JP3597302B2 - Eccentricity measuring device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an eccentricity measuring device and an eccentricity measuring method for measuring the amount of eccentricity of a test lens.
[0002]
[Prior art]
FIG. 9 shows a configuration of a conventional eccentricity measuring device. Conventional eccentric measuring device, a lens holder 52 of the lens under test holds a spindle 5 5 constituting the driving mechanism for rotationally driving the lens holder 52, the sample lens relative to the axis of rotation 5 5 a of the spindle 5 5 and a eccentric measuring unit 5 6 for measuring the eccentricity of 51. The center axis of the lens holder 52 is coaxially processing with respect to the rotation axis 5 5 a.
[0003]
In this arrangement, the sample lens 51 is supported by a lens holder 52, by rotating the lens holder 52 of the lens 51 for measuring the center of curvature of the opposite side lens surface 51a by eccentric measuring unit 5 6. Further, the center of curvature of the lens holder side lens surface 51b of the lens 51 is theoretically always on the axis of the rotary shaft 5 5 a. In this manner, the optical axis of the lens 51 to be detected can be detected and used as a reference axis such as the deflection of the outer shape of the lens 51 or the inclination of the aspheric axis.
[0004]
[Problems to be solved by the invention]
However, in the conventional eccentric measuring device is coaxially processed lens holder 52 with respect to the rotation axis 5 5 a of the spindle 5 5. Therefore, when replacing the lens holder 52 in accordance with the shape of the lens 51, after the replacement of the lens holder 52 or coaxial machining with respect to the rotation axis 5 5 a central axis of the new lens holder 52, or , there is a problem that must be replaced every spindle 5 5.
[0005]
The present invention has been made in view of the above-described conventional problems, and does not require the center axis of the replaced lens holder to be coaxially machined with respect to the rotation axis, and does not require replacement for each drive mechanism. It is an object of the present invention to provide an eccentricity measuring device and an eccentricity measuring method capable of promptly measuring eccentricity by immediately setting the center axis of the lens holder to be coaxial with the rotation axis.
[0006]
[Means for Solving the Problems]
The eccentricity measuring device according to the first aspect of the present invention is configured such that a lens holder for holding a test lens, a driving mechanism for rotating the lens holder, and a horizontal tilt of the lens holder with respect to a rotation axis of the driving mechanism are parallel. The lens holder is moved in a horizontal direction with respect to the rotation axis of the driving mechanism by using a tilt adjusting mechanism for adjusting using a flat plate and a reference sphere placed on the lens holder, and the central axis of the lens holder is driven. and a moving mechanism to match the rotation axis of the mechanism, the position adjusting means having said tilt adjusting device 構及 beauty said moving mechanism, while rotating the lens holder holding the sample lens by the driving mechanism, this An eccentricity measuring unit that measures the position of the center of curvature of the lens surface of the lens to be measured on the side opposite to the lens surface of the lens to be measured to determine the amount of eccentricity of the center of curvature of the lens surface; It is characterized in that.
[0007]
In the eccentricity measuring device according to the second aspect of the present invention, the test lens on the lens holder in the eccentricity measuring device according to the first aspect of the present invention penetrates the lens holder, the tilt adjustment mechanism, the moving mechanism, and the driving mechanism. The lens is held on the lens holder by the suction force of a vacuum suction means connected to the through hole provided.
[0008]
In the eccentricity measuring method according to the third aspect of the present invention , the parallel flat plate is held by a lens holder, the parallel flat plate is rotated, and light is irradiated on the plane of the parallel flat plate in this state. Then, the horizontal tilt of the lens holder is adjusted so that the position of the point image of the light reflected from the surface does not move, the parallel flat plate is replaced with a reference sphere, and the reference sphere is rotated. In this state, in this state, irradiate light on the surface of the reference sphere, and adjust the horizontal position of the lens holder so that the position of the point image of the light reflected from the surface does not move; The reference sphere is exchanged for a lens to be inspected and rotated, and in this state, light is irradiated to a lens surface opposite to the lens surface on the lens holder side, and reflected from the opposite lens surface. The position of the center of curvature of the lens surface is measured from the amount of movement of the point light From the measurement result, characterized in that to determine the amount of eccentricity of the center of curvature of the lens surface.
