JP2011242544A - Reflection deflector, relative tilt measuring device, and aspherical surface lens measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection deflector, a relative tilt measuring device, and an aspherical surface lens measuring device that enable, using one measuring system, measurement of a relative tilt of two surfaces formed mutually in parallel even when the two surfaces are located at both sides of an opaque component.SOLUTION: A portion of measurement light from an interferometer 30 is directed perpendicularly to a first test surface 71 via a reflection deflector 10B, and another portion of the measurement light is directed perpendicularly to a second test surface 72 without passing through the reflection deflector 10B. Based on a first analyzing image formed with measurement light that is reflected in a retroreflective manner from the first test surface 71 back to the interferometer 30 via the reflection deflector 10B and on a second analyzing image formed with measurement light that is reflected in a retroreflective manner from the second test surface 72 back to the interferometer 30, a relative tilt of the first test surface 71 and the second test surface 72 is analyzed.

Description

  The present invention relates to a reflective deflecting element that reflects and deflects measurement light and a measuring apparatus using the reflective deflecting element, and more particularly to measuring the relative inclination of two surfaces formed in parallel to each other or an aspherical surface. A reflection deflection element suitable as an optical element used for deflecting measurement light and irradiating the surface to be measured when measuring the tilting of the lens surface, a relative tilt measuring device equipped with the reflection deflection element, and an aspheric lens measurement Relates to the device.

  Conventionally, surface deviation (relative positional deviation between the axes of two lens surfaces constituting the aspherical lens) and surface tilt (respectively of the two lens surfaces constituting the aspherical lens) caused as manufacturing errors of the aspherical lens. Various measuring methods for measuring the relative inclination deviation between axes have been proposed.

  In the case of a molded aspherical lens, a hook-like protruding portion that is perpendicular to the optical axis may be formed around the lens portion. The two surfaces that are separated from each other in the optical axis direction that constitute the projecting portion are parallel to each other when no surface tilting occurs, and relatively inclined when the surface tilting occurs. Therefore, it is possible to determine the surface tilt by measuring the relative inclination (parallelism) of the two surfaces of the overhanging portion.

  For example, in Patent Document 1 below, a method is used in which an autocollimator is used to measure the inclinations of two upper and lower surfaces of an overhanging portion with respect to a reference plane, and the relative inclinations of the two surfaces are obtained based on the measurement results. Is described.

  Patent Document 2 listed below describes a method of measuring the transmitted wavefront of the overhang using an interferometer and obtaining the relative inclination of the two upper and lower surfaces of the overhang based on the measurement result. Yes.

Japanese Patent No. 3127003 JP 2008-249415 A

  The technique described in Patent Document 1 requires measurement of two surfaces of the overhanging portion (hereinafter, one is referred to as a first surface and the other as a second surface), and thus the measurement procedure is complicated. There is a problem of becoming. Although it is conceivable that a measurement system for measuring the first surface and a measurement system for measuring the second surface are provided separately to perform the measurement of the first surface and the measurement of the second surface simultaneously, two measurement systems are required. Therefore, there arises a problem that the device configuration becomes complicated.

  The technique described in Patent Document 2 is effective when the overhanging portion is transparent, but has a problem that it cannot be applied when it is opaque. Further, the present invention cannot be applied to the case where the first surface and the second surface of the projecting portion are arranged at positions shifted from each other in a direction perpendicular to the measurement optical axis.

  Such a problem is not limited to measuring the surface tilt of the aspherical lens, but the relative inclination of two surfaces formed in parallel to each other (for example, both surfaces of a parallel plate) is measured. This also occurs in some cases.

  The present invention has been made in view of such circumstances, and the relative inclination of two surfaces formed in parallel with each other can be obtained even when the two surfaces are located on both sides of an opaque member. It is an object of the present invention to provide a reflection deflection element that can be measured by one measurement system, a relative tilt measurement device and an aspherical lens measurement device including the reflection deflection element.

  In order to achieve the above object, a reflective deflection element according to the present invention includes a first reflective surface constituted by a first right conical surface having a first apex angle, and the first reflection surface inside the first right conical surface. A second conical surface having a second apex angle that is coaxial with respect to the one conical surface and is opposite to the first apex surface and that has a second apex angle that is 180 degrees with the first apex angle. And a reflective surface.

  In the reflective deflection element according to the present invention, both the first apex angle and the second apex angle can be set to 90 degrees. An alignment reflection plane perpendicular to the axes of the first reflection surface and the second reflection surface can be provided.

The relative inclination measuring apparatus according to the present invention is a relative inclination measuring apparatus that measures the relative inclination of the first test surface and the second test surface that are formed in parallel to each other.
The aforementioned reflective deflection element according to the present invention;
The measurement light composed of parallel light is emitted, and a part of the measurement light is irradiated perpendicularly to the first test surface through the reflective deflection element, and the other part of the measurement light is A measurement system for irradiating perpendicularly to the second test surface without a reflective deflection element;
A first analysis image formed by wavefront information carried by measurement light that is retroreflected from the first test surface and returns to the measurement system via the reflective deflection element, and retroreflected from the second test surface And a relative inclination analyzing means for analyzing a relative inclination between the first test surface and the second test surface based on the second analysis image formed by the measurement light that is returned to the measurement system. It is characterized by comprising.

  The relative inclination measuring apparatus according to the present invention may include an image reconstruction unit that reconstructs the first analysis image by inverting it in the radial direction. An interferometer can be used as the measurement system.

The aspherical lens measuring apparatus according to the present invention has two lens surfaces, at least one of which is a rotating aspherical surface, and is formed in parallel with each other on one side and the other side of the two lens surfaces. An aspherical lens measuring device for measuring surface tilt and surface deviation of an aspherical lens having a first test surface and a second test surface,
The aforementioned reflective deflection element according to the present invention;
The measurement light composed of parallel light is emitted, and a part of the measurement light is irradiated perpendicularly to the first test surface through the reflective deflection element, and the other part of the measurement light is An interferometer that irradiates perpendicularly to the second test surface without a reflective deflection element;
A first analysis image formed by wavefront information carried by measurement light that is retroreflected from the first test surface and returns to the interferometer via the reflective deflection element, and retroreflected from the second test surface A surface tilt analysis means for analyzing the surface tilt of the aspheric lens based on the second analysis image formed by the measurement light returned to the interferometer;
A null optical element that retroreflects the measurement light emitted from the interferometer and transmitted through the two lens surfaces;
Based on the transmitted wavefront interference fringe image for analysis formed by measurement light retroreflected from the null optical element, transmitted again through the two lens surfaces, and returned to the interferometer, the surface deviation of the aspheric lens is analyzed. And a surface misalignment analysis means.

