JP2010249543A - Eccentricity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To separately change the detection sensitivity of eccentricity amount for each detection object surface when measuring the plurality of detection object surfaces simultaneously in parallel in an eccentricity measuring device. <P>SOLUTION: The eccentricity measuring device 50 includes: an inspection light flux emitting optical system which includes an optical path branching part 5 branching the optical paths of inspection light fluxes, moving lenses 6A, 6B, 6C, an inspection light flux synthesis part synthesizing the inspection light fluxes L<SB>A</SB>, L<SB>B</SB>, L<SB>C</SB>, and a fixed lens 7 collecting the inspection light fluxes L<SB>A</SB>, L<SB>B</SB>, L<SB>C</SB>toward an inspection object lens 1; a reflected light flux branching part which branches the optical paths of reflected light fluxes L<SB>a</SB>, L<SB>b</SB>, L<SB>c</SB>at the inspection object surfaces 1a, 1b, 1c; a reflected image acquisition optical system which forms images of each reflected light flux onto a shared image surface, respectively; a camera 13 in which the imaging surfaces are arranged on the shared image surface; variable power parts 10A, 10B, 10C which change the optical variable power of the reflected image acquisition optical system for each optical path of the reflected optical flux; and an operation processing part which calculates eccentricity amounts of the inspection object surfaces 1a, 1b, 1c from the rotation loci of the reflected images obtained by the camera 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an eccentricity measuring device that measures the amount of eccentricity of a lens.

Conventionally, a lens eccentricity measuring device irradiates a test light beam focused on a spherical position of a test surface with no eccentricity on a test surface, acquires a reflected image by the reflected light beam, The amount of eccentricity was measured by converting the rotation radius of the rotation locus drawn by the reflected image when the inspection surface was rotated around the optical axis with the optical magnification of the measurement optical system. Since each light beam of the inspection light beam that is focused on the spherical center of the test surface without any eccentricity is perpendicularly incident on the test surface, the reflected image is formed in a spot shape on the image surface by the measurement optical system. The
For example, when the test lens has multiple test surfaces, such as a combination lens, it is necessary to perform the same eccentricity measurement for each test surface. There has been proposed an eccentricity measuring apparatus that acquires the respective reflected images simultaneously and improves the measurement efficiency of the eccentricity.
As such an eccentricity measuring apparatus, Patent Document 1 discloses that a light beam emitted from a light source is branched and simultaneously irradiated onto a plurality of test surfaces of a test lens, and a reflected image of each test surface is applied to one image sensor. A lens eccentricity measuring device that simultaneously measures the amount of eccentricity of each surface to be measured is described.

JP 2006-154171 A

However, the conventional eccentricity measuring apparatus as described above has the following problems.
In the technique described in Patent Document 1, when determining the amount of eccentricity of each test surface, each light beam of the inspection light beam is vertically incident on the test surface. It is constant and constant regardless of the radius of curvature. For this reason, the eccentricity detection sensitivities of the test surfaces are equal to each other.
Therefore, if there is a large difference in the amount of eccentricity of the test surface measured in parallel, there is a problem that the measurement accuracy of the test surface having the smaller eccentricity is lowered. For this reason, in order to accurately measure the amount of eccentricity of the test surface with the smaller amount of eccentricity, it is necessary to change the detection sensitivity and perform remeasurement, and thus there is a problem that the measurement efficiency deteriorates.

  The present invention has been made in view of the above problems, and when measuring a plurality of test surfaces simultaneously, the detection sensitivity of the eccentricity can be individually changed for each test surface. An object of the present invention is to provide an eccentricity measuring device.

  In order to solve the above-described problem, in the invention described in claim 1, the light source and a rotation holding unit that rotatably holds a test lens having a plurality of test surfaces are provided. Eccentricity of irradiating the rotated test lens with the inspection light beam generated by the light source, obtaining a rotation trajectory of a reflected image of the reflected light beam of the inspection light beam, and measuring the eccentricity of the plurality of test surfaces A measuring apparatus, an inspection light beam branching portion for branching an optical path of the inspection light beam from the light source into a plurality of optical paths, and a direction along the optical axis on each of the plurality of optical paths branched by the inspection light beam branching portion. A plurality of movable lenses provided so as to be movable, an inspection light beam combining unit that combines the optical paths of the inspection light beams respectively transmitted through the plurality of moving lenses so as to travel on the same optical axis, and the inspection light beam synthesis Each inspection light synthesized by the unit And an inspection light beam irradiation optical system having a fixed lens that condenses toward the test lens held by the rotation holding unit, and a plurality of optical paths of the reflected light beams on the plurality of test surfaces A reflected light beam branching unit that branches, and a reflected image acquisition optical system that forms a reflected image by the reflected light beam of each of the plurality of test surfaces branched by the reflected light beam branching unit on a common image plane, and An imaging unit in which an imaging surface is disposed on the common image plane in the reflected image acquisition optical system, and an optical magnification of at least one of the inspection light beam irradiation optical system and the reflected image acquisition optical system is set to the inspection light beam or the reflection A magnification change mechanism that changes for each optical path of the light beam, and magnification change information obtained by the magnification change mechanism. Based on the magnification change information, the plurality of objects to be covered are obtained from the rotation trajectory of each reflected image obtained by the imaging unit. Calculate the eccentricity of the surface inspection Configured to include an arithmetic processing unit for.

  According to a second aspect of the present invention, in the eccentricity measuring apparatus according to the first aspect, the reflected image acquisition optical system includes an imaging optical system capable of changing a magnification, and the zooming mechanism includes the imaging optical system. The optical magnification is changed, and the changed optical magnification information is used as the magnification change information, and the imaging magnification changing mechanism is sent to the arithmetic processing unit.

  According to a third aspect of the present invention, in the eccentricity measuring apparatus according to the first aspect, the reflected image acquisition optical system includes an imaging optical system provided so that a focal position can be adjusted, The converging position of each inspection light beam transmitted through the fixed lens by moving each moving lens of the inspection light beam irradiation optical system in the direction along the optical axis is determined from the optical ball center positions of the plurality of test surfaces. The light source is shifted in a direction along the optical axis, and a condensing position adjusting mechanism that sends information on the shift amount of each condensing position as the magnification change information to the arithmetic processing unit.

  According to a fourth aspect of the present invention, in the decentration measuring apparatus according to any one of the first to third aspects, the inspection light flux is optically reflected on the plurality of test surfaces from the optical data of the test lens. Calculating the rotation radius of the rotation trajectory of each reflected image when condensed toward the center position, and changing the rotation radius to a size within a predetermined range, and It is configured to include a zooming mechanism control unit that calculates at least one optical magnification of the reflected image acquisition optical system and controls the zooming operation of the zooming mechanism according to the optical magnification.

  According to the eccentricity measuring apparatus of the present invention, the rotation radius of the rotation trajectory of each reflected image on the test surface can be changed by the zoom mechanism, so that a plurality of test surfaces are measured simultaneously. In this case, there is an effect that the detection sensitivity of the amount of eccentricity can be individually changed for each test surface.

It is a typical schematic block diagram of the eccentricity measuring apparatus which concerns on the 1st Embodiment of this invention. It is a functional block diagram of the control unit of the eccentricity measuring apparatus which concerns on the 1st Embodiment of this invention. It is a typical schematic block diagram of the eccentricity measuring apparatus which concerns on the modification of the 1st Embodiment of this invention. It is a typical schematic block diagram of the eccentricity measuring apparatus which concerns on the 2nd Embodiment of this invention. It is a functional block diagram of the control unit of the eccentricity measuring apparatus which concerns on the 2nd Embodiment of this invention. It is a typical principle explanatory view of operation of an eccentricity measuring device concerning a 2nd embodiment of the present invention.

