JP2001304846A - Method and device for measuring lens array mold decentering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure with high accuracy and evaluate correctly the relative dislocation (displacement) of each lens which constitutes the mirror surface pieces or the absolute displacement between each lens face to the criterion arbitrarily set. SOLUTION: The lens array measuring method for mold decentering measures the relative displacement between the lens frame centers of curvature or between the paraxial centers of curvature, by moving a lens array metal mold toward the direction of a lens array and detecting each lens frame center of curvature or the position of the paraxial center of curvature. This measuring method for mold decentering removes the influence of the movement error to the eccentric measurement by storing the movement error toward the direction of the lens array of lens array mold which has been measured as the movement data and subtracting the movement error from the location data of the detected lens frame center of curvature of the paraxial center of curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the displacement of a lens surface of a mold for injection molding of a lens array used in a writing optical system of a laser printer or the like. This is effective in adjusting the assembly of the pieces (gold pieces) and evaluating the eccentricity of the lens array molded product.

[0002]

2. Description of the Related Art In a writing optical system of a laser printer or the like, an imaging optical element (lens array) in which lenses are linearly arranged is sometimes used, and the lens array is formed by molding plastic. There are many. In the mold used for molding, a mirror surface piece (gold piece) for transferring the lens surface is attached to the mold frame, and the mirror surface piece is precision processed by cutting or grinding so that the lens surface is aligned in a straight line. You. If the lens array becomes longer in the direction of its arrangement, the tool gradually wears and the processing conditions change as the lens surface is sequentially processed. Processing may not be possible. To prevent this, the mirror surface piece is divided into several pieces in the lens array arrangement direction and processed as several blocks. A method of forming a mold by sequentially arranging them in a mold frame has conventionally been adopted.

However, according to the above-mentioned conventional method, when the divided mirror surface pieces are arranged in a mold frame, if the lens surfaces are not aligned substantially in a straight line and at substantially equal intervals in the arrangement direction, the lens array to be formed is not formed. There has been a problem that the image forming positions of the individual lenses are displaced and the desired optical performance cannot be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a lens array molding die, in which a relative displacement (eccentricity) of each lens surface constituting a mirror surface piece or an absolute position of each lens surface with respect to an arbitrarily set reference. Measure the deviation with high accuracy,
The task is to make an accurate evaluation.

[0005]

The basic measurement principle adopted to solve the above-mentioned problem is that the lens array mold is moved in the lens array direction while the center of the curvature of each lens surface or near. This method detects the positions of the centers of curvature of the axes and detects their relative positional deviations or the absolute positional deviations of individual lens surfaces with respect to an arbitrarily set reference. Means taken to solve the problem is to move the lens array mold in the lens array arrangement direction,
By detecting the position of the center of curvature of each lens piece or the center of paraxial curvature that forms the lens array mold, the relative positional deviation between the centers of curvature of adjacent lens pieces or the center of paraxial curvature is measured. In the lens array mold eccentricity measurement method, the movement error of the lens array mold in the lens array direction is measured in advance and stored as the movement error data, and the detected lens mold center of curvature or paraxial is detected. The effect of the movement error on the eccentricity measurement is removed by subtracting the movement error data from the position data of the center of curvature. Further, by moving the lens array mold in the lens array arrangement direction and detecting the position of each lens mold curvature center or paraxial curvature center forming the lens array mold, an adjacent lens mold is detected. In a lens array mold eccentricity measuring device for measuring a relative displacement between centers of curvature or between paraxial curvature centers, a means for detecting a position of a center of curvature of a lens metal piece or a center of paraxial curvature, and a lens array mold are provided. A stage for moving in the lens array direction, means for detecting the position of the stage in the lens array direction, data detected by the center-of-curvature detecting means, and the lens-array-measurement-die-position detecting means Calculating means for determining the eccentricity of the lens array to be measured based on the detected data; A plane having a length equal to or longer than the stage stroke with respect to the moving direction of the moving stage (a moving plane reference plane), and a displacement meter for detecting a displacement in a direction substantially perpendicular to the moving direction of the plane. It was configured as follows. Further, a displacement gauge for detecting displacement of a surface having a length equal to or longer than a movement stroke of the lens array mold in the lens arrangement direction (a reference plane for the movement) or a displacement of the surface in a direction substantially perpendicular to the lens array arrangement direction. The displacement of the surface in a direction substantially perpendicular to the moving direction of the surface is detected by the displacement meter when one of the two is moved along with the movement of the lens array mold in the lens array arranging direction. By subtracting the displacement data from the position data of the center of the curvature of the lens or the center of the paraxial curvature, the error caused by the moving stage motion error on the eccentricity measurement is removed. Also,
The displacement data detected by the displacement meter is separated into the shape component of the surface and the motion error component of the moving stage, and only the motion error component of the moving stage is positioned at the center of the lens gold piece curvature or the center of the paraxial curvature. By subtracting from the data, the error that the moving stage motion error gives to the eccentricity measurement is removed. In addition, the number of the tracing stylus of the displacement meter is necessary for the type of motion error to be detected (1 is required for straightness error detection).
More than one unit is required for detecting the angle error such as the number, angle error, yawing, etc.). Further, the reference surface was used as a component surface of the lens array mold frame.

