JP2005083981A - Aspheric surface eccentricity measuring apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for measuring aspheric surface eccentricity allowing precise determination of an origin point of a probe without applying specific processing on a portion for holding an object to be inspected, without requiring a reference object having high surface precision. <P>SOLUTION: The aspheric surface eccentricity measuring apparatus 100 comprises: a holding section 101 which holds a double-sided aspheric lens 110; an air spindle 102 which rotates the holding section 101; a rotary encoder 104 which measures the rotation angle of the air spindle 102; a contact length measuring instrument 170 having the probe 171 which measures the three-dimensional profile of a surface to be inspected 110a; a length measuring instrument moving table 114 which moves the contact length measuring instrument 170, a microscope 150 which is placed, facing the air spindle 102 with the holding section 101 in between; and a microscope stage moving table 113 which moves the microscope 150. The microscope 150 is placed by the microscope stage moving table 113 so that its optical axis approximately coincides with a rotation axis 116 of the air spindle 102. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an eccentricity measuring apparatus and an eccentricity measuring method for an object such as an aspheric lens.

  Japanese Patent Laid-Open No. 10-38556 discloses one of three-dimensional shape measuring machines. Here, the surface to be measured of the rotating object to be measured is scanned with the probe. Thereby, the shape of a rotationally symmetric surface to be measured such as a lens is measured. This three-dimensional shape measuring machine is shown in FIG. In this figure, the measuring table 203 is rotated by an air spindle 204. An object to be measured 202 is held on the measurement table 203. The ruby ball 201a at the tip of the probe 201 is brought into contact with the surface to be measured. In this apparatus, the measurement surface is rotated by the rotation of the air spindle 204, and the probe 201 is also scanned in a predetermined direction. In this way, the surface shape of the object to be measured is measured based on the coordinates of the probe 201 and the rotation angle of the object to be measured (air spindle). At the time of measurement, it is necessary to determine the coordinates of the measurement origin of the probe 201 with respect to the rotation axis of the air spindle 204.

For this reason, the optical system 210 and a monitor 220 for displaying an image of the optical system 210 are provided. Here, the optical system 210 includes a laser diode 211, lenses 212, 214, and 215, a beam splitter 213, a CCD camera 216, and the like. First, instead of the object to be measured 202, the reference reflective spherical surface is placed on the opening of the measuring table 203 on the air spindle 204 so that the spherical center thereof coincides with the rotation axis. While detecting the reflection image of the reference reflection spherical surface with the optical system 210, the optical system 210 is moved to a position where a reflection image conjugate with the spherical center of the reference reflection surface is obtained, and the coordinates of the reflection image at that time are stored. Thereafter, the reference reflection spherical surface is removed, and the probe 201 is moved while the optical system 210 is fixed. Then, the position of the probe 201 is adjusted so that the position of the reflected image of the ruby ball 201a coincides with the position of the reflected image of the reference reflecting surface, and this position is set as the measurement origin. The coordinates of the probe 201 obtained as described above are used as the measurement origin, and the shape of the object to be measured 202 is measured.
Japanese Patent Laid-Open No. 10-38556

  In the above-described three-dimensional shape measuring machine, the reference reflection surface mounting portion needs to be coaxial with the rotation axis of the air spindle so that the spherical center of the reference reflection surface coincides with the rotation axis of the air spindle 204. Therefore, it is necessary to cut the reference reflection surface mounting portion with the cutting tool 205 while rotating the measurement table.

  Specifically, as shown in FIG. 14B, it is necessary to cut the upper end portion 203b of the inner peripheral portion 203a with respect to the cylindrical measuring table 203. In addition, when the surface of the object to be measured 202 that comes into contact with the measurement table 203 is a convex surface, it is only necessary to cut the upper end 203b of the inner peripheral portion 203a of the measurement table 203 in this way. However, when the surface of the object to be measured 202 that comes into contact with the measurement table 203 is a concave surface, the upper end of the outer peripheral portion of the measurement table 203 is further arranged so that the object to be measured 202 is arranged coaxially with the rotation axis. Cut the part.

  Thus, since processing of the measuring table 203 is necessarily required, man-hours other than measurement are required, and the preparation time becomes long.

  The air spindle 204 needs to be highly rigid and capable of high-speed rotation in order to perform cutting.

  Furthermore, it is necessary to prepare a reflection surface with good surface accuracy as a reference reflection surface other than the test object.

  The present invention has been made in consideration of such actual situations, and its purpose is to require a reference object with high surface accuracy without performing special processing on the portion holding the test object. It is another object of the present invention to provide an aspheric eccentricity measuring apparatus that can determine the origin position of a probe with high accuracy. Another object of the present invention is to provide such an aspheric eccentricity measuring method.

  One aspect of the present invention is directed to an aspheric eccentricity measuring apparatus for measuring the aspheric eccentricity of a test object, and includes the aspherical eccentricity measuring apparatus listed in the following items.

  1. An aspherical eccentricity measuring apparatus according to the present invention includes a holding mechanism that holds the test object, a rotating mechanism that rotates the holding mechanism, and an observation optical that is disposed at a position facing the rotating mechanism with the holding mechanism interposed therebetween. System, a first probe disposed between the holding mechanism and the observation optical system, and a first moving mechanism for moving the first probe, the optical axis of the observation optical system and the rotation mechanism The observation optical system is arranged such that the rotation axes of the observation optical system substantially coincide with each other.

  In this aspheric surface eccentricity measuring apparatus, the position of the rotation center of the rotation mechanism can be detected by the observation optical system. Therefore, the origin position of the first probe can be determined with high accuracy using the detection result.

  2. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the first item, wherein the observation optical system includes an objective lens, an eyepiece lens, and a scale member, and the scale member is formed at a predetermined interval. The scale member is arranged at a position conjugate with an observation image observed through the eyepiece.

  In this aspherical surface eccentricity measuring apparatus, it is possible to observe the state of rotation of the observation image with a simple configuration.

  3. Another aspheric eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the second item, wherein the rotation mechanism is rotated to observe the rotation of the observation image with respect to the scale, and a specific portion of the observation image is measured. The rotation center of the rotation mechanism is detected based on the observation result.

  This aspherical eccentricity measuring device can detect the center of rotation with a simple configuration.

  4). Another aspheric decentration measuring apparatus according to the present invention is the aspheric decentration measuring apparatus according to the first item, wherein the observation optical system includes an objective lens and an imaging element, and the imaging element is an observation image position formed by the objective lens. And a display device for displaying the observation image.

  In this aspherical eccentricity measuring apparatus, the state of rotation of the observation image can be observed at a position away from the measuring apparatus.

  5). Another aspheric eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third item, wherein the rotation mechanism is rotated to image rotation of the observation image, and the observation result of the specific portion of the observation image is obtained. Based on this, the position of the rotation center of the rotation mechanism is detected.

  In this aspherical eccentricity measuring apparatus, the center of rotation can be detected at a position away from the measuring apparatus.

  6). Another aspheric eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth item, wherein the first moving mechanism is arranged so that the rotation center position and the first probe coincide with each other. It is characterized by controlling.

  In this aspheric surface eccentricity measuring apparatus, the origin position of the first probe can be determined with high accuracy.

  7). Another aspheric eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth item, wherein the measurement is performed by the first probe with the rotation center position as the measurement origin of the first probe. It is characterized by performing.

  In this aspherical eccentricity measuring apparatus, highly accurate measurement is possible.

  8). Another aspherical eccentricity measuring apparatus of the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth item, wherein the position of the rotation center and the measurement origin position of the first probe are different from each other. The measurement position of the first probe is corrected based on the difference.

  In this aspherical surface eccentricity measuring apparatus, it is possible to perform high-precision measurement without strictly positioning the origin position of the first probe on the rotation axis.

  9. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth aspect, wherein the specific part of the observation image has a specific structure existing on the surface of the index member. Is arranged on the holding mechanism.

  In this aspherical surface eccentricity measuring apparatus, it is not necessary to create a specific pattern as an index, so that many objects can be used as the index member. The origin of the first probe can be adjusted at the position of the index member.

  10. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth aspect, wherein the specific part of the observation image is a specific structure artificially formed on the surface of the index member. The indicator member is arranged on the holding mechanism.

  In this aspherical eccentricity measuring device, since there is an index, detection becomes easy. The origin of the first probe can be adjusted at the position of the index member.

  11. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the first item, further comprising an optical system moving mechanism that moves the observation optical system in a direction perpendicular to the rotation axis of the rotating mechanism. It is characterized by that.

  In this aspherical eccentricity measuring apparatus, the observation optical system does not get in the way during measurement.

