenses are arranged on the optical axis, and each lens is accommodated on the optical axis in the lens barrel. In order to align the optical axes of the lenses so that the cores are aligned on the optical axis, the individual lenses are subjected to a centering process for processing the outer peripheral surface to perform centering.

In a lens centering apparatus, centering is performed by measuring the amount of eccentricity between the optical axis (optical center axis) of the lens lens to be processed and the rotation axis of the bell axis of the apparatus. As a representative example of the related art, there is a centering device described in Japanese Patent Application Laid-Open No. 07-164294.

FIG. 7 is a diagram showing the configuration of a conventional centering device. The work lens to be processed is clamped by the upper and lower bell axes and is driven to rotate by a shaft rotation motor. The eccentricity of the work lens is detected by the optical eccentricity measuring machine,
Based on the detection result, the grindstone is driven according to the rotation of the lens, and centering is performed.

When productivity is emphasized, the eccentricity of the lens after the centering process is measured without measuring the eccentricity every time on the centering apparatus, and the quality in the process may be guaranteed. As an eccentricity measuring method, a transmission method, a reflection method, and the like are disclosed as optical methods in an item of centering and inspection of “processing technology '90” by an optical element of the Japan Opto-Mechatronics Association.

On the other hand, as means for preventing loss of light amount due to surface reflection of a lens and for preventing flare and ghost, there is a process of bonding (joining) two or more lenses. Also in this step, the combined eccentricity of the bonded lenses was measured,
It is necessary to guarantee the quality in the process. As a method for measuring the eccentricity of the bonded lenses, there are an auto-collimation method, a transmission method, a reflection method, a laser method and the like as optical methods.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a method for measuring the eccentricity of an optical lens and an eccentricity measuring apparatus without depending on the skill of a measurer. The purpose of the present invention is to achieve high accuracy, simple and inexpensive measurement of eccentricity after cutting and after bonding (joining) of two or more lenses.

[0008] Another object of the present invention is to provide a post-centering process.
Another object of the present invention is to provide an optical lens eccentricity measuring method and an eccentricity measuring apparatus capable of performing highly efficient measurement for quality assurance after laminating (joining) of two or more lenses.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an eccentricity measuring method and an eccentricity measuring apparatus for an optical lens according to the present invention are arranged so that the outer diameter axis which is the center of the outer diameter of the optical lens and the lens have the same diameter. In the inspection for deviation from the optical axis connecting the centers of curvature of two surfaces, two jigs are prepared, the lens is rotated, and the amount of eccentricity is measured.

The first jig has positioning stoppers at two locations in contact with the outer peripheral surface of the lens, and abuts one of the spherical or aspherical surface of the lens with a circumferential line or surface. Performs the function of mechanical reference position setting. On the other hand, the second jig serves to press and rotate the lens against the positioning stopper side and the circumferential line or surface of the first jig while being in contact with the other outer peripheral surface of the lens. The second jig is characterized in that the lens is pressed against the circumferential line or surface of the first jig in a direction in which the lens is inclined, and a rubber member is used as a material of a portion that comes into contact with the lens. It is characterized by.

[0011]

FIG. 6 shows an overall system diagram of the configuration of an eccentricity measuring apparatus according to Embodiment 1 of the present invention. Figure
Fig. 6 shows the eccentricity measurement to check the deviation between the outer diameter axis, which is the center of the lens outer diameter of the optical lens, and the optical axis connecting the centers of curvature of the two surfaces of the lens. Does not measure the amount of eccentricity every time, and shows a configuration in which the amount of eccentricity of the lens can be measured after the centering processing.

In the apparatus for measuring the amount of eccentricity of the lens after the centering process shown in FIG. 6, reference numeral 1 denotes a laser, and 2 microscope objective lenses are arranged so that the light axis from the laser 1 coincides with the optical axis. . Further, the optical axis of the collimator lens 3 and the center of the concentric lattice 4 are aligned with the optical axis.

A measuring lens 5 is provided behind the concentric grating 4, and a diffraction image is magnified and projected on a screen 7 by a magnifying lens 6 at a distance L behind.

When the measuring lens 5 is rotated with the above configuration, the diffraction image of the concentric grating 4 rotates on the screen 7,
By reading the displacement of the rotation, the measurement lens 5
Can be measured.

The shift angle ω from the optical axis is given by the following equation.

Ω (shift angle) = d / Lm d is the displacement amount, as described above, L is distance, and m is magnification.