  The aspherical lens measurement device according to the present invention may include an image reconstruction unit that reconstructs the first analysis image by inverting it in the radial direction.

  In the present invention, the “right conical surface” means a side surface of the right cone, and the “vertical angle” means an angle twice the angle formed by the axis of the right cone and the generatrix.

  Further, the “first test surface” and the “second test surface” are not limited to planes, and include regions that can be regarded as being parallel to each other on a curved surface. For example, when two cylindrical surfaces are arranged to face each other so that the ridge lines of the respective cylindrical surfaces are parallel to each other, the region of the ridge line of one cylindrical surface is set as the first test surface and the other The area | region of the ridge line of a cylindrical surface can be made into a 2nd test surface.

  Further, “reconstructing the first analysis image by reversing in the radial direction” means that an array of pixels (strictly speaking, each density value of each pixel) constituting the first analysis image is an image center. On each half-line extending radially from the center of the image, a point at a predetermined distance from the center of the image is set as a reference point for reversal, and a pixel located in an outer region farther from the center of the image than the reference point is located at the center of the image from the reference point. The first analysis image before image processing is performed by performing image processing to change so as to be located in a near inner region or image processing to change pixels located in the inner region to be located in the outer region. Means to construct (form) a new first image for analysis having a different pixel arrangement.

  The reflective deflection element, the relative tilt measuring device, and the aspherical lens measuring device according to the present invention have the above-described features, and thus have the following effects.

  That is, according to the reflective deflection element of the present invention, the parallel light incident from the direction parallel to the conical axes of the first reflective surface and the second reflective surface is reflected on the first reflective surface at an angle equal to the first apex angle. By deflecting each of the two reflecting surfaces by an angle equal to the second apex angle, it is possible to emit light in a direction opposite to the incident direction by 180 degrees.

  Thus, even when the first test surface and the second test surface formed in parallel with each other are located on both front and back sides of the opaque member, the first test surface is measured from the measurement system located on the one test surface side. A part of the measurement light irradiated perpendicularly to the surface can be deflected by 180 degrees and irradiated perpendicularly to the other test surface, and the measurement light retroreflected from the other test surface Can be deflected 180 degrees and returned to the measurement system.

  Therefore, according to the relative inclination measuring apparatus of the present invention, even when the first test surface and the second test surface formed in parallel with each other are located on both sides of the opaque member, The relative inclination can be measured by one measuring system.

  Similarly, according to the aspherical lens measurement apparatus of the present invention, even when the first test surface and the second test surface formed in parallel to each other are located on both sides of the opaque member, The relative inclination of the surface can be measured by one measurement system, and the surface tilt of the aspherical lens can be obtained based on the measurement result.

It is a perspective view which shows schematic structure of the reflective deflection | deviation element concerning 1st Embodiment. It is sectional drawing which shows schematic structure of the reflective deflection | deviation element concerning 1st Embodiment. It is a perspective view which shows schematic structure of the reflective deflection | deviation element concerning 2nd Embodiment. It is sectional drawing which shows schematic structure of the reflective deflection | deviation element concerning 2nd Embodiment. It is a schematic block diagram of the relative inclination measuring apparatus which concerns on one Embodiment. It is a block diagram which shows the structure of the analyzer shown in FIG. It is a figure which shows the 1st image for analysis before reconstruction. It is a figure which shows the 1st image for analysis after reconstruction. It is a schematic block diagram of the aspherical lens measuring apparatus which concerns on one Embodiment. It is a schematic block diagram at the time of the surface inclination measurement of the aspherical lens measuring apparatus shown in FIG. It is a block diagram which shows the structure of the analysis control apparatus shown in FIG. It is the front view (A) and top view (B) of the aspherical lens used as a measuring object. In the explanatory diagram of the surface tilt and surface displacement of the aspherical lens ((A) is a state of only surface tilt, (B) is a state of only surface displacement, (C) is a state where both surface tilt and surface displacement occur). is there. It is a figure which shows the 1st image for analysis before reconstruction. It is a figure which shows the 1st image for analysis after reconstruction. It is a schematic block diagram which shows the measurement system of another form.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the above-mentioned drawings. In addition, each figure used for description of embodiment is rough explanatory drawing, and does not show a detailed shape and structure, The size of each member, the distance between members, etc. are changed suitably and shown. .

<First Embodiment of Reflective Deflection Element>
As shown in FIGS. 1 and 2, the reflective deflection element 10 according to the first embodiment includes a first reflective surface 11, a second reflective surface 12, and a reflective plane 13 for alignment.

The first reflecting surface 11 is configured by a first right conical surface having a _first apex angle α ₁ (see FIG. 2) of 90 degrees (a portion near the vertex P ₁ is virtually indicated by a two-dot chain line). cage, the second reflecting surface 12 is disposed on the first straight inside the conical surface with respect to a straight conical surface of the first coaxial (optical axis C ₁₀ in the drawing as a common axis) in and opposite Further, the second apex angle α ₂ (see FIG. 2) is constituted by a _second right conical surface (vertex P ₂ ) of 90 degrees. Further, the alignment reflective plane 13 is formed perpendicular to the axes of the first reflective surface 11 and the second reflective surface 12 (optical axis C ₁₀ ). The set angles of the first apex angle α ₁ and the second apex angle α ₂ are not limited to 90 degrees. α ₁ can be set to any angle X that satisfies 0 <X <180, and α ₂ can be set to an angle of (180−X) degrees accordingly. Thus, by setting the sum of the first apex angle α ₁ and the second apex angle α ₂ to be 180 degrees, the first conical surface on the plane including the optical axis C ₁₀ is set. The angle formed by the generatrix and the generatrix of the second conical surface is 90 degrees.

The reflective deflection element 10 reflects the parallel light incident on the first reflecting surface 11 along the optical axis C _10, in the first reflecting surface 11 radially inward of the optical axis C ₁₀ to deflect 90 degrees after, by reflecting to deflect 90 degrees in a direction (downward in the drawing) of the optical axis C ₁₀ in the second reflecting surface 12, it is configured to emit deflected 180 ° with respect to the incident direction of the incident light ing. Similarly, after the parallel light incident on the second reflecting surface 12 along the optical axis C _10, reflected to deflect 90 degrees radially outward of the optical axis C ₁₀ in the second reflecting surface 12, the by reflecting to deflect 90 degrees in the direction of the optical axis C ₁₀ in first reflecting surface 11 (downward in the drawing), and is configured to emit deflected 180 ° with respect to the incident direction of incident light. Further, the parallel light along the optical axis C ₁₀ incident on the alignment reflection plane 13 is configured to retroreflective.