[0006]

When the lens array mold is moved in the arrangement direction using the stage, the movement stage includes motion errors such as straightness error, angle error, and yawing, and the center of curvature of the lens surface due to the motion error, or The displacement of the paraxial curvature center becomes an eccentricity measurement error. Therefore, the motion error of the moving stage is measured in advance and stored as moving motion error data, and subtracted (corrected) from the displacement data of the center of the lens piece curvature or the paraxial curvature center detected during the eccentricity measurement. With this configuration, it is possible to remove the influence of the moving motion error on the eccentricity measurement. If there is a difference in measurement conditions such as a temperature difference and a humidity difference between the measurement of the movement error and the eccentricity measurement of the lens array mold, the movement may not be reproduced according to the stored movement error data. Therefore, by detecting the movement error of the moving stage in the eccentricity measurement in real time, it becomes possible to remove the correction error caused by the difference in the measurement conditions. In addition, a surface having a length equal to or longer than the movement stroke of the lens array mold in the lens arrangement direction (a reference surface for the movement).
Or, when one of the displacement gauges for detecting the displacement of the surface in a direction substantially perpendicular to the lens array arrangement direction, when moved along with the movement of the lens array mold in the lens array arrangement direction, By detecting the displacement of the surface in a direction substantially perpendicular to the moving direction by the displacement meter, the moving motion of the moving stage can be observed in real time, and the moving motion at the time of the eccentricity measurement can be faithfully detected. Thereby, a correction error caused by a difference in measurement conditions can be removed. Further, when detecting the movement error, if there is a shape error in the reference plane, it is detected as a movement error, which leads to a correction error and an eccentricity measurement error. Therefore, the displacement data detected by the displacement meter is separated into the shape component of the reference plane and the motion error component of the moving stage, and only the motion error component of the moving stage is positioned at the center of the lens gold piece curvature or the center of the paraxial curvature. Since the subtraction is performed from the data, the motion error of the moving stage can be corrected without being affected by the shape error of the reference plane. This eliminates the need to use a reference plane whose flatness is sufficiently guaranteed. In addition, when the reference plane displacement is measured in the eccentricity measurement, the displacement output is separated into the reference plane shape and the stage motion error in real time, so there is no need to measure in advance. It is possible to remove a correction error caused by the displacement. In addition, since there is no special restriction on the reference plane, the configuration surface of the lens array mold frame can be used as the reference plane, and accurate correction of the movement motion error of the moving stage can be performed without adding a special reference plane part to the apparatus. Becomes possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of the configuration of a mold will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a mold frame, in which a groove 1a is formed in the center. 2 is a mirror surface piece (gold piece), 3 is a lens surface,
One mirror surface piece is formed from two lens surfaces. In FIG. 1, there are a total of eight mirror pieces, each of which is fitted into a groove 1a formed in the mold frame and fixed in the mold frame 1 with a bolt (not shown). The mirror piece 2 fixed to the mold frame 1 needs to be installed so that the lens surfaces are aligned substantially linearly at equal intervals in the direction in which the lens surfaces are arranged.

Next, a description will be given of an apparatus and a measuring method for detecting the position of the lens surface in the mounting adjustment of the mirror surface piece or for evaluating the alignment accuracy (eccentricity) after all the mirror surface pieces are mounted on the mold frame. In FIG. 2, 1 is a mold frame (side view), 2 is a mirror piece (side section), 3 is a lens surface,
Represents the center of curvature of the lens surface. In order to detect the alignment of the lenses, the position of the center of curvature of the lens is detected, and the relative position deviation (relative eccentricity) of each lens center of curvature or the absolute position deviation (absolute eccentricity) with respect to an arbitrary set reference is detected. ) Is measured. Reference numeral 5 denotes an optical unit for detecting the center of curvature of the lens surface. In the optical system unit 5, the light from the light source 6 is turned back by the beam splitter 7, and is irradiated on the lens surface of the mirror piece through the lenses 8 and 9.