Next, the lens holding / rotating unit 81 is illustrated.
This will be described using 1 to 3. 1 is a plan view of the lens holding / rotating unit 81, FIG. 2 is a sectional view taken along the line BB of FIG. 1, and FIG. 3 is an enlarged plan view of a portion in contact with the outer periphery of the lens. The lens holding and rotating unit has a mounting base 81a for mounting on the eccentricity measuring device, and the mounting base 81a is provided with a hole at the center thereof for allowing laser light to pass therethrough. After the measuring lens 5 is inserted into the mounting base 81a of the lens holding and rotating unit, it is mounted on the eccentricity measuring device.

FIG. 3 is an enlarged plan view of a portion in contact with the outer periphery of the lens. A cylindrical member having two inner diameters ΦD2a and ΦD2b having different dimensions is provided in a direction extending in a direction perpendicular to the mounting base 61a. I have. ΦD1 in FIG. 3 indicates the outer diameter of the measurement lens 5, and the inner diameter ΦD2a of the cylinder comes into contact with the outer circumference of the measurement lens 5. The inner diameter ΦD2a has a circular shape as shown in FIGS. 1 and 3, and has a configuration in which two missing portions are symmetrically provided, and the missing length is less than the outer diameter ΦD1 of the measuring lens. Therefore, the relationship between the inner diameter ΦD2a and the outer diameter ΦD1 of the measurement lens is expressed by the following equation.

ΦD2a> ΦD1 On the other hand, the inner diameter ΦD2b is in contact with one surface of the spherical or aspherical surface of the measuring lens 5 by a circumferential line or surface. Inner diameter ΦD2a, ΦD2b and outer diameter ΦD of measuring lens 5
The relationship of 1 is expressed by the following equation.

ΦD2a> ΦD2b ΦD2b <ΦD1 Two edge portions 81 in one of the two missing portions of the circumference symmetrically provided on the circumference of the inner diameter ΦD2a.
b serves as a positioning stopper for the measurement lens 5.

A jig 81d for pressing and rotating the measuring lens 5 is provided in the other missing portion. Jig 81
d is arranged so that a force is applied in the tilt direction to the first jig which is circumferentially abutted by a line or surface to either the spherical surface or the aspherical surface of the measurement lens 5. It is characterized by doing. For this reason, the normal line of the portion where the jig 81d contacts the lens is oriented in a direction inclined with respect to the optical axis of the lens, in other words, in a direction inclined with the center line of the hole of the mounting base 81a.

The measuring lens 5 can be rotated by manually moving the rotary jig 81d while pressing it in the direction of the arrow in FIG. 1 in a state where the rotary jig 81d applies a force in the inclined direction. A rubber member is usually used for the lens contact portion of the rotating jig 81d.

That is, the eccentricity measuring method and the eccentricity measuring apparatus for the optical lens according to the present embodiment are arranged such that the deviation between the outer diameter axis which is the center of the outer diameter of the optical lens and the optical axis connecting the centers of curvature of the two surfaces of the lens. In the inspection, a first jig having positioning stoppers at two places in contact with the outer peripheral surface of the lens and abutting one of the spherical or aspherical surface portions of the lens with a circumferential line or surface. And a second jig for pressing and rotating the lens against a circumferential line or surface and the positioning stopper side of the first jig while contacting the other outer peripheral surface of the lens. I have.

FIG. 8 shows a study on the first jig. FIG. 8 shows the results of eccentricity measurement with various numbers of positioning stoppers and arrangements under the condition that the rotating member of the lens is arranged on the outer periphery of the lens and the positions of the positioning stoppers are provided at seven positions from NO1 to NO7. It is. According to the examination results, the number and arrangement of the positioning stoppers are determined by disposing the stoppers at two locations on the outer peripheral surface of the lens that are symmetrical with respect to the center line that connects the center of the lens and the center of the rotating member. It has been found that good results can be obtained by providing the lens on the side opposite to the rotating member with respect to the center line of the lens orthogonal to the rotating member.

The method for measuring the eccentricity of an optical lens according to the present invention,
And the eccentricity measuring device is characterized in that the second jig presses the lens against the circumferential line or surface of the first jig in a direction of inclining the lens, It is characterized by using a rubber member.

FIG. 9 shows the results of a study on the second jig, and shows the results of eccentricity measurement according to how the lens is pressed when the lens is pressed and rotated. When the rotating jig 81d, which is the second jig for rotating the lens, is arranged so as to be inclined with respect to the optical axis direction of the measurement lens 5, stable measurement can be performed, but the rotating jig 81d can be moved with respect to the optical axis. When pressure is applied in parallel or perpendicularly, measurement becomes impossible or scratches appear, indicating that it is not appropriate.

FIG. 10 shows the results of a study using a rubber member, a knurled or blasted metal member, and a knurled or blasted plastic member as the material of the second jig. is there. When a rubber member was used, stable measurement could be performed, but when a metal member or a plastic member was used, chattering occurred at the time of measurement, and it was found that accurate measurement was difficult.