[0009]
Hereinafter, the present invention will be described in detail with reference to FIG. The eccentricity measuring apparatus shown in FIG. 1 includes a lens holder 2 for receiving a lens surface 1b of a lens 1 to be inspected, a moving mechanism 3 for moving the lens holder 2 in a horizontal direction (an arrow X or Y direction), and an arrow. Position adjustment means including a tilt adjustment mechanism 4 for adjusting the tilt (tilt adjustment) in the α direction or the arrow β direction, a spindle 5 constituting a drive mechanism for rotating and driving the lens holder 2, and above the lens holder 2. An eccentricity measuring unit 6 for measuring the amount of eccentricity of the test lens 1 with respect to the rotation axis 5 a of the spindle 5.
[0010]
In the eccentricity measuring apparatus shown in FIG. 1 described above, when the lens holder 2 is replaced, a parallel flat board (not shown in FIG. 1) is arranged on the upper surface of a new lens holder 2 and the eccentricity measuring unit 6 is used. The tilt adjustment mechanism 4 adjusts the upper surface of the lens holder 2 so that the upper surface of the lens holder 2 is perpendicular to the rotation axis 5a of the spindle 5 (so that the upper surface of the lens holder 2 is horizontal).
[0011]
Next, a reference sphere formed by a reference sphere (not shown in FIG. 1) is placed on the lens holder 2, and the center axis of the lens holder 2 is aligned with the rotation axis 5 a of the spindle 5 using the eccentricity measuring unit 6. The horizontal position of the lens holder 2 is adjusted by the moving mechanism 3 so that
[0012]
Next, by holding the test lens 1 with the lens holder 2, the center of curvature of the lens surface 1b of the test lens 1 on the lens holder 2 side is theoretically always always on the axis of the rotation shaft 5a. . Then, the spindle 5 is rotated, and the center of curvature of the lens surface 1a of the test lens 1 on the side opposite to the lens holder 2 is measured by the eccentricity measuring unit 6. In this way, the optical axis of the lens 1 to be detected is detected and used as a reference axis for the deflection of the outer shape of the lens 1 to be tested and the inclination of the aspherical axis.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 2 is a schematic perspective view of the eccentricity measuring device according to the first embodiment of the present invention, FIG. 3 is a plan view showing a state in which the test lens 1 is mounted on a lens holder 2, and FIG. FIG. 5 shows a cross section of the COD in FIG. 3, and FIG. 6 shows a cross section of the COD in FIG. 3 in a state where the parallel flat board 26 is placed on the lens holder 2. Shows a cross section of a state where the reference sphere 27 is placed on the lens holder 2.
[0014]
The eccentricity measuring apparatus according to the first embodiment of the present invention includes a lens holder 2 for receiving a spherical surface of a lens 1 to be inspected, a round ant 8 constituting a moving mechanism 3 for moving the lens holder 2 in a horizontal direction, and a round ant 8 A tilt adjustment mechanism 4 that holds the lens holder 8 so as to be movable in the horizontal direction and adjusts the tilt of the lens holder 2, a spindle 5 that constitutes a drive mechanism that rotationally drives the lens holder 2, and is disposed above the lens holder 2. And an eccentricity measuring unit 6 for measuring the amount of eccentricity of the test lens 1 with respect to the rotation shaft 5a of the spindle 5. The moving mechanism 3 and the tilt adjusting mechanism 4 constitute a position adjusting means.
[0015]
As shown in FIG. 4, the round ants 8 are placed in a recess provided at the center of the tilt plate 11 constituting the tilt adjustment mechanism 4 so as to be movable in the horizontal direction. The shift knob 9 and the compression spring 10 hold the shift knob 9 in the Y direction. The tilt plate 11 is attached to the spindle 5 by a ball joint 12 and two tilt knobs 14. A compression spring 13 is arranged between the swing knob 14 and the spindle 5 as shown in FIG.
