JPH0613999B2 - Deviation measuring device for optical components - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an eccentricity measuring device for an optical component, and more particularly to an eccentricity amount of a lens surface, that is, an amount of deviation between a lens optical axis and a central axis on the lens surface. , And “taore”, that is, an eccentricity measuring device for an optical component that measures an inclination angle formed by the optical axis and the central axis.

[Conventional technology]

A conventional lens eccentricity measuring device is disclosed in JP-A-48-3936.
As described in Japanese Patent Laid-Open Publication No. JP-A-2003-264, the amount of eccentricity of one lens or lens system is measured by transmitted light.

As described above, conventionally, transmitted light is used to measure the amount of eccentricity, so that the amount of eccentricity on one surface of one lens or the lens molding surface of a mold used for molding a plastic lens and the " It was not possible to measure "Taore".

There is a three-dimensional measuring device as a conventional measuring device that does not use transmitted light, but since the measurement with this three-dimensional measuring device is a contact type, there is a risk that the stylus at the time of measurement may damage the lens surface. However, there is also a problem that the measurement requires a long time and the measurement efficiency is poor.

[Problems to be solved by the invention]

As described above, in the related art, since the eccentricity is measured by using the transmitted light, it is not possible to measure the eccentricity on one surface of the lens or the lens molding surface of the lens mold. Further, there is a problem that the three-dimensional measuring device is also damaged.

The present invention solves the above-mentioned problems of the prior art, and an eccentricity measuring device for an optical component capable of efficiently measuring the amount of eccentricity of one surface of a lens or the lens molding surface of a mold and "fall" in a non-contact manner. The purpose is to provide.

[Means for solving problems]

In order to achieve the above object, an eccentricity measuring device for an optical component according to the present invention includes a laser interference device having an optical axis in the Z direction and movable in the Z direction, and rotatable about the Z axis. X
And Y-direction movable and tiltable in the XZ and YZ planes for mounting and fixing the object to be measured, and the amount of movement of the sample mounting base in the X and Y directions. Each movement amount measuring device capable of measuring the above, each sample mounting table is tilted in the XZ plane and the YZ plane, each tilting knob capable of displaying the tilt amount, and the sample mounting table are mounted and fixed on the sample mounting table. Displacement of the measured object in the X direction can be measured.
A displacement measuring device provided integrally with the laser interference device,
A convergent light display device having a reference for displaying a reflected image of the converged laser light emitted from the laser interference device and converging on the surface of the object to be measured, and an interference fringe display device having a reference for displaying an outer peripheral line of the interference fringe. The eccentricity amount from the measurement amount of each movement amount measuring device in the X and Y directions when the sample mounting table is moved so that the reflected image of the converged laser beam displayed on the convergent light display device matches the reference. Then, the tilt amount of each tilt knob when the sample mounting table is tilted in the XZ plane and the YZ plane so that the outer peripheral line of the convergent laser beam displayed on the interference fringe display device becomes concentric with the reference as the center. It is designed to measure "taore".

[Examples] Before starting the description of the examples, the basic items of the present invention will be described.

The eccentricity measuring device of the optical component of the present invention is an object to be measured by using a laser interferometer in order to enable the measurement of the eccentricity of one surface of the lens which cannot be measured with transmitted light or the lens molding surface of the mold. Receives the reflected image of the laser light applied to the lens surface,
Displayed on the display device.

The sample mounting table on which the object to be measured is placed can be rotated around the optical axis of the laser interferometer, movable in a plane perpendicular to the optical axis, and tiltable out of the plane. Also,
A displacement measuring instrument capable of measuring the displacement of the object to be measured is provided integrally with the laser interferometer.

In such a configuration, when the displacement measuring device brought into contact with the side surface of the object to be measured placed on the sample mounting table is moved vertically along the optical axis direction of the laser interferometer, Correct the tilt of the sample mounting table so that the amount of displacement hardly changes. As a result, the central axis of the object to be measured and the optical axis of the laser interference device become parallel.