  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 apparatus according to a first embodiment of the present invention will be described.
FIG. 1 is a schematic configuration diagram of an eccentricity measuring apparatus according to a first embodiment of the present invention. FIG. 2 is a functional block diagram of the control unit of the eccentricity measuring apparatus according to the first embodiment of the present invention.

As shown in FIG. 1, the eccentricity measuring apparatus 50 of the present embodiment performs reflection eccentricity measurement of an optical element such as a test lens 1 that is an optical element having a plurality of test surfaces.
The number and shape of the test surfaces of the test lens 1 are not particularly limited, but in the following, as an example, the test surfaces 1a made of a convex surface and the test surface 1b made of a concave surface are bonded to the lenses 1A and 1B. An example in which the test surface 1c including a flat surface is provided in this order and is arranged or fixed to the substantially cylindrical lens frame 2 will be described.
A reference surface 2 a for positioning the central axis of the lens frame 2 is provided on the outer peripheral surface of the lens frame 2. A positioning surface 2b for positioning in the direction along the central axis of the lens frame 2 is provided on the end surface of the lens frame 2 on the side where the test surface 1c is disposed. On the inner peripheral surface of the lens frame 2, a lens mounting portion (not shown) for mounting the test lens 1 coaxially with the central axis of the lens frame 2 is provided.
The test surfaces 1a, 1b, and 1c of the test lens 1 are generally in relation to the central axis of the lens frame 2 due to manufacturing errors and pasting errors of the lenses 1A and 1B, or placement errors with respect to the lens frame 2, respectively. It is eccentric to some extent and the amount of eccentricity is also different.

The schematic configuration of the eccentricity measuring device 50 includes a spindle 3 (rotation holding unit), a light source 4, an optical path branching unit 5 (inspection beam branching unit), moving lenses 6A, 6B, 6C, a mirror 8, beam splitters 9B, 9C, and a fixed lens. 7, zoom units 10A, 10B, 10C, chopper 15, beam splitters 12A, 12B, mirror 11, camera 13 (imaging unit), and control unit 14A.
In order to input operation input necessary for the eccentricity measurement and information used for the eccentricity measurement to the control unit 14A, for example, an operation unit 14b composed of a keyboard, a mouse, etc., an image acquired by the camera 13, an eccentricity measurement result, etc. The monitor 14a to display is electrically connected.

The spindle 3 rotates the holding base portion 3a for positioning and holding the lens frame 2 around a certain rotation axis O. In the lens frame 2, the positioning surface 2b is in close contact with the holding base 3a, and the position of the lens frame 2 in the radial direction is determined by the central axis of the lens frame 2 determined from the reference surface 2a using, for example, an appropriate chuck mechanism. Is held so as to coincide with the rotation axis O of the holding table 3a.
The spindle 3 of the present embodiment is electrically connected to the control unit 14A, and the rotation operation such as the rotation speed and the rotation amount is controlled based on the control signal from the control unit 14A.

  The light source 4 generates an inspection light beam that irradiates the test surface of the test lens 1 in order to perform decentration measurement. In the present embodiment, a laser diode that generates divergent light is employed. As the oscillation wavelength of the light source 4, for example, a wavelength in an appropriate visible wavelength range can be adopted, but it is not limited to the visible wavelength range as long as it can be imaged by the camera 13 described later.

The optical path branching unit 5 branches the optical path of the inspection light beam from the light source 4 into a plurality of optical paths. In this embodiment, beam splitters 5A, 5B, and 5C are arranged in this order on the optical axis of the light source 4. Become.
Beam splitter 5A, the side as the inspection light beam L _A part of the inspection light beam from the light source 4 causes reflected (left side in FIG. 1), provided with a beam splitter surface 5a for transmitting another of the inspection light beam ing.
Beam splitter. 5B, as the inspection light beam L _B a part of the inspection light beam transmitted through the beam splitter 5A, with reflecting the inspection light beam L _A substantially the same direction, the other of the inspection light beam transmitted through the beam splitter 5A Is provided with a beam splitter surface 5b.
Beam splitter 5C is a part of the inspection light beam transmitted through the beam splitter 5B as the inspection light beam L _C, together with reflecting the inspection light beam L _A substantially the same direction, the other of the inspection light beam transmitted through the beam splitter 5B Is provided with a beam splitter surface 5c.

Moving the lens 6A is a light path of the inspection light beam L _A, it is movable in a direction along the optical axis traveling inspection light beam L _A, a lens group having a positive refractive power as a whole. Accordingly, and it is capable of changing the direction of the focusing position along the optical axis of the inspection light beam L _A.
Similarly, the movable lens 6B (6C) is an optical path of the inspection light beam _L B _{(L C),} is movable in a direction along the inspection light beam _L B _{(L C)} optical axis proceeds, positive as a whole This is a lens group having a refractive power of. Thereby, the condensing position in the direction along the optical axis of the inspection light beam L _B (L _C ) can be changed.
Therefore, the condensing position of the inspection light beam _{L A, L B, L C} is movable lens 6A, 6B, and 6C by moving individually, can be changed individually.

The moving lens 6A, 6B, 6C, the inspection light beam L _A, L _B, if changes each condensing position of the L _C, may be configured so that part of each lens group is movable.
Moreover, the moving lenses 6A, 6B, and 6C may be configured by single lenses.

Mirror 8 is disposed on the optical path of the light collected the inspection light beam L _A by moving the lens 6A, reflects the optical axis of the inspection light beam L _A, the reflected light axis is the rotational axis O and coaxial spindle 3 It is what you want to do.
Beam splitter 9B is disposed on the optical path of the inspection light beam L _B condensed by the moving lens 6B, reflects the optical axis of the inspection light beam L _B, the rotational axis O and coaxial optical axis after reflection spindle 3 so as thereby to, those comprising a beam splitter surface 9b which transmits the inspection light beam L _a reflected by the mirror 8.
Beam splitter 9C is disposed on the optical path of the inspection light beam L _C condensed by the moving lens 6C, it reflects the optical axis of the inspection light beam L _C, the rotational axis O and coaxial optical axis after reflection spindle 3 so as thereby to, those comprising a beam splitter surface 9c which transmits the inspection light beam L _B reflected by the inspection light beam L _a and the beam splitter 9B transmitted through the beam splitter 9B.

As described above, the mirror 8 and the beam splitters 9B and 9C travel along the same optical axis through the optical paths of the inspection light beams L _A , L _B and L _C transmitted through the plurality of moving lenses 6A, 6B and 6C, respectively. An inspection beam combining unit to be combined is configured.

The fixed lens 7 is arranged so that the optical axis of the lens is coaxial with the optical axes of the inspection light beams L _A , L _B , and L _C synthesized by the mirror 8 and the beam splitters 9B and 9C. It is a single lens or a lens group that collects light toward the test lens 1 held in this manner.

The moving lenses 6A, 6B, 6C, the mirror 8, the beam splitters 9B, 9C, and the fixed lens 7 described above constitute an inspection light beam irradiation optical system.
Further, the mirror 8 and the beam splitters 9B and 9C of the present embodiment allow the reflected light beams L _a , L _b , and L _{c on the} test surfaces 1a, 1b, and 1c of the test lens 1 by the fixed lens 7, respectively. Once condensed, the respective part, the inspection light beam L _a, L _B, proceed the optical path of L _C in opposite directions, each movable lens 6A, 6B, for entering the 6C, a plurality of the test surface The reflected light beam branching portion for branching the optical path of each reflected light beam into a plurality of optical paths is configured.

