JP2009097858A - Eccentricity measuring machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentricity measuring machine capable of measuring efficiently, without moving an optical system for changing the optical axis of a device, even if a focal distance of a specimen or a radius of curvature on an optical surface is changed. <P>SOLUTION: This eccentricity measuring machine 50 includes a light source part 3 for irradiating light to a test lens 5; a lens holding part 4 for positioning and holding the test lens 5 on a reference axis O for eccentricity measurement on an optical path of the light from the light source part 3; an telecentric observation optical system 6 arranged so that the optical axis P agrees with the reference axis O in order to observe light from the test lens 5 held by the lens holding part 4, and having at least an object side; a CCD camera 7 for determining a deviation amount from the reference axis O of light from the observation optical system 6; and an operation part 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an eccentricity measuring machine that measures eccentricity using an optical element as a subject.

Conventionally, various eccentricity measuring machines using optical elements such as lenses and curved mirrors as subjects have been proposed.
As such an eccentricity measuring apparatus, for example, in Patent Document 1, an inspection light beam is made incident on a test lens, and a reflection optical system is used so that the test light beam passes through the test lens through the same optical path. A lens transmission decentration measuring device for detecting the amount of transmission decentration of the lens is described.
Further, in Patent Document 2, the measurement light focused on the center of curvature of the lens surface is made incident on the lens to be tested held on the mounting table, and the inclination of the reflected light is detected. A lens eccentricity measuring device for measuring the amount of core is described.
That is, the lens eccentricity measuring apparatus of Patent Document 2 employs a reflection eccentricity measuring method.
Japanese Patent Laid-Open No. 2001-27580 JP 2005-221471 A

However, the conventional eccentricity measuring machine as described above has the following problems.
In the technique described in Patent Document 1, it is necessary to adjust the focus of the reflection optical system in order for the inspection light beam to pass through the same lens through the same optical path. In particular, if the focal length of the lens to be examined changes, it is necessary to exchange the reflective optical system or move in the optical axis direction to perform focus adjustment. Therefore, in order to enable general-purpose measurement corresponding to various focal lengths of the test lens, it is necessary to hold the reflection optical system so as to be movable in the optical axis direction.
The greater the range of movement of the reflective optical system, the greater the versatility of the eccentricity measuring machine, but the greater the range of movement, the worse the running accuracy related to the straightness of movement.For example, in the case of a range of movement of about several hundred millimeters, The deviation of the optical axis of the device caused by the movement becomes unacceptable in the eccentricity measurement. For this reason, in Patent Document 1, the eccentricity is measured with the rotation center axis of the test lens as a reference by measuring the amount of eccentricity while rotating the test lens.
Further, in the technique described in Patent Document 2, since the measurement light to be collected is incident on the lens surface at the center of curvature toward the lens to be examined, if the radius of curvature of the lens surface of the lens to be examined is changed, the light is condensed. Therefore, it is necessary to replace the condenser lens for use or move the condenser lens in the optical axis direction. For this reason, in order to perform general-purpose measurement, it is necessary to hold the condenser lens so as to be movable in the direction of the optical axis as in Patent Document 1, and the problem arises that the optical axis of the apparatus is shifted. The rotation mechanism is provided.
As described above, in both Patent Documents 1 and 2, it is necessary to hold some optical system so as to be movable in the optical axis direction in order to perform general-purpose measurement, so the optical axis of the apparatus is not stable, and the lens to be tested Is used to measure eccentricity. Therefore, there is a problem that it takes time to measure.
In addition, since the rotation mechanism of the lens to be examined is provided, there is a problem that the apparatus becomes complicated.
Although it is conceivable to adjust the optical axis of the apparatus every time the optical system is moved, there is a problem that the efficiency of measurement is deteriorated.

  The present invention has been made in view of the above problems, and without moving the optical system so as to change the optical axis of the apparatus even if the focal length of the subject or the radius of curvature of the optical surface changes. An object of the present invention is to provide an eccentricity measuring machine that can perform measurement efficiently.