Next, when the sample mounting base is rotated, the sample mounting base is moved within the plane so that the scale change of the displacement measuring instrument is minimized. As a result, the central axis of the object to be measured and the optical axis of the laser interference device coincide with each other.

The amount of movement when the sample mounting table is moved is the eccentric amount so that the reflection image reflected on the display device coincides with the center position of the reference line of the cross of the display device. When the sample mounting table is tilted so that the outer peripheral lines of the interference fringes near the center of the reference line are concentric circles, the tilt is "Taore".

The present invention has been made based on the above-mentioned standard items.

Hereinafter, description will be made with reference to examples.

FIG. 1 is a side view of an eccentricity measuring device for optical parts according to an embodiment of the present invention, FIG. 2 is a plan view of the eccentricity measuring device for optical parts according to FIG. 1, and FIG. FIG. 4 is a partial side view showing a converged state and a reflected state of a laser beam emitted from a laser interference device, and FIG. 4 is a partial side view showing a positional relationship between a central axis of an object to be measured and an optical axis in FIG. , FIG. 5 is a partial side view showing the relationship between the central axis of another object to be measured (aspherical surface), the optical axis, and the "flare".

In the figure, reference numeral 1 is a laser interference device having an optical axis in the Z direction (vertical direction in FIG. 1) and equipped with a reference lens 4 for converging laser light. It is attached to a support rod 3 which is erected on a support base 14 by 2 so as to be movable in the Z direction.

Reference numeral 10 denotes a sample mounting base supported on a supporting base 14 by a supporting rod 19. The sample mounting base 10 includes a rotating base 10a rotatable about the Z axis and a Y moving base movable in the Y direction. 10B and an X moving table 10c movable in the X direction are provided so that the DUT 8 can be placed and fixed on the rotary table 10a.

Reference numeral 11 denotes a motor mounted on the sample mounting base 10 used for rotating the rotary base 10a, and 12x denotes the sample mounting base 10.
X-moving knob attached to an X-moving table 10c used to move the sample mounting table 10c in the X-direction, and Y-moving attached to a Y-moving table 10b used to move the sample mounting table 10 in the Y-direction. It is a knob.

19x is an XZ plane tilt knob that can tilt the sample mounting table 10 in the XZ plane and display the tilt amount, 19y.
Is a YZ plane tilt knob that can tilt the sample mounting table 10 in the YZ plane and display the tilt amount.

Reference numeral 7 denotes a displacement measuring device having a contact 7b capable of measuring the displacement in the X direction of the object to be measured 8 mounted and fixed on the sample mounting table 10. The displacement measuring device 7 is a laser interferometer 1 The laser interference device 1 is integrally attached to the laser interference device 1 by a support bar 6 provided in parallel with the optical axis of the laser interference device 1.

Reference numerals 13x and 13y respectively denote an X movement amount measuring device and a Y movement amount measuring device which are erected on the support base 14 and can measure the movement amounts of the sample mounting base 10 in the X and Y directions, respectively.

Reference numeral 16 denotes a converged laser beam which is emitted from the laser interference device 1 and is converged on the lens surface 9 related to the surface of the DUT 5.
a and 5b are reflection images 1 of the converged laser beam 16 respectively.
7. The convergent light display device and the interference fringe display device, each of which can display the interference fringe outer peripheral line 18, have a cross reference line.

Next, the operation of the eccentricity measuring device for optical components will be described first for the case of the object to be measured 8 whose lens surface 9 is a spherical surface.

First, the DUT 8 is mounted and fixed on the rotary table 10a of the sample mounting table 10. Next, the support arm 2 and the displacement measuring instrument arm 7 are adjusted so that the side surface of the DUT 8 is brought into contact with the tentacle 7b of the displacement measuring instrument 7.

When the support arm 2 is moved up and down along the support rod 3, the displacement display of the displacement measuring instrument 7 does not change,
The tilt of the sample mounting table 10 is corrected by adjusting the XZ plane tilt knob 19x and the YZ plane tilt knob 19y. As a result, the central axis of the DUT 8 and the optical axis of the laser interference device 1 become parallel.