The zoom unit 10A is configured to form a reflection image of the test surface 1a by the reflected light beam La incident on the moving lens 6A and transmitted through the beam splitter 5A on _a fixed image plane. In the present embodiment, as an example, the imaging lenses A ₁ and A ₂ having different optical magnifications are held by the switching unit 10 a that holds each of them in a direction perpendicular to the optical axis.
The switching means 10a of the zooming unit 10A has either _one of the imaging lenses A ₁ and A ₂ facing the moving lens 6A across the beam splitter 5A and a position that is coaxial with the optical axis of the moving lens 6A ( Hereinafter, it can be selectively switched to the advancing position).
As a specific configuration of the switching unit 10a, for example, a switching movement mechanism such as a turret mechanism or a slide mechanism can be employed.
The switching unit 10a of the present embodiment is electrically connected to the control unit 14A, and switches to move any of the imaging lenses held by the switching unit 10a to the advanced position based on a control signal from the control unit 14A. In addition to performing the operation, the magnification change information of the reflected image changed by the optical magnification of the imaging lens moved to the advance position can be sent to the control unit 14A.

Further, the zoom unit 10B (10C) is reflected by the reflected light beam L _b (L _c ) incident on the moving lens 6B (6C) and transmitted through the beam splitter 5B (5C). Is formed on an image plane common to the zoom unit 10A.
The configuration of the zooming unit 10B (10C) includes imaging lenses B ₁ and B ₂ (C ₁ and C ₂ ) and switching means 10a having different optical magnifications.
The arrangement position of the zoom unit 10B (10C) is such that one of the imaging lenses B ₁ and B ₂ (C ₁ and C ₂ ) faces the moving lens 6B (6C) with the beam splitter 5B (5C) interposed therebetween. The position can be selectively switched to the advance position that is coaxial with the optical axis of the moving lens 6B (6C).

  Note that the variable magnification units 10A, 10B, and 10C each include two imaging lenses, which is an example, and may include three or more imaging lenses.

The chopper 15 guides any one of the reflected light beams L _a , L _b , and L _c that pass through the variable magnification units 10A, 10B, and 10C and is collected toward the common image plane to the common image plane. As described above, the timings of transmission and light shielding are switched with each other. For example, a mechanism such as a rotary shutter that transmits and blocks the reflected light beams L _a , L _b , and L _c can be employed.
The chopper 15 may be configured by a single mechanism having a plurality of transmission openings. However, in the following description, the chopper 15 is provided independently on each optical path of the reflected light beams L _a , L _b , and L _c . An example in which the transmission and light shielding timings are shifted by the control signal will be described.

Beam splitter 12A is condensed by the scaling unit 10A, it is disposed on the optical path of the reflected light beam L _a that passes through the chopper 15, and reflects the reflected light beam L _a, part a fixed image of the reflected light beam L _a A beam splitter surface 12a leading to the surface is provided.
Beam splitter 12B is condensed by the scaling unit 10B, it is disposed on the optical path of the reflected light beam L _b transmitted through the chopper 15, leading to certain image plane through the beam splitter 12A and a portion of the reflected light beam L _b A beam splitter surface 12b is provided.
Mirror 11 is condensed by the scaling unit 10C, is disposed on the optical path of the reflected light beam L _c transmitted through the chopper 15, a portion of the reflected light beam L _c beam splitter 12A, 12B to a certain image plane through the It is a guide.
The positional relationship between the beam splitter surfaces 12a and 12b and the mirror 11 according to the present embodiment is such that the light of the imaging lens arranged on the optical axis of the moving lenses 6A, 6B, and 6C by the zooming units 10A, 10B, and 10C, respectively. After the shaft is reflected, it is arranged to be coaxial.

  With such a configuration, the zooming units 10A, 10B, 10C, the beam splitters 12A, 12B, and the mirror 11 share a reflected image by the reflected light beam for each of the plurality of test surfaces branched by the reflected light beam branching unit. The reflected image acquisition optical system for forming an image on each image plane is configured.

The camera 13 has an imaging surface arranged on a common image plane of the reflected light beams L _a , L _b , and L _c reflected by the beam splitter surfaces 12 a and 12 b and the mirror 11, and a reflected image by these reflected light beams. Is taken.
The camera 13 is electrically connected to the control unit 14A, and can send a captured video signal to the control unit 14A.

  The functional block configuration of the control unit 14A includes a signal conversion unit 30, a storage unit 31, a measurement control unit 33, an arithmetic processing unit 32, and a display control unit 34, as shown in FIG.

  The signal conversion unit 30 converts the video signal transmitted from the camera 13 into luminance data, stores it in the storage unit 31 as two-dimensional image data for each image frame at an appropriate timing, and transmits it to the display control unit 34 It is.

  The storage unit 31 stores the two-dimensional image data sent from the signal conversion unit 30, and stores information used for the eccentricity measurement input by the operation unit 14b or the like.

The measurement control unit 33 is electrically connected to the operation unit 14b, the spindle 3, each chopper 15, and each switching unit 10a, and performs an eccentricity measurement operation of the eccentricity measurement device 50 based on an operation input input from the operation unit 14b. It is something to control.
In addition, the measurement control unit 33 selects the imaging lens that moves to the advance position based on the optical data of the lens 1 to be tested, which is input from the operation unit 14b and stored in the storage unit 31, and these imaging lenses. Each of the switching means 10a of the variable magnification units 10A, 10B, and 10C is driven so that moves to the advanced position. Information about the imaging lens moved to the advanced position or information about the magnification of the imaging lens moved to the advanced position is sent from each switching means 10a to the measurement control unit 33 as magnification change information. The magnification change information can be sent to the arithmetic processing unit 32. In the following description, it is assumed that the magnification change information is information for specifying the imaging lens moved to the advance position.

Processing unit 32, scaling unit 10A sent from the measurement control unit 33, 10B, and obtains the magnification change information by 10C, based on the scaling information, the reflected light beam L _a obtained by the camera _13, L _b, and calculates _{L c} test surface 1a from rotating loci of the reflected image due to, 1b, the eccentricity of 1c.

In such a configuration, the zoom units 10A, 10B, and 10C constitute a zoom mechanism that changes the optical magnification of the reflected image acquisition optical system for each optical path of the reflected light beam.
The variable magnification units 10A, 10B, and 10C include an imaging optical system in which the reflected image acquisition optical system can change the magnification, change the optical magnification of the imaging optical system, and change the information of the changed optical magnification. The information is an example in the case of an imaging magnification changing mechanism that is sent to the arithmetic processing unit.

  The display control unit 34 converts the image data sent from the signal conversion unit 30 into, for example, an NTSC signal and sends it to the monitor 14a, and displays the reflection image acquired by the camera 13 and its rotation locus on the monitor 14a. Or the amount of eccentricity of each test surface calculated by the arithmetic processing unit 32 is displayed on the monitor 14a.

  The device configuration of the control unit 14A may be realized by using the dedicated hardware for each function described above, but in this embodiment, the control unit 14A is configured by a computer including a CPU, a memory, an input / output interface, an external storage device, and the like. These functions are realized by executing appropriate control programs and arithmetic programs by this computer.