The light reflected from the lens surface travels backward through the lenses 9 and 8, passes through the beam splitter 7, and forms an image on the imaging surface of the CCD camera 10. The distance between the light source 6 and the lens 8 is adjusted in advance so that the light traveling between the lens 8 and the lens 9 is substantially parallel, and the focal point of the lens 9 and the center 4 of the lens surface curvature are substantially coincident. The position of the optical system unit 5 has been adjusted. The optical system unit 5 is mounted on a stage (not shown) that advances and retreats in the optical axis direction of the optical system (the direction of the arrow in FIG. 2), and can be retracted when a mold is detached from a measuring device, and can be measured. When the type of the mold is changed, the operation of making the focal point of the lens 9 substantially coincide with the lens surface curvature center 4 can be easily performed. The position of the CCD camera 10 is adjusted so that its imaging surface is near the focal point of the lens 8.

With the above configuration and arrangement, the position of the center of curvature 4 of the lens surface is determined by utilizing the principle of autocollimation.
It can be detected as the position of the spot image on the imaging surface of the CCD camera 10. The coordinates of the center of gravity position at the reflection spot image when is displayed on the monitor of the personal computer 12 via the image input unit 11 at the same time (1) from the lens surface that is imaged by the CCD camera 10 (X _c, Y c ) Is calculated (however, the X direction is a direction orthogonal to the lens array, and the Y direction is a lens array direction). In the following equation (1), n is the number of effective data in the calculation of the center of gravity of the spot.

(Equation 1) ・ ・ ・ ・ ・ ・ ・ ・ ・ (1)

Reference numeral 13 denotes a stage for moving the mold in the lens arrangement direction (the direction of the arrow in FIG. 2), which is driven by a stepping motor 14. The stepping motor 14 receives a pulse from the pulse controller 16 via the driver 15 and rotates. Further, a rotation origin position sensor (not shown) is attached to the stepping motor 14, and by counting the number of pulses, the position and movement amount of the stage with respect to the lens arrangement direction can be known. In addition, by attaching a detector such as a laser scale to the stage 13, it is possible to more accurately acquire and position the position of the stage.

As a measurement procedure, first, the barycentric coordinates (X _cj , Y _cj ) of the reflected spot image from an arbitrary lens surface are stored. Thereafter, the stage is moved by almost the pitch of the lens surface, and the barycentric coordinates ( _Xcj + 1, _Ycj + 1) of the reflected spot image from the adjacent lens surface are acquired. The center-of-curvature deviation D of the adjacent lens surfaces is calculated using the coordinates of both centroids according to the following equation (2). However, (2) _{f 1} of the focal length of the lens 9, _{f 2} is the focal length of the lens 8, a is the size of one pixel of the CCD camera.

(Equation 2) (J = 0, 1, 2, ...) ... (2)

Further, for example, with the position of the rightmost lens surface in the mold of FIG. 2 as a reference, the coordinates of the reflected spot image are set as ( _Xco , _Yco ), and the stage is moved by the pitch of the lens surface. However, by calculating the displacement D of the center of curvature of the lens surface each time by using the following equation (3),
The absolute displacement of each lens with respect to the reference lens surface can be obtained. The reference may be set to an optimal one in accordance with the method of using the lens array.

FIG. 3 shows a conceptual diagram of a measurement result based on the rightmost spot as a reference. D _{1 to} D ₇ are the measured lens surface curvature center position shifts.

[Equation 3] (J = 1, 2, 3,...) (3) In the above, the spherical lens array mold is the object to be measured,
Although the center of curvature of the lens surface is detected, if the object to be measured is an aspheric lens array mold, the center of paraxial curvature of the lens surface may be detected and eccentricity measurement may be performed in the same manner as described above. Although the following description will be made on the assumption that the spherical lens array mold is the object to be measured, the same applies to the case of the aspherical lens array mold, and the difference is that only the paraxial center of curvature is detected instead of the center of curvature.

When the eccentricity of the lens surface in the lens array mold is measured by the apparatus shown in FIG. 2, the lens array mold is moved by driving the stage 13 in the lens array arrangement direction as described above. There is a slight movement motion error, and the items include a horizontal straightness error, a vertical straightness error, an angle error, a rotation error, a positioning error in the moving direction, and the like. Due to these movement errors, the center of curvature of the lens surface of the lens array mold mounted on the stage is displaced, which results in an eccentricity measurement error.

In the embodiment shown in FIG. 4, during the movement of the moving stage for the entire stroke, the movement errors generated and reproduced at each position of the moving stage are measured in advance, and the lens surface curvature due to the movement error is measured. The center displacement is calculated and stored as motion error correction data.
Then, the motion error of the stage is corrected by subtracting them from the position data of the center of curvature of the lens surface detected at the time of the eccentricity measurement.

