JP4986530B2 - Shape measuring method and measuring jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of measuring the attitude and the shape of a measuring object at high precision without receiving the effect of the tilt of a positioning tool, dust and the chamfering of the tool etc., on the basis of the contour or the backside of the measurement object in a three-dimensional shape measurement apparatus for measuring a surface shape from an upper surface. <P>SOLUTION: The method is capable of measuring the attitude and the shape of a measurement object at high precision on the basis of the contour or the backside of the measurement object with three contour positioning bodies disposed at the outer side of the contour of the measurement object and a cylindrical support member contacted to the contour of the measurement object to support the backside of the contour of the measurement object. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method for measuring the posture and shape of a lens surface with respect to an object to be measured, such as a lens shape, based on the outer shape of the lens (for example, the outer diameter when the lens is circular), and a probe for measuring the shape from the upper surface. Manufacturing of mobile phone with camera, digital still camera, DVD lens with shorter wavelength, etc. The present invention relates to a shape measuring method and a measuring jig for measuring the shape and posture of a lens such as the eccentricity and tilting posture of a lens surface with respect to an object to be measured, for example, the outer shape or the back surface of the lens surface, in quality control. .

  As a method of measuring the lens shape, which measures the posture of the lens surface based on the outer diameter and back surface of the conventional lens surface, the apex is processed into a semi-spherical shape, the lower side surface is made into a cylinder, and the lower surface is flat. There are three pins (positioning jigs) configured as described above, a lens to be measured is installed on the three positioning jigs, and measurements are made (for example, see Patent Document 1). 14A to 14D show a conventional lens shape measuring method described in Patent Document 1. FIG.

  14A to 14D, the upper surface of the lens 102 supported by the three positioning jigs 120 is measured, and the XYZ position of the lens surface and the A axis with the X axis as the center of rotation are compared with the design formula of the lens 102. Each value of the axis, the B axis with the Y axis as the rotation center, and the C axis with the Z axis as the rotation center, that is, the posture is determined.

Further, the hemispherical portion 120a of the three jigs 120 is measured, and the distance between the top of the hemispherical surface of the jig 120 measured in advance from the data of the hemispherical portion 120a and the side surface position 120b with which the lens 102 contacts is in contact with the rear surface of the lens. Using the parameter of the distance h ₁ with respect to the position (lens back surface support portion) 120c, the lens side surface and the back surface position are calculated, and the attitude of the lens 102 with respect to this position is calculated.

JP 2002-71344 (6th page, FIG. 5)

  However, in the conventional configuration shown in FIG. 14A to FIG. 14D by measuring the spherical surface 102a of the lens 102 by the positioning jig 120, when the positioning jig 120 is slightly tilted, the lens side surface and the lens positioning jig are corrected. A minute gap is formed on either the upper side or the lower side of the tool 120, and the position of the hemisphere at the apex of the jig 120 deviates from the position of the lens outer diameter 102c. Arise.

  Further, since the lens back surface support portion 102c of the positioning jig 120 is configured with a plane that can be easily processed, micro dust is easily sandwiched between the flat surface portion and the lens back surface, and an error is caused in the measurement of the posture in the tilt direction. There was a problem that it was likely to occur.

  Further, by reducing the lens outer diameter 102c to about 3 mm, the lens edge portion 103 that can be supported is also reduced to about 0.4 mm, and the corner portion configured by the back surface support portion 120c and the cylindrical portion 120b that supports the side surface. Also, it becomes difficult to reduce the R processing 123, and by interfering with the edge 104 of the lens edge portion 103, the back surface of the lens edge portion 103 floats in the air without being supported by the back surface support portion 120c, resulting in a measurement error.

  The present invention solves the above-mentioned conventional problems, and in a shape measuring machine having a probe that measures only from the upper surface, or a three-dimensional shape measuring device that measures the shape from reflected light by applying light from the upper surface, It is an object of the present invention to provide a shape measuring method and a measuring jig for measuring the shape of an object to be measured such as the posture of the object to be measured based on the outer shape or the back surface of the object.

  In order to achieve the above object, the present invention is configured as follows.

According to the first aspect of the present invention, there are provided three holding units comprising an outer shape positioning sphere to be brought into contact with the outer periphery of the object to be measured and a back surface supporting member for supporting the back surface of the outer periphery of the object to be measured. The measurement object is placed on a measuring jig so that at least one of the three holding units holds the measurement object against the remaining two holding units with a constant force. Holding the object to be measured;
Measuring the upper surface of the object to be measured and the three outer positioning spheres to obtain the position coordinates of the upper surface of the object to be measured and the position coordinates of the three outer positioning balls;
From the radius of each of the three contour positioning spheres set in advance and the position coordinate data of the three contour positioning spheres, the position where the three contour positioning spheres contact the object to be measured is obtained.
The back surface of the object to be measured is obtained by using the difference between the heights of the back surface supporting members of the three holding units set in advance and the heights of the outer shape positioning balls and the data of the position coordinates of the three outer shape positioning balls. Obtain the inclination of the object to be measured with reference to
The posture and shape of the object to be measured are determined based on the outer shape of the object to be measured, based on the position of the three outer shape positioning balls in contact with the object to be measured, the inclination, and the position coordinate data of the object to be measured. A shape measuring method is provided.

According to the second aspect of the present invention, the cylindrical outer shape positioning body having a conical recess at the center to be in contact with the outer periphery of the object to be measured, and the back surface supporting the back surface of the outer periphery of the object to be measured. The object to be measured is placed on a measuring jig provided with three holding units composed of support members, and at least one of the three holding units holds the object to be measured. Hold the measured object so that it can be pressed against the unit with a certain force,
Measure the upper surface of the object to be measured and the conical recesses of the three outer shape positioning bodies from above to obtain the position coordinates of the upper surface of the object to be measured and the position coordinates of the three outer shape positioning bodies,
From the radius of the cylindrical portion of the three contour positioning bodies set in advance and the position coordinate data of the three contour positioning bodies, the position where the three contour positioning bodies contact the object to be measured is obtained.
Using the preset difference between the heights of the concave portions of the back support member and the outer shape positioning body of the three holding units and the position coordinate data of the three outer shape positioning bodies, the measured object Obtain the inclination of the measured object with respect to the back side of the object,
The posture and shape of the object to be measured are obtained based on the outer shape of the object to be measured, based on the position of the three outer shape positioning bodies in contact with the object to be measured, the inclination, and the position coordinate data of the object to be measured. A shape measuring method is provided.

  According to the third aspect of the present invention, after measuring the shape of the object to be measured, the position to be measured is changed by rotating the object to be measured at a predetermined angle with respect to the holding unit. Then, the shape measurement method according to the first or second aspect is provided, wherein the shape measurement of the object to be measured is performed again.

  According to the fourth aspect of the present invention, the measurement jig is provided with three eccentric position measurement reference spheres at positions where the position coordinates can be measured from the front surface and the back surface, respectively, from the surface side of the object to be measured. After measuring the shape of the surface of the object to be measured and the central coordinates and inclination of the three eccentric position measurement reference spheres, the shape of the back surface of the object to be measured and the three eccentricities from the back surface side of the object to be measured. Any one of the first to third aspects is characterized in that a center coordinate and an inclination of a reference sphere for position measurement are measured, and a deviation in coordinates between the front surface and the back surface of the object to be measured is obtained to obtain the shape of the object to be measured. A shape measuring method according to one embodiment is provided.

According to the fifth aspect of the present invention, the outer shape positioning sphere that contacts the outside of the outer periphery of the object to be measured;
Three holding units composed of a back surface supporting member that supports the back surface of the outer peripheral portion of the object to be measured are provided,
At least one holding unit among the three holding units provides a measuring jig provided with pressing means for pressing the object to be measured against the remaining two holding units with a constant force.

According to the sixth aspect of the present invention, a cylindrical outer shape positioning body having a conical recess at the center contacting the outside of the outer peripheral portion of the object to be measured;
Three holding units composed of a back surface supporting member that supports the back surface of the outer peripheral portion of the object to be measured are provided,
At least one holding unit among the three holding units provides a measuring jig provided with pressing means for pressing the object to be measured against the remaining two holding units with a constant force.

  According to a seventh aspect of the present invention, in the fifth or sixth aspect, the measurement jig further includes three eccentric position measurement reference spheres at positions where position coordinates can be measured from the front surface and the back surface, respectively. Provide measurement jigs.

  As described above, according to the shape measuring method and the measuring jig of the present invention, even when the surface perpendicular to the side surface of the object to be measured or the back surface of the object to be measured cannot be directly measured, the outer side of the outer periphery of the object to be measured The outer shape of the object to be measured is determined by the outer shape positioning ball or the outer shape positioning body of each of the three holding units in contact with the outer surface and the cylindrical back surface supporting member that supports the rear surface of the outer periphery of the object to be measured. In addition, the posture and shape of the surface to be measured can be measured with high accuracy.