In order to solve the above-described problem, the invention according to claim 1 is an eccentricity measuring device that measures eccentricity using an optical element as a subject, a light source unit that irradiates the subject with light, and the light source unit A holding unit that positions and holds the subject on a reference axis for eccentricity measurement on the optical path of light from the light source, and the reference axis for observing light from the subject held by the holding unit And an observation optical system in which at least the object side is telecentric, and observation means for determining the amount of deviation of the light emitted from the observation optical system from the reference axis. .
According to the present invention, the subject, which is positioned and held on the eccentric measurement reference axis by the holding unit, is irradiated with light from the light source unit, and the light from the subject passes through the observation optical system at least on the object side. Observe by observation means.
Since the observation optical system is telecentric on the object side, that is, the object side, only the light beam parallel to the optical axis of the observation optical system reaches the observation means among the light beams passing through the focus of the object. For this reason, the amount of deviation from the reference axis of the light emitted from the observation optical system observed on the observation means is obtained, and converted from the optical magnification of the observation optical system, so that the eccentricity of the subject with respect to a certain reference axis is obtained. The amount can be determined.
In addition, since the observation optical system is telecentric at least on the object side, the distance between the subject and the observation optical system can be arbitrarily set. For example, even if the subject is changed, the optical axis direction of the subject The decentration measurement can be performed without moving the observation optical system in accordance with the change in the shape.

According to a second aspect of the present invention, in the eccentricity measuring machine according to the first aspect, the observation optical system is a double-sided telecentric optical system.
According to the present invention, since the observation optical system is a double-sided telecentric optical system, the distance in the optical axis direction from the image-side observation means can be arbitrarily set, so that the observation means can be easily arranged.

According to a third aspect of the present invention, in the eccentricity measuring machine according to the first or second aspect, the optical magnification of the observation optical system can be switched.
According to the present invention, by switching the optical magnification of the observation optical system, an appropriate optical magnification can be selected according to the amount of decentration, so that good decentration measurement can be performed.
At this time, since the observation optical system is telecentric at least on the object side, it is possible to ignore a positional shift in the optical axis direction at least on the object side, and to simplify the switching means.

  According to the decentration measuring instrument of the present invention, since the observation optical system that is telecentric at least on the object side is used, the optical axis of the apparatus (eccentricity measuring instrument) is changed even if the focal length of the subject or the radius of curvature of the optical surface changes. There is an effect that the decentration measurement can be efficiently performed without moving the optical system.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
An eccentricity measuring machine according to the first embodiment of the present invention will be described.
FIG. 1 is a schematic front view showing a schematic configuration of an eccentricity measuring machine according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view in the axial direction of the holding unit holding the subject of the eccentricity measuring machine according to the first embodiment of the present invention. In FIG. 1, the optical axis of the light source unit 3 and the optical axis of the observation optical system 6 are adjusted so as to coincide with the optical axis P of the eccentricity measuring machine.

The eccentricity measuring machine 50 according to the present embodiment measures the eccentricity of an optical element by transmission eccentricity measurement using an optical element such as a lens or a curved mirror as a subject. Hereinafter, as an example of the optical element, an example in which the subject lens 5 including a biconvex lens is used as the subject will be described. However, the optical element is not limited to the optical element alone. For example, an optical element or an optical element group incorporated in a lens barrel or the like may be used.
As shown in FIG. 1, a schematic configuration of the eccentricity measuring device 50 includes a light source unit 3, a lens holding unit 4 (holding unit) that holds the lens 5 to be examined, an observation optical system 6, and a CCD camera 7. A monitor 9 is connected to the CCD camera 7 via a cable 8, and a calculation unit 11 is electrically connected to the CCD camera 7 and the monitor 9 via cables 10 and 12, respectively.

  The light source unit 3 irradiates the test lens 5 with light for eccentricity measurement. In the present embodiment, the light source 1 is a laser diode, and the collimating lens 2 is configured to collimate the divergent light from the light source 1 into a parallel light beam. It is comprised from these, and a parallel light beam is radiate | emitted.

The lens holding unit 4 holds the test lens 5 at a fixed position on the optical axis of the light source unit 3. In the present embodiment in which transmission eccentricity measurement is performed, the lens holding unit 4 is as shown in FIG. The cylindrical member is arranged such that the central axis O of the hole 4c penetrating in the optical axis direction with respect to the optical axis of the light source unit 3 is substantially coincident.
An optical axis that receives at least three lens surfaces 5b that are lens surfaces of the lens 5 on the light source unit 3 side at the end of the lens holding unit 4 opposite to the light source unit 3 and positions the lens surface 5b in the optical axis direction. A direction holding portion 4a and a radial direction holding portion 4b for positioning the edge surface 5c of the lens 5 to be tested in the radial direction are provided.
In this embodiment, the radial direction holding portion 4b has a diameter larger than the diameter of the hole portion 4c, and a chuck mechanism that can be fixed concentrically even when the lens 5 to be tested is replaced, for example, a mechanism such as a collet chuck is adopted. is doing.
The holding center axis of the radial holding part 4b is coaxial with the center axis O of the hole part 4c, and forms a reference axis O for eccentricity measurement.