<Second Embodiment of Reflection Deflection Element>
As shown in FIGS. 3 and 4, the reflective deflection element 10A according to the second embodiment includes a first reflective surface 11A, a second reflective surface 12A, and an alignment reflective plane 13A.

11 A of 1st reflective surfaces are comprised by the 1st right-angled cone surface ( _1st apex angle (beta) ₁ (refer FIG. 4) is 90 degree | times (the part close _| similar to the vertex _P1A is virtually shown with a dashed-two dotted line). The second reflecting surface 12A is coaxial with the first conical surface inside the first conical surface (the optical axis _C10A in the figure is a common axis) and is disposed in the opposite direction. In addition, the second apex angle β ₂ (see FIG. 4) is configured by a second right conical surface of 90 degrees (a portion near the vertex P _2A is virtually indicated by a two-dot chain line). The alignment reflection plane 13A is formed perpendicular to the axes (optical axis C _10A ) of the first reflection surface 11A and the second reflection surface 12A. The first apex angle beta ₁ and the second set angle of the apex angle beta ₂ is not limited to 90 degrees. β ₁ can be set to any angle X that satisfies 0 <X <180, and β ₂ can be set to an angle of (180−X) degrees accordingly. Thus, by setting the sum of the first apex angle β ₁ and the second apex angle β ₂ to be 180 degrees, the first right conical surface is formed on the plane including the optical axis C _10A. The angle formed by the generatrix and the generatrix of the second conical surface is 90 degrees.

The reflective deflection element 10A is reflected parallel light incident on the first reflecting surface 11A along the optical axis _{C 10A,} radially inward of the optical axis _{C 10A} in the first reflecting surface 11A to deflect 90 degrees After that, the second reflecting surface 12A is reflected so as to be deflected by 90 degrees in the direction of the optical axis _C10A (downward in the figure), so that the incident light is deflected by 180 degrees with respect to the incident direction and emitted. ing. Similarly, after the parallel light incident on the second reflecting surface 12A along the optical axis C _10A, reflected to deflect 90 degrees radially outward of the optical axis C _10A in the second reflecting surface 12A, the By reflecting on one reflecting surface 11A so as to be deflected by 90 degrees in the direction of the optical axis _C10A (downward in the figure), the incident light is deflected by 180 degrees with respect to the incident direction and emitted. The parallel light incident on the alignment reflection plane 13A along the optical axis _C10A is retroreflected.

As shown in FIGS. 1 and 2, the reflection deflecting element 10 of the first embodiment described above has the second reflecting surface 12 formed up to a region including the apex P ₂ of the second right conical surface. and it enables deflection of the incident light at a position close to the C _10. That is, the light incident on the outer edge portion of the first reflecting surface 11 can be emitted from the position close to the optical axis C ₁₀ via the second reflecting surface 12. Similarly, light incident on the second reflecting surface 12 from a position close to the optical axis C ₁₀ can be emitted via the outer edge portion of the first reflecting surface 11. This is the operational difference between the reflective deflection element 10 of the first embodiment and the reflective deflection element 10A of the second embodiment.

<Embodiment of relative tilt measuring apparatus>
The relative inclination measuring apparatus 20 shown in FIG. 5 includes a first test surface 71 formed of front and back surfaces of a parallel plate 70 such as a semiconductor wafer (held by the subject alignment adjustment stage 52 via the subject mounting table 54). The relative inclination of the second test surface 72 is measured, and includes the reflection deflecting element 10B, the interferometer 30, and the analysis unit 40. The subject mounting table 54 is formed with a first window portion 54a and a second window portion 54b each formed by a hole penetrating in the vertical direction in the figure.

The reflection deflection element 10B is of the same type as the reflection deflection element 10 described above, and includes a first reflection surface 11B and a second reflection surface 12B formed of a right conical surface having the optical axis _C10B as a common axis, and light. be provided with a perpendicular alignment for reflection plane 13B with respect to the axis C _10B, it is held by the reflective deflection element alignment stage 51.

The interferometer 30 directs the laser light source 31, the beam diameter converting lens 32, and the laser light output from the laser light source 31 through the beam diameter converting lens 32 upward in the figure on the light beam splitting surface 33a. Reflected from the beam splitter 33, the light beam from the beam splitter 33 is converted into measurement light composed of parallel light, and emitted along the measurement optical axis C ₃₀ , and the measurement light from the collimator lens 34 is converted into the measurement light. The reference standard plane 35a is bifurcated into two parts, one of which is reflected as a reference light toward the collimator lens 34 and the other is emitted toward the parallel plate 70 (held by the reference plate alignment adjustment stage 53). And). In addition, an imaging lens 36 and an imaging camera 37 (having an imaging element 38 made of a CCD, a CMOS, or the like) for capturing an interference fringe image are provided.

  The analysis unit 40 includes an analysis device 41 including a computer, a monitor device 42 that displays an interference fringe image and the like, and an input device 43 for performing various inputs to the analysis device 41. As shown in FIG. 6, the interference fringe image generation unit 44 and the relative inclination analysis unit 45 (this book) are configured by a storage unit such as a CPU and a hard disk mounted in a computer and a program stored in the storage unit. Constituting relative inclination analyzing means in the embodiment).

  The interference fringe image generation unit 44 includes an interference fringe image (first analysis image) carrying the tilt information of the first test surface 71 based on the image signal captured by the imaging camera 37 (see FIG. 5). The interference fringe image (second analysis image) carrying the tilt information of the second test surface 72 is generated, and the first analysis image is inverted and reconstructed in the radial direction. An image reconstruction unit 44a is provided.

  The relative inclination analysis unit 45 is configured so that the first test surface 71 and the second test surface 72 are relative to each other based on the generated first analysis image (reconstructed) and the second analysis image. It is configured to analyze the general inclination.

  Hereinafter, the operation of the relative inclination measuring apparatus 20 according to the present embodiment will be described. Since the alignment adjustment is performed prior to the measurement, the procedure will be briefly described first.

(Alignment adjustment)
<1> The inclination of the reference standard plate 35 is adjusted so that the reference standard surface 35a of the reference standard plate 35 is perpendicular to the measurement optical axis _C30 . This tilt adjustment is formed, for example, by installing a corner cube (not shown) on the reference standard surface 35a and irradiating measurement light, and reflected light from the corner cube and reflected light from the reference standard surface 35a. This is performed using the reference plate alignment adjustment stage 53 so that the interference fringe image is in a null fringe state.