FIGS. 4 and 5 show the configuration of the optical lens eccentricity measuring method and the eccentricity measuring apparatus according to the second embodiment of the present invention. The basic configuration is the same as that of the first embodiment.

FIG. 4 is a plan view of the lens holding and rotating unit 82 of the second embodiment, and FIG. 5 is a side view. The lens holding / rotating unit 82 has a mounting base 82a1 for mounting on the eccentricity measuring device, and the lens holding / rotating unit base 82a2 is mounted on the upper part thereof. The mounting base 82a1 and the lens holding / rotating unit base 82a2 have a structure with a hole through which laser light passes.

On the upper surface of the lens holding / rotating unit base 82a2, there are provided two positioning stoppers 82b for the lens, a cylindrical member 82c for holding the spherical or aspherical portion of the lens,
A lens rotating unit 82d and a lens pressing unit 82e are provided. The cylindrical member 82c that holds the spherical or aspherical part of the lens is provided so as to be concentric with the measuring lens 5, and the two lens positioning stoppers 82b are provided so as to be on the outer circumference of the measuring lens 5. Is done. The distance connecting the two lens positioning stoppers 82b is smaller than the diameter of the measuring lens 5.

The lens rotating roller 82d1 of the lens rotating unit 82d has a value of 5 at the intersection of a straight line passing through the center of the measuring lens 5 and the circumcircle of the measuring lens 5 perpendicular to the line connecting the two lens positioning stoppers 82b. Touch The contact point is a position far away from the lens positioning stopper 82b.

The lens rotating roller 82d1 is fixed to a lens pressing shaft 82e5 by a fixing jig 82d2, and is connected to a power source 82d5 via a flexible joint 82d3 and a driving motor 82d4. The lens is rotated by the driving motor 82d4 via the rotating roller 82d1, and the eccentricity measurement is performed.

The lens pressing unit 82e includes a lens pressing base 82e1, a slider fixing jig 82e2, a slider section 82e3,
Pressing shaft fixing jig 82e4, lens pressing shaft 82e5,
It comprises a lens pressure spring 82e6 and a pressure spring fixing jig 82e7.

The lens pressing base 82e1 is provided on the upper surface of the lens holding / pressing unit base 82a2, and the upper surface has a convex shape and fits with the slider portion 82e3. The slider portion 82e3 to be fitted is fixed to the lens pressing base 82e1 by a slider fixing jig 82e2. The slider portion 82e3 and the lens pressing shaft 82e5 are connected by a screw or the like, and are fixed by a pressing shaft fixing jig 82e4. The lens pressing spring 82e6 is mounted on the lens pressing shaft 82d5 side of the lens pressing shaft 82e5, and is fixed to the lens pressing shaft 82e5 with a pressing spring fixing jig 82e7.

The connection between the lens pressing shaft 82e5 and the fixing jig 82d2 of the lens rotation unit 82d is performed by pressing the lens rotation roller 82d1 in the direction of pressing the lens against the cylindrical member 82c holding the spherical or aspherical portion of the lens. It is configured to be inclined.

When the diameter of the measuring lens 5 is different, the slider 82e3 is moved back and forth, and fine adjustment is made by moving the lens pressing shaft 82e5 back and forth. Measurement lens when measuring eccentricity
5 can be controlled by changing the compression ratio of the lens pressure spring 82e6 by moving the pressure spring fixing jig 82e7 back and forth with respect to the measurement lens 5.

With this configuration, the measuring lens 5 during the eccentricity measurement is rotated by the driving motor 82d4 via the lens rotating roller 82d1. Even with a simple configuration as shown in FIGS. 4 and 5, automatic and accurate eccentricity measurement can be performed in response to a change in the diameter of the measurement lens. Further, in the present invention, since it is possible to control the pressure applied when rotating the measurement lens at the time of eccentricity measurement,
It can flexibly cope with a measurement lens having a small outer diameter, and can accurately measure the amount of eccentricity.

In the above description, the measurement of the eccentricity of a single lens has been described as an example. However, the same measurement can be performed for a bonded lens.

[0039]

As described above, the eccentricity measuring method and the eccentricity measuring device of the optical lens according to the present invention use the outer diameter axis which is the center of the outer diameter of the optical lens and the center of curvature of the two surfaces of the lens. In the inspection for deviation from the optical axis to be connected, two positioning stoppers are provided in contact with the outer peripheral surface of the lens, and a circumferential line or surface is applied to one surface of the spherical or aspherical portion of the lens. While contacting the first jig in contact with the other outer peripheral surface of the lens, the second jig for pressing and rotating the lens against the positioning stopper side and the circumferential line or surface of the first jig and rotating the lens. By providing,
The eccentricity of the optical lens can be measured with high accuracy and high efficiency even outside the centering device. In addition, the apparatus of the present invention has a feature that the eccentricity measurement can be easily performed with an inexpensive configuration, and the automatic measurement can be performed, so that stable and high-precision measurement can be performed without being affected by the skill of the measurer.

