JP5853167B2 - Lens measuring apparatus, lens measuring method and lens manufacturing method - Google Patents

Description

  The present invention relates to a lens measuring device, a lens measuring method, and a lens manufacturing method used for a digital still camera or the like.

  In recent years, an image photographing apparatus using an optical lens such as a digital still camera has been reduced in size and weight. In addition, with the downsizing of the lens barrel that drives a plurality of lenses for the purpose of changing the photographing magnification, the miniaturization of the optical lens itself is also progressing.

  In addition, the lens itself and the lens barrel are becoming smaller in size, and the degree of integration of image pickup devices represented by CCDs has been increasing year by year, and high image quality has been demanded.

  Under such circumstances, in recent years, the precision of parts of optical system parts typified by lenses has been strictly demanded.

  Conventionally, in order to easily measure the lens thickness, for example, a measuring instrument as shown in FIG. 7 is used. The measuring instrument shown in FIG. 7 includes a pair of measuring elements that contact the lens 7. One measuring element is fixed to the main body, and the other measuring element is connected to the micrometer and is configured to be movable so that the distance from the one measuring element changes. That is, by sandwiching the lens 7 with a pair of measuring elements, the thickness of the lens 7 can be measured with a micrometer.

A three-dimensional shape measuring machine is also used for measuring the lens shape. According to the three-dimensional shape measuring machine, the lens shape such as the lens thickness can be measured with high accuracy.
JP-A-8-304228

  However, with the measuring instrument shown in FIG. 7, it is possible to easily measure the thickness of the lens, but it is difficult to accurately measure the thickness of the lens. That is, in the measuring machine, it is necessary to measure the thickness of the lens by bringing the measuring element into contact with the thickest part or the thinnest part of the lens according to the uneven shape of the lens. However, it is difficult to know in advance which part of the lens is thickest or thin, and this part is searched while repeating measurement.

  Further, if measurement is performed in a state where the lens itself is inclined with respect to the axis of the measuring element, a measurement error occurs geometrically. That is, since it is difficult to hold the lens itself, an individual error of the measurer occurs, and it is difficult to accurately measure the lens thickness.

  On the other hand, if a three-dimensional shape measuring machine is used, the shape of the lens can be measured with high accuracy, but the three-dimensional shape measuring machine is expensive, the scale of the device is relatively large, and the measurement time is also long. It does not meet the desire to efficiently measure and manage the lens shape.

  In addition, there is a means for optical measurement from the focal position of the lens, but this is also relatively large in scale as with a three-dimensional shape measuring machine and takes a long measurement time. It does not meet the desire to measure and manage.

  The present invention has been made in view of the above points, and an object thereof is to accurately and efficiently measure the shape of a lens.

A lens measuring apparatus according to the present invention includes a measuring table, an X-axis stage and a Y-axis stage, and is fixedly installed with respect to the measuring table, a lens moving unit that moves the lens in the plane of the XY axes. A first position measuring means having a measuring element that is capable of moving back and forth in the Z-axis direction intersecting the plane as the lens moves and maintains contact with one surface of the lens. A first position measuring means for measuring the position of the contact in the Z-axis direction; and a second position measuring means fixedly installed on the measuring table, and intersects the plane as the lens moves. A second position measuring means for measuring the position of the contact point in the Z-axis direction, having a measuring element that maintains contact with the other surface of the lens so as to be movable back and forth in the Z-axis direction; In the X-axis direction and the Y-axis direction of the lens A lens shape calculation unit that obtains the shape of the lens based on the amount of movement and the measurement results of the first and second position measuring means, and the first and second position measuring means include the X-axis stage and The position of an arbitrary XY coordinate point in the Z-axis direction is measured only by moving the lens in the plane of the XY axis by driving the Y-axis stage, and the X of the point on both surfaces of the lens is measured. Assume that the positions in the axial direction, the Y-axis direction, and the Z-axis direction are acquired simultaneously .