  12 Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the first item, wherein the second probe disposed between the holding mechanism and the first probe, and the second probe are provided. A second moving mechanism for moving is provided.

  In this aspherical eccentricity measuring apparatus, the object to be measured can be measured from both sides.

  13. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth aspect, wherein the second probe disposed between the holding mechanism and the first probe, A second moving mechanism for moving the second probe is provided, and the second moving mechanism is controlled so that the rotation center position and the second probe coincide with each other.

  In this aspherical surface eccentricity measuring apparatus, the origin position of the second probe can be determined with high accuracy.

  14 Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth aspect, wherein the second probe disposed between the holding mechanism and the first probe, A second moving mechanism for moving the second probe, and when the rotation center position and the measurement origin position of the second probe are different, the measurement position of the second probe is determined by the difference between the two positions. It is characterized by correcting.

  In this aspheric surface eccentricity measuring apparatus, it is possible to perform highly accurate measurement without strictly positioning the origin position of the second probe on the rotation axis.

  15. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the thirteenth item, in which the first probe position when the rotational center position is coincident with the rotational center position. The position of the second probe is the same in the direction along the rotation axis.

  In this aspherical eccentricity measuring apparatus, the error between the origin position of the first probe and the origin position of the second probe is reduced.

  16. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the thirteenth item, in which the first probe position when the rotational center position is coincident with the rotational center position. The position of the second probe is different in a direction along the rotation axis.

  In this aspheric surface eccentricity measuring apparatus, the amount of movement of the first probe and the second probe can be small.

  17. Another aspherical eccentricity measuring apparatus according to the present invention is the aspherical eccentricity measuring apparatus according to the third or fifth item, wherein the observation optical system is a variable magnification optical system.

  In this aspherical surface eccentricity measuring device, the field of view is wide when the magnification is low, so that the center of rotation can be found quickly. If the magnification is high, the center of rotation can be detected with high accuracy.

  One aspect of the present invention is directed to an aspheric eccentricity measuring method for measuring the aspheric eccentricity of a test object, and includes the aspheric eccentricity measuring methods listed in the following items.

  18. In the aspherical eccentricity measuring method of the present invention, the first index member held by the holding portion rotated by the rotation mechanism is observed by the observation optical system, and the rotation center of the index provided on the first index member is determined. Align the optical axis of the observation optical system approximately with the optical axis of the observation optical system, and roughly match the rotation axis of the rotation mechanism, and rotate the first index member and the holding unit while maintaining the position of the observation optical system. With the probe removed from the mechanism, the first probe made of a spherical member is inserted into the field of view of the observation optical system, the top of the first probe is placed on the optical axis of the observation optical system, and its position is measured. The process of setting the origin position and irradiating the object along the rotation axis while rotating the object to detect the locus of the spot of the reflected light on the first object surface of the object. And a step of detecting the rotation angle of the test object corresponding to each point on the locus of the spot; Based on the locus of the reflected light spot on the first test surface of the test object and the rotation angle of the test object, the shift amount of the first test surface of the test object with respect to the rotation axis of the paraxial curvature center Detecting the direction of the reflected light spot on the second test surface of the test object by irradiating the test object with light along the rotation axis while rotating the test object. And the step of detecting the rotation angle of the test object corresponding to each point on the locus of the spot, and the locus of the reflected light spot on the second test surface of the test object and the rotation angle of the test object Based on the step of obtaining the shift amount and direction of the second test surface of the test object relative to the rotation axis of the paraxial curvature center, and bringing the first probe into contact with the first test surface of the test object The three-dimensional zone of the first test surface of the test object at a predetermined position from the rotation axis of the rotation mechanism by the first probe while rotating the test object Process of acquiring the state data, the shift amount and the direction of the rotation axis of the rotation mechanism of the center of paraxial curvature of the first test surface of the test object, and the paraxial of the second test surface of the test object Shift amount and direction of the rotation center of the center of curvature with respect to the rotation axis, three-dimensional shape data of the annular zone of the first test surface at a predetermined position from the rotation axis, and the paraxial curvature radius of the first test surface And a step of obtaining an aspheric eccentric amount and direction of the aspheric surface of the first test surface of the test object from the paraxial radius of curvature of the second test surface and the thickness of the test object. It is characterized by that.

  In this aspherical decentering measurement method, the position of the rotation center of the rotation mechanism is detected by the observation optical system, and the origin position of the first probe can be determined with high accuracy using the detection result. It is possible to measure aspheric decentration.

  19. Another aspherical eccentricity measuring method of the present invention is the second aspherical eccentricity measuring method according to the eighteenth item, wherein the first probe member and the holding member are removed from the rotating mechanism, and the second probe is made of a spherical member. Is inserted in the field of view of the observation optical system, the top of the second probe is placed at the position where the rotation center of the index of the observation optical system is located, and the position is set as the origin of measurement, and the test object The second probe is brought into contact with the second test surface, and the second probe is rotated on the second test surface of the test object at a predetermined position from the rotation axis of the rotation mechanism by rotating the test object. The step of acquiring the annular three-dimensional shape data, the shift amount and direction of the rotation mechanism of the rotation mechanism at the center of the paraxial curvature of the first test surface of the test object, and the first at a predetermined position from the rotation axis 3D shape data of the test surface and the paraxial radius of curvature of the first test surface , The amount and direction of shift of the rotation mechanism of the rotation mechanism at the center of paraxial curvature of the second test surface of the test object with respect to the rotation axis, and the annular three-dimensional shape data of the second test surface at a predetermined position from the rotation axis And the abscissa radius of the second test surface, the thickness and refractive index of the test object, and the aspheric aspheric eccentricity and direction of the second test surface of the test object are obtained. And a process.

  In this aspheric surface eccentricity measuring method, the origin position of the second probe can be determined with high accuracy. The error between the origin position of the first probe and the origin position of the second probe is reduced.

  20. Another aspherical eccentricity measuring method of the present invention is the second aspherical eccentricity measuring method according to item 18, further comprising a second index member having a thickness different from that of the first indicator member held by the holding part rotated by the rotating mechanism. The index member is observed with the observation optical system, the center of rotation of the index provided on the second index member is substantially coincided with the optical axis of the observation optical system, and the optical axis of the observation optical system and the rotation axis of the rotation mechanism are The second probe made of a spherical member is inserted into the field of view of the observation optical system with the second index member and the holding part removed from the rotation mechanism while keeping the position of the observation optical system approximately the same. , Placing the top of the surface of the second probe at the position where the center of rotation of the index of the observation optical system is located, and setting the position as the origin of measurement, and the second surface of the test object on the second test surface With the second probe while rotating the specimen. A step of acquiring annular three-dimensional shape data of the second test surface of the test object at a predetermined position from the rotation axis of the rotation mechanism, and rotation of the paraxial curvature center of the first test surface of the test object Shift amount and direction with respect to the rotation axis of the mechanism, the three-dimensional shape data of the annular zone of the first test surface at a predetermined position from the rotation axis, the paraxial radius of curvature of the first test surface, and the test object Shift amount and direction of the rotation mechanism of the rotation mechanism at the paraxial curvature center of the second test surface of the second test surface, the annular three-dimensional shape data of the second test surface at a predetermined position from the rotation shaft, And determining the direction and direction of the aspheric aspheric surface of the second test surface of the test object from the paraxial radius of curvature of the test surface and the thickness and refractive index of the test object. It is characterized by that.

  In this aspheric surface eccentricity measuring method, the origin position of the second probe can be determined with high accuracy. The amount of movement of the first probe or the second probe can be small.

  According to the present invention, it is possible to determine the origin position of the probe with high accuracy without performing special processing on the portion holding the test object and without requiring a reference object with high surface accuracy. A spherical eccentricity measuring device and an aspherical eccentricity measuring method are provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 schematically shows a configuration of an aspheric eccentricity measuring apparatus according to a first embodiment of the present invention. The xyz coordinate system in FIG. 1 is as shown in the upper left of the figure, and the y direction is a direction perpendicular to the paper surface, and the direction going from the front of the paper surface to the back is a plus.

  As shown in FIG. 1, the aspherical eccentricity measuring apparatus 100 measures a cylindrical holding portion 101, an air spindle 102, a motor 103 for rotating the air spindle 102, and a rotation angle of the air spindle 102. And a rotary encoder 104. The air spindle 102 is a rotation mechanism that rotates the holding unit 101. The holding unit 101 is a holding mechanism that appropriately holds either one of the double-sided aspheric lens 110 that is a test object and the plastic plate 109. Here, the plastic plate 109 is an object to be detected for detecting the rotating shaft 116 of the air spindle 102.