Next, the operation of the eccentricity measuring device 50 will be described.
First, the optical path in the eccentricity measuring apparatus 50 will be briefly described.
The divergent light beam generated by the light source 4 travels through the beam splitters 5A, 5B, and 5C sequentially. The light beam reflected by the beam splitter surface 5a of the beam splitter 5A is incident on the movable lens 6A as the inspection light beam L _A, the light beam reflected by the beam splitter surface 5b of the beam splitter 5B passes through the beam splitter 5A inspection enters the moving lens 6B as a light flux L _B, a beam splitter 5A, the light beam reflected is transmitted through 5B in the beam splitter surface 5c of the beam splitter 5C enters the moving lens 6C as the inspection light beam L _C.
The positions of the moving lenses 6A, 6B, and 6C are such that the converging positions of the inspection light beams L _A , L _B , and L _C through the fixed lens 7 are optical on the test surfaces 1a, 1b, and 1c in the direction along the optical axis, respectively. It is set to a position that is a typical ball center position.

Here, the “optical ball center position” indicates the position of the ball center on the outermost surface on the incident side of the inspection light beam such as the test surface 1a, and the test surfaces 1b and 1c. When there is an optical medium other than air and a refracting surface on the incident side of the inspection light beam, the apparent spherical center position viewed from the incident direction via these is represented.
The arrangement positions of the moving lenses 6A, 6B, 6C are optical data such as the radius of curvature, refractive index, and inter-surface distance of each optical surface of the mirror 8, the beam splitters 9B, 9C, the fixed lens 7, and the test lens 1. Is calculated in advance based on the above.

The inspection light beams L _A , L _B , and L _{C that} have passed through the moving lenses 6A, 6B, and 6C are combined on the rotation axis O of the spindle 3 by the inspection light beam combining unit including the mirror 8 and the beam splitters 9B and 9C. Then, the light passes through the fixed lens 7 as an axial light beam, and is collected by the fixed lens 7 toward the optical spherical positions of the test surfaces 1a, 1b, and 1c, respectively.
Therefore, inspection light beam _{L A,} L B, each ray of _{L C} is the test surface 1a, 1b, if there is eccentricity 1c, respectively test surface 1a, 1b, light (incident angle to normal incidence 1c is Therefore, each reflected light beam L _a , L _b , L _c travels backward in the optical path. When the surface to be inspected is decentered, it is reflected in a direction slightly different from the incident direction according to the amount of decentering, is collected by the fixed lens 7, and proceeds through the inspection light beam combining unit in the direction opposite to the incident direction. .

Part of the reflected light beams L _a , L _b , and L _c are reflected by the mirror 8 and the beam splitter surfaces 9b and 9c, respectively, are incident on the moving lenses 6A, 6B, and 6C, and are collected. A part of the light passes through the beam splitters 5A, 5B, and 5C, and a real image is formed on an image plane that is conjugate with the optical spherical positions of the test surfaces 1a, 1b, and 1c. That is, the spot-like reflected image _F A, _{respectively,} F B, _{F C} is formed.
In this state, when an operation input is performed from the operation unit 14b and the spindle 3 is rotated via the measurement control unit 33, the reflected images F _A , F according to the amount of eccentricity of the test surfaces 1a, 1b, 1c. _{B 1} and F 2 _C rotate with respect to the optical axes of the fixed lens 7 and the moving lenses 6A, 6B, and 6C provided coaxially with the rotation axis O.

The reflected luminous fluxes L _a , L _b , and L _c after the image formation are formed by the imaging lenses A ₁ , B ₁ , and C ₁ in the example of FIG. The light is transmitted, and part of each is reflected by the beam splitters 12 </ b> A and 12 </ b> B and the mirror 11 to form an image on the imaging surface of the camera 13.
At that time, the timing of the chopper 15 is controlled by the measurement control unit 33, and any one of the reflected light beams L _a , L _b , and L _c reaches the imaging surface of the camera 13 alternately, and each spot image S _a , S _b and S _c are formed.

Next, the eccentricity measurement in the eccentricity measuring device 50 will be described.
The control unit 14 </ b> A performs imaging by the camera 13 while rotating the spindle 3. Thus, the reflected image F _A by the light beam irradiated onto the test lens 1 by the inspection light beam irradiation optical _system, F _B, F _C is formed by the reflected image acquisition optical system, during the rotation of the spindle 3, the test surface 1a Depending on the amount of eccentricity of 1b and 1c, for example, a circular locus of rotation radii r _A , r _B and r _C is drawn around the optical axis and rotated.
Assuming that the optical magnifications of the zooming units 10A, 10B, and 10C are M _A , M _B , and M _C , respectively, when the imaging lenses A ₁ , B ₁ , and C ₁ are at the advanced positions, M _A = M _A1 and M _B = M _B1 and M _C = M _C1 . Thus, the reflected image _{F A, F B, F C} rotation radius _r A _of, r B, _{r C,} respectively _{M A,} M B, is converted to the rotation radius of the _{M C} times. For this reason, spot images S _a , S _b , and S _c that rotate in a circle are formed on the imaging surface of the camera 13.

Since these spot images S _a , S _b , and S _c are alternately picked up at a certain timing by the chopper 15, the image data acquired by the signal conversion unit 30 from the camera 13 can be rearranged appropriately. The rotation trajectory for each of the spot images S _a , S _b and S _c can be easily obtained. Therefore, the spot image S _a, S _b, even if overlap the rotation trajectory of the S _c, without performing such complicated image processing, so readily trajectory is separated, easily and accurately, each of the rotational radius Is calculated.
The spot images S _a , S _b , and S _c are displayed on the monitor 14a through the signal conversion unit 30 and the display control unit 34 of the control unit 14A (see FIG. 1).

The arithmetic processing unit 32 acquires rotation trajectories of the spot images S _a , S _b , and S _c by image processing, performs arithmetic processing such as circle fitting, for example, and performs rotation radii of the spot images S _a , S _b , and S _c . R _A , R _B and R _C are calculated. In the example shown in FIG. 1, the spot image _{S a,} S b, the center _O a rotational locus of _{S c,} O b, since the _{O c} are close, is depicted so as to overlap each other, operation It does not mean that the respective center positions calculated in the process match.
Then, the arithmetic processing unit 32 calculates the rotation radii r _A , r _B , and r _C of the reflected images F _A , F _B , and F _C according to the following formulas (1) to (3).

r _A = R _A / M _A (1)
r _B = R _B / M _B (2)
r _C = R _C / M _C (3)

Here, the arithmetic processing unit 32 specifies that the imaging lenses A ₁ , B ₁ , and C ₁ are arranged at the advance positions based on the magnification change information from the magnification units 10A, 10B, and 10C, and the storage unit In the above formulas (1) to (3), M _A = M _A1 , M _B = M _B1 , M _C = M from the information of the optical magnifications of the imaging lenses A ₁ , B ₁ and C ₁ stored in 31. Calculation with _C1 substituted.

Next, the arithmetic processing unit 32, a rotational radius r _A calculated from the equation (1), the optical path length of the optical system including a fixed lens 7 and the movable lens 6A reflected light beam L _a is transmitted, and the optical magnification The amount of eccentricity ε _A of the test surface 1a is calculated.
Further, the arithmetic processing unit 32 calculates the rotation radius r _B calculated from the above equation (2) from the optical path length of the optical system including the fixed lens 7 and the moving lens 6B through which the reflected light beam L _b is transmitted, and the optical magnification. An apparent amount of eccentricity ε _B ′ of the surface 1b is calculated. The eccentricity of the apparent epsilon _B ', eccentricity epsilon _A, and the optical data of subject lens 1, and calculates the eccentricity epsilon _B of the test surface 1b.
Further, the arithmetic processing unit 32 calculates the rotation radius r _C calculated from the above equation (3) from the optical path length of the optical system including the fixed lens 7 and the moving lens 6C through which the reflected light beam L _c is transmitted, and the optical magnification. The apparent amount of eccentricity ε _C ′ of the surface 1c is calculated. Then, the eccentric amount ε _c of the test surface 1 _c is calculated from the apparent eccentric amount ε _C ′, the eccentric amounts ε _A , ε _B , and the optical data of the lens 1 to be tested.
The arithmetic processing unit 32 sends the numerical data of the eccentric amounts ε _A , ε _B , and ε _c calculated in this way to the display control unit 34 and displays them on the monitor 14 a via the display control unit 34.
Thereby, the measurement of the eccentric amount regarding the test surfaces 1a, 1b, and 1c is completed.
Thus, according to the eccentricity measuring apparatus 50, the amount of eccentricity for each test surface of the test lens 1 having the three test surfaces adjacent to each other can be measured in parallel.