The lens measuring method according to the present invention includes a lens moving step of moving the lens in the plane of the XY axis by a lens moving unit having an X axis stage and a Y axis stage, and the plane as the lens moves. The measuring element of the first position measuring means, which has a measuring element that maintains contact with one surface of the lens so as to be movable back and forth in the intersecting Z-axis direction, and is fixed to the measuring table, By driving the X-axis stage and the Y-axis stage in the lens moving step, the lens is moved forward and backward in the Z-axis direction only by moving in the plane of the XY axis, and the measuring element and one surface of the lens A first position measuring step of measuring a position in the Z-axis direction of an arbitrary XY coordinate point corresponding to a movement amount of the lens in the X-axis direction and the Y-axis direction; and movement of the lens In Accordingly, a second position measuring means is provided which has a measuring element which can move forward and backward in the Z-axis direction intersecting the plane and maintains contact with the other surface of the lens, and is fixed to the measuring table. The probe is moved forward and backward in the Z-axis direction only by moving the lens in the plane of the XY axis by driving the X-axis stage and the Y-axis stage in the lens moving step. A second position measuring step of measuring a position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the movement amount of the lens in the X-axis direction and the Y-axis direction, which is a contact point with the other surface of the lens; And a lens shape calculation step for obtaining the shape of the lens based on the amount of movement of the lens by the lens movement step and the measurement results of the first and second position measurement steps, the first position measurement step and the first 2-position measuring worker And is performed at the same time, it is assumed that the acquired X-axis direction of a point on the surface of both of the lens, the position of the Y-axis and Z-axis directions at the same time.

The lens manufacturing method according to the present invention includes a lens manufacturing step of manufacturing a lens, a lens shape measurement step of measuring the shape of the lens produced by the lens manufacturing process, the lens shape measuring step, X-axis A lens moving step of moving the lens in the plane of the XY axis by a lens moving unit having a stage and a Y-axis stage; and one of the lenses that can move forward and backward in the Z-axis direction intersecting the plane as the lens moves The X-axis stage and the Y-axis stage in the lens moving process include a measuring element that maintains contact with the surface, and the measuring element of the first position measuring means that is fixedly installed with respect to the measuring table. The contact point between the measuring element and one surface of the lens by moving the lens in the XY-axis plane by driving A first position measuring step of measuring a position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the movement amount of the lens in the X-axis direction and the Y-axis direction, and intersecting the plane as the lens moves A measuring element that maintains contact with the other surface of the lens so that it can advance and retreat in the Z-axis direction, and the measuring element of the second position measuring means that is fixedly installed with respect to the measuring table, By moving the X-axis stage and the Y-axis stage in the lens moving step, the lens is moved forward and backward in the Z-axis direction only by moving in the plane of the XY axis, and the other surface of the measuring element and the lens A second position measuring step of measuring a position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the amount of movement of the lens in the X-axis direction and the Y-axis direction; and the lens moving step The amount of lens movement caused by A lens shape calculation step for obtaining the shape of the lens based on the measurement results of the first and second position measurement steps, and the first position measurement step and the second position measurement step are performed simultaneously, The positions of the points on both surfaces of the lens in the X-axis direction, the Y-axis direction, and the Z-axis direction are acquired simultaneously .

  According to the lens measuring device of the present invention, the lens can be moved while maintaining the posture of the lens, and the position of an arbitrary point on both lens surfaces can be measured. Can be measured. At the same time, by measuring the shape of both lens surfaces by two position measuring means, it is not necessary to hold the lens again, and the shape of the lens can be measured with high accuracy.

  Further, according to the lens measurement method of the present invention, it is possible to move the lens while maintaining the posture of the lens and measure the position of any point on both lens surfaces. The shape can be measured. At the same time, by measuring the shape of both lens surfaces by two position measurement steps, it is not necessary to hold the lens again, and the shape of the lens can be measured with high accuracy.

  Furthermore, according to the lens manufacturing method according to the present invention, the lens can be moved while maintaining the posture of the lens, and the position of any point on both lens surfaces can be measured. The shape can be measured. At the same time, by measuring the shape of both lens surfaces by two position measurement steps, it is not necessary to hold the lens again, and the shape of the lens can be measured with high accuracy. As a result, the shape of the manufactured lens can be measured accurately and efficiently, and the productivity of the lens can be improved.