[0016]
As shown in FIG. 4, the eccentricity measuring section 6 includes a semiconductor laser 18 for emitting a laser beam. The laser beam from the semiconductor laser 18 is converted into a parallel beam via a collimator lens 19 and is incident on a polarizing prism 20. . The transmitted light that has passed through the polarizing prism 20 is condensed at the focal position of the first condenser lens 22 through the quarter-wave plate 21, and the center of curvature of the surface 1 a to be measured in the lens 1 to be measured is focused on. If the focal position of the first condenser lens 22 is set, the transmitted light that has entered the test surface 1a is reflected by the test surface 1a and reenters the polarizing prism 20. Then, the light beam incident on the polarizing prism 20 is reflected on the polarization plane of the polarizing prism 20 and is incident on a second condenser lens 23 arranged on the side of the polarizing prism 20.
[0017]
The point image formed by the second condenser lens 23 is magnified by the magnifying lens 24, and light emitted from the magnifying lens 24 is collected on a light position detecting element 25 for detecting the center position of the magnified image. Be lighted.
[0018]
Next, the operation of the eccentricity measuring device according to the first embodiment will be described. When the lens holder 2 is replaced, as shown in FIG. 6, the parallel flat plate 26 is placed on a new lens holder 2 and the spindle 5 is rotated in the direction of the arrow shown in FIG. The two tilt knobs 14 are operated to adjust the tilt plate 11 so that the position of the point image detected by the light position detecting element 25 of the measuring unit 6 does not move.
[0019]
By such adjustment, the portion of the lens holder 2 that holds the test lens 1 is in a state perpendicular to the rotation axis 5a of the spindle 5.
[0020]
Next, as shown in FIG. 7, the parallel flat plate 26 is removed from the lens holder 2, and a reference sphere 27 forming a reference sphere is placed instead. At this time, the spherical center 27a of the reference sphere 27 is theoretically on the central axis 2a of the lens holder 2. Then, when the spindle 5 is driven to rotate in the arrow direction shown in FIG. The position of the round ant 8 in the horizontal direction (X, Y directions) is adjusted by operating. As a result, the center axis 2a of the lens holder 2 and the rotation axis 5a of the spindle 5 match.
[0021]
When the test lens 1 is held by the lens holder 2, the center of curvature of the lens surface 1 b of the test lens 1 on the lens holder 2 side is theoretically always set on the rotation axis 5 a of the spindle 5. Next, the spindle 5 is driven to rotate, and the amount of eccentricity of the lens surface 1a of the lens 1 to be inspected opposite to the lens holder 2 is imaged on the optical position detecting element 25 of the eccentricity measuring unit 6 as a point image. From the amount of movement.
[0022]
As an inherent effect of the first embodiment, since the horizontal movement and the tilt are performed by the two elements of the round dovetail 8 and the tilt plate 11, a structure that is compact in the rotation axis direction can be achieved.
[0023]
(Embodiment 2)
Embodiment 2 will be described with reference to FIG. FIG. 8 shows a cross section of the COD of FIG. 3. In the eccentricity measuring device of the second embodiment shown in FIG. 8, the same elements as those of the eccentricity measuring device of the first embodiment shown in FIG. Those having the function of are denoted by the same reference numerals.
[0024]
The eccentricity measuring apparatus according to the second embodiment shown in FIG. 8 is provided with a lens holder 2, a round dovetail 8, a tilt plate 11, a through hole 17 through which air that passes through the center position of the spindle 5 is provided, and the tilt plate. It is characterized in that an O-ring 15 for preventing air leakage is arranged between the outer periphery of the lower end of the head 11 and a portion of the spindle 5 supporting the lower end of the tilt plate 11.
[0025]
In the eccentricity measuring apparatus according to the second embodiment, the test lens 1 is placed on the lens holder 2, and a suction pipe of a vacuum generator (not shown) is connected to the through-hole 17 and vacuum-adsorbed, thereby holding the test lens 1. The measurement is performed while being held on the lens holder 2. Other operations are the same as those of the eccentricity measuring apparatus of the first embodiment.
[0026]
An inherent effect of the second embodiment is that the test lens 1 is held by vacuum suction, so that the test lens does not shift with respect to the lens holder 2 and measurement can be performed with high accuracy. Other effects are the same as those of the eccentricity measuring apparatus according to the first embodiment.