  Further, three cylindrical outer shape positioning bodies arranged outside the outer peripheral portion of the object to be measured, and a conical concave portion for measurement opened in the center of the outer shape positioning body are provided in the cylindrical outer shape positioning body. If it is installed at a position close to the support height of the outer shape of the object to be measured on the side surface, the posture and shape of the object to be measured can be measured with a minimum error in the XY directions even if the outer shape positioning body is slightly inclined.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram of an object to be measured, for example, a measurement jig, according to the first embodiment of the present invention. FIG. 2A is a plan view of the measurement jig according to the first embodiment of the present invention as viewed from above, and is supported by three holding claws from three directions on the outer peripheral portion of the lens. 3 and 4A are a perspective view and an enlarged cross-sectional side view of the schematic configuration of the one holding claw, respectively.

  In FIG. 1, reference numeral 1 denotes a lens as a measurement object (for example, a circular spherical or aspherical lens having a diameter of 3 to 7 mm), and 2 is connected to a known three-dimensional shape measuring apparatus 70 and from above the lens 1 in the XY directions. A stylus that scans in two directions (in two directions perpendicular to the vertical direction and perpendicular to each other), focuses in the Z direction (vertical direction), and measures the shape of the lens surface 1a and the like of the lens 1, and 3 is a horizontal direction. Are arranged at equal intervals around the lens 1 of the object to be measured so as to be in contact with the object to be measured along (for example, when three are arranged, they are arranged at intervals of 120 degrees) and the lens 1 A holding unit that supports a side surface of the outer peripheral portion (a side surface of the lens edge portion 7 when the lens edge portion 7 is provided, a side surface of the outer peripheral portion of the lens itself when the lens edge portion 7 is not provided) and a back surface of the outer peripheral portion of the lens 1. An example of a holding claw is a holding claw, and 4 is a part of the holding claw 3 and is oblique to the lateral direction (for example, at an inclination angle of 20 ° to 45 °) toward the lens placement position A0. Each of the three outer diameter position reference spheres 4 is an outer diameter position reference sphere as an example of an outer shape positioning sphere supported by the conical portion 4b at the tip of the protruding outer diameter position reference sphere support member 4A. By supporting the side surface of the outer peripheral portion of the lens 1 by contacting the side surface of the spherical surface with the side surface of the outer peripheral portion of the lens 1, the side surface of the outer peripheral portion of the lens 1 of each of the three outer diameter position reference spheres 4 Even if the attitude to the lens changes, the radial position of the lens 1 can be accurately supported by the three outer diameter position reference balls 4. The three outer diameter position reference spheres 4 have the same diameter.

  The three holding claws 3 support the back surface of the outer peripheral portion of the lens 1 in addition to the three outer diameter position reference spheres 4 supported one by one by the three outer diameter position reference sphere support members 4A. 3 is provided with three cylindrical lateral pins 5 that function as an example of a back support member. The three cylindrical lateral pins 5 have the same diameter, respectively project along the lateral direction toward the lens placement position A0, and the back surface of the outer peripheral portion of the lens 1 of the lens 1 has three cylinders. By supporting by the cylindrical surface of each tip of the lateral pin 5, the contact area between the lens 1 and the cylindrical lateral pin 5 is smaller than when supporting the back surface of the outer peripheral portion of the lens 1 with a flat surface. Thus, dust or the like is less likely to be sandwiched between the back surface of the outer peripheral portion of the lens 1 and the cylindrical lateral pin 5, and the position of the lens back surface of the outer peripheral portion of the lens 1 can be directly supported.

  Further, the holding claw 3 is provided with a length adjusting mechanism 6, and the length adjusting mechanism 6 includes an outer diameter position reference sphere support member 4 </ b> A and a cylindrical lateral pin 5 that respectively protrude toward the lens placement position A <b> 0 side. The amount of protrusion can be adjusted independently. Specifically, the outer diameter position reference sphere support member 4A can be projected to the first through hole 6d of the length adjustment mechanism casing 6c so as to be able to protrude obliquely to the lens placement position A0 with respect to the lateral direction. By screwing the first adjustment screw 6a inserted and screwed into the length adjustment mechanism casing 6c, the inner end of the first adjustment screw 6a has an outer diameter position reference ball support member 4A in the first through hole 6d. The outer diameter position reference sphere support member 4A is fixed in the first through hole 6d by contacting and pressing the side surface of the outer diameter position reference sphere support member 4A. Conversely, if the first adjustment screw 6a is loosened with respect to the length adjustment mechanism casing 6c, the outer diameter position reference ball support member 4A is advanced and retracted in the first through hole 6d of the length adjustment mechanism casing 6c. Length adjustment (projection amount adjustment) can be performed. As a result, the outer diameter position reference sphere 4 fixed to the distal end of the outer diameter position reference sphere support member 4A can be freely adjusted in position obliquely on the XZ plane, and the support height of the side surface of the outer peripheral portion of the lens 1 can be adjusted. It is possible to adjust the height to a suitable support position before measuring the lens shape according to the height dimension of the lens edge portion 7.

  Further, the length adjustment mechanism 6 can independently adjust the protrusion amounts of the outer diameter position reference ball support member 4A and the cylindrical lateral pin 5 that protrude toward the lens placement position A0. . Specifically, the cylindrical lateral pin 5 is inserted in the second through hole 6e of the length adjustment mechanism casing 6c so as to be able to protrude in the lateral direction toward the lens placement position A0, and is thus length-adjusted. By screwing the second adjustment screw 6b screwed into the casing 6c, the inner end portion of the second adjustment screw 6b contacts and presses the side surface of the cylindrical lateral pin 5 in the second through hole 6e, and the cylinder The lateral pin 5 is fixed in the second through hole 6e. Conversely, if the second adjusting screw 6b is loosened with respect to the length adjusting mechanism casing 6c, the cylindrical lateral pin 5 is advanced and retracted in the second through hole 6e of the length adjusting mechanism casing 6c to adjust the length. (Projection amount adjustment) can be performed. As a result, the position of the tip of the cylindrical lateral pin 5 can be freely adjusted along the lateral direction in the XY plane, and the lens shape is adjusted to the width of the lens edge portion 7 on the outer peripheral portion of the lens 1. It is possible to adjust to a suitable support position before the measurement. A more specific length adjustment procedure will be described later.

  Each holding claw 3 includes a lens pressing spring 8 that extends along the axial direction of the outer diameter position reference ball support member 4 </ b> A at the top of each holding claw 3. The lens 1 is supported so as not to rattle. As shown in FIG. 2B, the lens holding spring 8 has a circular through hole 8a at the lens end, and the outer diameter reference sphere 4 is located in the through hole 8a. A1 and A2 in FIG. The three-dimensional shape connected to the stylus 2 with the tip of the stylus 2 inserted into the through hole 8a from above the through hole 8a and the lower end of the stylus 2 contacting the outer diameter reference sphere 4 as shown in FIG. The measurement device 70 can measure the position coordinates of the outer diameter position reference sphere 4. At this time, in order to prevent the lens 1 from being distorted by the urging force of the lens pressing spring 8, the lens edge portion 7 is placed at the tip of the lens pressing spring 8 from above the lens edge portion 7 at a position above each cylindrical lateral pin 5. Is trying to support.

  Each holding claw 3 includes three outer diameter reference spheres 4 that support the side surface of the outer peripheral portion of the lens 1, three cylindrical lateral pins 5 that respectively support the rear surface of the outer peripheral portion of the lens 1 at the tip, The lens holding spring 8 and the members can be integrally moved back and forth along the radial direction of the lens 1.

  Reference numeral 11 denotes a holding claw preload urging spring as an example of a pressing means, and one holding claw 3 (for example, the lower right holding claw 3 in FIG. 2A) of the three holding claws 3 is held by a holding claw preload urging. The spring 11 is pressed against the side surface of the outer periphery of the lens 1 with a constant force in the center direction of the lens 1 (along the arrow 11A pointing upward to the left) by the biasing force of the spring 11, and is constant with the biasing force of the holding claw preload biasing spring 11. The pressure is applied by force, and the side surface of the outer peripheral portion of the lens 1 is pressed and supported by the equal force of the three holding claws 3.

  As an example, the diameter of the outer diameter position reference sphere 4 is 1 mm, and its processing accuracy has a sphericity of 0.1 μm or less (for example, 50 nm or less), and the width of the lens edge portion 7. Is about 0.4 mm to 0.5 mm.

  As described above, the measuring jig generally includes three holding claws 3, one holding claw preload biasing spring 11, and the support plate 10.