The observation optical system 6 is arranged so that the reference axis O and the optical axis P coincide with each other in order to observe the light from the test lens 5 held by the lens holding unit 4, and at least the object side is a telecentric optical system. It is. In the present embodiment, a one-side telecentric optical system comprising an imaging lens 6a arranged on the subject lens 5 side and a pinhole 6b having an aperture hole arranged at a substantially focal position on the CCD camera 7 side of the imaging lens 6a. Is adopted.
As a result, only the light beam parallel to the optical axis P of the light incident on the imaging lens 6a from the object side (the test lens 5 side) is emitted to the image side through the pinhole 6b.

If the hole diameter of the pinhole 6b is too large, a light beam other than the component parallel to the optical axis P is transmitted and a blurred spot image is observed on the CCD camera 7, so it is preferable to make it small, but it is too small. If too much, the light quantity of the spot image becomes too small. On the other hand, if it is too small, diffraction will occur at the pinhole 6b and it will not function as a telecentric optical system.
Therefore, in the present embodiment, as one example, it is set pore size d of pinholes 6b to 10 times the Airy disk diameter d _A.
Here, the Airy disk diameter d _A is expressed by d _A = 2.44λ / NA, where NA is the numerical aperture of the imaging lens 6a and λ is the wavelength of the light source unit 3.

The CCD camera 7 observes a spot image of the transmitted light of the observation optical system 6, and an imaging surface is installed on the optical axis P at a position separated from the pinhole 6b by a certain distance.
The video signal of the CCD camera 7 is enlarged and displayed on the monitor 9 via the cable 8 so that the measurer can observe it. Further, the video signal of the CCD camera 7 is sent to the calculation unit 11 via the cable 10.

The calculation unit 11 performs image processing such as noise removal processing on the video signal from the CCD camera 7 as necessary to obtain image data including luminance values for each pixel of the image sensor and observed. Calculates the center position of the spot image on the imaging surface, calculates the distance and position on the imaging surface measured from the intersection of the optical axis P and the imaging surface, and performs an operation for conversion to the eccentric amount of the lens 5 to be examined. is there.
These calculation results can be converted into video signals and displayed on the monitor 9 via the cable 12.

  As the device configuration of the calculation unit 11, dedicated hardware may be used. In the present embodiment, a calculation program and a control program are executed by a computer having a CPU, a memory, an external storage device, an input / output interface, and the like. It is realized by executing.

  In this embodiment, alignment for aligning the optical axis P and the reference axis O is performed by fixing the positions of the CCD camera 7, the observation optical system 6 and the light source unit 3, and tilting the lens holding unit 4 with respect to the optical axis P. Alignment is performed by moving and shifting. Therefore, the lens holding unit 4 is held movably between the observation optical system 6 and the light source unit 3 by a moving mechanism such as a tilt moving stage and a shift moving stage (not shown).

If this alignment is performed only once before the start of the eccentricity measurement, it does not have to be performed for each eccentricity measurement. Therefore, in addition to the above apparatus configuration, an appropriate adjustment jig can be used together. .
Here, an example of alignment between the optical axis P and the reference axis O after matching the optical axis of the observation optical system 6 and the optical axis of the light source unit 3 will be briefly described.
First, in order to adjust the tilt of the lens holding unit 4, for example, a parallel plane plate with high parallelism is disposed on the optical axis direction holding unit 4 a of the lens holding unit 4. Then, by turning on the light source unit 3, the light beam that directly passes through the parallel plane plate and the light beam that passes through the parallel plane plate after being sequentially reflected by the upper and lower surfaces of the parallel plane plate on the imaging surface of the CCD camera 7. Generate interference fringes. Then, the tilt adjustment of the lens holding unit 4 is performed so that the interference fringes are null.
Next, in order to adjust the shift of the lens holding unit 4, for example, a ball lens having no eccentricity is disposed in the optical axis direction holding unit 4 a of the lens holding unit 4. Then, by turning on the light source unit 3, the eccentricity measurement is performed via the ball lens and the observation optical system 6, and the lens holding unit 4 is set to the optical axis P so that the eccentricity on the imaging surface of the CCD camera 7 becomes zero. The lens holder 4 is shifted and moved in the orthogonal direction.