  The aspherical eccentricity measuring apparatus 100 further includes a contact type length measuring device 170, a contact type length measuring device 180, and a length measuring device moving table 114. Here, the contact-type length measuring device 170 measures the three-dimensional shape of the upper test surface 110 a of the double-sided aspheric lens 110. The contact-type length measuring device 180 measures the three-dimensional shape of the test surface 110b below the double-sided aspheric lens 110. The length measuring device moving table 114 is equipped with a contact length measuring device 170 and a contact length measuring device 180.

  The contact-type length measuring device 170 has a probe 171 that is a spherical contactor, and the contact-type length measuring device 180 has a probe 181 that is a spherical contactor. The length measuring device moving table 114 moves the contact type length measuring device 170 and the contact type length measuring device 180 in the xyz direction in order to arrange the contact type length measuring device 180 at a predetermined position. Here, the predetermined position is a measurement reference position, a shape measurement position, or a retracted position.

  The aspheric eccentricity measuring apparatus 100 further includes a microscope 150, a spot locus detection unit 130, a microscope stage 112, and a microscope stage moving table 113. Here, the microscope 150 is an observation optical system for detecting the rotation axis 116 of the air spindle 102. The spot trajectory detection unit 130 detects the trajectory of a light spot that is irradiated with light on the object and reflected by the surface to be examined. A microscope 150 and a spot locus detection unit 130 are mounted on the microscope stage 112. The microscope stage moving table 113 moves the microscope stage 112 in the xz direction.

  The microscope 150 is located on the side facing the air spindle 102 with the holding unit 101 interposed therebetween. The microscope stage moving table 113 is a retracted position that does not interfere with the microscope 150 and the spot locus detection unit 130 during shape measurement, with the microscope 150 at the detection position of the rotating shaft 116 of the air spindle 102, the spot locus detection unit 130 at the spot locus detection position. Move to. The microscope stage moving table 113 moves the microscope 150 in the z direction for focusing.

  The aspheric surface eccentricity measuring apparatus 100 further includes a calculation unit 160 and a monitor 161. Here, the calculation means 160 controls the apparatus moving unit, processes the information obtained by the spot locus detection unit 130 and the rotary encoder 104, the upper contact type length measuring device 170 or the lower contact type length measuring device 180, and the rotary encoder. 104, processing of the information obtained and calculation of aspheric decentration. The monitor 161 displays the calculation result and the observation screen of the microscope 150.

  FIG. 2A shows the positional relationship of the upper contact-type length measuring device 170 and the lower contact-type length measuring device 180 as viewed from the negative direction of the y-axis, and FIG. The positional relationship of the contact-type length measuring device 170 and the lower contact-type length measuring device 180 as viewed from the positive direction of the x axis is shown.

  The measurement directions of the upper contact type length measuring device 170 and the lower contact type length measuring device 180 are both in the z direction, and the two are in a parallel relationship. As shown in FIG. 2A, the probe 171 is located above the probe 181 in the z direction. This reduces the amount of movement from the reference position in the Z direction when measuring the shape of the test surface.

  As shown in FIG. 2 (B), the contact-type length measuring device 170 and the contact-type length measuring device 180 are installed at a distance in the y-axis direction. For this reason, the probe 171 and the probe 181 are located apart from each other by a specific distance in the y direction. Thus, when one of the surfaces to be measured of the double-sided aspheric lens 110 is measured, the other does not interfere with the double-sided aspheric lens 110, the air spindle 102, or the like.

  At the time of shape measurement, one of the probe 171 and the probe 181 is selectively disposed at a position away from the rotation axis 116 of the air spindle 102 by a specific distance in the minus direction of the y direction. The contact-type length measuring device 170 and the contact-type length measuring device 180 measure the positions of the probe 171 and the probe 181 in the z-axis direction (direction parallel to the rotation axis 116), and send the information to the calculation means 160. The direction in which the probe 171 and the probe 181 are arranged with respect to the rotating shaft 116 at the time of shape measurement is not limited to only the minus in the y direction.

  The calculation means 160 acquires information measured by the contact-type length measuring device 170 and the contact-type length measuring device 180 in synchronization with the rotation angle of the double-sided aspheric lens 110. This information is positional information of the probe 171 and the probe 181 in a direction parallel to the rotation axis 116. Further, the rotation angle of the double-sided aspheric lens 110 is measured by the rotary encoder 104. As a result, the calculation means 160 acquires the three-dimensional annular zone shape data of the test surface of the double-sided aspheric lens 110 in the direction parallel to the rotation axis 116.

  The microscope 150 includes a light source 151, an objective lens 152, a TV camera 153, and a scale 154. Illumination light emitted from the light source 151 is bent in direction by a reflection optical system (not shown) in the microscope. The illumination light passes through the objective lens 152 and illuminates the object to be observed. The image of the surface of the object to be observed is enlarged by the objective lens 152 and formed on the TV camera 153. A scale 154 is disposed inside the optical system of the microscope 150. The scale 154 has a scale formed at a predetermined interval. The position where the scale 154 is arranged is a position conjugate with an observation image observed through the eyepiece. This position is also an image position formed by the objective lens 152. That is, the scale 154 is installed so that the scale size on the TV camera 153 does not change even when the magnification of the objective lens 152 is changed. The output of the TV camera 153 of the microscope 150 can be observed on the monitor 161.

The spot locus detection unit 130 includes a light source 131, a collimator lens 132, a half mirror 133, two imaging optical elements 134 and 136, and an imaging element 135. The two imaging optical elements 134 and 136 form an imaging optical system. The light source 131 is, for example, a lamp. The half mirror 133 directs the illumination light emitted from the light source 131 to the double-sided aspheric lens 110 that is the test object. Further, the half mirror 133 directs the return light from the double-sided aspheric lens 110 to the image sensor 135. That is, the half mirror 133 constitutes a separation optical element that separates light traveling toward the double-sided aspherical lens 110 and light returning from the double-sided aspherical lens 110. The separation optical element is not limited to the half mirror 133, and may be configured by a prism instead of the half mirror 133.

  Although the imaging optical element 134 is omitted from FIG. 1 and drawn with a single lens, it is usually composed of a lens group including a plurality of lenses. A part of the lens group is movable along the optical axis. Therefore, by adjusting those positions, the light from the light source 131 can be converged to a desired point. The lens position can be adjusted on a stage using a motor or the like. If the control is performed by the calculation means 160, it can be performed by remote operation.

  The illumination light emitted from the light source 131 enters the imaging optical element 134 through the collimating lens 132 and the half mirror 133. The illumination light is applied to the double-sided aspheric lens 110 by the imaging optical element 134. In that case, illumination light is irradiated so that it may converge on the paraxial curvature center of the test surface 110a or the paraxial curvature center of the test surface 110b. Then, the light reflected by the test surface 110a or 110b enters the imaging optical element 136 through the imaging optical element 134 and the half mirror 133. This light is converged by the imaging optical element 136 and forms a beam spot on the image sensor 135.

  The plastic plate 109 has a thickness of several mm and a size that can be firmly fixed to the holding unit 101. This plastic plate 109 is highly versatile. The plastic plate 109 is printed on the upper surface (side observed with the microscope 150). This printing is in color, and an appropriate pattern is printed. This pattern is composed of fine particles. Therefore, when it magnifies with the microscope 150, the particle | grains which comprise the pattern can be observed.

  Alternatively, the upper surface of the plastic plate 109 may have a fine grained shape. Also in this case, when magnifying and observing with the microscope 150, the grain of a grain can be observed. Therefore, the particles constituting the pattern and the particles of the grain are regarded as a specific structure. Then, when these particles are observed while the plastic plate 109 is rotated, the rotation shaft 116 can be detected with high accuracy.

  The procedures [1] to [3] for matching the probe 171 of the contact type length measuring device 170 and the probe 181 of the contact type length measuring device 180 on the rotation axis will be described below with reference to FIGS. 3, 4 and 5. .

[1] Rotating shaft position detecting step (FIG. 3)
FIG. 3A shows a main part of the aspherical eccentricity measuring apparatus in the rotation axis position detecting step, and FIG. 3B shows an image obtained with a microscope at that time.

  As shown in FIG. 3A, the holding unit 101 holds a plastic plate 109 for detecting the rotation shaft 116. Subsequently, the microscope 150 is moved by the microscope stage moving table 113. At this time, the microscope 150 is moved so that the center of the observation part of the microscope 150 and the rotation axis 116 of the air spindle 102 are substantially coincident with each other. Thereby, the microscope 150 is arranged so that its optical axis substantially coincides with the rotation axis 116 of the air spindle 102. Specifically:

  The light source 151 of the microscope 150 is turned on, and the captured image is observed by the monitor 161. Then, while observing the image displayed on the monitor 161, the particles on the upper surface of the plastic plate 109 are made observable. In order to focus on the upper surface of the plastic plate 109, the microscope 150 is moved in the vertical direction in FIG. The microscope 150 is moved by the microscope stage moving table 113. The plastic plate 109 side may be moved.