  In FIG. 2A, 9 is a jig used for measuring the eccentric positions of the front and back surfaces of the lens 1 in the measuring jig, and includes three eccentric position measuring reference balls that can be measured from the upper surface and the lower surface. Yes, used when measuring the eccentric position of the front and back of the lens 1. Reference numeral 10 denotes a support plate constituting a part of the measurement jig, and the three holding claws 3 and the like and the eccentric position measurement reference sphere 9 are installed on the support plate 10. The eccentric position measuring reference sphere 9 is supported in the through hole 10 b of the support plate 10, and the eccentric position measuring reference sphere 9 is exposed on both surfaces of the support plate 10, so that the stylus 2 is exposed from both the front and back sides of the support plate 10. Can be contacted. A through hole 10a is formed at the center of the support plate 10, and the length adjustment of the cylindrical lateral pin 5 and the length adjustment of the outer diameter position reference ball support member 4A, which will be described later, are performed in FIGS. 12A and 12B, respectively. The illustrated length adjusting jig 60 can be fitted. 11, as described above, the holding claw pressure biasing spring for biasing the holding claw 3 with a constant force toward the center of the lens and pressing the lens 1 with a uniform force by the three holding claws 3. It is.

  As shown in FIG. 4A, the tip of the edge of the lens edge portion 7 has a gap 50 between the outer diameter reference sphere 4 and the cylindrical lateral pin 5 supported obliquely. The cylindrical lateral pin 5 does not mechanically interfere with each other, and the lens 1 can be stably installed.

  The procedure of the lens shape measurement operation performed using the lens shape measurement jig having the structure will be described with reference to FIGS. 4B and 4C.

  At the lens mounting position A0 at the center of the support plate 10 such that the side surface of the outer peripheral portion of the lens 1 is in contact with the outer diameter position reference sphere 4 of two of the three holding claws 3. After placing the lens 1, the outer diameter position reference sphere 4 of the remaining one holding claw 3 is brought into contact with the side surface of the outer peripheral portion of the lens 1 by the urging force of the pressure urging spring 11 to hold the three pieces. The claw 3 holds the lens 1 from the outer periphery with a constant force and holds it at the lens placement position A0.

  In this state, first, the XYZ position coordinates of the three outer diameter position reference spheres 4 are acquired from the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S1).

  Next, based on the acquired XYZ position coordinates, the stylus 2 of the three-dimensional shape measuring apparatus 70 is moved, and the stylus 2 is moved out of the three outer diameter position reference spheres 4 at the tips of the three holding claws 3. A three-dimensional shape in which the XYZ position coordinates of the outer diameter position reference sphere 4 are connected to the stylus 2 by contacting one outer diameter position reference sphere 4 (see the stylus 2 shown at the position A1 or A2 in FIG. 1). Measurement is performed by the measurement device 70 and the measurement result is stored in the storage unit 71 of the three-dimensional shape measurement device 70.

This measurement is performed by scanning the stylus 2 concentrically within the XY plane with the top of the top surface of the outer diameter position reference sphere 4 as the center, so that the XYZ position coordinates near the top surface of the outer diameter position reference sphere 4 are 3 The arc center of the outer diameter position reference sphere 4 and the Z position height of the outer diameter position reference sphere 4 are measured using the radius of the outer diameter position reference sphere 4 measured by the dimension shape measuring apparatus 70 and obtained in advance. Each is calculated by the calculation unit 72 connected to the three-dimensional shape measuring apparatus 70 (step S2), and the XYZ position of the outer diameter position reference sphere 4 is determined. Thereby, XYZ data (XYZ position coordinate data) (X ₁ , Y ₁ , Z ₁ ) of the _first outer diameter position reference sphere 4 is calculated, and the calculation result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70. (Step S3).

Next, the remaining two outer diameter position reference spheres 4 are sequentially measured in the same manner, and all the XYZ position coordinates of the three outer diameter position reference spheres 4 are respectively measured and calculated. XYZ data (XYZ position coordinate data) (X ₁ , Y ₁ , Z ₁ ), (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) of the reference sphere 4 are obtained and stored. Store in the unit 71 (step S4).

  Thereafter, the lens surface 1a of the lens 1 is scanned on the XY axes with the stylus 2, and the XYZ position coordinates are measured with the three-dimensional shape measuring device 70 (see the stylus 2 shown at the position A3 in FIG. 1). The center is obtained by the calculation unit 72 and stored in the storage unit 71 (step S5). For example, it is impossible to attach the lens 1 horizontally to the three-dimensional shape measuring apparatus 70 with sub-micron accuracy or less. With the lens 1 attached obliquely, the apex does not become the center of the lens 1. Therefore, data measurement is performed at a plurality of points on the XY axes, and when the lens 1 is an aspherical surface, the tilt of the lens 1 and the center position of the lens 1 in the tilted state of the lens 1 can be obtained by calculation from this measurement data. it can. Specifically, the posture of the lens 1 can be obtained by changing the XY position, the inclination about the XY axis, and the Z position so that the sum of the squares of the differences between the design formula and the measurement data is minimized.

  Next, using this measurement center as the start point of the measurement coordinates, the XYZ position coordinates of the entire lens surface 1a are measured concentrically with the lens surface 1a, and the shape data of the lens 1 is acquired and stored in the storage unit 71 ( Step S6).

Next, the calculation unit 72 obtains a difference between the measured shape data and the design equation of the lens 1 to be measured, and design coordinates (the lens surface defined by the design equation) so that the sum of squares of the difference is minimized. The above XYZ coordinates or the design coordinates that define the shape of the lens 1 are translated in the XYZ directions or rotated in the A, B, and C directions, which are the rotation directions around the XYZ axes, respectively. Is calculated as an alignment amount (X _a , Y _a , Z _a , A _a , B _a , C _a ) based on the coordinates of the three-dimensional shape measuring apparatus 70 and stored in the storage unit 71 (step S7).

Thereafter, the XYZ data of the three outer diameter position reference spheres 4 obtained by the measurement of the three outer diameter position reference spheres 4, the centers of the three outer diameter position reference spheres 4 measured in advance and the cylindrical direction Using the respective heights (Z position heights of the outer diameter position reference sphere 4) h ₁ , h ₂ , and h ₃ of the pins, the calculation unit 72 uses the lens in the three outer diameter position reference spheres 4. The jig surface height Z _1j = Z ₁ -h ₁ , Z _2j = Z ₂ -h ₂ , Z _3j = Z ₃ -h ₃ where the back surface of 1 is in contact with the cylindrical lateral pin 5 is calculated and stored. It memorize | stores in the part 71 (step S8).

Next, position coordinates (X ₁ , Y ₁ , Z _1j ) of three points of jig surface heights Z _1j , Z _2j , Z _3j at positions where they contact the lens outer diameter of the three outer diameter position reference spheres 4, A plane equation P1 passing through (X ₂ , Y ₂ , Z _2j ), (X ₃ , Y ₃ , Z _3j ) is calculated (step S9).

Next, the angle formed by the plane equation P1 and the X and Y axes, that is, the tilt angles A _p and B _p of the back surface of the outer peripheral portion of the lens 1 are calculated by the calculation unit 72 and stored in the storage unit 71 (step 71). S10). From the plane equation, the normal vector of the plane can be easily obtained, and the vector of the obtained normal vector viewed on the XZ plane and the YZ plane can be easily obtained. Therefore, the angle formed by these two vectors and the Z axis ( Tilt angles A _p , B _p ) can be determined from the inner product.

Next, when the outer shape of the lens 1 is not circular, the first and second outer diameter position reference spheres 4 installed in the portion defined as the lens reference side surface in the side surface of the outer periphery of the lens 1. the angle C _p coordinates and X axis calculated by the stylus 2, stores the tilt angle of the side surface of the outer peripheral portion of the lens 1 in the storage unit 71 are acquired by computing unit 72 (step S11). However, if the outer shape of the lens 1 is circular, this step S11 is omitted.

Thereafter, the radii R ₁ , R ₂ , R ₃ of the _three outer diameter position reference spheres 4 measured in advance and the XY coordinates of the three outer diameter position reference spheres 4 obtained in the above are used as the centers, and the radius Center coordinates X _c and Y _c of the circle inscribed in the three drawn circles are calculated by the calculation unit 72 (step S12).

Then, the X _c, the value of Y _c, the plane equation P1 previously obtained, the X _c, by substituting Y _c, the reference height Z _c at the center position with respect to the side surface of the outer peripheral portion of the lens 1 Calculation is performed by the calculation unit 72 (step S13).