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

Embodiment 1 of the Invention
As shown in FIGS. 1 to 3, the lens measurement device 1 according to the embodiment of the present invention includes a measurement table 2, a stage 3 disposed on the measurement table 2, and a first disposed on the measurement table 2. A first position measuring device 4; a second position measuring device 5 disposed opposite to the first position measuring device 4 on the measuring table 2; the stage 3, the first position measuring device 4 and the second position measuring device; 5 and the like.

  The stage 3 includes a first stage base 31 fixed on the measurement table 2, an X-axis stage 32, a second stage base 33 fixed on the X-axis stage 32, a Y-axis stage 34, And a lens holder 6 that holds the lens 7 to be measured. This stage 3 is an example of a lens moving unit.

  The X-axis stage 32 is a flat stage disposed on the stage base 31 and has a predetermined X-axis parallel to the surface of the measuring table 2 (the surface on which the stage 3 and the like are disposed). It is configured to be movable along.

  The second stage base 33 is formed in a rectangular parallelepiped shape and is fixed on the X-axis stage 32. That is, when the X-axis stage 32 moves along the X-axis, the second stage base 33 moves along the X-axis together with the X-axis stage 32.

  The Y-axis stage 34 is a flat stage attached to the surface of the second stage base portion 33 that faces one side in the X-axis direction, and is on the X-axis and the surface of the measuring table 2. It is configured to be movable along the orthogonal Y axis. That is, when the X axis stage 32 moves along the X axis, the Y axis stage 34 moves along the X axis together with the X axis stage 32 and the second stage base 33.

  These X-axis stage 32 and Y-axis stage 34 are driven by pulse motors 32a and 34a, respectively. Specifically, the X-axis stage 32 and the Y-axis stage 34 move along the X-axis and the Y-axis, respectively, according to the pulse signal from the control device 10. The control device 10 can recognize the movement amounts of the X-axis stage 32 and the Y-axis stage 34 based on the number of pulses of the transmitted pulse signal.

  The lens holding unit 6 is attached to a surface of the Y-axis stage 34 that faces one side in the X-axis direction.

  The first position measuring device 4 includes a first measuring device 41 and an installation table 42 that is fixed on the measuring table 2 and for installing the first measuring device 41. The first position measuring device 4 is an example of a first position measuring unit.

  The first measuring device 41 is a linear gauge having a device main body 41a and a measuring element 41b provided so as to be able to advance and retreat from the apparatus main body 41a, and can measure a displacement amount of the measuring element 41b. And the 1st measuring device 41 is attached to the installation stand 42 with the attitude | position in which the measuring element 41b can advance / retreat to the Z-axis direction orthogonal to an X-axis and a Y-axis. The first measuring device 41 is configured to measure the amount of displacement of the measuring element 41b in the Z-axis direction.

  The second position measuring machine 5 includes a second measuring device 51 and an installation table 52 that is fixed on the measuring table 2 and on which the second measuring device 51 is installed. The second position measuring device 5 is provided at a position facing the first position measuring device 4 with the lens holding unit 6 interposed therebetween. The second position measuring device 5 is an example of a second position measuring unit.

  Similar to the first measuring device 41, the second measuring device 51 is a linear gauge having a device main body 51a and a measuring member 51b provided so as to be able to advance and retreat from the device main body 51a. The measuring member 51b is in the Z-axis direction. It is attached to the installation stand 52 in such a posture that it can freely move forward and backward.

  More specifically, the measuring element 41b of the first measuring device 41 and the measuring element 51b of the second measuring device 51 are configured to advance and retreat on substantially the same straight line extending in the Z-axis direction.