  Next, the air spindle 102 is rotated by the motor 103 in an observable state. When viewed on the monitor 161 while the air spindle 102 is rotating, particles on the upper surface of the plastic plate 109 are moved by rotation as shown in FIG.

  FIG. 3B schematically shows how the particles move. As can be seen from FIG. 3B, the particles move so as to draw concentric circles (concentrically). Therefore, if the movement trajectory of the particles is known, the rotation axis can be determined.

  Therefore, the state of the particles moving concentrically is photographed with the microscope 150. A plurality of images are acquired while the air spindle 102 rotates once. For example, in the case of obtaining ten images, if the time for one revolution of the air spindle 102 is t seconds, images are taken and recorded every t / 10 seconds. When the image capture is completed, a feature point (for example, one particle or a plurality of particles) common to each image is extracted by image processing. Then, the positions of the same feature points are plotted. Thereby, the point on the rotating shaft 116 of the air spindle 102 can be detected.

  The coordinate position in the two directions x and y of the point on the rotation axis 116 is recorded.

  The position detection on the rotation shaft 116 may not be a method based on image processing. As shown in FIG. 3B, since the monitor 161 has a scale 154, the measurer may detect the center of rotation using this scale.

[2] Upper probe position adjustment (rotation axis matching operation) step (FIG. 4)
FIG. 4A shows a main part of the aspherical eccentricity measuring apparatus in the upper probe position adjustment process, and FIG. 4B shows an image obtained with a microscope at that time.

  As shown in FIG. 4A, the plastic plate 109 on the holding unit 101 is removed, and the holding unit 101 is also removed from the air spindle 102. Subsequently, the contact-type length measuring device 170 is moved so that the probe 171 of the contact-type length measuring device 170 enters the observation field of view of the microscope 150. At that time, the position of the microscope 150 is not moved. Further, the contact type length measuring device 170 is moved by the length measuring device moving table 114.

  When the probe 171 is observed with the microscope 150, as shown in FIG. 4B, only the top portion of the surface is in focus. Thereby, the position of the probe 171 can be determined. When the diameter of the probe is large, since the focus is adjusted over a wide range of the microscope observation part, the top position of the surface tends to be difficult to understand when performing alignment. However, when the observation magnification of the microscope 150 is high, if the probe is moved up and down by several μm and the focus is intentionally shifted, a black and dark image can be obtained only at the surface top position of the probe. Therefore, it is preferable to binarize the black and dark image by image processing, and detect the surface top position of the probe from the center value of the binarized image.

  The surface top position of the probe may be detected visually by the measurer. Similarly, when the surface top position of the probe is detected visually, detection is performed in a state where the focus of the microscope 150 is aligned with the surface top of the probe. Alternatively, the position of the surface top may be detected based on the position of the black and dark image by moving the focus up and down by moving the position of the probe of several μm up and down.

  As described above, the coordinates of the points x and y on the rotation axis are obtained by the rotation axis position detection step [1]. Further, the surface top position of the probe 171 can also be obtained by a microscope. Therefore, the coordinates of the points x and y on the rotation axis are matched with the surface top position of the probe 171. This operation is performed by finely adjusting the length measuring device moving table 114. Thereby, the probe 171 of the upper contact type length measuring device 170 can be positioned on the rotating shaft 116 of the air spindle 102. The coordinates of the length measuring device moving table 114 at that time are set as the measurement origin position of the upper contact type length measuring device 170.

[3] Lower probe position adjustment (rotating axis matching operation) step (FIG. 5)
FIG. 5A shows the main part of the aspherical eccentricity measuring apparatus in the position adjustment process of the lower probe, and FIG. 5B shows an image obtained with a microscope at that time.

  Here, the position adjustment of the lower probe is performed in the same manner as the position adjustment (rotation axis matching operation) step of [2]. As shown in FIG. 5A, the position of the microscope 150 is not moved, and the contact-type length measuring device 180 is moved so that the probe 181 of the contact-type length measuring device 180 enters the observation field of view of the microscope 150. The movement of the contact type length measuring device 180 is performed by the length measuring device moving table 114.

  As in [2], the probe 181 can observe the surface top as shown in FIG.

  Thereafter, the length measuring device moving table 114 is finely adjusted while detecting the surface top position of the probe 181. Thereby, the probe 181 of the lower contact type length measuring device 180 can be positioned on the rotating shaft 116 of the air spindle 102. The coordinates of the length measuring device moving table 114 at that time are set as the measurement origin position of the lower contact type length measuring device 180.

  Through the above steps [1] to [3], the measurement origins (probe positions) of the upper contact type length measuring device 170 and the lower contact type length measuring device 180 are made to coincide with the position on the rotating shaft 116 with high accuracy. It becomes possible.

  The positioning of the contact-type length measuring device does not need to be performed every time the object is measured. That is, once the setting is made, it is not necessary to perform the setting again unless the mechanical positional relationship between the rotating shaft 116 of the air spindle 102 and the contact type length measuring device is changed.

  Next, procedures [4] to [7] for measuring a double-sided aspheric lens after positioning the contact-type length measuring device will be described.

[4] Test lens centering step (FIG. 6)
FIG. 6 shows an aspheric decentering measuring apparatus in the test lens centering step.

  As shown in FIG. 6, the holding unit 101 is installed on the air spindle 102. The holding unit 101 is for holding a test object. Next, the optical axis of the spot locus detection unit 130 is approximately matched with the rotation axis 116 of the air spindle 102. Here, the spot trajectory detection unit 130 is installed on the microscope stage 112. Therefore, the movement of the spot locus detection unit 130 can be performed by the microscope stage movement table 113.

  The position of the lens 134 of the spot locus detection unit 130 is adjusted, and the measurement light beam emitted from the spot locus detection unit 130 is incident on the upper aspherical surface 110a. At that time, the measurement light beam is incident perpendicular to the paraxial spherical surface. The paraxial spherical surface here is a paraxial spherical surface in the vicinity of the symmetry axis of the upper aspherical surface 110a. The light incident on the upper aspherical surface 110a is reflected by the upper aspherical surface 110a. The reflected light passes through the imaging optical element 134, the path is changed by the half mirror 133, and enters the imaging optical element 136. The light is imaged on the image sensor 135 by the imaging optical element 136.

  Therefore, the air spindle 102 is rotated by the motor 103 while the measurement light beam from the spot locus detection unit 130 remains incident on the upper aspherical surface 110a. Here, in an ideal state where the test surface is not shifted and tilted with respect to the rotation axis 116, the measurement light beam perpendicularly incident on the upper aspherical surface 110a is reflected vertically and returns to the same optical path. Therefore, the light (spot) imaged on the image sensor 135 does not move even if the test surface rotates. On the other hand, when there is a shift and tilt on the surface to be measured (exactly, since the spot trajectory detection unit 130 irradiates the measurement light beam in the range of the paraxial curvature that can be regarded as a substantially spherical surface, it occurs only on the aspherical surface. It is not necessary to consider the item of tilt to be performed, it is only necessary to consider the shift). At this time, the spot moves on the circumference of a circle having a predetermined radius. The value of the predetermined radius is a dimension (value) obtained by multiplying the shift amount of the paraxial curvature center of the test surface by the observation optical magnification of the spot locus detection unit 130.

  While the air spindle 102 is rotated by the motor 103, the output of the image sensor 135 and the output of the rotary encoder 104 are input to the calculation means 160. Then, the calculation means 160 calculates the shift amount and direction of the paraxial curvature center of the upper aspherical surface 110a from the position of each point of the reflection spot and the rotational position of the double-sided aspherical lens 110 at each point.

  Subsequently, the shift amount is reduced from the calculated shift amount and direction. This may be achieved by adjusting the position of the double-sided aspheric lens 110 on the holding unit 101. When the shift amount becomes sufficiently small, the position adjustment of the double-sided aspheric lens 110 is finished. Then, the shift amount and direction of the paraxial curvature center of the aspherical surface 110a are obtained again.

  Next, the position of the optical system of the spot trajectory detection unit 130 is changed, and the measurement light beam is incident on the lower aspherical surface 110b with the aspherical surface 110a being transmitted. At that time, the measurement light beam is incident perpendicular to the paraxial spherical surface. The paraxial spherical surface here is a paraxial curved surface near the symmetry axis of the lower aspherical surface 110b. The measurement light beam reflected by the lower aspherical surface 110 b passes through the imaging optical element 134, the path is changed by the half mirror 133, and enters the imaging optical element 136. The light is imaged on the image sensor 135 by the imaging optical element 136.