Next, the difference between the alignment amount (X _a , Y _a , Z _a , A _a , B _a , C _a ) and the tilt angles A _p , B _p on the back surface of the outer periphery of the lens 1 and the center position is calculated. By _calculating by the portion 72, the eccentric amount dX = X _a −X _c , dY = Y _a −Y _c , dZ = Z _a −Z _c and the tilt amount with respect to the outer peripheral portion reference (in other words, the outer shape reference) of the lens 1. dA = A _a −A _p , dB = B _a −B _p , dC = C _a −C _p are calculated and stored in the storage unit 71 (step S < _b > 14). If the outer shape of the lens 1 is circular, dC = C _a −C _p is not calculated.

  As a result, the shape of the lens 1 is measured by calculating the posture of the lens 1 by the calculation unit 72 based on the calculated eccentricity and tilt amount based on the calculated outer circumference reference (in other words, the outer shape reference) of the lens 1. be able to.

  According to the shape measurement method and the measurement jig according to the first embodiment, even when the side surface of the outer peripheral portion of the lens 1 or the back surface of the lens 1 cannot be directly measured, the lens is disposed outside the outer peripheral portion of the lens 1. Based on the outer diameter or the back surface of the lens 1, the three outer diameter position reference spheres 4 and cylindrical lateral pins 5 that support the back surface of the lens 1 provided at three locations on the outer periphery of the lens 1. 1 can be measured with high accuracy, and therefore the lens shape can be measured with high accuracy.

  Further, the three outer diameter position reference spheres 4 support the outer peripheral side surface of the lens 1 from the oblique direction with respect to the lateral direction by the outer diameter position reference sphere support member 4A. The radial position of the radial position reference sphere 4 is variable by the length adjustment mechanism 6, and the radial positions of the three cylindrical lateral pins 5 are variable by the length adjustment mechanism 6. The cylindrical lateral pin 5 is configured as a holding claw 3 as an example of one holding unit, and the holding jig of the holding claw 3 is configured as a lens by configuring the measurement jig with three holding units. Measurements can be made without changing each dimension.

  The length adjustment of the cylindrical lateral pin 5 and the length adjustment of the outer diameter position reference sphere support member 4A will be described in detail below.

  FIG. 12A shows the configuration of a length adjusting jig 60 that adjusts the length of each of the cylindrical lateral pins 5 of the three holding claws 3 and the length of the outer diameter position reference ball support member 4A. The length adjusting jig 60 is formed of a two-stage cylindrical shape including a first-stage smaller cylindrical part 60a and a second-stage larger cylindrical part 60b. The outer diameter of the first-stage smaller cylindrical portion 60a is the same size as the inner diameter on the back surface side of the lens edge portion 7 of the lens 1 and is made to have a thickness comparable to the diameter of the tip of the cylindrical lateral pin 5. . Furthermore, the second larger cylindrical portion 60b is made of a cylinder that is enlarged by the edge width dd of the lens edge portion 7 so as to be the same as the outer diameter of the side-side reference lens edge portion 7 of the outer peripheral portion of the lens 1 to be measured. It is created with the same thickness as the lens edge portion 7.

  As shown in FIG. 12B, the smaller cylindrical portion 60a of the length adjusting jig 60 is attached so as to fit in the central through hole 10a of the support plate 10 of the measuring jig. Next, the outer diameter position reference sphere 4 supported by the outer diameter position reference sphere support member 4 </ b> A obliquely by the length adjustment mechanism 6 comes to substantially the center of the second-stage cylindrical portion 60 b of the length adjustment jig 60. Adjust the length as follows. Specifically, after the first adjustment screw 6a is loosened to adjust the position of the outer diameter position reference ball support member 4A with respect to the length adjustment mechanism case 6c, the first adjustment screw 6a is tightened and the outer diameter is adjusted at that position. The position reference sphere support member 4A is fixed. Further, the length of the cylindrical lateral pin 5 is adjusted so as to come into contact with the side surface position of the first-stage cylindrical portion 60 a of the length adjusting jig 60. Specifically, after the second adjusting screw 6b is loosened to adjust the position of the cylindrical lateral pin 5 relative to the length adjusting mechanism case 6c, the second adjusting screw 6b is tightened and the cylindrical lateral pin 5 is tightened at that position. To fix.

  By using such a length adjustment jig 60 shown in FIG. 12A, the position of the cylindrical lateral pin 5 can be easily adjusted even if the lens edge portion 7 is as small as about 0.4 mm.

  In addition, the positions of the three holding claws 3 can be adjusted in this way (in other words, the position of the outer diameter position reference sphere 4 supported by the outer diameter position reference sphere support member 4A can be adjusted, and the horizontal direction of the cylinder). It is possible to adjust the position of the pin 5), and it is not necessary to design and manufacture the outer diameter position reference sphere 4, which requires high-precision processing, according to the shape of the lens 1 to be measured. Even when the model is switched, the length adjustment jig 60 or the simple jig 60C shown in FIG. 11 can be used at low cost.

  A simple jig 60 </ b> C shown in FIG. 11 is constituted by, for example, a cylindrical block gauge 60 </ b> C having a known thickness, and measures the heights of the three outer diameter position reference spheres 4 and the cylindrical lateral pins 5. Is. This block gauge 60C is used as follows.

  First, in order to adjust the positions of the three cylindrical lateral pins 5 before using the block gauge 60C, only the first smaller cylindrical portion 60a of the length adjusting jig 60 is used. Specifically, for example, the cylindrical portion 60a is fitted into the central through hole 10a of the support plate 10 of the measurement jig from the upper side to the lower side in FIG. The positions of the three cylindrical transverse pins 5 are adjusted by bringing the tips of the pins 5 into contact with each other.

  Next, after removing the cylindrical portion 60 a of the length adjusting jig 60 from the central through hole 10 a of the support plate 10, a calibration block gauge 60 C is connected with three cylindrical lateral pins 5 as shown in FIG. Place to support.

  Next, as indicated by A4 in FIG. 11, the stylus 2 scans the upper surface of the block gauge 60C to measure the upper surface, and the position coordinate of the upper surface of the block gauge 60C is measured by the three-dimensional shape measuring device 70 connected to the stylus 2. The obtained position coordinates are stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70.

  Next, as shown by A5 and A6 in FIG. 11, the three-dimensional shape measuring device 70 connected to the stylus 2 sequentially scans the three outer diameter position reference spheres 4 and measures their position coordinates, Each vertex coordinate is calculated by the calculation unit 72 and the calculation result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70.

Next, the XY position coordinates which are the vertex coordinates of the three outer diameter position reference spheres 4 are added to the plane equation obtained by subtracting the thickness of the block gauge 60C from the plane obtained from the measurement data of the position coordinates of the upper surface of the block gauge 60C. assignment, and calculated by the arithmetic unit 72 the difference between Z _1d between each vertex height of the three outer diameter position reference sphere 4 Z position and three outer diameter position reference ball 4 in this _{case, Z 2d,} the Z _3d as calibration parameters To do.

  Finally, the calculated data is stored in the storage unit 71.

In this way, the calibration parameters stored in the storage unit 71 are used as calibration parameters at the time of lens shape measurement (jig surface heights Z _1j , Z _2j , Z _3j (three outer diameters measured in advance). It is treated in the same manner as the heights h ₁ , h ₂ , and h ₃ of the center of the position reference sphere 4 and the pin upper surface in the cylindrical direction).

(Second Embodiment)
5A and 5B are detailed views of a holding claw 3A according to another example of the measurement jig in the second embodiment of the present invention. The difference from the first embodiment is that a spherical lateral pin 13 having a spherical tip shape is used instead of the cylindrical lateral pin 5.

  5A and 5B, when the lens surface is processed to the vicinity of the edge of the outer peripheral portion of the lens 1A on the back surface of the outer peripheral portion of the lens 1A (in other words, when there is no lens edge portion), at the support position near the edge. The back surface of the outer peripheral portion of the lens 1A is an inclined surface and is supported by a spherical lateral pin 13 having a tip shape of a spherical surface 13a. The three spherical lateral pins 13 are measured in advance with the three-dimensional shape measuring device 70 by scanning the stylus 2 in advance with respect to the XYZ position coordinates of the apex positions of the outer diameter position reference sphere 4 and the spherical lateral pin 13. The distance between the two adjacent outer diameter position reference spheres 4 at one holding claw 3 is calculated by the calculation unit 72. Further, the calculation unit 72 obtains the tangent of the inclination toward the lens center near the support point from the design formula of the lens 1A. A value obtained by multiplying the tangent by the difference between the distances of the two holding claws 3 in the center direction with respect to this inclination and one holding claw 3 is used as the height h of the lens back surface support position.

  As an example, the height h (the height of the lens back surface support position) h which is the position of the side surface of the outer peripheral portion of the lens 1A supported by the outer diameter position reference sphere 4 is about 1 mm, and is determined by the spherical surface 13a of the spherical lateral pin 13. The position for supporting the back surface of the lens 1A is a position approximately 1 mm inside from the edge of the outer periphery of the lens 1A.