Next, the operation of the eccentricity measuring device 50 will be described focusing on the measurement principle of the eccentricity measurement.
FIG. 3A is a schematic schematic optical path diagram in the case where the test lens has a positive refractive power and a short focal length. FIG. 3B is a schematic schematic optical path diagram when the test lens has a positive refractive power and a long focal length. FIG. 3C is a schematic schematic optical path diagram when the test lens has negative refractive power.

As shown in FIG. 1, in the light source unit 3, divergent light from the light source 1 is converted into a parallel light beam by the collimator lens 2, passes through the hole of the lens holding unit 4, and is irradiated to the lens 5 to be examined.
For example, as shown in FIG. 3A, the light transmitted through the test lens 5 is the same as the test lens 5 when the test lens 5 is a lens having a positive refractive power and a short focal length f. It is imaged at the focal point S _f in the optical path between the observation optical system 6, a diverging state, and enters the imaging lens 6a. Since the observation optical system 6 is one-side telecentric optical system, of the light connecting the real image at the focal position S _f, only the light beam parallel to the optical axis P is the pinhole 6b passes through the imaging lens 6a after transmission, CCD A spot image is reached on the observation surface I which is the imaging surface of the camera 7. In the figure, the symbol H indicates the principal point position of the lens 5 to be examined (the same applies hereinafter).
The CCD camera 7 sends a video signal to the calculation unit 11.
The arithmetic unit 11 converts the video signal sent from the CCD camera 7 into image data, detects a spot image of light transmitted through the observation optical system 6 on the imaging surface, and intersects the optical axis P and the imaging surface. Is used as the origin to determine the coordinates of the luminance center position of the spot image and the distance δ from the origin.

The distance δ is the shift amount in a plane orthogonal to the optical axis P of the focal position S _f of the lens 5 determined by ε transmission eccentricity of the lens 5, an optical magnification M of the observation optical system 6 Therefore, the following equation is satisfied.
ε = tan ⁻¹ {δ / (f · M)} (1)
Accordingly, the transmission eccentricity ε of the lens 5 to be measured is obtained by calculating the distance δ by the calculation unit 11. Also, the direction of eccentricity can be obtained from the coordinates of the luminance center position of the spot image.

The calculation unit 11 converts the information of these calculation results into a video signal, sends it to the monitor 9 via the cable 12, and displays the calculation result.
As described above, the CCD camera 7 and the calculation unit 11 according to the present embodiment constitute observation means for obtaining the shift amount δ of the light emitted from the observation optical system 6 from the reference axis O.

Further, as shown in FIG. 3B, a case is considered in which the subject is a subject lens 15 having a positive refractive power and a long focal length f. In this case, the radial holding portion 4b of the lens holding portion 4 is configured such that the holding central axis does not change even if the lens diameter changes, but the curvature of the lens surface 15b held by the optical axis direction holding portion 4a is not changed. Since the radius and the lens thickness between the lens surface 15b and the lens surface 15a generally change from the lens 5 to be examined, the principal point position H is shifted in the optical axis direction.
Light transmitted through the sample lens 15, for example, is condensed toward the focal point S _f located behind the observation plane I. In this case, convergent light having an imaging position different from that of the test lens 5 is incident on the imaging lens 6a. However, since the observation optical system 6 is a one-side telecentric optical system, only the light beam parallel to the optical axis P is used. However, after passing through the imaging lens 6 a, it passes through the pinhole 6 b and reaches the observation surface I that is the imaging surface of the CCD camera 7.
Therefore, the transmission eccentricity ε and the direction of eccentricity can be obtained in exactly the same manner as in FIG.

Further, as shown in FIG. 3C, consider a case where the subject is a subject lens 25 having negative refractive power. In this case, the radial holding portion 4b of the lens holding portion 4 is configured so that the holding central axis does not change even if the lens diameter changes, but the convex lens surface 25b held by the optical axis direction holding portion 4a. Since the curvature radius of the lens and the lens thickness between the lens surface 25b and the concave lens surface 25a generally vary from the lens 5 to be tested, the principal point position H deviates in the optical axis direction.
Light transmitted through the sample lens 25 as light scattered from the focal point S _f in the light source unit 3 side, is incident on the imaging lens 6a, since the observation optical system 6 is one-side telecentric optical system, also light Only the light beam parallel to the axis P passes through the pinhole 6b after passing through the imaging lens 6a and reaches the observation surface I which is the imaging surface of the CCD camera 7.
Therefore, the transmission eccentricity ε and the direction of eccentricity can be obtained in exactly the same manner as in FIG.