  Therefore, the air spindle 102 is rotated by the motor 103 while the measurement light beam from the spot locus detection unit 130 remains incident on the lower aspherical surface 110b. Then, when there is a shift and tilt on the test surface, the spot due to the reflection of the test surface moves on the image sensor 135. At this time, the measurement light beam passes through the upper aspherical surface 110a. Therefore, the movement of the spot due to reflection on the lower aspherical surface 110b is affected by the upper aspherical surface 110a.

  While the air spindle 102 is rotated by the motor 103, the output of the image sensor 135 and the output of the rotary encoder 104 are input to the calculation means 160. Then, the calculation means 160 calculates the shift amount and direction of the paraxial curvature center of the lower aspherical surface 110b from the position of each point of the reflection spot and the rotational position of the double-sided aspherical lens 110 at each point. In this calculation, information on the shift amount and direction of the paraxial curvature center of the aspherical surface 110a, the paraxial radius of curvature of the aspherical surfaces 110a and 110b, and the thickness and refractive index of the double-sided aspherical lens 110 are used. .

[5] Upper surface side ring three-dimensional shape measuring step (FIG. 7)
FIG. 7A shows an aspherical eccentricity measuring apparatus in the upper surface side zone three-dimensional shape measuring step, and FIG. 7B shows the main part of the aspherical eccentricity measuring apparatus in FIG. It shows a view from the positive direction of the axis.

  In the shape measurement, as shown in FIG. 7A, the microscope 150 and the spot locus detection unit 130 are retracted to a position that does not interfere with the shape measurement. This evacuation is performed by moving the microscope stage 112. The microscope stage 112 is moved by a microscope stage moving table 113.

  Next, the probe 171 is brought into contact with the aspherical surface 110a for measurement. The probe 171 is moved by moving the upper contact type length measuring device 170 by the length measuring device moving table 114. Further, the contact position of the probe 171 is a desired measurement position, and as shown in FIG. 7B, this position is a position in the minus direction from the rotation axis 116 to the y axis.

  When the probe 171 is brought into contact with the upper aspherical surface 110 a, the air spindle 102 is rotated by the motor 103. Then, the length of the test surface 110a is measured by the upper contact type length measuring device 170. At the same time, the rotary position is detected by the rotary encoder 104. Here, the length measurement value and the rotation position are sequentially input to the calculation means 160. Thereby, the annular three-dimensional shape data of the upper aspherical surface 110a is obtained.

[6] Lower surface side ring three-dimensional shape measuring step (FIG. 8)
FIG. 8A shows an aspheric eccentricity measuring apparatus in the lower surface side annular zone three-dimensional shape measuring step, and FIG. 8B shows the main part of the aspheric eccentricity measuring apparatus of FIG. It shows a view from the positive direction of the axis.

  When the process [5] is completed, the probe 171 is then separated from the upper aspherical surface 110a. At this time, the state where the upper contact type length measuring device 170 and the probe 171 are viewed from the plus direction of the x-axis is as shown in FIG. As shown in the drawing, the upper contact type length measuring device 170 and the probe 171 are retracted to a position where they do not interfere with the double-sided aspherical lens 110. Subsequently, the probe 181 is brought into contact with the lower aspherical surface 110b. The contact position of the probe 181 is a desired measurement position. As shown in FIG. 8B, this position is a position in the minus direction from the rotation axis 116 to the y axis.

  When the probe 181 is brought into contact with the lower aspherical surface 110 b, the air spindle 102 is rotated by the motor 103. Then, the length of the test surface 110b is measured by the lower contact type length measuring device 180. At the same time, the rotary position is detected by the rotary encoder 104. Here, the length measurement value and the rotation position are sequentially input to the calculation means 160. Thereby, the three-dimensional shape data of the annular zone of the lower aspherical surface 110b is obtained.

[7] Aspheric Decentration Calculation Step After the above measurement is completed, the calculation means 160 obtains the aspheric eccentric amount and direction of each aspheric surface based on the measurement result. In this calculation, the shift amount and direction of the air spindle 102 with respect to the rotational axis 116 of the center of paraxial curvature of the aspherical surface 110 a which is the upper surface of the double-sided aspherical lens 110, and the aspherical surface 110 a at a certain position from the rotational axis 116. The three-dimensional shape data of the annular zone, the shift amount and direction of the air spindle 102 at the center of the paraxial curvature of the aspherical surface 110b on the lower surface with respect to the rotational axis 116, and the annular tertiary of the aspherical surface 110b at a position from the rotational axis 116 The measurement result of the original shape data, the paraxial radius of curvature of the aspherical surface 110a and the aspherical surface 110b, and the thickness of the double-sided aspherical lens 110 are used.

  In the present embodiment, the probe 171 of the upper contact type measuring instrument 170 and the probe 181 of the lower contact type measuring instrument 180 can be made to coincide with the rotating shaft 116 of the air spindle 102 with high accuracy. Thereby, since the diameter of the ring-shaped three-dimensional shape data can be made accurate, highly accurate aspheric eccentricity measurement can be performed.

Second Embodiment FIG. 9 schematically shows a configuration of an aspheric eccentricity measuring apparatus according to a second embodiment of the present invention. In FIG. 9, members indicated by the same reference numerals as those shown in FIG. 1 are similar members. Therefore, the detailed description is abbreviate | omitted.

  The aspheric eccentricity measuring apparatus of the present embodiment is different from the first embodiment in the following points.

  As shown in FIG. 9, in the aspherical eccentricity measuring apparatus 100A of the present embodiment, the microscope 150 includes an eyepiece 155 instead of the TV camera 153 shown in FIG. Therefore, the position of the rotating shaft 116 of the air spindle 102, the position of the probe 171 of the contact-type length measuring device 170, and the position of the probe 181 of the contact-type length measuring device 180 are detected visually.

  Further, the microscope 150 includes a low-magnification objective lens 152A, a high-magnification objective lens 152B, and an objective lens switching unit 156 for switching them. The objective lens switching unit 156 can switch the observation magnification of the microscope 150 between low magnification and high magnification.

  The origin positions in the z direction of the probe 171 of the upper contact type length measuring device 170 and the probe 181 of the lower contact type length measuring device 180 are separated by a predetermined distance in the z axis direction, as shown in FIG. A probe 171 for measuring the upper side surface of the test object is located on the upper side with respect to the probe 181. Thereby, when measuring the three-dimensional shape of the annular zone of the test surface of the test object, the moving amount of the length measuring device can be reduced.

  The positional relationship between the probe 171 and the probe 181 viewed from the plus direction of the x-axis is substantially the same as that in FIG. Here, as in the first embodiment, the length measuring directions of the upper contact type length measuring device 170 and the lower contact type length measuring device 180 are both parallel in the z-axis direction. While one length measuring device is measuring the length, the other length measuring device is configured not to interfere with the test object, the air spindle 102 or the like. Specifically, the upper contact type length measuring device 170 and the lower contact type length measuring device 180 are installed on the length measuring device moving table 114 at a distance in the y-axis direction.

  In this embodiment, in order to detect the rotation shaft 116 of the air spindle 102, two types of plastic plates are used as the object to be observed. Both are used for detecting the origin position of the probe in the measuring direction. One is a plastic plate 121 for the probe 171 of the upper contact type length measuring device 170. The other is a plastic plate 122 for the probe 181 of the lower contact type length measuring device 180.

  Both the plastic plates 121 and 122 have an appropriate pattern printed in color on the upper surface for observation with the microscope 150. Therefore, the rotary shaft 116 of the air spindle 102 can be detected by magnifying and observing the pattern with the microscope 150.

  Other configurations are the same as those of the apparatus of the first embodiment.

  The procedures [1] to [3] for matching the probe 171 of the contact type length measuring device 170 and the probe 181 of the contact type length measuring device 180 on the rotation axis will be described below with reference to FIGS.

[1] Upper probe z position rotation axis position detection step (FIG. 10)
FIG. 10A shows the main part of the aspherical eccentricity measuring apparatus in the upper probe z-position rotation axis position detection step, and FIG. 10B shows an image obtained with a microscope with a low-magnification objective lens at that time. FIG. 10C shows an image obtained by a microscope using a high-magnification objective lens at that time.

  First, the position on the rotating shaft 116 of the air spindle 102 is detected for the upper probe z position. Therefore, the plastic plate 121 is held by the holding portion 101 as shown in FIG.

  Subsequently, the operation shifts to the operation of making the measurement optical axis of the microscope 150 substantially coincide with the rotation axis 116 of the air spindle 102. In this operation, the microscope 150 is moved by the microscope stage moving table 113.