  According to the second embodiment, instead of the cylindrical lateral pin 5 of the first embodiment, the spherical lateral pin 13 whose spherical surface 13a is in contact with the back surface of the lens 1A is used. Compared with the case of supporting with the pin 5, the back surface of the lens 1A does not have the flat lens edge portion 7, but the back surface of the inclined lens 1A can be supported with high accuracy, and a suitable lens shape measurement is performed. Can do.

(Third embodiment)
FIG. 6 is a detailed view of a holding claw 3B as another example of the measurement jig according to the third embodiment of the present invention. The difference from the first embodiment is that instead of the outer diameter position reference sphere 4, a cylindrical conical positioning pin 14 (as an example of an outer shape positioning body) having a concave conical surface 14 a at the center is provided at the outer diameter position. It is a point fixed to the tip of the reference sphere support member 4A.

  In FIG. 6, the side surface of the concave cone positioning pin 14 that contacts the side surface of the outer peripheral portion of the lens 1 is configured in a cylindrical shape, and the portion of the cylindrical concave cone positioning pin 14 that contacts the side surface of the outer peripheral portion of the lens 1. A concave conical surface 14 a is provided in the concave cone positioning pin 14 at the same height as the height. The taper angle of the conical surface 14a of each concave cone positioning pin 14 and the outer diameter of the concave cone positioning pin 14 are separately measured in advance. As an example, the concave cone positioning pin 14 has an outer diameter of 1 mm, and the accuracy of the concave conical surface 14a is 1 μm or less. As an example, the concave conical surface 14a has a shape that is recessed by 0.3 mm with respect to a thickness of 0.5 mm to 1.0 mm.

  The procedure for measuring the lens shape of the measurement jig in the third embodiment using the concave cone positioning pin 14 of FIG. 6 will be described with reference to FIGS. 7A and 7B.

  The three holding claws 3B each having the lens 1 configured in the form of FIG. 6 are placed on the support plate 10 of the measuring jig having the same configuration as that of FIG. The lens 1 is supported by three holding claws 3B.

  In this state, first, the XYZ position coordinates of the three concave cone positioning pins 14 are acquired from the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S21).

  Next, based on the acquired XYZ position coordinates, the stylus 2 of the three-dimensional shape measuring apparatus 70 is moved, and the stylus 2 is moved out of the three concave cone positioning pins 14 at the tips of the three holding claws 3. The stylus 2 is brought into contact with one concave cone positioning pin 14 (see the stylus 2 shown in the position of A1 or A2 in FIG. 1), and the XYZ position coordinates of the concave cone positioning pin 14 are connected to the stylus 2. Measurement is performed by the three-dimensional shape measuring apparatus 70 and the measurement result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70.

This measurement is performed by scanning the stylus 2 concentrically within the XY plane around the apex of the cone on the conical surface 14a of the concave cone positioning pin 14 to obtain XYZ position coordinates near the apex of the upper surface of the concave cone positioning pin 14. Is measured by the three-dimensional shape measuring device 70, and the arc position of the concave cone positioning pin 14 and the Z position of the concave cone positioning pin 14 are obtained using the taper angle (inclination angle) of the concave cone positioning pin 14 obtained in advance. The height is calculated by the calculation unit 72 connected to the three-dimensional shape measuring apparatus 70 (step S22), and the XYZ position of the concave cone positioning pin 14 is determined. Thus, XYZ data (XYZ position coordinate data) (X ₁ , Y ₁ , Z ₁ ) of the _first concave cone positioning pin 14 is calculated, and the calculation result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70. (Step S23).

Next, the remaining two concave cone positioning pins 14 are similarly measured sequentially, and all the XYZ position coordinates of the three concave cone positioning pins 14 are respectively measured and calculated, and the three concave cone positioning pins 14 are calculated. XYZ data (XYZ position coordinate data) (X ₁ , Y ₁ , Z ₁ ), (X ₂ , Y ₂ , Z ₂ ), (X ₃ , Y ₃ , Z ₃ ) are obtained and stored in the storage unit 71. Store (step S24).

  Thereafter, the lens surface 1a of the lens 1 is scanned on the XY axes with the stylus 2, and the XYZ position coordinates are measured with the three-dimensional shape measuring device 70 (see the stylus 2 shown at the position A3 in FIG. 1). The center is obtained by the calculation unit 72 and stored in the storage unit 71 (step S25). For example, it is impossible to attach the lens 1 horizontally to the three-dimensional shape measuring apparatus 70 with sub-micron accuracy or less. With the lens 1 attached obliquely, the apex does not become the center of the lens 1. Therefore, data measurement is performed at a plurality of points on the XY axes, and when the lens 1 is an aspherical surface, the tilt of the lens 1 and the center position of the lens 1 in the tilted state of the lens 1 can be obtained by calculation from this measurement data. it can. Specifically, the posture of the lens 1 can be obtained by changing the XY position, the inclination about the XY axis, and the Z position so that the sum of the squares of the differences between the design formula and the measurement data is minimized.

  Next, using this measurement center as the start point of the measurement coordinates, the XYZ position coordinates of the entire lens surface 1a are measured concentrically with the lens surface 1a, and the shape data of the lens 1 is acquired and stored in the storage unit 71 ( Step S26).

Next, the calculation unit 72 obtains a difference between the measured shape data and the design equation of the lens 1 to be measured, and design coordinates (the lens surface defined by the design equation) so that the sum of squares of the difference is minimized. The XYZ coordinates above or the design coordinates that define the shape of the lens 1 are translated in the XYZ directions or rotated in the A, B, and C directions that are rotation directions around the XYZ axes. An alignment amount (X _a , Y _a , Z _a , A _a , B _a , C _a ) based on the coordinates of the three-dimensional shape measuring apparatus 70 is calculated and stored in the storage unit 71 (step S27).

Thereafter, the XYZ data of the three concave cone positioning pins 14 obtained by the measurement of the three concave cone positioning pins 14 and the taper height (recessed) of each of the three concave cone positioning pins 14 measured in advance. Using the calculation unit 72, the back surface of the lens 1 in the three concave cone positioning pins 14 is in contact with the cylindrical lateral pin 5 by using the Z position height h ₁ , h ₂ , h ₃ of the cone positioning pin 14. The jig surface heights Z _1j = Z ₁ -h ₁ , Z _2j = Z ₂ -h ₂ , Z _3j = Z ₃ -h ₃ are calculated and stored in the storage unit 71 (step S28).

Next, the position coordinates (X ₁ , Y ₁ , Z _1j ) of the three points of the jig surface heights Z _1j , Z _2j , and Z _3j at the positions in contact with the lens outer diameter of the three concave cone positioning pins 14, ( X ₂ , Y ₂ , Z _2j ), (X ₃ , Y ₃ , Z _3j ) is calculated as a plane equation P1 (step S29).

Next, the angle formed by the plane equation P1 and the X and Y axes, that is, the tilt angles A _p and B _p of the back surface of the outer peripheral portion of the lens 1 are calculated by the calculation unit 72 and stored in the storage unit 71 (step 71). S30). From the plane equation, the normal vector of the plane can be easily obtained, and the vector of the obtained normal vector viewed on the XZ plane and the YZ plane can be easily obtained. Therefore, the angle formed by these two vectors and the Z axis ( Tilt angles A _p , B _p ) can be determined from the inner product.

Next, when the outer shape of the lens 1 is not circular, the position coordinates of the first and second concave conical positioning pins 14 installed on the portion defined as the lens reference side surface of the outer peripheral side surface of the lens 1 obtains an angle C _p in the X-axis with the stylus 2, stores the tilt angle of the side surface of the outer peripheral portion of the lens 1 in the storage unit 71 are acquired by computing unit 72 (step S31). However, if the outer shape of the lens 1 is circular, this step S11 is omitted.

Thereafter, the radii R ₁ , R ₂ , R _{3 of the} positions of the three concave cone positioning pins 14 that are in contact with the lens 1 and the XY coordinates of the three concave cone positioning pins 14 obtained in advance are set as the centers. The central coordinates X _c and Y _c of the circle inscribed in the three circles drawn with the radius are calculated by the calculation unit 72 (step S32).

Then, the X _c, the value of Y _c, the plane equation P1 previously obtained, the X _c, by substituting Y _c, the reference height Z _c at the center position with respect to the side surface of the outer peripheral portion of the lens 1 Calculation is performed by the calculation unit 72 (step S33).

Next, the difference between the alignment amount (X _a , Y _a , Z _a , A _a , B _a , C _a ) and the tilt angles A _p , B _p on the back surface of the outer periphery of the lens 1 and the center position is calculated. By _calculating by the portion 72, the eccentric amount dX = X _a −X _c , dY = Y _a −Y _c , dZ = Z _a −Z _c and the tilt amount with respect to the outer peripheral portion reference (in other words, the outer shape reference) of the lens 1. dA = A _a −A _p , dB = B _a −B _p , dC = C _a −C _p are calculated and stored in the storage unit 71 (step S34). If the outer shape of the lens 1 is circular, dC = C _a −C _p is not calculated.