  The control device 10 includes a microcomputer, and can send and receive signals directly or indirectly via the pulse motors 32a and 34a, the first and second measuring devices 41 and 51, a driver (not shown), and the like. It is connected. The control device 10 transmits a control signal to the drivers of the pulse motors 32a and 34a to move the X-axis stage 32 and the Y-axis stage 34. The control device 10 receives outputs from the first and second measuring devices 41 and 51, and acquires and stores the displacement amounts of the measuring elements 41b and 51b of the first and second measuring devices 41 and 51. The control device 10 calculates the shape of the lens 7 based on the amount of movement of the X-axis and Y-axis stages 32 and 34 and the amount of displacement from the first and second measuring devices 41 and 51, which will be described in detail later. It is an example of the lens shape calculation part to perform.

  A method for measuring the lens shape by the lens measuring apparatus 1 configured as described above will be described below.

  When the lens 7 is held by the lens holding unit 6, the tip of the probe 41 b of the first measuring device 41 is placed on one lens surface 71 of the lens 7 and the measurement of the second measuring device 51 is performed as shown in FIG. The tip of the probe 51b is in contact with the other lens surface 72 of the lens 7 in a biased state, and the lens 7 is sandwiched between the probe 41b and the probe 51b.

  The lens 7 held by the lens holding unit 6 can move in the X-axis and Y-axis directions by driving the X-axis stage 32 and the Y-axis stage 34, while the first and second position measuring devices 4 and 4. Since 5 is fixedly installed on the measuring table 2, driving the X-axis stage 32 and the Y-axis stage 34 causes the lens 7 to move to the first and second position measuring machines according to the amount of movement. 4 and 5 can be moved in the X and Y axis directions. The measuring elements 41b and 51b of the first and second position measuring devices 4 and 5 are movable in the Z-axis direction and are urged against the lens surfaces 71 and 72 of the lens 7, so that the lenses 7 moves forward and backward in the Z-axis direction and maintains contact with the lens surfaces 71 and 72. As a result, by simply driving the X-axis stage 32 and the Y-axis stage 34, the Z of any XY coordinate point corresponding to the amount of movement of the X-axis stage 32 and the Y-axis stage 34 on both lens surfaces 71 and 72 is obtained. The axial position can be measured by the first and second position measuring machines 4 and 5.

  That is, by moving the lens 7 in the X-axis and Y-axis directions and measuring the displacement amount of the measuring elements 41b and 51b in the Z-axis direction, the XYZ coordinate system of each point on the lens surfaces 71 and 72 is measured. The position coordinates at can be obtained.

  The 0 point (reference point) of the XYZ coordinates may be set arbitrarily. With respect to the Z-axis direction, the Z-axis direction position of the tips of both the measuring elements 41b and 51b in a state where the lens holding unit 6 does not hold the lens 7 and the tips of the measuring elements 41b and 51b are in contact with each other. 0. In this case, the positive and negative directions of each axis may be arbitrarily set. In the present embodiment, in the X-axis direction, the direction in which the X-axis stage 32 moves away from the first and second position measuring devices 4 and 5 is positive, and the X-axis stage 32 is the first and second position measuring devices 4 and 4. The direction approaching 5 is negative. Regarding the Y-axis direction, the direction in which the Y-axis stage 34 moves away from the measurement table 2 (ie, upward) is positive, and the direction in which the Y-axis stage 34 approaches the measurement table 2 (ie, downward) is negative. Regarding the Z-axis direction, the second position measuring device 5 side is positive, and the first position measuring device 4 side is negative.

-Lens thickness measurement-
Below, the thickness measurement of the lens 7 is demonstrated. Here, the lens thickness refers to the width of the lens on a line connecting the spherical centers of both side surfaces of the lens.

  In the present embodiment, the lens 7 is a spherical lens, and the thickness T of the lens 7 is calculated from the center coordinates C1, C2 and the radii R1, R2 of both lens surfaces of the lens 7. Details are shown in FIGS. If the center coordinate C1 and radius R1 of one lens surface 71 and the center coordinate C2 and radius R2 of the other lens surface 72 in the lens 7 are known, the lens thickness T can be calculated from the geometric relationship.