  First, the objective lens of the microscope 150 is switched to the low-magnification objective lens 152A by the objective lens switching unit 156. Then, the upper surface of the plastic plate 121 is observed with the objective lens 152A. At that time, the upper surface is observed by the eyepiece 155 of the microscope 150, but the microscope 150 is moved in the Z direction so that the observation is possible (that is, for focusing).

  Subsequently, in this state, the air spindle 102 is rotated by the motor 103. A pattern is printed on the upper surface of the plastic plate 121. Therefore, when the air spindle 102 is rotated, the printed pattern is rotated in synchronization with the rotation operation. Naturally, the particles constituting the pattern also rotate and can be observed from the eyepiece 155 of the microscope 150.

  Observation with the low-magnification objective lens 152A makes it easy to find the center of rotation even when the position on the rotation axis 116 is away from the observation optical axis of the microscope 150, as shown in FIG. is there.

  The center of rotation of the pattern on the upper surface of the rotating plastic plate 121 is approximately matched with the center observed by the eyepiece lens 155 while being observed with the low-magnification objective lens 152A. This is performed by moving the microscope 150 in the x and y axis directions by the microscope stage moving table 113. A scale 154 for reading the position is arranged inside the optical system of the microscope 150. Therefore, the position adjustment of the microscope 150 is performed by the microscope stage moving table 113 so as to be aligned with the center of the scale 154.

  Next, the objective lens switching unit 156 switches the objective lens to the high-magnification objective lens 152B. That is, the high-magnification objective lens 152B is arranged on the observation optical axis of the microscope 150. In this state, the pattern of the rotating plastic plate 121 is observed again through the eyepiece lens 155.

  Since the high-magnification objective lens 152B is switched, the position of the rotation center can be observed more clearly as shown in FIG. Therefore, the rotation center position is read by the scale 154 that is simultaneously observed by the eyepiece 155.

  Here, it is assumed that the rotation center of the plastic plate 121 (pattern) is away from the center of the observation field of view of the microscope 150. In this case, fine adjustment of the position of the microscope 150 is performed in the x and y directions so that the rotation center of the pattern comes to a position that is not so far from the center of the scale 154. Then, it is easy to confirm in which direction the position of the probe is deviated during the subsequent probe alignment.

[2] Upper probe position adjustment (rotation axis matching operation) step (FIG. 11)
FIG. 11A shows the main part of the aspherical eccentricity measuring apparatus in the upper probe position adjusting step, and FIG. 11B shows an image obtained with a microscope using a low-magnification objective lens at that time. (C) shows an image obtained with a microscope using a high-magnification objective lens at that time.

  The plastic plate 121 on the holding unit 101 is removed from the holding unit 101. Then, the objective lens of the microscope 150 is switched to the low-magnification objective lens 152A by the objective lens switching unit 156.

  Subsequently, the probe 171 of the contact type length measuring device 170 is moved by the length measuring device moving table 114 so that the probe 171 enters the observation field of view of the microscope 150. Note that the position of the microscope 150 is not moved. In this state, since the objective lens is the low-magnification objective lens 152A, a wide observation field can be obtained. Therefore, as shown in FIG. 11B, it is easy to find even if the position of the probe is away from the rotating shaft 116 of the air spindle 102.

  When the probe 171 is found with the low-magnification objective lens 152A, a rough position adjustment is performed. Thereafter, the objective lens switching unit 156 switches to the high magnification objective lens 152B.

  Subsequently, the probe 171 is observed using the high-magnification objective lens 152B. Then, as shown in FIG. 11C, since only the top portion of the surface is focused, it is possible to determine the position of the probe.

  Inside the optical system of the microscope 150 is a scale 154 for reading the position. Therefore, the position of the surface top of the probe 171 is read by the scale.

  In the upper probe z position rotation axis position detection step [1], the coordinates of the points x and y on the rotation axis 116 are detected. Therefore, the length measuring device moving table 114 is finely adjusted so that the coordinates of the points x and y on the rotating shaft 116 coincide with the surface top position of the probe 171. Thereby, the probe 171 of the upper contact type length measuring device 170 can be positioned on the rotating shaft 116 of the air spindle 102. In addition, the coordinates of the length measuring device moving table 114 at that time are set as the measurement origin position of the upper contact type length measuring device 170.

  Note that the fine adjustment of the length measuring device moving table 114 may prevent the probe 171 from being exactly aligned with the rotating shaft 116 of the air spindle 102. In that case, from the coordinates of the points x and y of the position of the probe detected by the microscope 150 and the coordinates of the points x and y on the rotation axis 116 detected by the rotation axis position detection process of [1], the three-dimensional zone What is necessary is just to correct | amend the measurement diameter at the time of a shape. This correction can also be applied in the first embodiment.

When the annular zone is measured three-dimensionally, the measurement radius R when the probe 171 is moved by r [mm] in the negative direction of the y-axis can be expressed by the following equation.

The angle difference θ _Δ generated at that time can be expressed by the following equation.

Here, r is a distance [mm] by which the probe 171 is moved from the probe origin by the length measuring device moving table 114, α is a distance [μm] per scale of the scale 154 of the microscope 150, and (X _O , Y _O ). Is the coordinate position of the rotation center of the air spindle, and (X _P , Y _P ) is the coordinate position of the probe surface top. As for the angle, the counterclockwise direction is positive.

[3] Lower probe z position rotation axis position detection step (FIG. 12)
FIG. 12A shows the main part of the aspherical eccentricity measuring device in the lower probe z position rotation axis position detection step, and FIG. 12B shows an image obtained with a microscope using a low-magnification objective lens at that time. FIG. 12C shows an image obtained with a microscope using a high-magnification objective lens at that time.

  Similar to the upper probe z position rotation axis position detection step of [1], the position of the rotation axis 116 at the lower probe z position is detected.

  As shown in FIG. 12A, the holding plate 101 holds the plastic plate 122. Thereby, the position on the rotating shaft 116 of the air spindle 102 in the lower probe z position is detected. As will be described later, the surface top (observation side surface top) of the probe 181 of the lower contact type length measuring device 180 is observed with the microscope 150. Therefore, the plastic plate 122 is held such that the position of the upper surface thereof is substantially equal to the height of the top of the observation side surface of the probe 181.

  Subsequently, the operation shifts to the operation of making the measurement optical axis of the microscope 150 substantially coincide with the rotation axis 116 of the air spindle 102. In this operation, the microscope 150 is moved by the microscope stage moving table 113.

  The objective lens of the microscope 150 is switched to the low-magnification objective lens 152A by the objective lens switching unit 156. Then, the upper surface of the plastic plate 122 is observed with the objective lens 152A. At that time, the upper surface is observed by the eyepiece 155 of the microscope 150, but the microscope 150 is moved in the Z direction so that the observation is possible.

  In this state, the air spindle 102 is rotated by the motor 103. A pattern is printed on the upper surface of the plastic plate 122. Therefore, when the air spindle 102 is rotated, the pattern rotates in synchronization with the rotation operation. Naturally, the particles constituting the pattern also rotate and can be observed from the eyepiece 155 of the microscope 150.

  When observing with a low-magnification objective lens 152A, as shown in FIG. 12B, it is easy to find even when the position on the rotation axis 116 is away from the observation optical axis of the microscope 150.

  The rotation center of the pattern on the upper surface of the rotating plastic plate 122 is approximately matched with the center observed by the eyepiece lens 155 while being observed with the low-magnification objective lens 152A. This is performed by moving the microscope 150 in the x and y axis directions by the microscope stage moving table 113. A scale 154 for reading the position is arranged inside the optical system of the microscope 150. Therefore, the position adjustment of the microscope 150 is performed by the microscope stage moving table 113 so as to be aligned with the center of the scale 154.

  Next, the objective lens switching unit 156 switches the objective lens to the high-magnification objective lens 152B. That is, the high-magnification objective lens 152B is arranged on the observation optical axis of the microscope 150. In this state, the pattern of the rotating plastic plate 122 is observed through the eyepiece 155 again.

  Since switching to the high-magnification objective lens 152B is performed, the position of the rotation center can be observed more clearly as shown in FIG. Therefore, the rotation center position is read by the scale 154 that is simultaneously observed by the eyepiece 155.

  Here, it is assumed that the rotational center of the pattern of the plastic plate 121 is separated from the center of the observation field of view of the microscope 150. In this case, fine adjustment of the position of the microscope 150 is performed in the x and y axis directions so that the rotation center of the pattern comes to a position that is not so far from the center of the scale 154. Then, it is easy to confirm to which position the probe is displaced during the subsequent probe alignment.