In the present invention, since the second jig presses the lens in a direction inclined with respect to the circumferential line or surface of the first jig, unstable movement during measurement of the measurement lens, It is possible to prevent the occurrence of scratches due to the movement. At the same time, the use of a rubber member as the material of the portion in contact with the lens makes the rotation of the measuring lens smooth, thereby enabling stable and accurate measurement.

[Brief description of the drawings]

FIG. 1 is a plan view of a lens holding and rotating unit of an eccentricity measuring device according to a first embodiment of the present invention;

FIG. 2 is a sectional view of a lens holding and rotating unit according to the first embodiment of the present invention;

FIG. 3 is an enlarged plan view of a lens holding and rotating unit according to the first embodiment;

FIG. 4 is a plan view of a lens holding and rotating unit according to a second embodiment of the eccentricity measuring device of the present invention;

FIG. 5 is a side view of a lens holding and rotating unit according to a second embodiment of the present invention;

FIG. 6 is an overall system diagram of an embodiment of an eccentricity measuring device of the present invention,

FIG. 7 is an overall system diagram of a conventional eccentricity measuring device,

FIG. 8 is a diagram showing a result of study of the number of positions and the positions of the lens holding / rotating units according to the present invention;

FIG. 9 is a diagram showing a result of study on the inclination direction of the rotary pressing jig of the lens holding / rotating unit of the present invention;

FIG. 10 is a diagram showing a result of study on members of a rotary pressing jig of the lens holding / rotating unit of the present invention;

[Explanation of symbols]

 1 Laser 2 Microscope objective lens 3 Collimator lens 4 Concentric grating 5 Measurement lens 6 Magnifying lens 7 Screen 81a Mounting base for lens holding / rotating unit 81b Positioning stopper 81d Pressing and rotating jig 82 Lens holding / rotating unit 82a1 Mounting base 82a2 Lens holding / rotating unit base 82b Positioning stopper 82c Cylindrical member holding the measurement lens 82d Lens rotation unit 82d1 Lens rotation roller 82d2 Fixing jig 82d3 Flexible joint 82d4 Driving motor 82d5 Power supply 82e Lens pressing unit 82e1 Lens pressing base 82e2 Slider fixing jig 82e3 Slider Part 82e4 Pressure shaft fixing jig 82e5 Lens pressure shaft 82e6 Lens pressure spring 82e7 Pressure spring fixing jig

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Claims (7)

[Claims] 1. An optical lens eccentricity measuring device for inspecting a deviation between an outer diameter axis which is a center of an outer diameter of an optical lens and an optical axis connecting centers of curvature of two surfaces of the lens. A first stopper which has a positioning stopper at two places in contact with the surface, and which comes into contact with either one of the spherical or aspherical surface of the lens by a circumferential line or surface.
And a second jig for rotating while pressing the lens against the positioning stopper side of the first jig and the circumferential line or surface while being in contact with the other outer peripheral surface of the lens. An eccentricity measuring device for an optical lens, comprising: 2. The eccentricity of an optical lens according to claim 1, wherein said second jig presses said lens against a circumferential line or surface of said first jig in a direction to incline said lens. measuring device. 3. A rubber member is used as a material of a portion where said second jig contacts said lens.
3. The optical lens eccentricity measuring device according to 2. 4. The weight of the second jig, which presses the lens against a circumferential line or surface of the first jig in a direction to incline the lens, can be controlled. Optical lens eccentricity measuring device. 5. An eccentricity measuring method for an optical lens for inspecting a deviation between an outer diameter axis which is a center of an outer diameter of an optical lens and an optical axis connecting centers of curvature of two surfaces of the lens. The lens has a positioning stopper at two places in contact with the first lens, and a first line abuts on one surface of either the spherical portion or the aspherical portion of the lens with a circumferential line or surface.
A second jig for rotating the lens while pressing the lens on the positioning stopper side of the first jig and the circumferential line or surface, while setting the lens on the jig of FIG. Measuring the amount of eccentricity of the lens by using the following method. 6. The second jig rotates the lens while pressing the lens against a circumferential line or surface of the first jig in a direction in which the lens inclines, thereby reducing the amount of eccentricity of the lens. 6. The method for measuring eccentricity of an optical lens according to claim 5, wherein the measurement is performed. 7. The apparatus according to claim 6, wherein the second jig is capable of controlling a load for pressing the lens against a circumferential line or surface of the first jig in a direction in which the lens is inclined. Optical lens eccentricity measurement method.