For example, as shown in FIG. 5, when both lens surfaces 71 and 72 of the lens 7 are concave surfaces, the center coordinates C1 (a1, b1, c1) of the first lens surface 71 and the center of the second lens surface 72 are used. From the distance L to the coordinate C2 (a2, b2, c2), the radius R1 of the first lens surface 71, and the radius R2 of the second lens surface 72, the thickness T of the lens 7 is
T = L−R1−R2 (1)
It is represented by

As shown in FIG. 6, when both lens surfaces 71 and 72 of the lens 7 are convex surfaces, the thickness T of the lens 7 is
T = −L + R1 + R2 (2)
It is represented by

In this embodiment, in order to obtain the thickness T of the lens 7 from such a geometrical relationship, the center coordinates C1 and C2 and the radii R1 and R2 of the both lens surfaces 71 and 72 of the lens 7 are used as the both lens surfaces 71. , 72 by measuring the coordinates of each of the four points. In other words, the equation of the sphere is expressed as follows in the XYZ coordinate system where the center coordinate of the sphere is (a, b, c) and the radius is R:
(X−a) ² + (y−b) ² + (z−c) ² = R ² (3)
Therefore, a, b, c, and R are calculated by substituting the measured four coordinates into the equation (3) and solving the four simultaneous equations.

  A distance L between the centers of the lens surfaces 71 and 72 is calculated from the calculated center coordinates C1 and C2 of the lens surfaces 71 and 72.

  The thickness T of the lens 7 can be calculated from the radii R1, R2 calculated in this way and the center-to-center distance L.

  As described above, the lens measuring apparatus 1 moves the lens 7 while maintaining the posture in the XYZ coordinates, and the amount of movement of the lens 7 and the first position measuring device 4 and the second position at the moved position. The thickness T of the lens 7 can be calculated by obtaining the coordinates of any four points on the lens surfaces 71 and 72 of the lens 7 from the measured values of the position measuring device 5.

  In the present embodiment, the contact-type first position measuring device 4 and the second position measuring device 5 are used as the first position measuring means and the second position measuring means, but other means such as non-contact shape measurement is used. Measuring means such as a machine may be used.

<< Embodiment 2 of the Invention >>
Next, a method for manufacturing a lens according to Embodiment 2 will be described.

  In the lens manufacturing method according to the second embodiment, first, the lens 7 is manufactured in the lens manufacturing step, and then the shape of the lens 7 is measured by the lens shape measuring method in the lens shape measuring step. To do. That is, the lens measuring device 1 is incorporated in a part of a lens production line.

  A known lens manufacturing method is employed for the lens manufacturing step. For example, in the case of a glass lens, it has a material processing step from the lens raw material until the lens material is formed, and a lens processing step of polishing the lens material to finish it as a lens.

  The material processing process includes a compounding process for preparing lens materials, a melting / cooling process for melting the prepared lens materials and cooling them to glass materials, and a molding process for molding glass materials into lens shapes by grinding and pressing, And a preparation step for removing the thermal distortion of the glass molded into a lens shape.

  The lens processing process includes grinding and polishing processes that gradually grind and polish the surface roughness and surface shape of the pressed glass, and a centering process that processes the lens outer periphery so that it is not decentered with respect to the optical axis. And a coating process for coating the lens surface.

  The shape of the lens thus manufactured is measured by the lens shape measurement method according to the first embodiment in the lens shape measurement step. Then, it is determined whether or not the lens shape such as the lens thickness is within a predetermined allowable error, and a lens that is within the allowable error is defined as a completed lens.

  Therefore, according to the second embodiment, the shape of the manufactured lens can be measured accurately and easily. As a result, the accuracy of the manufactured lens can be improved, and the shape of the lens can be measured quickly, so that the productivity of the lens can be improved.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the embodiment.

  That is, in the embodiment, the stage 3 is moved in the X-axis and Y-axis directions, but the present invention is not limited to this. For example, it may be moved in a plane that intersects at an angle other than a right angle to the Z-axis direction. In this case, since the movement amount of the stage 3 affects not only the XY coordinates of the lens but also the Z coordinate, it is necessary to correct the measurement results obtained by the first and second position measuring machines according to the movement amount of the stage 3. There is.