Thus, in this embodiment, since the observation optical system 6 is telecentric on the side of the test lens 5, the distance in the optical axis direction between the imaging lens 6a and the test lens 5 is in principle related to the decentration measurement. Therefore, unlike the conventional eccentricity measurement, it is not necessary to move the positions of the observation optical system 6 and the CCD camera 7 in accordance with the focal length of the lens 5 to be examined.
Therefore, since the moving mechanism in the optical axis direction can be omitted, the apparatus can be simplified.
Further, even when the measurement is performed with the test lens 5 replaced, the eccentricity measurement can be performed without changing the positional relationship between the observation optical system 6 and the lens holding unit 4. As a result, since there is no running error that occurs when the observation optical system 6 is moved by the moving mechanism, it is possible to perform decentration measurement quickly without re-adjusting the optical axis position, etc. The measurement efficiency when measuring the lenses 5 sequentially can be improved.
Further, since the positional relationship between the observation optical system 6 and the lens holding unit 4 can be fixed and the eccentricity measurement can be performed, the measurement can be performed while the reference axis O for the eccentricity measurement is constant. Therefore, for example, there is no need to perform decentration measurement while rotating the test lens 5 as in the case where the reference axis of decentration measurement is substituted with the lens central axis, and the measurement time for each test lens 5 is shortened. Can do. Also, the direction of eccentricity can be easily measured.

[Second Embodiment]
Next, an eccentricity measuring machine according to the second embodiment of the present invention will be described.
FIG. 4 is a schematic front view showing a schematic configuration of an eccentricity measuring machine according to the second embodiment of the present invention.

As shown in FIG. 4, an eccentricity measuring device 60 of the present embodiment is obtained by replacing the observation optical system 6 with an observation optical system 16 in the eccentricity measuring device 50 of the first embodiment. Hereinafter, a description will be given centering on differences from the first embodiment.
The observation optical system 16 is a double-sided telecentric optical system. In the present embodiment, as an example, the imaging lenses 16a and 16c, which are arranged from the object side so that the focal positions overlap with each other, and the aperture hole are positioned in the vicinity of the common focal position. A description will be given of an example including the arranged pinholes 16b.
The optical axis P of the observation optical system 16 is adjusted and arranged so as to be on the reference axis O, similarly to the observation optical system 6.

According to the eccentricity measuring device 60, the parallel light beam from the light source unit 3 is transmitted through the lens 5 to be tested, and only the light beam parallel to the optical axis P of the observation optical system 16 is transmitted through the pinhole 16b. The light is refracted by 16c and emitted toward the CCD camera 7 as a light beam parallel to the optical axis P.
For this reason, a spot image similar to that in the first embodiment reaches the imaging surface of the CCD camera 7 except that the light beam is incident vertically. For this reason, the eccentricity measurement can be performed as in the first embodiment.
Furthermore, according to the present embodiment, the optical magnification M of the observation optical system 6 is determined by the ratio of the focal lengths of the imaging lenses 16a and 16b, and is in the optical axis direction between the imaging surface of the CCD camera 7 and the observation optical system 16. It does not depend on distance. Therefore, even if the position of the CCD camera 7 in the optical axis direction changes with respect to the observation optical system 16, the measurement accuracy of the eccentricity measurement is not affected at all. For this reason, assembly and position adjustment of the apparatus are facilitated.

[Third Embodiment]
Next, an eccentricity measuring machine according to the third embodiment of the present invention will be described.
FIG. 5 is a schematic front view showing a schematic configuration of an eccentricity measuring machine according to the third embodiment of the present invention.

As shown in FIG. 5, the eccentricity measuring machine 70 of the present embodiment is obtained by replacing the observation optical system 16 with observation optical systems 17 and 18 in the eccentricity measuring machine 60 of the second embodiment. Hereinafter, a description will be given focusing on differences from the second embodiment.
Each of the observation optical systems 17 and 18 is a both-side telecentric optical system. For example, instead of the imaging lens 16a of the second embodiment, imaging lenses 17a and 18a are provided, respectively, and instead of the pinhole 16b, pinholes 17b and 18b are provided, respectively. Instead, an optical system including the imaging lenses 17c and 18c can be employed.
In the observation optical systems 17 and 18, the optical magnification M is changed by appropriately combining the focal lengths of the respective imaging lenses.
The observation optical systems 17 and 18 are each held by a movable holding mechanism (not shown) so as to be able to advance and retreat toward the reference axis O. Each optical axis is adjusted at each advance position during assembly, Switching operation can be performed manually or automatically so as to advance to a position corresponding to each reference axis O.