[4] Lower probe position adjustment (rotation axis matching operation) step (FIG. 13)
FIG. 13A shows the main part of the aspherical eccentricity measuring apparatus in the lower probe position adjustment process, and FIG. 13B shows an image obtained with a microscope with a low-magnification objective lens at that time. 13C shows an image obtained with a microscope using a high-magnification objective lens at that time.

  The plastic plate 122 on the holding unit 101 is removed from the holding unit 101. Then, the objective lens of the microscope 150 is switched to the low-magnification objective lens 152A by the objective lens switching unit 156.

  Subsequently, the probe 181 of the contact-type length measuring device 180 is moved by the length measuring device moving table 114 so that the probe 181 enters the observation field of view of the microscope 150. Note that the position of the microscope 150 is not moved. In this state, since the objective lens is the low-magnification objective lens 152A, a wide observation field can be obtained. Therefore, as shown in FIG. 13B, it is easy to find even if the position of the probe is away from the rotating shaft 116 of the air spindle 102.

  When the probe 181 is found with the low-magnification objective lens 152A, a rough position adjustment is performed. Thereafter, the objective lens switching unit 156 switches to the high magnification objective lens 152B.

  Subsequently, the probe 181 is observed using the high-magnification objective lens 152B. Then, as shown in FIG. 13C, since only the top portion of the surface is focused, it is possible to determine the position of the probe.

  Inside the optical system of the microscope 150 is a scale 154 for reading the position. Therefore, the position of the top surface of the probe 181 is read by the scale.

  [3] In the lower probe z position rotation axis position detection step, the coordinates of the points x and y on the rotation axis 116 are detected. Therefore, the length measuring device moving table 114 is finely adjusted so that the coordinates of the points x and y on the rotating shaft 116 coincide with the surface top position of the probe 181. Thereby, the probe 181 of the lower contact type length measuring device 180 can be positioned on the rotating shaft 116 of the air spindle 102. Further, the coordinates of the length measuring device moving table 114 at that time are set as the measurement origin position of the lower contact type length measuring device 180.

  In some cases, the probe 181 cannot be exactly aligned with the rotation axis 116 of the air spindle 102 due to fine adjustment of the length measuring device moving table 114. In that case, from the coordinates of the points x and y of the probe position detected by the microscope 150 and the coordinates of the points x and y on the rotation axis 116 detected by the rotation axis position detection step [3], the three-dimensional zone What is necessary is just to correct | amend the measurement radius at the time of shape. This correction can also be applied in the first embodiment.

When the annular zone three-dimensional measurement is performed, the measurement radius R when the probe 181 is moved by r [mm] in the negative direction of the y-axis can be expressed by the following equation.

The angle difference θ _Δ generated at that time can be expressed by the following equation.

Here, r is a distance [mm] by which the probe 181 is moved from the probe origin by the length measuring device moving table 114, α is a distance [μm] per scale of the scale 154 of the microscope 150, and (X _O , Y _O ). Is the coordinate position of the rotation center of the air spindle, and (X _P , Y _P ) is the coordinate position of the probe surface top. As for the angle, the counterclockwise direction is positive.

  Through the steps [1] to [4], the measurement origins of the upper contact type length measuring device 170 and the lower contact type length measuring device 180 can be made to coincide with the position on the rotating shaft 116 with high accuracy. Become. Alternatively, it is possible to know the deviation between the measurement origin of the upper contact type length measuring device 170 and the lower contact type length measuring device 180 and the position on the rotating shaft 116. This makes it possible to correct the measurement radius when the annular zone is three-dimensional.

  The positioning of the contact-type length measuring device does not need to be performed every time the object is measured. Once the setting is made, it is not necessary to set again unless the mechanical positional relationship between the rotating shaft 116 of the air spindle 102 and the probes 171 and 181 changes.

  The procedure for measuring the double-sided aspherical lens is the same as that in the first embodiment, and is therefore omitted.

  Further, when the plastic plate 121 is disposed on the holding portion 101, it is preferable that the upper surface position of the plastic plate 121 coincides with the measurement position of the upper aspherical surface 110a. Similarly, when the plastic plate 122 is disposed on the holding unit 101, it is preferable that the upper surface position of the plastic plate 122 coincides with the measurement position of the lower aspherical surface 110b. Specifically, the thickness of the plastic plates 121 and 122 and the height of the holding part are set so as to be in such a preferable state. In this way, it is not necessary to greatly change the z-direction position of the probes 171 and 181 when measuring the aspherical lens 110 after the steps [2] and [3] are completed.

  Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention. May be.

1 schematically shows a configuration of an aspheric eccentricity measuring apparatus according to a first embodiment of the present invention. (A) shows the positional relationship of the upper contact type length measuring device and the lower contact type length measuring device shown in FIG. 1 as seen from the negative direction of the y axis, and (B) shows the upper side contact type length measuring device. The positional relationship seen from the positive direction of the x-axis of the contact-type length measuring device and the lower contact-type length measuring device is shown. (A) shows the main part of the aspheric surface eccentricity measuring apparatus in the rotation axis position detecting step, and (B) shows an image obtained with a microscope at that time. (A) shows the main part of the aspherical eccentricity measuring apparatus in the position adjustment process of the upper probe, and (B) shows an image obtained with a microscope at that time. (A) shows the main part of the aspherical eccentricity measuring device in the position adjustment process of the lower probe, and (B) shows an image obtained with a microscope at that time. 1 shows an aspheric decentering measuring device in a test lens centering step. (A) shows the aspheric eccentricity measuring device in the upper surface side ring three-dimensional shape measuring step, and (B) shows the main part of the aspheric eccentricity measuring device of (A) from the positive direction of the x-axis. It shows how it was seen. (A) shows the aspherical eccentricity measuring device in the lower surface side ring three-dimensional shape measuring step, and (B) shows the main part of the aspherical eccentricity measuring device of (A) from the positive direction of the x-axis. It shows how it was seen. The structure of the aspherical surface eccentricity measuring apparatus of 2nd embodiment of this invention is shown roughly. (A) shows the main part of the aspherical eccentricity measuring device in the upper probe z position rotation axis position detection step, (B) shows an image obtained with a microscope with a low magnification objective lens at that time, (C ) Shows an image obtained with a microscope using a high-magnification objective lens at that time. (A) shows the main part of the aspherical eccentricity measuring device in the upper probe position adjustment step, (B) shows an image obtained with a microscope with a low magnification objective lens at that time, (C) It sometimes shows an image obtained with a microscope using a high-magnification objective lens. (A) shows the main part of the aspherical eccentricity measuring device in the lower probe z position rotation axis position detection step, (B) shows an image obtained with a microscope with a low magnification objective lens at that time, ( C) shows an image obtained with a microscope using a high-magnification objective lens at that time. (A) shows the main part of the aspherical eccentricity measuring device in the lower probe position adjustment step, (B) shows an image obtained with a microscope with a low magnification objective lens at that time, (C), An image obtained with a microscope using a high-magnification objective lens at that time is shown. (A) schematically shows the configuration of the three-dimensional shape measuring machine disclosed in Japanese Patent Application Laid-Open No. 10-38556, and (B) shows a cross section of the holding portion shown in (A). .

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Aspherical eccentricity measuring apparatus, 100A ... Aspherical eccentricity measuring apparatus, 101 ... Holding part, 102 ... Air spindle, 103 ... Motor, 104 ... Rotary encoder, 109 ... Plastic plate, 110 ... Double-sided aspherical lens, 110a ... Covered Inspection surface, 110b ... Test surface, 112 ... Microscope stage, 113 ... Microscope stage movement table, 114 ... Measuring instrument movement table, 116 ... Rotating shaft, 121 ... Plastic plate, 122 ... Plastic plate, 130 ... Spot locus detector 131 ... Light source, 132 ... Collimating lens, 133 ... Half mirror, 134 ... Imaging optical element, 135 ... Imaging element, 136 ... Imaging optical element, 150 ... Microscope, 151 ... Light source, 152 ... Objective lens, 152A ... Low Magnification objective lens, 152B ... High magnification objective lens, 153 ... TV camera, 54 ... Scale, 155 ... Eyepiece lens, 156 ... Objective lens switching unit, 160 ... Calculation means, 161 ... Monitor, 170 ... Upper contact type measuring instrument, 171 ... Probe, 180 ... Lower contact type measuring instrument, 181 ... probe.