The motor 11 is driven to rotate the rotary table 10a, and the X movement knobs 12x, Y are adjusted so that the displacement display of the displacement measuring device 7 becomes a predetermined value (a preset outer shape error of the object 8 to be measured, for example, 2 μm). Adjust the moving knob 12y. By this adjustment, the center axis of the outer shape of the DUT 8 and the optical axis of the laser interference device 1 are aligned in the XZ plane.

The laser interferometer 1 is turned on to operate, the reference lens 4 is adjusted, and the laser light from the laser interferometer 1 is converged on the lens surface 9 of the DUT 8 (see FIG. 3). The converged laser light 16 is reflected by the lens surface 9, and the reflected image is received by the laser interference device 1, and the converged light display device 5
a and the interference fringe display device 5b. The reflected image 17 displayed on the convergent light display device 5a of the reflected image of the convergent laser light is at the center position 15a of the cross reference line of the convergent light display device 5a shown in FIG. 3 if the lens 9 has no eccentricity. If they coincide, but the lens surface 9 is decentered, as shown in FIG. 3, the central position 15 of the cross reference line of the convergent light display device 5a
It is displayed deviating from a. The reason is that, in the case of eccentricity, the center axis of the lens surface 9 and the outer shape center axis of the object to be measured 8 do not coincide with each other. Therefore, the center axis of the lens surface 9 is naturally the laser interference at the center of the object to be measured 8. This is because it does not match the optical axis of the device 1.

Therefore, if the center axis of the lens surface 9 and the optical axis of the laser interference device 1 are aligned, they should be the same.
Does not coincide with the optical axis of the laser interferometer 1, and if they do coincide, the laser light 16 emitted from the laser interferometer 1 that completely overlaps the forward path and the return path is incident on the lens surface 9 at the incident angle. Then, since the light is reflected at the same angle to the side opposite to the central axis 21r of the lens surface 9, it deviates from the forward path and returns to the laser interferometer 1 as in 16r to receive the light.

For this reason, the reflected image 17 that should originally appear at the center position 15a of the cross reference line of the convergent light display device 5a is, as shown in FIG. 3, from the center position 15a of the cross reference line of the convergent light display device 5a. The display is shifted. Further, if the outer peripheral line of the interference fringe appearing on the interference fringe display device 5b also has an eccentricity, this converged laser beam is deviated from the outward path and is received by the laser interference device 1 to be received. A circle centered on the center position 15b of the line is not formed.

By the way, FIG. 4 shows that the centering is performed non-parallel to the center direction of the spherical surface forming the lens surface 9, and in the case of the lens of the mold product, the molding parting surface (molding take-out surface) is This is an example of a molded product formed by opening in a non-parallel manner, and since the lens surface 9 of the DUT 8 is a spherical surface, the optical axis 20 thereof is the most of the lens surface 9 as shown in FIG. It passes through a high position and is parallel to the central axis 21, and there is no "fall". Since the reflected image 17 displayed on the convergent light display device 5a is a reflected image from the center of the outer shape of the DUT 8, the center position 15a of the cross reference line of the convergent light display device 5a in FIG. From the amount of deviation from the reflection image 17,
The eccentricity amount 22 shown in the figure can be generally determined.

Then, the X moving knob 1 is adjusted so that the reflected image 17 coincides with the center position 15a of the cross reference line of the convergent light display device 5a.
The desired eccentricity amount 22 is calculated by operating the 2x, Y movement knob 12y and inputting an immediate fixed amount of the X movement amount measuring device 13x, Y movement amount measuring device 13y at that time to a microcomputer (not shown). It

Next, the case where the object 8A (see FIG. 5) whose lens surface 9A is an aspherical surface will be described.

The operation of aligning the central axis 21A of the DUT 8A and the optical axis of the laser interference device 1 is the same as that of the DUT 8 (lens surface 9 is a spherical surface) described above. Further, the laser interferometer 1 is operated so that the convergent laser display device 5a and the interference fringe display device 5b reflect the converged laser light reflected image 17 and the interference fringe display device 18 respectively.
The method of displaying is also the same.