<2> The inclination of the parallel plate 70 is adjusted so that the parallel plate 70 is perpendicular to the measurement optical axis _C30 . This tilt adjustment is performed, for example, by irradiating the second test surface 72 of the parallel plate 70 with the measurement light via the reference standard plate 35, and the reflected light from the second test surface 72 and the reflection from the reference standard surface 35a. The object alignment adjustment stage 52 is used so that the interference fringe image formed by the light (reference light) is in a null fringe state.

<3> As the optical axis _{C 10B} of the reflective deflection element 10B is parallel to the measurement optical axis _{C 30,} adjusts the inclination of the reflective deflection element 10B. This tilt adjustment is performed by, for example, irradiating measurement light onto the alignment reflection plane 13B of the reflective deflection element 10B via the reference standard plate 35, and reflecting light from the alignment reflection plane 13B and reflection light from the reference standard surface 35a. The reflection deflection element alignment adjustment stage 51 is used so that the interference fringe image formed by (reference light) becomes a null fringe state.

  Note that if the alignment cannot be completely adjusted by such alignment adjustment, it is preferable to obtain the remaining alignment error and correct the measurement error due to the alignment error at the time of analysis.

  After alignment adjustment, the relative inclination of the first test surface 71 and the second test surface 72 of the parallel plate 70 is measured. Hereinafter, the operation during the measurement will be described.

(Function during measurement)
<1> Laser light is emitted from the laser light source 31 shown in FIG. This laser light enters the beam splitter 33 through the beam diameter conversion lens 32.

  <2> The laser light incident on the beam splitter 33 is reflected upward in the figure on the light beam splitting surface 33 a of the beam splitter 33 and enters the collimator lens 34. The light beam incident on the collimator lens 34 is converted into parallel light and emitted toward the reference standard plate 35.

  <3> The light beam incident on the reference standard plate 35 is split into reference light that is retroreflected and measurement light that is transmitted through the reference standard surface 35a.

  <4> A part of the measurement light transmitted through the reference reference surface 35a passes through the first window portion 54a of the subject mounting table 54 and enters the first reflection surface 11B of the reflection deflection element 10B, and the first reflection. By sequentially reflecting on the surface 11B and the second reflecting surface 12B, the surface is deflected by 180 degrees and irradiated perpendicularly to the first test surface 71 of the parallel plate 70.

  <5> On the other hand, the other part of the measurement light transmitted through the reference reference surface 35a passes through the second window portion 54b of the subject mounting table 54, and passes through the second plate portion 54 of the parallel plate 70 without passing through the reflective deflection element 10B. 2 Irradiated perpendicularly to the test surface 72.

  <6> The measurement light irradiated on the first test surface 71 via the reflective deflection element 10B is retroreflected from the first test surface 71 (at this time, the measurement light is tilted on the first test surface 71). Is incident on the second reflecting surface 12B of the reflective deflecting element 10B (which carries wavefront information in accordance with the above), and is sequentially reflected by the second reflecting surface 12B and the first reflecting surface 11B, thereby being deflected by 180 degrees, and the original optical path Is substantially reversely moved to enter the reference standard surface 35a and is combined with the reference light to form interference light (hereinafter referred to as “first interference light”).

  <7> On the other hand, the measurement light irradiated on the second test surface 72 is retroreflected from the second test surface 72 (at this time, the measurement light has wavefront information corresponding to the inclination of the second test surface 72). Carried by the light source, and substantially reversely travels along the original optical path and enters the reference standard surface 35a, and is combined with the reference light to form interference light (hereinafter referred to as “second interference light”).

  <8> The first interference light is incident on the imaging lens 36 via the collimator lens 34 and the beam splitter 33, and is condensed on the imaging element 38 of the imaging camera 37 by the imaging lens 36 to be interference fringes. An image (hereinafter referred to as “first interference fringe image”) is formed. The formed first interference fringe image is picked up by the image pickup camera 37, and the image signal is output to the interference fringe image generation unit 44 (see FIG. 6).

  <9> Similarly, the second interference light enters the imaging lens 36 via the collimator lens 34 and the beam splitter 33, and is condensed on the imaging element 38 of the imaging camera 37 by the imaging lens 36. Thus, an interference fringe image (hereinafter referred to as “second interference fringe image”) is formed. The formed second interference fringe image is picked up by the image pickup camera 37, and the image signal is output to the interference fringe image generation unit 44. In the present embodiment, the first interference fringe image is formed on a ring-shaped region on the image sensor 38, and the second interference fringe image is formed inside the ring-shaped region. The first interference fringe image and the second interference fringe image can be captured simultaneously.

  <10> Based on the image signal input to the interference fringe image generation unit 44, the interference fringe image generation unit 44 uses the first analysis image (an image obtained by digitizing the first interference fringe image) and the second analysis image (the first analysis image). 2, an image obtained by digitizing the interference fringe image) is generated, and the image data (hereinafter, the image data of the first analysis image is “first analysis image data” and the image data of the second analysis image is “second”. Analysis image data ”) is input to the relative inclination analysis unit 45 described above. Note that, since the first interference fringe image is captured through the reflective deflection element 10B, when the first analysis image is generated based on the image data, the first interference fringe image is normally captured as shown in FIG. In contrast to the interference fringe image, the interference fringe image is inverted in the radial direction. Therefore, the image reconstruction unit 44a reconstructs the first analysis image by inverting it in the radial direction, and uses the image data of the first analysis image (see FIG. 8) after the reconstruction for the first analysis. Output as image data.

Specifically, the reconstruction of the first analysis image is performed according to the following procedure. First, in the first analysis image before reconstruction, a point at a predetermined distance e from the image center O is set as a reversal reference point on each half line extending radially from the image center O. FIG. 7 shows a circle E formed by connecting one half line R and a reference point of inversion on each half line. Hereinafter, the reference point of inversion will be described as a circle E. Then, the image is reconstructed by performing image processing for changing the pixels located in the outer region of the circle E to be located in the inner region of the circle E on each half line. In FIG. 7, on the half line R, the pixels located at the two points K ₁ and K ₂ outside the circle E are rearranged at the two points K ′ ₁ and K ′ ₂ inside the circle E, respectively. Illustrated.