  As a result, the shape of the lens 1 is measured by calculating the posture of the lens 1 by the calculation unit 72 based on the calculated eccentricity and tilt amount based on the calculated outer circumference reference (in other words, the outer shape reference) of the lens 1. be able to.

  According to the shape measuring method and the measuring jig according to the third embodiment, the concave cone positioning pin 14 which is an example of three cylindrical positioning bodies arranged outside the outer peripheral portion of the lens 1; By setting the concave conical surface 14a for measurement opened in the center of the concave cone positioning pin 14 at a position close to the supporting height of the side surface of the outer peripheral portion of the lens 1 on the side surface of the concave cone positioning pin 14, Even if the concave cone positioning pin 14 is slightly inclined, the error in the XY direction is minimized, and the lens shape can be measured with high accuracy.

(Fourth embodiment)
FIG. 8 is a detailed view of a holding claw 3C as still another example of the measurement jig according to the fourth embodiment of the present invention. A difference from the third embodiment is that instead of the cylindrical concave cone positioning pin 14 having a concave conical surface 14a, a spherical shape having another concave conical surface 15a in the center (as another example of the outer shape positioning body). The concave conical positioning pin 15 is fixed to the tip of the outer diameter position reference sphere support member 4A.

  In FIG. 8, the portion of the concave cone positioning pin 15 that contacts the side surface portion of the outer peripheral portion of the lens 1 is formed in a spherical shape, and is provided at the same height as the height of the portion that contacts the side surface of the outer peripheral portion of the lens 1. The concave cone positioning pin 15 is configured to have a concave conical surface 15a. The taper angle and outer diameter of each concave cone positioning pin 15 are separately measured in advance.

  The measurement procedure in the measurement jig using the concave cone positioning pin 15 of FIG. 8 is the same as that of the measurement jig of FIG.

  According to the fourth embodiment, by forming the outer shape portion of the concave cone positioning pin 15 in a spherical shape, the processing accuracy of the portion that contacts the side surface of the outer peripheral portion of the lens 1 can be further increased, and the accuracy can be increased. Lens shape measurement can be performed.

(Fifth embodiment)
As measurement jigs in the fifth embodiment of the present invention, FIGS. 9A to 9C each show a back support member 3 provided on the tip of a cylindrical lateral pin 5 that supports the back surface of the outer periphery of the lens 1. Here are two examples.

  First, FIG. 9A and FIG. 9B each support the back surface of the lens edge part 7 of the outer peripheral part of the lens 1 with the back surface support members 5A and 5B processed into a triangular pyramid shape. The back support member 5A has a right triangular side face whose oblique side is oriented obliquely along the upper right direction, whereas the back support member 5B has a right triangular side face whose oblique side is fixed to the tip of the cylindrical transverse pin 5. Although different in that they have, both support the back surface of the lens edge portion 7 on the outer peripheral portion of the lens 1 at the top of the triangular pyramid of the back surface support members 5A and 5B.

  9C supports the back surface of the lens edge portion 7 on the outer peripheral portion of the lens 1 at the top of the quadrangular pyramid of the back surface support member 5C processed into a quadrangular pyramid shape.

  The measurement jig in the fifth embodiment is used as follows. For example, in the measurement jig according to the first embodiment, in FIG. 1, the cylindrical lateral pin 5 that supports the back surface is the cylindrical lateral direction in which the back surface support member 5 </ b> A is fixed to the tip as shown in FIG. 9A. When the pin 5 is changed, the lens back surface support height at the upper end of the apex of the triangular pyramid of the back surface support member 5A is set in advance, and the XYZ position coordinates of the vertex position of the outer diameter position reference sphere 4 and the vertex position of the back surface support member 5A are preliminarily determined. Scanning with the stylus 2 and measuring with the three-dimensional shape measuring device 70 in advance, calculating the distance of each Z position height with the three holding claws 3, and using it as the Z position height of the back surface support position. .

  With this configuration, even if dust or the like adheres to the bottom surface portion of the lens 1, the lens surface can be supported directly by supporting the lens surface with the pointed back support member 5 </ b> A so that the lens surface can be directly supported. It becomes possible to support 1 without inclining, and it becomes possible to perform highly accurate measurement.

(Sixth embodiment)
In the shape measuring method using the measuring jig in the sixth embodiment of the present invention, three reference spheres for measuring the front and back eccentric positions provided on the measuring jig are shown in FIGS. 10A to 10D. 9 shows a measurement flow of the posture of the lens 1 represented by the amount of eccentricity and the amount of tilt of the lens 1 on the back surface of the lens 1 with respect to the surface of the lens 1.

  The flow in FIGS. 10A and 10B is a measurement method based on the lens outer diameter, and the measurement is performed in the same procedure as in FIGS. 7A and 7B. That is, the operations in steps S41 to S54 in the flows of FIGS. 10A and 10B are the same as the operations in steps S21 to S34 in the flows of FIGS. 7A and 7B.

  After step S54, three eccentric position measurement reference spheres 9 (referred to simply as “reference three spheres” in FIGS. 10C to 10D) are measured from the surface side of the lens 1 (step S55). This step S55 means that the measurement of the three reference balls is sequentially performed one by one, and specifically, the measurement operation of the following steps S56 to S59 is performed.

  Next, the XYZ position coordinates of the three eccentric position measurement reference spheres 9 are acquired from the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S56).

  Next, based on the acquired XYZ position coordinates, the stylus 2 of the three-dimensional shape measuring apparatus 70 is moved, and the stylus 2 is measured for the first eccentric position of the three eccentric position measuring reference balls 9. A three-dimensional shape measuring apparatus 70 in which the XYZ position coordinates of the first eccentric position measuring reference sphere 9 are connected to the stylus 2 by making contact with a portion near the apex of the reference sphere 9 for scanning and scanning on the XY axis. And the measurement result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S57).

Next, the first eccentric position measuring reference sphere 9 is scanned with the stylus 2 on the XY axis or concentrically with the apex of the first eccentric position measuring reference sphere 9 as a reference. XYZ position coordinates near the top of the upper surface of the eccentric position measuring reference sphere 9 are measured by the three-dimensional shape measuring device 70, and the radius of the first eccentric position measuring reference sphere 9 measured in advance is used. XYZ data (XYZ position coordinate data) of the center of the first eccentric position measuring reference sphere 9 measured from the surface side of the lens 1, that is, the XYZ position coordinates of the first eccentric position measuring reference sphere 9 : (X _1f , Y _1f , Z _1f ) is calculated, and the calculation result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S58).

Next, the remaining two eccentric position measurement reference spheres 9 are sequentially measured in the same manner, and all the XYZ position coordinates of the three eccentric position measurement reference spheres 9 are respectively measured and calculated. XYZ data (XYZ position coordinate data) (X _1f , Y _1f , Z _1f ), (X _2f , Y _2f , Z _2f ), (X _3f , Y _3f , Z _3f ) of the position measurement reference sphere 9 are obtained. And stored in the storage unit 71 (step S59).

  Next, for each of the measurement jigs, the lens 1 is turned upside down (in other words, the measurement jig is turned upside down while holding the lens 1 on the measurement jig), FIG. 7A and FIG. In the same procedure as 7B, the back surface of the lens 1 on the back surface side is measured on the XY axes to calculate the measurement center (step S60).

  Next, the back surface of the lens 1 is measured, and the shape data of the back surface of the lens 1 is acquired (step S61).

Next, design coordinates (XYZ coordinates on the lens surface defined by the design formula, or so as to minimize the difference between the design formula of the back surface shape of the lens 1 stored in the storage unit 71 and the measurement data in advance, or The design coordinates that define the shape of the lens 1 are translated in the XYZ directions or rotated in the A, B, and C directions that are rotation directions around the XYZ axes, and the sum of squares of the differences at each measurement point is minimized. The obtained value is calculated as an alignment amount (X _ab , Y _ab , Z _ab , A _ab , B _ab , C _ab ) based on the coordinates of the three-dimensional shape measuring apparatus 70 and stored in the storage unit 71 (step S62). ).

  Thereafter, the front and back eccentric position measurement reference sphere 9 is measured from the back side of the lens 1 by the same method as described above without shifting the position of the measurement jig. That is, first, three eccentric position measuring reference spheres 9 are measured from the back side of the lens 1 (step S63). This step S63 means that the measurement of the three reference balls is sequentially performed one by one, and specifically, the measurement operation of the following steps S64 to S67 is performed.

  Next, the XYZ position coordinates of the three eccentric position measurement reference spheres 9 are acquired from the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S64).