By the way, since the lens surface 9A of the object to be measured 8A is an aspherical surface, there is only one optical axis 20A, and unlike the case of a spherical surface, the aspherical lens has an eccentricity 22A and a "fall" 23. And exist. Therefore, XZ plane tilt knob 19
Adjust "x" and YZ plane tilt knob 19y to make "Taore"
To reduce. Along with the decrease of “flare”, the reflected image 17 of the DUT 8A rotated by the motor 11 on the convergent light display device 5a and the interference fringe outer peripheral line 18 on the interference fringe display device 5b.
The circular motion centered around a turn of the ball becomes smaller, and when the "fall" disappears, the circular motion converges to a central point.

This is also the same as the case of the eccentricity amount, with the central axis of the lens surface 9,
It should be the same if the optical axis of the laser interference device 1 is the same, but the normal line of the lens surface 9 and the optical axis of the laser interference device 1 are not the same, and if they are the same, both the forward and return paths are complete. Since the laser light emitted from the laser interference device 1 overlapping with the above is deviated from the outward path and returned to the laser interference device 1 to be received, the reflected image 17 and the interference fringe display device 5b which should originally converge on one point of the converged light display device 5a. This is because the outer peripheral line 18 of the interference fringes causes a circular motion as the lens rotates. At this time, if the tilt amounts displayed on the XZ plane tilt knob 19x and the YZ plane tilt knob 19y are input to the microcomputer, "Taore" 23 is calculated.

The X-moving knob 12x and the Y-moving knob 12y are adjusted to move the sample mounting table 10, and the reflected image 17 and the interference fringe concentric circle 1
The center of 8 is made to coincide with the center positions 15a and 15b of the cross reference line of each display device. The eccentricity amount 22A is calculated by inputting the immediate fixed amounts of the X movement measuring device 13x and the Y movement amount measuring device 13y at that time to the microcomputer.

Stated concretely, the allowable value of eccentricity is usually 10 μm
By using the optical component eccentricity measuring device according to the present invention, an eccentricity amount measuring device in units of interference fringes (0.3 μm / line) is possible.

In this embodiment, the one-sided measurement of the lens has been described, but it goes without saying that the eccentricity and the “flapping” can be measured on the mold lens surface by the same method. As described above, according to the present invention, the laser beam is used for the measurement of the eccentricity of the lens single surface or the lens molding surface of the mold, which is impossible by the conventional measurement by the transmitted light. It becomes possible by using it. In addition, laser light can be used for non-contact measurement, and unlike contact-type measurement such as a three-dimensional measuring instrument, the entire lens surface can be measured at a time, which can greatly reduce the measurement time. There is an effect that surface damage due to contact of the stylus can be prevented as in the contact type.

Further, according to the present invention, since the outer shape of the object to be measured can be made parallel or coincident with the optical axis of the laser interference device 1, the eccentricity of each lens surface with respect to the outer shape of the object to be measured,
It is possible to measure "flare", and it is possible to accurately indicate the content and amount to be corrected when correcting the eccentricity of the lens molding surface of the mold.

In addition, since it is possible to separate the amount of eccentricity of the lens surface that has not been separately captured by the conventional measuring method and the "flare", it is also effective when correcting the eccentricity of the lens molding surface of the mold.

It should be noted that the calibration method of the present apparatus can be performed by using, instead of the lens, a sphere that originally does not have eccentricity and "fall", that is, a reference sphere with a predetermined accuracy.

A reference sphere is fixed to the sample mounting table 10 and a reflection image 1 of laser light is obtained.
The X moving table 10c and the Y moving table 1 are arranged so that 7 and 18 come to the center position of the cross reference line of the display devices 17 and 18.
Move 0b. When the center position of the cross reference line is met, the displacement measuring instrument 7 is finely moved vertically and horizontally to find the maximum value (or minimum value), and if it is fixed, the position is moved in the X direction from the optical axis. It is the farthest reference sphere radius position, and the plane including this radius position and the optical axis forms the XZ plane.