Note that the points K ₁ and K ′ ₁ have the same distance from the circle E on the half line R (the same applies to the points K ₂ and K ′ ₂ ). This is a straight cone apex angle (corresponding to alpha ₁ in FIG. 2) and the right circular cone apex angle of which constitutes a second reflecting surface 12B which constitute the first reflecting surface 11B (corresponding to the alpha ₂ in FIG. 2) are both This is because it is set to 90 degrees. When each vertex angle is set to an angle different from 90 degrees, the ratio of each distance from the circle E between the point K ₁ and the point K ′ ₁ is appropriately determined according to the set angle. (The same applies to the point K ₂ and the point K ′ ₂ ). Further, in FIG. 7, the pixels located in the region outside the reversal reference point (circle E) are changed so as to be located in the inner region. In some cases, the pixels located in this area are changed so as to be located in the outer area. For example, instead of the parallel plate 70, the relative inclination of the front and back surfaces (first test surface and second test surface) of a parallel plate (not shown) having an opening in the center (region near the optical axis) is determined. When measuring, the measurement light emitted from the second test surface side is passed through the second reflection surface 12B and the first reflection surface 11B of the reflection deflection element 10B in this order by passing through the opening at the center of the parallel plate. In this case, when the first test surface is irradiated, the first analysis image formed at that time is inverted and reconstructed.

  <11> Based on the first analysis image data and the second analysis image data input to the relative inclination analysis unit 45, the analysis is performed in the relative inclination analysis unit 45, and the first test surface of the parallel plate 70 The relative inclination of 71 and the second test surface 72 is obtained. Specifically, by analyzing the first analysis image after reconstruction (a normal fringe analysis method can be applied), the inclination of the first test surface 71 with respect to the reference reference surface 35a is obtained, By analyzing the second analysis image, the inclination of the second test surface 72 with respect to the reference standard surface 35a is obtained. Then, based on the inclinations of the first test surface 71 and the second test surface 72 with respect to the reference standard surface 35a, the relative inclinations of the test surface 71 and the second test surface 72 are obtained.

<Embodiment of Aspherical Lens Measuring Device>
The aspherical lens measuring apparatus 25 shown in FIG. 9 measures the surface tilt and the surface deviation of the aspherical lens 90 (held by the subject alignment adjustment stage 52A via the lens mounting table 55), and reflects it. A deflection element 10C, an interferometer 30A, an analysis unit 40A, and a null optical element 60 are provided. The lens mounting table 55 includes a first window portion 55a, a second window portion 55b (see FIG. 10), and a third window portion 55c (see FIG. 9) each formed by a hole penetrating in the vertical direction in the drawing. Is formed.

  As shown in FIG. 12, the aspheric lens 90 includes a lens portion 91 having two lens surfaces (a first lens surface 91a and a second lens surface 91b), at least one of which is a rotating aspheric surface, and the lens portion. It has an overhang portion 92 formed like a bowl on the outer periphery of 91. In the present embodiment, the overhang portion 92 is configured to be opaque with respect to the measurement light, and a first test surface in which the upper surface of the overhang portion 92 in the drawing is formed on the first lens surface 91a side. 92a, and a second test surface 92b (designed parallel to the first test surface 92a) in which the lower surface of the overhanging portion 92 in the drawing is formed on the second lens surface 91b side. Has been.

In the present embodiment, as shown in FIG. 13A, the central axis C _{91a of} the first lens surface 91a (determined by the aspherical expression of the first lens surface 91a) and the second lens surface 91b. the central axis _{C 91b} relative tilt angle gamma (two central axes _C 91a and (as determined by the aspheric expression of the second lens surface _91b), the angle between the _{C 91b} of; two central axes _{C 91a,} C _{When 91b} does not cross each other, the angle formed by each direction vector is defined as the surface tilt of the aspherical lens 90. The first lens surface 91a and its center axis C _91a are inclined with the center point Q ₁ of the first lens surface 91a (the intersection of the center axis C _91a and the first lens surface 91a) as the rotation center, and the second lens surface It is assumed that 91b and its center axis C _91b are inclined with the center point Q ₂ of the second lens surface 91b (the intersection of the center axis C _91b and the second lens surface 91b) as the rotation center.

Further, as shown in FIG. 13 (B), in the present embodiment, the relative positional deviation d (the central axis of the central axis _{C 91b} of the center axis _{C 91a} and the second lens surface 91b of the first lens surface 91a (C _91a and C _91b are parallel to each other) is defined as a surface deviation of the aspheric lens 90.

Further, as shown in FIG. 13C, when both the surface tilt and the surface deviation occur in the aspherical lens 90, the surface tilt is removed from the state shown in FIG. 13C (first lens). the surface 91a and the central axis _{C 91a,} and the center point _{Q 1} is rotated about the two central axes _{C 91a,} remains in the state) which is adapted _{C 91b} are parallel to each other, the two central axes _{C 91a} , C _91b is defined as the surface displacement of the aspherical lens 90.

The reflection deflection element 10C is of the same type as the reflection deflection element 10A described above. As shown in FIG. 9, the first reflection surface 11C and the first reflection surface 11C are formed of a right conical surface having the optical axis C _10C as a common axis. The second reflection surface 12C and an alignment reflection plane 13C perpendicular to the optical axis C _10C are provided, and are held by a reflection deflection element alignment adjustment stage 51A.

The interferometer 30A has a laser light source 31A, a beam diameter conversion lens 32A, and a laser beam output from the laser light source 31A via the beam diameter conversion lens 32A directed upward in the figure at the light beam splitting surface 33Aa. The beam splitter 33A that reflects the light, the light beam from the beam splitter 33A converted into parallel measurement light, the collimator lens 34A emitted along the measurement optical axis C _30A , and the measurement light from the collimator lens 34A A reference standard plate 35A (held by the reference plate alignment adjustment stage 53A) is branched into two on the reference standard surface 35Aa, one of which is reflected as reference light toward the collimator lens 34A and the other is emitted toward the aspherical lens 90. And). In addition, an imaging lens 36A for capturing an interference fringe image and an imaging camera 37A (having an imaging element 38A made of a CCD, a CMOS, or the like) are provided.

  The analysis unit 40A includes an analysis device 41A composed of a computer or the like, a monitor device 42A that displays an interference fringe image and the like, and an input device 43A for performing various inputs to the analysis device 41A. As shown in FIG. 11, an interference fringe image generation unit 44A, a surface tilt analysis unit 46 (this book) composed of a storage unit such as a CPU and a hard disk mounted in a computer, a program stored in the storage unit, and the like. And a surface misalignment analysis unit 47 (which configures a surface misalignment analysis unit in the present embodiment).