In this embodiment, if the scaling unit 10A, 10B, 10C of the optical magnification _{M A, M B, M C} is the assumed to have the test surface 1a, 1b, the ε constant eccentricity 1c is, respectively Are set so that the difference between the rotation radii M _A · r _A , M _B · r _B , and M _C · r _C is minimized and the maximum rotation radius is just within the range of the imaging surface of the camera 13.
This setting is calculated by the calculation processing unit 32 based on the information of the lens 1 to be examined input from the operation unit 14b and the setting condition of the decentering amount ε, and based on the calculation result, the measurement control unit 33 It is preferable to set automatically. In this case, the control unit 14A including the arithmetic processing unit 32 and the measurement control unit 33 collects the inspection light beam from the optical data of the test lens toward the optical spherical positions of the plurality of test surfaces. Calculate the rotation radius of the rotation trajectory of each reflected image, change the rotation radius to a size within a predetermined range, calculate the optical magnification of each reflected image acquisition optical system, and according to the optical magnification Thus, a zooming mechanism control unit that controls the zooming operation of the zooming mechanism is configured.

By setting in this way, the detection sensitivity with respect to the eccentricity ε is maximized in the optical magnification switching range of the zooming units 10A, 10B, and 10C, and the apparent eccentricity between the test surfaces is increased. The difference in detection sensitivity can be minimized.
Therefore, the scaling unit 10A, 10B, includes an image forming lens of various optical magnification 10C, by taking sufficiently wide optical magnification _{M A,} M B, the switching range of _{M C,} the lens configuration of the lens 1 Thus, even when the variation in the apparent amount of eccentricity becomes large, the amount of eccentricity can be measured simultaneously in a state where there is little variation in the detection sensitivity of the amount of eccentricity of each test surface.

  In actual measurement, the maximum eccentricity of the surface to be measured may be larger or smaller than the eccentricity ε. In such a case, the measurer performs an operation input for switching the optical magnification of each zooming unit from the operation unit 14b as necessary while observing the size of the rotation trajectory displayed on the monitor 14a. The detection sensitivity can be adjusted.

  As described above, according to the eccentricity measuring device 50, the rotation radius of the rotation trajectory of each reflected image on the test surface can be changed by the zoom mechanism, so that a plurality of test surfaces can be simultaneously used. When measuring in parallel, the detection sensitivity of the eccentricity can be individually changed for each surface to be measured.

Next, a modification of this embodiment will be described.
FIG. 3 is a schematic schematic configuration diagram of an eccentricity measuring apparatus according to a modification of the first embodiment of the present invention.

As shown in FIG. 3, the eccentricity measuring device 51 of the present modified example deletes the chopper 15 from the eccentricity measuring device 50 of the first embodiment, includes a control unit 14B instead of the control unit 14A, and includes the camera 13 The incident positions of the reflected light beams L _a , L _b and L _c are changed. Hereinafter, a description will be given centering on differences from the first embodiment.

The control unit 14B is obtained by deleting the control function of the chopper 15 in the control unit 14A of the first embodiment by deleting the chopper 15, and the other functional configuration and apparatus configuration are the same as those of the control unit 14A. Have
The incident positions of the reflected light beams L _a , L _b , and L _c with respect to the camera 13 divide the imaging surface into rectangular areas G _A , G _B , and G _C that do not overlap each other, and each of these rectangular areas G _A , G _B , G It is set so that the optical axis of the reflected image acquisition optical system is incident on the center of _C.
For example, the optical path by the zooming unit 10A and the optical path by the zooming unit 10B are juxtaposed in the plane of FIG. 3, and the optical path by the zooming unit 10B and the optical path by the zooming unit 10C are in the depth direction of the page of FIG. in parallel to the overlapping position, Thus, the rectangular area G _a of the imaging surface into three rectangular regions divided into four screen of the monitor _14a, G _B, be mentioned arrangement as image G _C is displayed it can.

According to this modification, the rotation trajectories of the spot images S _a , S _b , and S _c are included in the rectangular areas G _A , G _B , and G _{C with the} centers O _a , O _b , and O _c being different from each other. Can be acquired as a rotation trajectory. Therefore, the image stored in the storage unit 31 is acquired by the signal converting section 30, the rectangular area G _A by the processing unit _32, G _B, by image processing by masking each G _C, the spot image S The rotation trajectories of _a , S _b , and S _c are acquired, and the respective rotation radii can be calculated.
Therefore, the eccentricity measurement similar to that of the first embodiment can be performed without using the chopper 15.
According to this modification, since the chopper 15 is not used, the device configuration of the eccentricity measuring device 51 and the control function of the control unit 14B can be simplified.

[Second Embodiment]
An eccentricity measuring device 52 according to the second embodiment of the present invention will be described.
FIG. 4 is a schematic schematic configuration diagram of an eccentricity measuring apparatus according to the second embodiment of the present invention. FIG. 5 is a functional block diagram of a control unit of the eccentricity measuring apparatus according to the second embodiment of the present invention. FIG. 6 is a schematic principle explanatory diagram of the operation of the eccentricity measuring apparatus according to the second embodiment of the present invention.

In the decentration measuring apparatus 50 of the first embodiment, the zooming mechanism changes the optical magnification of the imaging optical system of the reflected image acquisition optical system, whereas this embodiment shown in FIGS. In the eccentricity measuring device 52, the magnification changing mechanism changes the optical magnification of the inspection light beam irradiation optical system. Thus, by changing the magnification of the inspection light beam irradiation optical system, the condensing position of the inspection light beam is changed, and the rotation radius of the rotation locus of the reflected image is changed.
As in the first embodiment, the decentration measuring device 52 can be configured to simultaneously decenter and measure the three test surfaces of the test lens 1 in order to simplify the illustration. Hereinafter, an example in which the lens 1B is deleted from the test lens 1 as the test lens and the eccentricity measurement of the lens 1A having the two test surfaces 1a and 1b is performed will be described.

The schematic configuration of the eccentricity measuring device 52 includes a spindle 3 (rotation holding unit), a light source 4, an optical path branching unit 16 (inspection beam branching unit), moving lenses 6A and 6B, condensing position adjusting mechanisms 17A and 17B, a beam splitter 22A, 9B, fixed lens 7, beam splitter 20, mirror 8, focus lens 19A, condenser lens 18A, beam splitter 21, chopper 15, camera 13 (imaging unit), focus lens 19B, condenser lens 18B, mirror 24, and control A unit 14C is provided.
The control unit 14C is electrically connected with an operation unit 14b similar to the control unit 14A of the first embodiment and a monitor 14a.
Hereinafter, a description will be given focusing on differences from the eccentricity measuring apparatus 50 of the first embodiment.