  Further, a Z-axis stage (not shown) may be provided on the stage 3 so that the lens 7 can be moved not only in the X-axis and Y-axis directions but also in the Z-axis direction. In this case, since the movement amount of the stage 3 affects not only the XY coordinates of the lens but also the Z coordinate, it is necessary to correct the measurement results obtained by the first and second position measuring machines according to the movement amount of the stage 3. There is.

  Furthermore, in the above-described embodiment, the center coordinates and radii of the lens surfaces 71 and 72 are obtained by substituting the coordinates of the four measurement points into Expression (3), but the present invention is not limited to this. The center coordinates and the radius may be obtained by calculating or approximating the shapes of the lens surfaces 71 and 72 by a known method such as a least square method. In addition, it is not restricted to a center coordinate and a radius, You may calculate and approximate the whole shape of the lens surfaces 71 and 72 by another well-known method.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  In the lens measuring device, the lens measuring method, and the lens manufacturing method according to the present invention, it is possible to measure the shape such as the lens thickness with high accuracy and efficiency, and an optical apparatus using a lens represented by a digital camera. Therefore, it is possible to control the accuracy with high accuracy and low cost, and it can be applied to general optical equipment using an optical lens.

It is a top view of the lens measuring device concerning the embodiment of the present invention. It is a front view of a lens measuring device. It is a right view of a lens measuring device. It is an enlarged view which shows the mode of the measuring element after lens holding | maintenance. It is a side view of a biconcave lens. It is a side view of a biconvex lens. It is explanatory drawing for demonstrating the micrometer which measures the conventional lens thickness.

1 Lens measurement device 3 Stage (Lens moving part)
4 1st position measuring machine (1st position measuring means)
5 Second position measuring machine (second position measuring means)
6 Lens holder 7 Lens 71 Lens surface (one lens surface)
72 Lens surface (the other lens surface)
10 Control device (lens shape calculation unit)

Claims (6)