  The interference fringe image generation unit 44A is an interference carrying the tilt information of the first test surface 92a based on the image signal captured by the imaging camera 37A (see FIG. 9) during measurement using the reflective deflection element 10C. A fringe image (first analysis image) and an interference fringe image (second analysis image) carrying the tilt information of the second test surface 92 b are generated, and at the time of measurement using the null optical element 60 An image reconstruction unit 44Aa is configured to generate an analysis transmitted wavefront interference fringe image based on an image signal captured by the imaging camera 37A, and reconstructs the first analysis image by inverting it in the radial direction. It has.

  The surface tilt analysis unit 46 is configured to analyze the surface tilt of the aspheric lens 90 based on the generated first analysis image (reconstructed) and the second analysis image. Yes.

  The surface deviation analysis unit 47 is configured to analyze the surface deviation of the aspherical lens 90 based on the generated transmitted wavefront interference fringe image for analysis.

The null optical element 60 is transmitted through the lens portion 91 of the aspheric lens 90, the null mirror unit 61 for retro-reflects the light beam to diverge once converged, the optical axis C ₆₀ which is the center axis of the null mirror portion 61 And a reflection plane portion 62 arranged vertically, and is held by a null optical element alignment adjustment stage 56.

  The reflection deflecting element 10C and the null optical element 60 are further supported in turn by an electric X-axis stage 57, an electric Y-axis stage 58, and an electric Z-axis stage 59, and automatically when the aspherical lens 90 is measured. The position is adjusted.

  Hereinafter, the operation of the aspheric lens measuring apparatus 25 according to the present embodiment will be described. Since the alignment adjustment is performed prior to the measurement, the procedure will be briefly described first.

(Alignment adjustment)
<1> reference surface 35Aa of the reference plate 35A is, so as to be perpendicular to the measurement optical axis _{C 30A,} adjust the inclination of the reference plate 35A. This inclination adjustment is formed by, for example, installing a corner cube (not shown) on the reference standard surface 35Aa and irradiating measurement light, and reflecting light from the corner cube and reflected light from the reference standard surface 35Aa. This is performed using the reference plate alignment adjustment stage 53A so that the interference fringe image is in a null fringe state.

<2> The inclination of the aspheric lens 90 is adjusted so that the protruding portion 92 of the aspheric lens 90 is perpendicular to the measurement optical axis C _30A . For example, the tilt adjustment is performed by irradiating the second test surface 92b of the projecting portion 92 with the measurement light via the reference standard plate 53A, and the reflected light from the second test surface 92b and the reference standard surface 35Aa. This is performed using the subject alignment adjustment stage 52A so that the interference fringe image formed by the reflected light (reference light) is in a null fringe state.

<3> As the optical axis _{C 10C} reflective deflection element 10C is parallel to the measurement optical axis _{C 30A,} adjust the inclination of the reflective deflection element 10B. This tilt adjustment is performed, for example, by moving the reflective deflection element 10C so as to be positioned above the aspherical lens 90 in the drawing using the electric X-axis stage 57, the electric Y-axis stage 58, and the electric Z-axis stage 59. The alignment reflecting plane 13C of the reflective deflection element 10C is irradiated with measurement light via the reference standard plate 53A, and formed by the reflected light from the alignment reflecting plane 13C and the reflected light (reference light) from the reference standard surface 35Aa. The reflection fringe element alignment adjustment stage 51A is used so that the interference fringe image is in a null fringe state.

<4> as the optical axis _{C 60} of the null optical element 60 is parallel to the measurement optical axis _{C 30A,} adjust the inclination of the null optical element 60. This tilt adjustment is performed, for example, by moving the null optical element 60 so as to be positioned above the aspherical lens 90 in the drawing using the electric X-axis stage 57, the electric Y-axis stage 58, and the electric Z-axis stage 59. The measurement light is irradiated to the alignment reflective plane portion 62 of the null optical element 60 through the reference standard plate 53A, and is formed by the reflected light from the reflective plane 62 and the reflected light (reference light) from the reference standard surface 35Aa. The null optical element alignment adjustment stage 56 is used so that the interference fringe image is in a null fringe state.

  Note that if the alignment cannot be completely adjusted by such alignment adjustment, it is preferable to obtain the remaining alignment error and correct the measurement error due to the alignment error at the time of analysis.

  After the alignment adjustment, the aspheric lens 90 is measured. Hereinafter, the operation during the measurement will be described.

(Function during measurement)
<1> As shown in FIG. 9, the null optical element 60 is moved by the electric X-axis stage 57, the electric Y-axis stage 58 and the electric Z-axis stage 59 so as to be positioned above the aspherical lens 90 in the drawing. At this time, the relative position of the null optical element 60 with respect to the aspheric lens 90 is adjusted. This position adjustment is performed using, for example, the method described in Patent Document 2 described above.

  <2> After the null optical element 60 is installed, laser light is emitted from the laser light source 31A. This laser light enters the beam splitter 33A via the beam diameter conversion lens 32A, is reflected upward in the drawing by the light beam splitting surface 33Aa of the beam splitter 33A, and enters the collimator lens 34A. The light beam incident on the collimator lens 34A is converted into parallel light and emitted toward the reference standard plate 35A.

  <3> The light beam incident on the reference standard plate 35A is split into reference light that is retroreflected and transmitted measurement light on the reference standard surface 35Aa.

  <4> Part of the measurement light transmitted through the reference reference surface 35Aa passes through the third window portion 55c of the lens mounting base 55 and enters the lens portion 91 of the aspheric lens 90, and passes through the lens portion 91. Then, the null mirror unit 61 of the null optical element 60 is irradiated.

  <5> The measurement light irradiated to the null mirror unit 61 is retroreflected from the null mirror unit 61 and re-enters the lens unit 91 of the aspheric lens 90, passes through the lens unit 91, and enters the reference standard surface 35 </ b> Aa. Then, it is combined with the reference light to form interference light (hereinafter referred to as “transmitted wavefront interference light”).

  <6> The transmitted wavefront interference light is incident on the imaging lens 36A via the collimator lens 34A and the beam splitter 33A, and is condensed on the imaging element 38A of the imaging camera 37A by the imaging lens 36A to be interference fringes. An image (hereinafter referred to as “transmission wavefront interference fringe image”) is formed. The formed transmitted wavefront interference fringe image is picked up by the image pickup camera 37A, and the image signal is output to the interference fringe image generation unit 44A (see FIG. 11).