The optical path branching section 16 branches the optical path of the inspection light beam from the light source 4 into a plurality of optical paths. In this embodiment, the beam splitter 16A disposed on the optical axis of the light source 4 and the side of the beam splitter 16A And a mirror 16B disposed on the surface.
Beam splitter 16A is a part of the inspection light beam from the light source 4 is transmitted through the inspection light beam L _A, provided with a beam splitter surface 16a for reflecting the other of the inspection light beam laterally (the lower side in FIG. 4) ing.
Mirror 16B is for the inspection light beam reflected by the beam splitter surface 16a of the beam splitter 16A as the inspection light beam L _B, reflecting the inspection light beam L _A substantially the same direction.

Moving the lens 6A is by condensing position adjusting mechanism 17A, is movably held along the optical axis traveling inspection light beam L _A on the optical path of the inspection light beam L _A, thereby, along the optical axis of the inspection light beam L _A The condensing position in the direction can be changed.
Similarly, moving the lens 6B is the focusing position adjustment mechanism 17B, is held movably in the direction along the optical axis traveling inspection light beam L _B in the optical path of the inspection light beam L _B, thereby, the inspection light beam L _B The condensing position in the direction along the optical axis can be changed.
Therefore, the condensing positions of the inspection light beams L _A and L _B can be individually changed by moving the moving lenses 6A and 6B individually.

The condensing position adjusting mechanism 17A (17B) changes the condensing position of the inspection light beam L _A (L _B ), for example, by using a stepping motor having an appropriate encoder as a drive source, among the moving lenses 6A (6B). A lens moving mechanism that moves at least one lens along the optical axis.
Further, as shown in FIG. 5, the condensing position adjusting mechanism 17A (17B) is electrically connected to the control unit 14C, and the movement operation is controlled by the control signal from the control unit 14C. Position information of the moving lens 6A (6B) is sent to the control unit 14C by position detection means such as an encoder of the adjustment mechanism 17A (17B).

The beam splitter 22 </ b> _A is disposed on the optical path of the inspection light beam LA collected by the moving lens 6 </ b> _A , reflects the optical axis of the inspection light beam LA, and the reflected optical axis is coaxial with the rotation axis O of the spindle 3. The beam splitter surface 22a is provided so that
The same beam splitter 9B as that in the first embodiment is disposed between the beam splitter 22A and the fixed lens 7.

As described above, the beam splitters 22A and 9B constitute an inspection light beam combining unit that combines the optical paths of the inspection light beams L _A and L _B transmitted through the plurality of moving lenses 6A and 6B so as to travel on the same optical axis. is doing.

Fixed lens 7 has the same construction as the above-described first embodiment, the lens optical axis is beam splitter 22A, the inspection light beam L _A synthesized by _9B, is aligned with the optical axis coaxial with the L _B The inspection light beams L _A and L _B can be condensed toward the lens 1A held on the spindle 3 via the lens frame 2.

The moving lenses 6A and 6B, the beam splitters 22A and 9B, and the fixed lens 7 described above constitute an inspection light beam irradiation optical system.
In addition, the beam splitters 22A and 9B of the present embodiment are partially inspected when the reflected light beams L _a and L _{b on the} test surfaces 1a and 1b of the lens 1A are collected by the fixed lens 7, respectively. The light beams L _A and L _B travel in the opposite direction and pass through.

Beam splitter 20 is condensed by the fixed lens 7 is disposed on the optical path of the beam splitter 9B, 22A the transmitted reflected beam L _b, reflecting part of the reflected light beam L _b on the side (right side in FIG. 4) The beam splitter surface 20a is provided.
Mirror 8 is condensed by the fixed lens 7, a beam splitter 9B, is disposed on the optical path of the reflected light beam L _a that has passed through 22A, the reflected light beam L reflected beam portions reflected by the beam splitter 20 of _a L _b And is reflected in substantially the same direction.

The optical path of the reflected light beam L _a by the mirror 8 is disposed in the reflected light axis coaxial with the mirror 8, a focusing lens 19A which is movable in the direction along the optical axis, the focus lens and condensed to condensing lens 18A on the fixed image plane imaging surface is disposed in the condensed reflected light beam L _a camera 13 by 19A, and chopper 15, the reflected light beam L _a transmitted through the chopper 15 a beam splitter 21 having a beam splitter surface 21a for combining reflected light beams L _b which is reflected by the mirror 24 to be described later, and to reflect coaxially, and the camera 13 are disposed in this order.

Further, on the optical path of the reflected light beam L _b which is reflected by the beam splitter surface 20a of the beam splitter 20 is arranged on an optical axis coaxially reflected by the beam splitter surface 20a, so as to be movable in the direction along the optical axis transmitting the focus lens 19B provided, and focused to condenser lens 18B of the reflected light beam L _b which is condensed on a common image plane and the reflected light beam L _a by the focus lens 19B, a chopper 15, the chopper 15 a mirror 24 for reflecting the reflected light beam L _b on the beam splitter surface 21a of the beam splitter 21 are arranged in this order.

The chopper 15 of this embodiment is such that any one of the reflected light beams L _a and L _b transmitted through the condensing lenses 18A and 18B and condensed toward the common image plane is guided to the common image plane. In addition, the timing of transmission and light shielding is switched between each other, and the same configuration as in the first embodiment is provided, and the timing of transmission and light shielding is shifted by the control signal of the control unit 14C.

  With such a configuration, the focus lenses 19A and 19B, the condensing lenses 18A and 18B, the beam splitter 21, and the mirror 24 generate a reflected image by the reflected light beam for each of the plurality of test surfaces branched by the reflected light beam branching unit. The reflected image acquisition optical system is formed to form images on a common image plane.

The camera 13 of the present embodiment has the same configuration as that of the first embodiment, is electrically connected to the control unit 14C, and can send a captured video signal to the control unit 14C. The imaging surface is disposed on a common image plane of the reflected light beams L _a and L _b reflected by the beam splitter surface 21a and the mirror 24, respectively.

  As shown in FIG. 5, the functional block configuration of the control unit 14C is obtained by replacing the measurement control unit 33 of the control unit 14A of the first embodiment with a measurement control unit 33C. The device configuration of the control unit 14C is the same as that of the control unit 14A.

The measurement control unit 33C is electrically connected to the condensing position adjustment mechanisms 17A and 17B in place of the switching units 10a of the first embodiment, and the condensing position adjustment mechanism 17A and the switching units 10a. It differs from the measurement control unit 33 only in that the operation of 17B is controlled.
That is, the measurement control unit 33C moves the positions of the moving lenses 6A and 6B by the condensing position adjustment mechanisms 17A and 17B based on the optical data of the lens 1A input from the operation unit 14b and stored in the storage unit 31. , so the inspection light beam L _a that has passed through the fixed lens _7, the condensing position of the L _B, to be able to shift each test surface 1a, the optical respective spherical center position of 1b in the direction along the optical axis Yes.
Further, the condensing position adjusting mechanisms 17A and 17B send information on the moving positions of the movable lenses 6A and 6B to the measurement control unit 33C as magnification change information, and the measurement control unit 33C performs calculation processing on the magnification change information. It can be sent to the unit 32.

  In such a configuration, the condensing position adjusting mechanisms 17A and 17B constitute a magnification changing mechanism that changes the optical magnification of the inspection light beam irradiation optical system for each optical path of the inspection light beam.

Next, the operation of the eccentricity measuring device 52 will be described focusing on differences from the first embodiment.
FIG. 6 is a schematic principle explanatory diagram of the operation of the eccentricity measuring apparatus according to the second embodiment of the present invention.