[0027]
【The invention's effect】
According to the first aspect of the present invention described above, it is not necessary to coaxially machine the center axis of the replaced lens holder with respect to the rotation axis, and it is not necessary to replace each drive mechanism. immediately coaxial axis with respect to the rotation axis, it is possible to quickly provide an eccentric measurement apparatus capable of measuring the eccentricity of the Kenre lens.
[0028]
According to the second aspect of the present invention, the test lens is held by the vacuum suction through the through-hole with respect to the lens holder, so that the test lens is not displaced with respect to the lens holder, and the position of the test lens is reduced. An eccentricity measuring device capable of accurately measuring the amount of eccentricity can be provided.
[0029]
According to the third aspect of the present invention, it is possible to provide an eccentricity measuring method capable of easily and accurately measuring the amount of eccentricity at the center of curvature of a lens to be inspected by using a plane-parallel disk and a reference sphere.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an eccentricity measuring device of the present invention.
FIG. 2 is a schematic perspective view of the eccentricity measuring device according to the first embodiment of the present invention.
FIG. 3 is a plan view showing a state where a test lens is placed on a lens holder.
FIG. 4 is a diagram showing an AOB cross section and an eccentricity measuring unit in FIG. 3;
FIG. 5 is a diagram showing a COD cross section in FIG. 3;
FIG. 6 is a cross-sectional view of a state where a parallel flat board is placed on a lens holder.
FIG. 7 is a view showing a cross section taken along the line AOB in FIG. 3 in a state where the reference sphere 27 is placed on the lens holder 2.
FIG. 8 is a schematic sectional view of an eccentricity measuring device according to a second embodiment of the present invention.
FIG. 9 is a schematic sectional view of a conventional eccentricity measuring device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Test lens 1a Lens surface 1b Lens surface 2 Lens holder 3 Moving mechanism 4 Tilt adjusting mechanism 5 Spindle 5a Rotary shaft 6 Eccentricity measuring unit 8 Round dovetail 9 Shift knob 10 Compression spring 11 Azimuth plate 12 Ball joint 13 Compression spring 14 Aori knob 26 Parallel flat board 27 Reference sphere

Claims (3)

A lens holder for holding the test lens,
A drive mechanism for rotating the lens holder,
A tilt adjustment mechanism for adjusting the horizontal tilt of the lens holder with respect to the rotation axis of the drive mechanism using a parallel flat plate,
A moving mechanism for moving the lens holder in a horizontal direction with respect to the rotation axis of the driving mechanism by using a reference sphere placed on the lens holder, and aligning the center axis of the lens holder with the rotation axis of the driving mechanism. ,
And position adjusting means having said tilt adjusting device 構及 beauty the moving mechanism,
With the lens holder holding the test lens being rotated by the driving mechanism, the position of the center of curvature of the lens surface of the test lens opposite to the lens surface on the lens holder side is measured, and the position of the lens surface is measured. An eccentricity measuring unit for determining the amount of eccentricity at the center of curvature;
An eccentricity measuring device comprising: The test lens on the lens holder is held on the lens holder by a suction force of vacuum suction means connected to a through hole provided through the lens holder, the tilt adjustment mechanism, the moving mechanism, and the driving mechanism. The eccentricity measuring device according to claim 1, wherein:   Holding the parallel flat board with a lens holder, rotating the parallel flat board, and irradiating light on the surface of the parallel flat board in this state;
  Adjust the horizontal tilt of the lens holder so that the position of the point image of the light reflected from the surface does not move,
  Replace the plane parallel plate with a reference sphere, and rotate the reference sphere,
  In this state, light is irradiated on the surface of the reference sphere,
  Adjust the horizontal position of the lens holder so that the position of the point image of the light reflected from the surface does not move,
  Replace the reference sphere with the lens to be inspected, and rotate it,
  In this state, light is applied to the lens surface on the opposite side to the lens surface on the lens holder side, and the position of the center of curvature of the lens surface is determined based on the movement amount of the point image of the light reflected from the opposite lens surface. Measure
  An eccentricity measuring method, wherein an eccentricity amount of a center of curvature of the lens surface is obtained from the measurement result.

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