  <7> Based on the image signal input to the interference fringe image generation unit 44A, an analysis transmitted wavefront interference fringe image (an image obtained by digitizing the transmitted wavefront interference fringe image) is generated in the interference fringe image generation unit 44A. Data (hereinafter referred to as “transmission wavefront interference fringe image data for analysis”) is input to the above-described surface deviation analysis unit 47.

  <8> As shown in FIG. 10, the reflective deflection element 10 </ b> C is moved by the electric X-axis stage 57, the electric Y-axis stage 58 and the electric Z-axis stage 59 so as to be positioned above the aspherical lens 90 in the drawing.

  <9> After the reflective deflection element 10C is installed, laser light is emitted from the laser light source 31A. This laser light enters the beam splitter 33A via the beam diameter conversion lens 32A, is reflected upward in the drawing by the light beam splitting surface 33Aa of the beam splitter 33A, and enters the collimator lens 34A. The light beam incident on the collimator lens 34A is converted into parallel light and emitted toward the reference standard plate 35A.

  <10> The light beam incident on the reference standard plate 35A is split into reference light that is retroreflected and measurement light that is transmitted through the reference standard surface 35Aa.

  <11> Part of the measurement light transmitted through the reference reference surface 35Aa passes through the first window portion 55a of the lens mounting base 55 and enters the first reflective surface 11C of the reflective deflection element 10C, and the first reflective surface By being sequentially reflected by 11C and the second reflecting surface 12C, it is deflected by 180 degrees and irradiated perpendicularly to the first test surface 92a of the aspherical lens 90.

  <12> On the other hand, the other part of the measurement light transmitted through the reference standard surface 35Aa passes through the second window 55b of the lens mounting table 55, and passes through the second deflecting element 10C and passes through the second aspherical lens 90. 2 Irradiated perpendicularly to the test surface 92b.

  <13> The measurement light irradiated on the first test surface 92a via the reflective deflection element 10C is retroreflected from the first test surface 92a (at this time, the measurement light is tilted on the first test surface 92a). Is incident on the second reflecting surface 12C of the reflective deflecting element 10C) and is sequentially reflected by the second reflecting surface 12C and the first reflecting surface 11C to be deflected by 180 degrees, so that the original optical path Is substantially reversely incident on the reference reference surface 35Aa and is combined with the reference light to form interference light (hereinafter referred to as “first interference light”).

  <14> On the other hand, the measurement light irradiated on the second test surface 92b is retroreflected from the second test surface 92b (at this time, the measurement light has wavefront information corresponding to the inclination of the second test surface 92b). Carried by the light source, and substantially reversely travels along the original optical path to enter the reference standard surface 35Aa and is combined with the reference light to form interference light (hereinafter referred to as “second interference light”).

  <15> The first interference light is incident on the imaging lens 36A via the collimator lens 34A and the beam splitter 33A, and is condensed on the imaging element 38A of the imaging camera 37A by the imaging lens 36A to be interference fringes. An image (hereinafter referred to as “first interference fringe image”) is formed. The formed first interference fringe image is captured by the imaging camera 37A, and the image signal is output to the interference fringe image generation unit 44A (see FIG. 11).

  <16> Similarly, the second interference light enters the imaging lens 36A via the collimator lens 34A and the beam splitter 33A, and is condensed on the imaging device 38A of the imaging camera 37A by the imaging lens 36A. Thus, an interference fringe image (hereinafter referred to as “second interference fringe image”) is formed. The formed second interference fringe image is picked up by the image pickup camera 37A, and the image signal is output to the interference fringe image generation unit 44A. In the present embodiment, the first interference fringe image is formed on a ring-shaped region on the image sensor 38A, and the second interference fringe image is formed inside the ring-shaped region. The first interference fringe image and the second interference fringe image can be captured simultaneously.

  <17> A first analysis image (an image obtained by digitizing the first interference fringe image) and a second analysis image (first analysis image) in the interference fringe image generation unit 44A based on the image signal input to the interference fringe image generation unit 44A. 2, an image obtained by digitizing the interference fringe image) is generated, and the image data (hereinafter, the image data of the first analysis image is “first analysis image data” and the image data of the second analysis image is “second”. Is referred to as “analysis image data”), and is input to the above-described plane tilt analysis unit 46. Note that, since the first interference fringe image is captured through the reflective deflection element 10C, when the first analysis image is generated based on the image data, the first interference fringe image is normally captured as shown in FIG. In contrast to the interference fringe image, the interference fringe image is inverted in the radial direction. Therefore, in the image reconstruction unit 44Aa, the first analysis image is reconstructed by inverting it in the radial direction, and the image data of the first analysis image (see FIG. 15) after the reconstruction is used for the first analysis. Output as image data.

  <18> Based on the first analysis image data and the second analysis image data input to the surface tilt analysis unit 46, an analysis is performed in the surface tilt analysis unit 46, and the first test of the aspheric lens 90 is performed. The relative inclination between the surface 92a and the second test surface 92b is obtained, and the surface tilt of the aspherical lens 90 is obtained based on the result.

  <19> Based on the transmitted wavefront interference fringe image data for analysis input to the phase shift analyzer 47, the plane shift of the aspheric lens 90 is obtained. Specifically, the entire coma aberration of the aspherical lens 90 is obtained based on the transmitted wavefront interference fringe image data for analysis, and the total coma aberration is generated due to the surface tilt obtained in the above procedure <18>. By subtracting the coma aberration due to the surface tilt, the coma aberration due to the surface deviation caused by the surface deviation is obtained. The surface deviation of the aspherical lens 90 is obtained based on this surface deviation coma aberration. Details of such a method are described in Patent Document 2 described above.

<Deformation of measurement system>
In the relative tilt measuring device 20 and the aspherical lens measuring device 25 described above, the interferometers 30 and 30A are used as the measurement system. However, an autocollimator 80 as shown in FIG. 16 can also be used as the measurement system. is there.

  The autocollimator 80 includes a light source 81, a condenser lens 82, a light source side focusing mirror 83 on which a marked line such as a crosshair is formed, a beam splitter 84 (light beam splitting surface 84a), an objective lens 85, an imaging side focusing mirror 86, a connection lens. An image lens 87 and an imaging camera 88 are provided, and the light source side focusing mirror 83 and the imaging side focusing mirror 86 are respectively disposed on the focal plane of the objective lens 85.