In this embodiment, one displacement measuring device 7 is provided, but if a plurality of displacement measuring devices 7 are attached to the support bar 6 and arranged in the Z direction (upward and downward). ,
When the central axis of the DUT 8 and the optical axis of the laser interferometer 1 are made parallel to each other, it is not necessary to move the support arm 2 up and down, which is advantageous in that the measurement efficiency is further improved.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide an eccentricity measuring device for an optical component, which is capable of efficiently measuring the eccentricity amount and “flapping” of one surface of a lens in a non-contact manner.

[Brief description of drawings]

1 is a side view of an eccentricity measuring apparatus for optical parts according to an embodiment of the present invention, FIG. 2 is a plan view of the eccentricity measuring apparatus for optical parts according to FIG. 1, and FIG. 3 is a laser in FIG. FIG. 5 is a partial side view showing a converged state and a reflected state of the laser light emitted from the interference device, FIG. 4 is a partial side view showing the positional relationship between the central axis and the optical axis of the DUT in FIG. 1, and FIG. FIG. 6 is a partial side view showing the relationship between the center axis of another object to be measured (aspherical surface), the optical axis, and “Taore”. 1 ... Laser interference device, 2 ... Support arm, 3 ... Support rod, 4 ... Reference lens, 5a ... Converging light display device, 5b ... Interference fringe display device, 6 ... Support bar, 7
...... Displacement measuring device, 7a ...... Displacement measuring device arm, 7b ......
Tactile, 8, 8a ... DUT, 9, 9A ... Lens surface,
10 ... Sample mounting table, 10a ... Rotary table, 10b ... Y
Mobile stand, 10c ... X mobile stand, 11 ... Motor, 12x
...... X movement knob, 12y …… Y movement knob, 13x…
... X movement amount measuring device, 13y ... Y movement amount measuring device, 14 ...
… Supporting stand, 19x …… XZ plane tilt knob, 19y …… Y
Z-plane tilt knob. 15a: the center position of the cross reference line of the convergent light display device,
15b ... The center position of the cross reference line of the interference fringe display device,
16 ... Laser light emitted from the laser interference device, 16
r: reflected laser light from the object to be measured, 17: reflected image of the converged laser light displayed on the convergent light display device, 18: outer peripheral line of interference fringes displayed on the interference fringe display device, 20, 20A
…… Optical axis, 21, 21r …… Central axis.

Claims (2)

[Claims] 1. A laser interference device having an optical axis in the Z direction and movable in the Z direction, and a laser interfering device rotatable about the Z axis, movable in the X and Y directions, and in the XZ and YZ planes. A sample mounting table which is capable of inclining inside and capable of mounting and fixing an object to be measured, and respective movement amount measuring devices capable of measuring the movement amounts of the sample mounting table in the X and Y directions; X mount
It is possible to measure the displacement in the X direction of each of the tilt knobs that can be tilted in the Z plane and the YZ plane and display the tilt amount, and the object to be measured mounted and fixed on the sample mounting table.
A displacement measuring device provided integrally with the laser interference device,
A convergent light display device having a reference for displaying a reflected image of the converged laser light emitted from the laser interference device and converging on the surface of the object to be measured, and an interference fringe display device having a reference for displaying an outer peripheral line of the interference fringe. The eccentricity amount from the measurement amount of each movement amount measuring device in the X and Y directions when the sample mounting table is moved so that the reflected image of the converged laser beam displayed on the convergent light display device matches the reference. Then, the tilt amount of each tilt knob when the sample mounting table is tilted in the XZ plane and the YZ plane so that the outer peripheral line of the convergent laser beam displayed on the interference fringe display device becomes concentric with the reference as the center. An eccentricity measuring device for optical parts, which measures "taore" from. 2. An eccentricity measuring device for an optical component according to claim 1, wherein a plurality of displacement measuring devices are provided in the Z direction.