Claims (20)

An aspheric eccentricity measuring device for measuring the aspheric eccentricity of a test object,
A holding mechanism for holding the test object;
A rotating mechanism for rotating the holding mechanism;
An observation optical system disposed at a position facing the rotation mechanism across the holding mechanism;
A first probe disposed between the holding mechanism and the observation optical system;
A first moving mechanism for moving the first probe;
The aspherical eccentricity measuring apparatus, wherein the observation optical system is arranged so that an optical axis of the observation optical system and a rotation axis of the rotation mechanism are substantially coincident with each other. The observation optical system includes an objective lens, an eyepiece lens, and a scale member. The scale member has a scale formed at a predetermined interval, and the scale member is conjugated with an observation image observed through the eyepiece lens. The aspherical eccentricity measuring apparatus according to claim 1, wherein the aspherical eccentricity measuring apparatus is arranged at a proper position. 3. The rotation mechanism of the rotation mechanism is detected by rotating the rotation mechanism, observing the rotation of the observation image with respect to the scale, and detecting the rotation center of the rotation mechanism based on an observation result of a specific portion of the observation image. An aspheric surface eccentricity measuring device described in 1. The observation optical system includes an objective lens and an image pickup device, and the image pickup device is disposed at an observation image position formed by the objective lens and includes a display device that displays the observation image. 2. The aspheric surface eccentricity measuring apparatus according to 1. The rotation mechanism is rotated, the rotation of the observation image is imaged, and the position of the rotation center of the rotation mechanism is detected based on the observation result of the specific portion of the observation image. The aspheric eccentricity measuring device described. The aspherical eccentricity measuring apparatus according to claim 3, wherein the first moving mechanism is controlled so that the rotation center position and the first probe coincide with each other. The aspherical eccentricity measuring apparatus according to claim 3 or 5, wherein the measurement by the first probe is performed using the rotation center position as a measurement origin of the first probe. 6. The measurement position of the first probe is corrected based on a difference between the rotation center position and the measurement origin position of the first probe based on a difference between the two positions. An aspheric surface eccentricity measuring device as described in 1. The specific part of the observation image has a specific structure existing on a surface of the index member, and the index member is placed on the holding mechanism. Aspheric eccentricity measuring device. The specific part of the observation image has a specific structure artificially formed on the surface of the index member, and the index member is placed on the holding mechanism. 5. The aspheric surface eccentricity measuring apparatus according to 5. The aspherical eccentricity measuring apparatus according to claim 1, further comprising an optical system moving mechanism that moves the observation optical system in a direction perpendicular to a rotation axis of the rotating mechanism. The aspherical eccentricity according to claim 1, further comprising: a second probe disposed between the holding mechanism and the first probe; and a second moving mechanism for moving the second probe. measuring device. A second probe disposed between the holding mechanism and the first probe; and a second moving mechanism for moving the second probe, wherein the rotation center position and the second probe coincide with each other. The aspherical eccentricity measuring apparatus according to claim 3 or 5, wherein the second moving mechanism is controlled as described above. A second probe disposed between the holding mechanism and the first probe; and a second moving mechanism for moving the second probe; the rotation center position and the measurement origin of the second probe The aspherical eccentricity measuring apparatus according to claim 3 or 5, wherein when the position is different, the measurement position of the second probe is corrected based on a difference between both positions. The position of the first probe when coincident with the rotation center position and the position of the second probe when coincident with the rotation center position are the same in the direction along the rotation axis, The aspheric surface eccentricity measuring apparatus according to claim 13. The position of the first probe when it coincides with the rotation center position and the position of the second probe when it coincides with the rotation center position are different in a direction along the rotation axis. Item 14. The aspheric eccentricity measuring device according to Item 13. 6. The aspheric decentration measuring apparatus according to claim 3, wherein the observation optical system is a variable magnification optical system. An aspheric eccentricity measuring method for measuring an aspheric eccentricity of a test object,
The first index member held by the holding unit rotated by the rotation mechanism is observed by the observation optical system, and the center of rotation of the index provided on the first index member is made substantially coincident with the optical axis of the observation optical system. A step of approximately matching the optical axis of the observation optical system with the rotation axis of the rotation mechanism;
With the position of the observation optical system as it is, with the first index member and the holding part removed from the rotation mechanism, the first probe made of a spherical member is inserted into the field of view of the observation optical system, and the surface of the first probe Placing the apex at the position where the rotation center of the index of the observation optical system was, and setting the position as the origin position of the measurement;
While rotating the test object, the test object is irradiated with light along the rotation axis to detect the locus of the reflected light spot on the first test surface of the test object, and on the spot trajectory. Detecting the rotation angle of the test object corresponding to each point;
Based on the locus of the reflected light spot on the first test surface of the test object and the rotation angle of the test object, the shift amount with respect to the rotation axis of the paraxial center of curvature of the first test surface of the test object And the process of finding its direction,
While rotating the test object, the test object is irradiated with light along the rotation axis to detect the spot of the reflected light spot on the second test surface of the test object, and on the spot trajectory. Detecting the rotation angle of the test object corresponding to each point;
Based on the locus of the reflected light spot on the second test surface of the test object and the rotation angle of the test object, the shift amount with respect to the rotation axis of the paraxial center of curvature of the second test surface of the test object The first probe is brought into contact with the first test surface of the test object, and the test object is rotated while the test probe is rotated at the predetermined position from the rotation axis of the rotation mechanism. Obtaining the annular three-dimensional shape data of the first test surface of the inspection;
The amount and direction of shift of the rotation mechanism of the rotation mechanism of the paraxial curvature center of the first test surface of the test object and the rotation axis of the rotation mechanism of the rotation mechanism of the paraxial curvature center of the second test surface of the test object Shift amount and direction thereof, the annular three-dimensional shape data of the first test surface at a predetermined position from the rotation axis, the paraxial radius of curvature of the first test surface, and the second test surface A step of determining an aspheric eccentric amount and direction of the aspheric surface of the first test surface of the test object from the paraxial radius of curvature and the thickness of the test object. Aspheric eccentricity measurement method. The aspheric eccentricity measuring method according to claim 18, further comprising:
With the first index member and the holding part removed from the rotation mechanism, the second probe made of a spherical member is inserted into the field of the observation optical system, and the top of the second probe is used as the index of the observation optical system. Arranging at the position where the center of rotation was located, and making that position the origin position of measurement,
While the second probe is brought into contact with the second test surface of the test object and the test object is rotated, the second probe of the test object at a predetermined position from the rotation axis of the rotation mechanism is rotated by the second probe. A step of acquiring the three-dimensional shape data of the annular zone of the inspection surface;
A shift amount and direction of the rotation mechanism of the rotation mechanism at the paraxial curvature center of the first test surface of the test object, and the annular three-dimensional shape data of the first test surface at a predetermined position from the rotation shaft, , A paraxial radius of curvature of the first test surface, a shift amount and a direction of the rotation mechanism of the rotation mechanism at the center of the paraxial curvature of the second test surface of the test object at a predetermined position from the rotation axis From the annular three-dimensional shape data of the second test surface, the paraxial radius of curvature of the second test surface, the thickness and refractive index of the test sample, the second test surface of the test sample 19. The method of measuring an aspherical eccentricity according to claim 18, further comprising the step of obtaining an aspherical eccentric amount of the aspherical surface and a direction thereof. The aspheric eccentricity measuring method according to claim 18, further comprising:
A second index member having a thickness different from that of the first index member held by the holding unit rotated by the rotation mechanism is observed by an observation optical system, and the center of rotation of the index provided on the second index member is determined. Approximately matching the optical axis of the observation optical system, and approximately matching the optical axis of the observation optical system and the rotation axis of the rotation mechanism;
With the position of the observation optical system as it is, with the second index member and the holding part removed from the rotation mechanism, the second probe made of a spherical member is inserted into the field of view of the observation optical system, and the surface of the second probe Placing the apex at the position where the rotation center of the index of the observation optical system was, and setting the position as the origin position of the measurement;
While the second probe is brought into contact with the second test surface of the test object and the test object is rotated, the second probe of the test object at a predetermined position from the rotation axis of the rotation mechanism is rotated by the second probe. A step of acquiring the three-dimensional shape data of the annular zone of the inspection surface;
A shift amount and direction of the rotation mechanism of the rotation mechanism at the paraxial curvature center of the first test surface of the test object, and the annular three-dimensional shape data of the first test surface at a predetermined position from the rotation shaft, , A paraxial radius of curvature of the first test surface, a shift amount and a direction of the rotation mechanism of the rotation mechanism at the center of the paraxial curvature of the second test surface of the test object at a predetermined position from the rotation axis From the annular three-dimensional shape data of the second test surface, the paraxial radius of curvature of the second test surface, the thickness and refractive index of the test sample, the second test surface of the test sample 19. The method of measuring an aspherical eccentricity according to claim 18, further comprising the step of obtaining an aspherical eccentric amount of the aspherical surface and a direction thereof.

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