  Next, based on the acquired XYZ position coordinates, the stylus 2 of the three-dimensional shape measuring apparatus 70 is moved, and the stylus 2 is measured for the first eccentric position of the three eccentric position measuring reference balls 9. A three-dimensional shape measuring apparatus 70 in which the XYZ position coordinates of the first eccentric position measuring reference sphere 9 are connected to the stylus 2 by making contact with a portion near the apex of the reference sphere 9 for scanning and scanning on the XY axis. The measurement result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S65).

Next, the first eccentric position measuring reference sphere 9 is scanned with the stylus 2 on the XY axis or concentrically with the apex of the first eccentric position measuring reference sphere 9 as a reference. XYZ position coordinates near the top of the upper surface of the eccentric position measuring reference sphere 9 are measured by the three-dimensional shape measuring device 70, and the radius of the first eccentric position measuring reference sphere 9 measured in advance is used. XYZ data (XYZ position coordinate data) of the center of the first eccentric position measuring reference sphere 9 measured from the back side of the lens 1, that is, the XYZ position coordinates of the first eccentric position measuring reference sphere 9 : (X _1b , Y _1b , Z _1b ) is calculated, and the calculation result is stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70 (step S66).

Next, the remaining two eccentric position measurement reference spheres 9 are sequentially measured in the same manner, and all the XYZ position coordinates of the three eccentric position measurement reference spheres 9 are respectively measured and calculated. XYZ data (XYZ position coordinate data) (X _1b , Y _1b , Z _1b ), (X _2b , Y _2b , Z _2b ), (X _3b , Y _3b , Z _3b ) of the position measurement reference sphere 9 are obtained. And stored in the storage unit 71 (step S67).

  Thereafter, the position coordinates of the surface of the lens 1 are determined with reference to the three eccentric position measurement reference spheres 9 measured from the front surface side of the lens 1, and the three eccentric positions measured from the back surface side of the lens 1. The position coordinates of the back surface of the lens 1 are determined with reference to the measurement reference sphere 9, and the center of each eccentric position measurement reference sphere 9 is the same. By calculating the decentering amount and tilt amount of the back surface of the lens 1 on the basis, the attitude of the lens 1 represented by the decentering amount and tilt amount of the lens 1 on the back surface with respect to the front surface of the lens 1 is calculated (step S68). . This calculation method is known, and is described in, for example, [0013] et seq. In JP-A-2000-71344.

  With this configuration, it is possible to measure not only the eccentricity and tilt attitude of the lens 1 based on the outer shape but also the eccentricity and tilt attitude of the back surface with respect to the lens surface.

(Seventh embodiment)
FIG. 11 shows a calibration procedure of the measuring jig in the shape measuring method using the measuring jig in the seventh embodiment of the present invention. In FIG. 11, the holding claw 3 is described with an example of the first embodiment configured by an outer diameter position reference sphere 4 that is diagonally supported by an outer diameter position reference sphere support member 4 </ b> A and a cylindrical lateral pin 5. However, in the holding claws 3A, 3B, and 3C having the configurations of FIGS. 5A and 5B, FIG. 6, FIG. 8, and FIGS. 9A to 9C according to the second to fifth embodiments, the measurement is performed with substantially the same calibration procedure. Calibration of the jig can be performed (position adjustment of the three outer diameter position reference spheres 4).

  The three cylindrical lateral pins 5 of the holding claws 3 are placed on the three cylindrical lateral pins 5 so as to support a columnar block gauge 60C having a known thickness.

  Next, as indicated by A4 in FIG. 11, the stylus 2 scans the upper surface of the block gauge 60C to measure the upper surface, and the position coordinate of the upper surface of the block gauge 60C is measured by the three-dimensional shape measuring device 70 connected to the stylus 2. The plane equation P2 is calculated by the calculation unit 72 of the three-dimensional shape measuring apparatus 70 from the obtained position coordinate data, and stored in the storage unit 71 of the three-dimensional shape measuring apparatus 70.

  Next, as shown by A5 and A6 in FIG. 11, the three-dimensional shape measuring device 70 connected to the stylus 2 sequentially scans the three outer diameter position reference spheres 4 and measures their position coordinates, Each vertex coordinate is calculated by the calculation unit 72, and the calculation result is stored in the storage unit 71.

Next, the vertex P of the three outer diameter position reference spheres 4 is changed to the plane equation P3 obtained by subtracting the thickness of the block gauge 60C from the plane equation P2 regarding the plane obtained from the measurement data of the position coordinates of the upper surface of the block gauge 60C. By substituting the XY position coordinates as coordinates, the differences Z _1d , Z _2d , and Z _3d between the Z positions of the three outer diameter position reference spheres 4 and the vertex heights of the three outer diameter position reference spheres 4 at this time are calibrated. The calculation unit 72 calculates it as a parameter, stores it in the storage unit 71, and sets it as a calibration parameter at the time of lens shape measurement.

  Thus, by calibrating these parameters with the above-described method as described in the first embodiment on the basis of the block gauge 60C, the height positions of the three outer diameter position reference spheres 4 on the nanometer order are obtained. Calibration is possible.

(Eighth embodiment)
In the shape measuring method using the measuring jig according to the eighth embodiment of the present invention, the lens 1 is rotated with respect to the measuring jig, and the lens surface and the three outer diameter positioning bodies are respectively measured. Thus, a method of measuring the attitude of the lens 1 on the basis of the outer diameter with higher accuracy will be described with reference to FIG.

The lens 1 is rotated at a predetermined angle (for example, 90 ° to 180 °) with respect to the holding claw 3 that supports the outer shape of the lens 1 with respect to the measurement jig, and the posture data at each rotation angle is the original. It is possible to perform highly accurate measurement by converting rotational coordinates to a position and obtaining an average of posture data. For example, in the measurement, the lens 1 is rotated from the upper surface of the lens 1 by 90 ° with respect to the measurement jig at four positions (0 ° position, 90 ° position, 180 ° position, 270 °). At each position, the attitude of the lens 1 is measured, and the attitude data at each rotational position is converted to the original 0 ° rotational coordinates, and the average of the attitude data is obtained. In another example, the posture of the lens 1 is measured at two positions (0 ° position and 180 ° position) rotated from the 0 ° position by 180 ° from the upper surface of the lens 1, and at each rotated position. Rotation coordinates are converted to the original 0 ° position of the posture data, and the average of the posture data is obtained. Specifically, the eccentric amounts dX ₀ , dY ₀ , tilt dA ₀ , dB _{0 at the 0} ° position, and eccentric amounts dX ₉₀ , dY ₉₀ , tilt dA ₉₀ , dB ₉₀ , 180 at the 90 ° position, respectively. Decentering amounts dX ₁₈₀ , dY ₁₈₀ , tilt dA ₁₈₀ , dB ₁₈₀ at 270 ° positions, and decentering amounts dX ₂₇₀ , dY ₂₇₀ , tilt dA ₂₇₀ , dB ₂₇₀ at 270 ° positions, the average decentering dX _a of the lens is , DX _a = (dX ₀ + dX ₉₀ + dX ₁₈₀ + dX ₂₇₀ ) / 4. Similarly, eccentric _{dY a = (dY 0 + dY} 90 + dY 180 + dY 270) / 4, tilt _{dA a = (dA 0 + dA} 90 + dA 180 + dA 270) / 4, tilt _{dB a = (dB 0 + dB} 90 + dB 180 + dB 270 ) / 4.

  According to the eighth embodiment, the lens 1 is measured with respect to the jig at the 0 ° position from the upper surface of the lens 1 and the 180 ° position obtained by rotating the lens 1 180 ° from the 0 ° position. The posture of the lens 1 is measured, the posture at the position of 180 ° is coordinate-converted, and compared with the posture at the position of 0 °, and the average of the posture data is obtained, thereby performing higher-precision measurement. I can do it.

  In the case of a plastic molded lens, the 0 ° position has a plastic pouring portion that is generated during molding, and can uniquely determine the rotation direction of the lens. In this case, the direction of the lens in which the design coordinates of the lens coincide with the coordinate system of the three-dimensional shape measuring apparatus can be marked as 0 degrees. On the other hand, when the lens is a molded product of glass, the lens is molded to be rotated. In this case, since the position in the rotation direction cannot be specified only by the shape of the lens, for evaluation, the position in the rotation direction is simply designated with magic ink or the like, and the position designated with this magic ink is used as a reference, for example. The 0 ° position can be designated as the front of the mark, the 90 ° position can be designated as the right of the mark, and the lens can be rotated.

  It is to be noted that, by appropriately combining any of the various embodiments, the effects possessed by them can be produced.