First, the optical path in the eccentricity measuring device 52 will be briefly described.
A divergent light flux generated by the light source 4, by the optical path branching unit 16, passes through the beam splitter 16A, the inspection light beam L _A is incident on the moving lens 6A, the beam splitter surface 16a of the beam splitter 16A, reflected by the mirror 16B move It is branched into a test beam L _B entering the lens 6B.
The positions of the moving lenses 6A and 6B are such that the converging positions of the inspection light beams L _A and L _B through the fixed lens 7 are centered on the optical spherical center positions of the test surfaces 1a and 1b, respectively, in the direction along the optical axis. As described above, it is moved to a position shifted by an appropriate shift amount (including a shift amount = 0).
This is because, by moving the moving lenses 6A and 6B, each optical magnification of each inspection light beam irradiation optical system composed of the moving lens 6A and the fixed lens 7, and the moving lens 6B and the fixed lens 7 is changed for each optical path of the inspection light beam. This is equivalent to

The inspection light beams L _A and L _{B that} have passed through the moving lenses 6A and 6B are combined on the rotation axis O of the spindle 3 by the inspection light beam combining unit constituted by the beam splitters 22A and 9B, and the fixed lens 7 is used as the axial light beam. The light passes through and is irradiated on the test surfaces 1a and 1b, respectively.
At this time, the light beams of the inspection light beams L _A and L _B are perpendicular to the test surfaces 1a and 1b, respectively, if the condensing position is an optical ball center position and the test surfaces 1a and 1b are not decentered. Since the incident light beam (incident angle is 0 °), each reflected light beam L _a , L _b travels backward in the optical path. Such a reflected light beam is equivalent to a light beam emitted from the optical spherical center position of the test surface.

On the other hand, when the condensing position is shifted from the optical ball center position and the test surfaces 1a and 1b are not decentered, the light beams of the inspection light beams L _A and L _B are respectively measured according to the shift amount. The light beam is incident obliquely on the inspection surfaces 1a and 1b. In this case, for example, as indicated by broken lines in FIG. 6, the reflected light beams L _a and L _b form reflected images F _A and F _B that are real images on the optical path between the fixed lens 7 and the lens 1A, respectively. After that, the light is diverged and becomes a light beam directed toward the fixed lens 7 side.

The reflected light beams L _a and L _b incident on the fixed lens 7 are collected by the fixed lens 7, pass through the beam splitters 9 B and 22 A, and reach the beam splitter 20 and the mirror 8.
In the beam splitter 20, a part of the reflected light beam Lb is reflected by the beam splitter surface 20 a, is sequentially transmitted through the focus lens 19 </ _b > B, the condenser lens 18 </ _b > B, and the chopper 15, and is reflected by the mirror 24. Reflected by the splitter surface 21a toward the camera 13 side.
The measurer moves the focus lens 19B along the optical axis to focus the focal position of the optical system including the fixed lens 7, the focus lens 19B, and the condenser lens 18B on the reflected image F _B (see FIG. 6). by combining so that the reflected image F _B of the test surface 1b, can be imaged as a spot image S _b via the condenser lens 18B on the imaging surface of the camera 13.

Further, the mirror 8 is reflected the reflected light beam _{L a} that has passed through the beam splitter 20, the focusing lens 19A, the condenser lens 18A, chopper 15, are sequentially transmitted through the beam splitter 21 is focused on the camera 13 side.
The measurer moves the focus lens 19A along the optical axis to focus the focal position of the optical system including the fixed lens 7, the focus lens 19A, and the condenser lens 18A on the reflected image F _A (see FIG. 6). Accordingly, the reflected image F _A of the test surface 1a can be formed as _a spot image Sa on the imaging surface of the camera 13 via the condenser lens 18A.

When the test surfaces 1a and 1b are decentered, the reflected images F _A and F _B are formed at positions separated from the rotation axis O on the surface orthogonal to the optical axis according to the amount of decentering, and the spindle 3 rotates. Also draw a circular rotation trajectory.
The rotation radii of these rotation trajectories are such that the optical magnification of the inspection light beam irradiation optical system is larger than that in the case where the inspection light beams L _A and L _B are focused toward the optical spherical center of the test surfaces 1a and 1b. Since it has changed, the size of the turning radius changes. When the reflected images F _A and F _B are formed on the image side with respect to the optical spherical center position, the radius of rotation is enlarged. Therefore, as shown in FIG. 6, the rotational radius of the reflected images F _A and F _B formed on the optical path between the lens 1A and the fixed lens 7 has an eccentricity ε _A similar to that in the first embodiment. , Ε _B , the radius of rotation is increased compared to r _A and r _B.
The magnification of the rotation radius according to the shift amount of the condensing position of the moving lenses 6A and 6B is as follows: the curvature radius and the refractive index of the moving lenses 6A and 6B, the beam splitters 22A and 9B, the fixed lens 7 and the lens 1A. The calculation processing unit 32 can calculate the distance based on optical data such as the inter-surface distance.
The rotation trajectories of the reflected images F _A and F _B are the rotation trajectories of the spot images S _a and S _b on the imaging surface of the camera 13, and are displayed on the monitor 14a as in the first embodiment.

Next, the eccentricity measurement in the eccentricity measuring device 52 will be described.
The control unit 14C captures the spot images S _a and S _b by the camera 13 in the same manner as the control unit 14A of the first embodiment, and the calculation processing unit 32 rotates the locus of the spot images S _a and S _b . Rotational radii R _A ′ and R _B ′ are calculated.
Next, the arithmetic processing unit 32 in advance are calculated magnification m _A of the optical system between the reflected image F _A and the spot image S _a stored in the storage unit _31, and the reflected image F _B and the spot image S _b Rotational radii r _A ′ and r _B ′ of the reflected images F _A and F _B are calculated based on the magnification m _B of the optical system between
Next, the arithmetic processing unit 32 changes the magnification from the optical data stored in the storage unit 31 such as the test surfaces 1a and 1b, the fixed lens 7 and the moving lenses 6A and 6B, and the condensing position adjustment mechanisms 17A and 17B. Based on the information on the position of the moving lenses 6A and 6B acquired as information, the eccentricity ε _A of the test surface 1a is calculated from the rotation radius r _A ′.
Next, in addition to the same information, the arithmetic processing unit 32 calculates the amount of eccentricity ε _B of the test surface 1b from the rotation radius r _B ′ based on the value of the amount of eccentricity ε _A thus calculated.
Next, the arithmetic processing unit 32 sends the numerical data of the eccentric amounts ε _A and ε _B calculated in this way to the display control unit 34 and displays them on the monitor 14 a via the display control unit 34.
Thereby, the measurement of the eccentric amount regarding the test surfaces 1a and 1b is completed.
Thus, according to the eccentricity measuring apparatus 52, the eccentricity amount for each test surface of the lens 1A having two test surfaces adjacent to each other can be measured simultaneously.

In this embodiment, when it is assumed that the condensing positions of the inspection light beams L _A and L _B have a certain amount of eccentricity ε, the rotation of the respective spot images S _a and S _b The radii R _A ′ and R _B ′ are set to have a constant size, preferably the same size, and the larger radius of rotation is set so as to be just within the range of the imaging surface of the camera 13.
This setting is calculated by the calculation processing unit 32 based on the lens 1A information input from the operation unit 14b and the setting condition of the decentering amount ε, and the measurement control unit 33C automatically calculates based on the calculation result. It is preferable to set to. In this case, the control unit 14C including the arithmetic processing unit 32 and the measurement control unit 33C collects the inspection light beam from the optical data of the test lens toward the optical spherical positions of the plurality of test surfaces. Calculate the rotation radius of the rotation trajectory of each reflected image, change the rotation radius to a size within a predetermined range, calculate the optical magnification of the inspection light beam irradiation optical system, and according to the optical magnification Thus, a zooming mechanism control unit that controls the zooming operation of the zooming mechanism is configured.