According to the eccentricity measuring device 70, the same eccentricity measurement as that of the eccentricity measuring device 60 can be performed. Further, when the amount of eccentricity is changed by changing the test lens 5, the observation optical systems 17 and 18 are switched. Since the optical magnification suitable for the amount of eccentricity can be selected, highly accurate eccentricity measurement can be performed.
In this case, since the position of the observation optical systems 17 and 18 in the optical axis direction does not affect the accuracy of the eccentricity measurement, the position of the movable holding mechanism in the direction orthogonal to the optical axis may be positioned with high accuracy. Therefore, such switching can be performed with a simple mechanism.

  In the above description, an example in which the light source unit is a parallel light source has been described. However, if the light source unit 3 is configured in this manner, the light amount that does not pass through the observation optical system 6 by matching the optical axis of the light source unit 3 with the reference axis O. However, when the light quantity of the light source unit 3 has a margin, it is not necessary to emit a strict parallel light beam.

  In the above description, as the observation optical system, a one-side telecentric optical system composed of an imaging lens and a pinhole, and a double-sided telecentric optical system composed of two imaging lenses and a pinhole disposed between them are used. However, these are merely examples, and the configuration of the telecentric optical system is not limited to these. A telecentric optical system having various configurations can be employed as necessary in order to change the aperture diameter and the optical magnification according to the amount of eccentricity of the subject and the resolution of the observation means.

In the above description, as an example of the eccentricity measurement, an example in which transmission eccentricity measurement is performed has been described. However, the present invention can also be applied to an eccentricity measuring machine that easily performs reflection eccentricity measurement. For example, by arranging a beam splitter between the subject and the observation optical system and using this beam splitter to illuminate the subject with incident light from the observation optical system side, the reflection eccentricity measurement is performed. An eccentricity measuring machine is obtained.
In addition, according to the eccentricity measuring apparatus that performs such reflection eccentricity measurement, the eccentricity of a reflection type optical element such as a curved mirror can be measured as an object in addition to an optical element such as a lens.

In the above description, the example in which the observation unit includes the CCD camera 7, the monitor 9, and the calculation unit 11 and automatically calculates the amount of eccentricity by calculation processing has been described. For example, the GUI on the monitor 9 is used. By performing a cursor operation using, etc., the measurer may specify an eccentric position from the image, and the calculation unit 11 may acquire the cursor position and calculate the deviation amount δ to obtain the eccentric amount.
Further, instead of such observation means, a transmissive or reflective screen is disposed at the position of the observation surface I, and the measurer measures the position of the bright spot on the screen, thereby obtaining the amount of eccentricity. May be.

  Further, all the constituent elements described in the above embodiments can be appropriately combined and implemented within the scope of the technical idea of the present invention, if technically possible.

It is a typical front view showing a schematic structure of an eccentricity measuring machine concerning a 1st embodiment of the present invention. It is an axial direction sectional view of a holding part holding a subject of an eccentricity measuring machine concerning a 1st embodiment of the present invention. FIG. 6 is a schematic schematic optical path diagram when a test lens has a positive refractive power and a short focal length, a positive refractive power and a long focal length, and a negative refractive power. It is a typical front view which shows schematic structure of the eccentricity measuring machine which concerns on the 2nd Embodiment of this invention. It is a typical front view which shows schematic structure of the eccentricity measuring machine which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

3 Light source part 4 Lens holding part (holding part)
5, 15, 25 Test lenses 6, 16, 17, 18 Observation optical system 7 CCD camera 9 Monitor 11 Calculation unit O Reference axis P Optical axes 50, 60, 70 Eccentricity measuring machine

Claims (3)

An eccentricity measuring device for measuring eccentricity using an optical element as a subject,
A light source unit for irradiating the subject with light;
A holding unit that positions and holds the subject on a reference axis for eccentricity measurement on an optical path of light from the light source unit;
In order to observe the light from the subject held by the holding unit, the observation optical system is arranged so that the optical axis coincides with the reference axis, and at least the object side is telecentric;
An eccentricity measuring machine comprising: observation means for obtaining a deviation amount of the light emitted from the observation optical system from the reference axis.   The decentration measuring apparatus according to claim 1, wherein the observation optical system is a double-sided telecentric optical system.   The decentration measuring apparatus according to claim 1 or 2, wherein the optical magnification of the observation optical system can be switched.

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