On the measurement optical axis C ₈₀ of the autocollimator 80, arranged reflective deflection elements (not shown) (can be used as the above embodiments), the measurement light portion from the autocollimator 80, the reflective deflection element And irradiates the first test surface (not shown) perpendicularly to the first test surface (not shown) and irradiates the other part of the measurement light perpendicularly to the second test surface (not shown) without going through the reflective deflection element. To do. Light that is retroreflected from the first test surface and returns to the autocollimator 80 via the reflective deflection element is collected by the objective lens 85, and a first marked line image is formed on the imaging-side focus mirror 86. On the other hand, the light retroreflected from the second test surface is similarly condensed by the objective lens 85, and a second marked line image is formed on the imaging-side focus mirror 86. The first and second marked line images are imaged and imaged on the image sensor 89 in the imaging camera 88 via the imaging lens 87, and the image data is analyzed by an analysis device (not shown). Thus, the relative inclination of the first test surface and the second test surface can be obtained. Since the first marked line image is captured through the reflective deflection element, it is a marked line image that is inverted in the radial direction with respect to the normally captured marked line image. Therefore, it is preferable to reconstruct the first marked line image by inverting it in the radial direction.

  As mentioned above, although embodiment of this invention was described, an aspect of this invention is not limited to the above-mentioned embodiment, The thing of a various aspect can be made into embodiment.

  For example, the reflection deflection elements 10 and 10A described above include the reflection planes 13 and 13A for alignment, respectively, but the reflection deflection elements (not shown) having such a configuration not including the reflection plane for alignment are formed. Is also possible.

  The interferometers 30 and 30A described above are Fizeau types, but other types of interferometers such as a Michelson type may be used.

10, 10A, 10B, 10C Reflective deflection element 11, 11A, 11B, 11C First reflective surface 12, 12A, 12B, 12C Second reflective surface 13, 13A, 13B, 13C Alignment reflective plane 20 Relative tilt measuring device 25 Spherical lens measuring device 30, 30A Interferometer 31, 31A Laser light source 32, 32A Beam diameter conversion lens 33, 33A Beam splitter 33a, 33Aa Beam splitting surface 34, 34A Collimator lens 35, 35A Reference standard plate 35a, 35Aa Reference standard surface 36, 36A Imaging lens 37, 37A Imaging camera 38, 38A Imaging device 40, 40A Analysis unit 41, 41A Analysis device 42, 42A Monitor device 43, 43A Input device 44, 44A Interference fringe image generation unit 44a, 44Aa Image reconstruction Part 45 Relative slope analysis part 46 Surface tilt analysis unit 47 Surface deviation analysis unit 51, 51A Reflection deflection element alignment adjustment stage 52, 52A Object alignment adjustment stage 53, 53A Reference plate alignment adjustment stage 54 Object mounting table 55 Lens mounting table 56 Null optical element alignment adjustment stage 57 Electric X-axis stage 58 Electric Y-axis stage 59 Electric Z-axis stage 60 Null optical element 61 Null mirror part 62 Reflective plane part 70 Parallel plate 71, 92a First test surface 72, 92b Second test surface 80 Autocollimator 81 Light source 82 a condenser lens 83 light source side focal mirror 85 objective lens 86 imaging side focal mirror 90 aspherical lens 91 lens portion 92 projecting portion _{C 10, C 10A, C 10B} , C 10C, C 60 the optical axis _{C 30,} C _30A, C ₈₀ measuring optical axes C _91a , C _{9 1b} center axis P ₁ , P ₂ vertex Q ₁ , Q ₂ center point α ₁ , β ₁ first vertex angle α ₂ , β ₂ second vertex angle O image center E circle (inversion reference point)
e Predetermined distances K ₁ , K ₂ , K ′ ₁ , K ′ ₂ pixel positions R Half-line

Claims (8)

  A first reflecting surface constituted by a first right conical surface having a first apex angle, and coaxially and oppositely arranged with respect to the first right conical surface inside the first right conical surface; And a second reflecting surface constituted by a second right conical surface having a second apex angle, the sum of which is 180 degrees with respect to the first apex angle. element.   2. The reflective deflection element according to claim 1, wherein both the first apex angle and the second apex angle are set to 90 degrees.   3. The reflection deflection element according to claim 1, further comprising an alignment reflection plane perpendicular to the axes of the first reflection surface and the second reflection surface. A relative inclination measuring device for measuring a relative inclination of a first test surface and a second test surface formed in parallel with each other,
The reflective deflection element according to any one of claims 1 to 3,
The measurement light composed of parallel light is emitted, and a part of the measurement light is irradiated perpendicularly to the first test surface through the reflective deflection element, and the other part of the measurement light is A measurement system for irradiating perpendicularly to the second test surface without a reflective deflection element;
A first analysis image formed by wavefront information carried by measurement light that is retroreflected from the first test surface and returns to the measurement system via the reflective deflection element, and retroreflected from the second test surface And a relative inclination analyzing means for analyzing a relative inclination between the first test surface and the second test surface based on the second analysis image formed by the measurement light that is returned to the measurement system. A relative tilt measuring device comprising:   The relative inclination measuring device according to claim 4, further comprising an image reconstruction unit that inverts and reconstructs the first analysis image in the radial direction.   6. The relative tilt measuring apparatus according to claim 4, wherein the measuring system is an interferometer. At least one of the two lens surfaces has a rotating aspheric surface, and a first test surface and a second test surface formed in parallel with each other on one side and the other side of the two lens surfaces, respectively. An aspherical lens measuring device for measuring surface tilt and surface deviation of an aspherical lens,
The reflective deflection element according to any one of claims 1 to 3,
The measurement light composed of parallel light is emitted, and a part of the measurement light is irradiated perpendicularly to the first test surface through the reflective deflection element, and the other part of the measurement light is An interferometer that irradiates perpendicularly to the second test surface without a reflective deflection element;
A first analysis image formed by wavefront information carried by measurement light that is retroreflected from the first test surface and returns to the interferometer via the reflective deflection element, and retroreflected from the second test surface A surface tilt analysis means for analyzing the surface tilt of the aspheric lens based on the second analysis image formed by the measurement light returned to the interferometer;
A null optical element that retroreflects the measurement light emitted from the interferometer and transmitted through the two lens surfaces;
Based on the transmitted wavefront interference fringe image for analysis formed by measurement light retroreflected from the null optical element, transmitted again through the two lens surfaces, and returned to the interferometer, the surface deviation of the aspheric lens is analyzed. An aspherical lens measuring device comprising: a surface deviation analyzing means.   The aspherical lens measurement apparatus according to claim 7, further comprising an image reconstruction unit that inverts and reconstructs the first analysis image in the radial direction.

Images