By setting in this way, the detection sensitivity with respect to the eccentricity ε can be maximized, and the difference in the apparent eccentricity detection sensitivity between the test surfaces can be reduced to a certain range or less.
For this reason, even when the variation in the apparent amount of eccentricity increases due to the lens configuration of the lens 1A, the amount of eccentricity is measured simultaneously in a state where the variation in the detection sensitivity of the amount of eccentricity of each test surface is small. It can be performed.

In actual measurement, the maximum eccentricity of the surface to be measured may be larger or smaller than the eccentricity ε. In such a case, the measurer observes the size of the rotation trajectory displayed on the monitor 14a, and adjusts the positions of the moving lenses 6A and 6B from the operation unit 14b with the condensing position adjusting mechanisms 17A and 17B as necessary. It is also possible to adjust the detection sensitivity of the eccentricity amount by performing an operation input for changing.
Further, the detection sensitivity of the eccentric amount in the present embodiment can be changed continuously and steplessly according to the moving amount of the moving lenses 6A and 6B.

  As described above, according to the eccentricity measuring device 52, the rotation radius of the rotation trajectory of each reflected image on the test surface can be changed by the zoom mechanism, so that a plurality of test surfaces can be simultaneously used. When measuring in parallel, the detection sensitivity of the eccentricity can be individually changed for each surface to be measured.

In the above description, as an example, when three systems of the inspection light beam irradiation optical system and the reflected light beam acquisition optical system are provided corresponding to the test lens 1 having three test surfaces, two test samples are also provided. The example in the case where two systems of the inspection light beam irradiation optical system and the reflected light beam acquisition optical system are provided corresponding to the lens 1A having the surface has been described. However, even when the number of test surfaces is larger, all the measurement surfaces are measured. You may increase the system | strain of a test | inspection light beam irradiation optical system and a reflected light beam acquisition optical system to four or more systems so that it can measure simultaneously.
However, the number of surfaces to be inspected and the number of systems of the inspection light beam irradiation optical system and the reflected light beam acquisition optical system are not necessarily matched. For example, even if the configuration of the eccentricity measuring device 50 is employed when there are three or more test surfaces, the measurement is performed for each of the three test surfaces adjacent to each other, thereby making it possible to measure the test surface for each surface. Compared with the case where the eccentricity measurement is performed, the eccentricity amount can be measured more quickly.

In the description of the first embodiment, the zooming unit 10A and the like have been described as an example in which each of the imaging lenses A ₁ and A _{2 and the} like having different optical magnifications is provided. However, this is an example. Thus, the number of imaging lenses provided in each zooming unit may be set as necessary, and is not limited to two.

  In the description of the first embodiment, the example in which the imaging magnification changing mechanism changes the optical magnification step by step by switching the imaging lenses having different optical magnifications has been described. A mechanism may be employed.

In addition, all the components described in the above embodiments can be implemented in appropriate combination within the scope of the technical idea of the present invention.
For example, an imaging magnification changing mechanism for changing the optical magnification may be added to the reflected image acquisition optical system of the decentration measuring device 52.

1 Test Lens 1A Lens (Test Lens)
1a, 1b, 1c Test surface 3 Spindle (rotation holding part)
4 Light source 5 Optical path branching section (inspection light beam branching section)
6A, 6B, 6C Moving lens 7 Fixed lens 8, 11, 24 Mirror 9B, 9C, 12A, 12B, 20, 21 Beam splitter 10A, 10B, 10C Zooming unit 10a Switching means 13 Camera (imaging unit)
14A, 14B, 14C Control unit 14a Monitor 14b Operation unit 15 Chopper 16 Optical path branching unit 17A, 17B Condensing position adjusting mechanism 18A, 18B Condensing lens 19A, 19B Focus lens 31 Storage unit 32 Arithmetic processing unit 33, 33C Measurement control unit 50, 51, 52 eccentric measuring device _{A 1, A 2, B 1} , B 2, C 1, C 2 imaging lens _{F A, F B, F C} reflected image _{L A, L B, L C} inspection light beam _{L a} , _L b, _{L c} reflected light beam _{M A, M B, M C} optical magnification _{R A, R B, R C} , R A ', R B' rotation radius _{r A, r B, r C} , r A ', r _B 'Rotating radius (Rotating radius of reflected image)
S _a , S _b , S _c Spot image O Rotation axis

Claims (4)

A light source and a rotation holding unit that rotatably holds a test lens having a plurality of test surfaces, and irradiating the test lens generated by the light source onto the test lens rotated by the rotation holding unit An eccentricity measuring device that acquires a rotation trajectory of a reflected image by a reflected light beam of the inspection light beam and measures an eccentricity amount of the plurality of test surfaces,
An inspection light beam branching portion for branching the optical path of the inspection light beam from the light source into a plurality of optical paths;
A plurality of moving lenses provided so as to be movable in a direction along the optical axis on the plurality of optical paths branched by the inspection light beam branching section, and optical paths of the inspection light beams respectively transmitted through the plurality of moving lenses. An inspection light beam combining unit that combines the light beams so as to travel on the same optical axis, and the inspection light beams combined by the inspection light beam combining unit are condensed toward the test lens held by the rotation holding unit. An inspection light beam irradiation optical system having a fixed lens that
A reflected light beam branching portion for branching an optical path of each reflected light beam on the plurality of test surfaces into a plurality of optical paths;
A reflected image acquisition optical system that forms a reflected image by the reflected light beam for each of the plurality of test surfaces branched by the reflected light beam branching unit on a common image plane;
An imaging unit in which an imaging surface is arranged on the common image plane in the reflected image acquisition optical system;
A magnification changing mechanism that changes the optical magnification of at least one of the inspection light beam irradiation optical system and the reflected image acquisition optical system for each optical path of the inspection light beam or the reflected light beam;
An arithmetic processing unit that obtains magnification change information by the magnification change mechanism and calculates eccentric amounts of the plurality of test surfaces from the rotation trajectories of the reflected images obtained by the imaging unit based on the magnification change information; An eccentricity measuring device comprising: The reflected image acquisition optical system includes:
It has an imaging optical system that can change magnification,
The zoom mechanism is
2. The imaging magnification changing mechanism according to claim 1, further comprising an imaging magnification changing mechanism that changes an optical magnification of the imaging optical system and sends the changed optical magnification information as the magnification change information to the arithmetic processing unit. Eccentricity measuring device. The reflected image acquisition optical system includes:
It has an imaging optical system that can adjust the focal position,
The zoom mechanism is
The converging position of each inspection light beam transmitted through the fixed lens by moving each moving lens of the inspection light beam irradiating optical system in the direction along the optical axis, and the optical ball center position of the plurality of test surfaces 2. A condensing position adjustment mechanism that shifts from a position along the optical axis to a direction along the optical axis and sends information on a shift amount of each condensing position as the magnification change information to the arithmetic processing unit. The eccentricity measuring apparatus as described.   From the optical data of the test lens, calculate the rotation radius of the rotation trajectory of each reflected image when the inspection light beam is condensed toward the optical ball center position of the plurality of test surfaces, Is changed to a size within a predetermined range, the optical magnification of at least one of the inspection light beam irradiation optical system and the reflected image acquisition optical system is respectively calculated, and according to the optical magnification, The eccentricity measuring apparatus according to any one of claims 1 to 3, further comprising a zooming mechanism control unit that controls a zooming operation of the zooming mechanism.

Images