A measuring table;
A lens moving unit that has an X-axis stage and a Y-axis stage and moves the lens in the plane of the XY axis;
1st position measurement means installed fixedly with respect to the said measuring stand, Comprising: It contact | abuts with one surface of the said lens so that it can advance / retreat to the Z-axis direction which cross | intersects the said plane with the movement of the said lens First position measuring means for measuring the position of the contact point in the Z-axis direction,
A second position measuring means fixedly installed on the measuring table, wherein the second position measuring means is brought into contact with the other surface of the lens so as to advance and retract in the Z-axis direction intersecting the plane as the lens moves. Second position measuring means for measuring the position of the contact point in the Z-axis direction,
A lens shape calculation unit that obtains the shape of the lens based on the amount of movement of the lens in the X-axis direction and the Y-axis direction by the lens moving unit and the measurement results of the first and second position measuring means,
The first and second position measuring means are configured such that the lens is moved in the plane of the XY axis by driving the X-axis stage and the Y-axis stage, so that one surface and the other surface of the lens are moved. Measuring the position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the amount of movement in the X-axis direction and the Y-axis direction on both surfaces of the lens, and the X-axis direction of the points on both surfaces of the lens; Acquire the position in the Y-axis direction and the Z-axis direction at the same time ,
The lens shape calculation unit
Determining the spherical center of each surface of the lens based on the positions of the plurality of points on each surface of the lens in the X-axis direction, Y-axis direction, and Z-axis direction,
A lens measuring device that calculates a lens thickness that is a width of the lens on a straight line connecting the spherical centers of both surfaces of the obtained lens. The first and second position measuring means are arranged on a substantially straight line.
The lens measuring device according to claim 1. A lens moving step of moving the lens in the plane of the XY axes by a lens moving unit having an X axis stage and a Y axis stage;
A measuring element is provided that is fixed to a measuring table and has a measuring element that can move forward and backward in the Z-axis direction intersecting the plane as the lens moves and maintains contact with one surface of the lens. The probe of the one-position measuring means is moved forward and backward in the Z-axis direction only by moving the lens in the plane of the XY axis by driving the X-axis stage and the Y-axis stage in the lens moving step. A position where an arbitrary XY coordinate point corresponding to the amount of movement of the lens in the X-axis direction and the Y-axis direction, which is a contact point between the measuring element and one surface of the lens, is measured. A one-position measurement process;
It has a measuring element that maintains its contact with the other surface of the lens so that it can advance and retract in the Z-axis direction intersecting the plane as the lens moves, and is fixedly installed with respect to the measuring table. The probe of the second position measuring means is moved forward and backward in the Z-axis direction only by moving the lens in the plane of the XY axis by driving the X-axis stage and the Y-axis stage in the lens moving step. The position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the amount of movement of the lens in the X-axis direction and the Y-axis direction, which is a contact point between the probe and the other surface of the lens, is measured. A second position measuring step;
A lens shape calculating step for obtaining the shape of the lens based on the amount of movement of the lens by the lens moving step and the measurement results of the first and second position measuring steps,
The first position measurement step and the second position measurement step are performed at the same time, and simultaneously acquire the positions of the points on both surfaces of the lens in the X-axis direction, the Y-axis direction, and the Z-axis direction ,
The lens shape calculation step includes
Determining the spherical center of each surface of the lens based on the positions of the plurality of points on each surface of the lens in the X-axis direction, Y-axis direction, and Z-axis direction,
A lens measurement method for calculating a lens thickness which is a width of the lens on a straight line connecting the spherical centers of both surfaces of the obtained lens. The first and second position measuring means are arranged on a substantially straight line.
The lens measurement method according to claim 3 . A lens manufacturing process for manufacturing a lens;
Including a lens shape measurement step for measuring the shape of the lens produced by the lens production step,
The lens shape measuring step includes
A lens moving step of moving the lens in the plane of the XY axes by a lens moving unit having an X axis stage and a Y axis stage;
A measuring element is provided that is fixed to a measuring table and has a measuring element that can move forward and backward in the Z-axis direction intersecting the plane as the lens moves and maintains contact with one surface of the lens. The probe of the one-position measuring means is moved forward and backward in the Z-axis direction only by moving the lens in the plane of the XY axis by driving the X-axis stage and the Y-axis stage in the lens moving step. A position where an arbitrary XY coordinate point corresponding to the amount of movement of the lens in the X-axis direction and the Y-axis direction, which is a contact point between the measuring element and one surface of the lens, is measured. A one-position measurement process;
It has a measuring element that maintains its contact with the other surface of the lens so that it can advance and retract in the Z-axis direction intersecting the plane as the lens moves, and is fixedly installed with respect to the measuring table. The probe of the second position measuring means is moved forward and backward in the Z-axis direction only by moving the lens in the plane of the XY axis by driving the X-axis stage and the Y-axis stage in the lens moving step. The position in the Z-axis direction of an arbitrary XY coordinate point corresponding to the amount of movement of the lens in the X-axis direction and the Y-axis direction, which is a contact point between the probe and the other surface of the lens, is measured. A second position measuring step;
A lens shape calculation step for obtaining the shape of the lens based on the amount of movement of the lens by the lens movement step and the measurement results of the first and second position measurement steps;
The first position measurement step and the second position measurement step are performed at the same time, and simultaneously acquire the positions of the points on both surfaces of the lens in the X-axis direction, the Y-axis direction, and the Z-axis direction ,
The lens shape calculation step includes
Determining the spherical center of each surface of the lens based on the positions of the plurality of points on each surface of the lens in the X-axis direction, Y-axis direction, and Z-axis direction,
The lens manufacturing method which calculates the lens thickness which is the width | variety of the said lens on the straight line which connects the spherical-surface center of both surfaces of the calculated | required said lens . The first and second position measuring means are arranged on a substantially straight line.
The lens manufacturing method according to claim 5 .

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