  The shape measuring method and the measuring jig of the present invention are each a three-dimensional shape measuring apparatus for measuring a surface shape from the upper surface, and each of three holding units arranged outside the outer peripheral portion of a measured object, for example, a lens. With the outer shape positioning sphere or the outer shape positioning body and the back surface supporting member such as a cylindrical shape that supports the back surface of the outer peripheral portion of the lens, the orientation of the lens surface and the lens shape of the lens surface with reference to the outer shape (for example, outer diameter) or the back surface Measurement can be performed with high accuracy.

Schematic configuration diagram of a measuring jig capable of performing the shape measuring method in the first embodiment of the present invention Schematic plan view of the measurement jig in the first embodiment of the present invention The top view of the lens pressing spring of the said jig for a measurement in the said 1st Embodiment of this invention The perspective view which shows schematic structure of one holding nail | claw of the said measuring jig in the said 1st Embodiment of this invention. The expanded sectional side view which shows schematic structure of the said 1 holding nail | claw of the said measurement jig | tool in the said 1st Embodiment of this invention. Flowchart of lens shape measurement operation performed using the measurement jig in the first embodiment of the present invention. FIG. 4B is a continuation of the flow of FIG. 4B, and a flowchart of the lens shape measurement operation performed using the measurement jig in the first embodiment of the present invention. The perspective view which shows schematic structure of one holding nail | claw of the measurement jig | tool in 2nd Embodiment of this invention. The expanded sectional side view which shows schematic structure of one holding nail | claw of the jig | tool for measurement in 2nd Embodiment of this invention. The expanded sectional side view which shows the schematic structural example of the holding nail | claw of the jig | tool for a measurement in 3rd Embodiment of this invention. Flowchart of lens shape measurement operation performed using the measurement jig in the third embodiment of the present invention. FIG. 7A is a continuation of the flowchart of FIG. 7A and is a flowchart of the lens shape measurement operation performed using the measurement jig in the third embodiment of the present invention. The expanded sectional side view which shows the schematic structural example of the holding nail | claw of the jig | tool for measurement in 4th Embodiment of this invention. The expanded side view which shows the structural example of the back surface supporting member of the jig | tool for a measurement in 5th Embodiment of this invention. The expanded side view which shows another structural example of the back surface supporting member of the said jig | tool for a measurement in 5th Embodiment of this invention. The expanded side view which shows another structural example of the back surface supporting member of the said jig | tool for a measurement in 5th Embodiment of this invention. Flowchart of outer diameter reference measurement and front / back eccentricity measurement in the shape measurement method according to the sixth embodiment of the present invention. FIG. 10A is a continuation of the flow of FIG. 10A, and is a flowchart of the outer diameter reference measurement and the front / back eccentricity measurement in the shape measurement method according to the sixth embodiment of the present invention. FIG. 10B is a continuation of the flow of FIG. 10B, and is a flowchart of the outer diameter reference measurement and the front / back eccentricity measurement in the shape measurement method according to the sixth embodiment of the present invention. FIG. 10C is a continuation of the flow of FIG. 10C and is a flowchart of the outer diameter reference measurement and the front / back eccentricity measurement in the shape measurement method according to the sixth embodiment of the present invention. Explanatory drawing which shows the procedure of jig | tool calibration in the shape measuring method using the jig for lens shape measurement in 7th Embodiment of this invention. The perspective view which shows the jig for length adjustment in the said jig for a measurement in the said 1st Embodiment of this invention. The perspective view which shows the use condition of the said jig for length adjustment Explanatory drawing which shows the procedure of the high precision measurement in the shape measurement method using the jig | tool for shape measurement of the lens in 8th Embodiment of this invention. Plan view for explaining a conventional measuring method based on the outer diameter Side view of positioning jig for explaining conventional outer diameter standard measuring method Side view of a lens measurement state with a positioning jig for explaining a conventional outer diameter reference measurement method Side view of a lens measurement state with a positioning jig for explaining a conventional outer diameter reference measurement method

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A Lens 2 Stylus 3, 3A, 3B, 3C Holding claw 4 Outer diameter position reference sphere supported diagonally 4A Outer diameter position reference sphere support member 4b Conical part 5 Cylindrical lateral pin 5A, 5B, 5C Back surface support member 6 Length adjusting mechanism 6a First adjusting screw 6b Second adjusting screw 6c Length adjusting mechanism case 6d First through hole 6e Second through hole 7 Lens edge 8 Lens holding spring 8a Through hole 9 Eccentric position measuring reference ball 10 Support plate 10a Through hole 10b Through hole 11 Pressure biasing spring 13 Spherical lateral pin 14 Concave cone positioning pin 14a Conical surface of concave shape 50 Gap 60 Length adjusting jig 60a Small cylindrical portion 60b Larger cylinder Unit 60C Block gauge 70 Three-dimensional shape measuring device 71 Storage unit 72 Calculation unit 103 Lens edge unit back surface 120 Positioning jig 120 c Back support

Claims (7)

The measurement object is placed on a measurement jig provided with three holding units each composed of an outer shape positioning sphere to be brought into contact with the outer periphery of the measurement object and a back surface support member for supporting the back surface of the outer periphery of the measurement object. And placing the object to be measured so that at least one of the three holding units presses the object to be measured against the remaining two holding units with a constant force.
Measuring the upper surface of the object to be measured and the three outer positioning spheres to obtain the position coordinates of the upper surface of the object to be measured and the position coordinates of the three outer positioning balls;
From the radius of each of the three contour positioning spheres set in advance and the position coordinate data of the three contour positioning spheres, the position where the three contour positioning spheres contact the object to be measured is obtained.
The back surface of the object to be measured is obtained by using the difference between the heights of the back surface supporting members of the three holding units set in advance and the heights of the outer shape positioning balls and the data of the position coordinates of the three outer shape positioning balls. Obtain the inclination of the object to be measured with reference to
The posture and shape of the object to be measured are determined based on the outer shape of the object to be measured, based on the position of the three outer shape positioning balls in contact with the object to be measured, the inclination, and the position coordinate data of the object to be measured. A shape measuring method characterized by the above. Three holding units comprising a cylindrical outer shape positioning body having a conical recess at the center to be brought into contact with the outer periphery of the object to be measured and a back surface supporting member for supporting the back surface of the outer periphery of the object to be measured. The object to be measured is placed on a measuring jig provided, and at least one of the three holding units presses the object to be measured against the remaining two holding units with a constant force. Holding the object to be measured,
Measure the upper surface of the object to be measured and the conical recesses of the three outer shape positioning bodies from above to obtain the position coordinates of the upper surface of the object to be measured and the position coordinates of the three outer shape positioning bodies,
From the radius of the cylindrical portion of the three contour positioning bodies set in advance and the position coordinate data of the three contour positioning bodies, the position where the three contour positioning bodies contact the object to be measured is obtained.
Using the preset difference between the heights of the concave portions of the back support member and the outer shape positioning body of the three holding units and the position coordinate data of the three outer shape positioning bodies, the measured object Obtain the inclination of the measured object with respect to the back side of the object,
The posture and shape of the object to be measured are obtained based on the outer shape of the object to be measured, based on the position of the three outer shape positioning bodies in contact with the object to be measured, the inclination, and the position coordinate data of the object to be measured. A shape measuring method characterized by the above.   After measuring the shape of the object to be measured, after changing the support position of the object to be measured by rotating the object to be measured at a predetermined angle with respect to the holding unit, again, the shape of the object to be measured The shape measurement method according to claim 1, wherein measurement is performed.   The measurement jig is provided with three eccentric position measurement reference spheres at positions where the position coordinates can be measured from the front surface and the back surface, respectively, and the shape of the surface of the object to be measured from the surface side of the object to be measured After measuring the center coordinates and inclination of the three eccentric position measurement reference spheres, the shape of the back surface of the object to be measured and the center coordinates and inclinations of the three eccentric position measurement reference balls from the back surface side of the object to be measured. The shape measuring method according to any one of claims 1 to 3, wherein the shape of the object to be measured is obtained by measuring the difference between the coordinates of the front and back surfaces of the object to be measured. . An outer positioning ball that contacts the outside of the outer periphery of the object to be measured;
Three holding units composed of a back surface supporting member that supports the back surface of the outer peripheral portion of the object to be measured are provided,
A measuring jig provided with pressing means for pressing at least one holding unit of the three holding units against the remaining two holding units with a constant force. A cylindrical outer shape positioning body having a conical concave portion at the center contacting the outside of the outer peripheral portion of the object to be measured;
Three holding units composed of a back surface supporting member that supports the back surface of the outer peripheral portion of the object to be measured are provided,
A measuring jig provided with pressing means for pressing at least one holding unit of the three holding units against the remaining two holding units with a constant force. The measurement jig according to claim 5 or 6, further comprising three eccentric position measurement reference spheres at positions where position coordinates can be measured respectively from the front surface and the back surface.

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