An example of a method for measuring a motion error will be described with reference to FIG. ₁₇ a to 17 _d in Figure 4 is the probe of all displacement meter, 18 is a reference plane to be displacement detection target. The stage 13 is a stage used for eccentricity measurement. Either a displacement meter probe or a reference plane may be mounted on the stage table. In this case, the reference plane 18 is mounted on the stage 13, and It shall be accompanied by movement. The displacement meter remains fixed regardless of the movement of the stage 13.

The displacement of the reference plane 18 in the direction perpendicular to the direction of movement caused by the movement of the stage 13 in the direction of the arrow is 1
_{7 a, 17 b, 17 c} , 17 d, each of the displacement output _{h a, h b, h c} , and _{h d,} also the spacing in the horizontal direction 17 _a and 17 _{b L} 1, 17 _c and 17 _d the spacing in the vertical direction and L _2. The horizontal linearity errors of _{E s,} the vertical straightness error _{E v,} the angular error _{E p,} a rotation error and _{E r.} In this case, assuming that the parallelism error between the reference plane and the stage movement is sufficiently small with respect to the stage motion error, and the shape error of the reference plane is sufficiently small with respect to the stage motion error, each motion error shall be expressed as follows: Can be.

[Formula 4] _{E s = h a E V =} h c E P = tan- 1 ((h b -h a) / L 1) E r = tan- 1 ((h d -h c) / L 2)・ ・ ・ ・ ・ ・ ・ (4)

When the die to be measured is mounted on the stage table, the displacement of the center of curvature of the lens surface due to each movement error due to the movement of the stage can be expressed by the following equation.
However horizontal straightness error E _s d the displacement of the center of curvature by _s, the vertical straightness of the positional deviation of the center of curvature by the error E _v d _v, angular error E _p d the displacement of the center of curvature by _p, the rotation the displacement of the center of curvature by the error E _r d _r, the displacement of the center of curvature by the positioning error E _t d
_Let it be _t . L ₀ is representative of the vertical distance to the lens surface the center of curvature from the stage table surface.

[Equation 5] _{d s = E s d v =} E v d p = L o tan E p d r = L o tan E r d t = E t ······· (5) positioning error _{d t} is It is attached to the stage 13 and is detected using a laser scale (not shown) for detecting the amount of displacement in the movement direction of the stage 13.

Considering the influence of such a motion error, the equations (2) and (3) are as follows. By calculating them, the stage motion error is removed (corrected).
The obtained eccentricity measurement result is obtained.

(Equation 6) ・ ・ ・ ・ ・ ・ ・ (6)

Equation 7 ・ ・ ・ ・ ・ ・ ・ (7)

[0021] For example, when the lens surface of the lens mold to be measured and there was eight, positional deviation d _sj center of curvature due to the motion errors in stage position of the eight to be positioned during _{measurement, d} pj, _{d yj,} d Each of _tj (j = 1 to 8) may be measured in advance by the configuration shown in FIG. 4, and the eccentricity may be calculated using the equation (6) or the equation (7) when measuring the eccentricity.

Further, the configuration of the apparatus of FIG. 2, reference plane 18 as shown in FIG. 4, by adding a displacement gauge probe ₁₇ a to 17 _d, or reference plane 18, displacement gauge probe ₁₇ a to 17
_d is placed on the table of the moving stage, and at the time of the eccentricity measurement, the reference plane 18 accompanying the movement of the moving stage is set.
By detecting a displacement in a direction substantially perpendicular to the moving direction of the moving stage, a movement error of the moving stage may be detected in real time.

When measuring the eccentricity, the displacement of the reference plane accompanying the movement of the stage is detected in real time, and the eccentricity from which the motion error and the stage motion error have been removed can be calculated by the above-described method. In the above-described method, there is a time gap between the acquisition of the motion error data and the eccentricity data, so that the motion error cannot be exactly corrected accurately due to the influence of temperature, humidity, disturbance, and the like. However, if it is configured to detect the motion error in real time during the eccentricity measurement, the temperature,
Humidity, disturbance and the like are exactly the same, and accurate correction of the stage motion error is possible.

In addition, when a movement error of the stage is detected by detecting a displacement of the reference plane in a direction perpendicular to the moving direction accompanying the stage movement, if there is a shape error in the reference plane, the shape error component is also displaced. Since it is detected by the meter and regarded as a stage motion error, an error may occur in the motion error correction. Therefore, if the shape of the reference plane is measured in advance, and the reference plane shape component is subtracted from the displacement output accompanying the stage movement of the reference plane in the eccentricity measurement, and it is configured as motion error data, the reference plane shape error Accurate extraction of the stage motion error which is not affected is possible. In measuring the shape of the reference plane, the shape of the reference plane in the direction of movement in the position where the motion error data is detected may be measured in advance using a laser interferometer or using a scanning type shape measuring instrument.

[0025] In the configuration in FIG. 4, the displacement gauge probe ₁₇ for detecting the vertical displacement a, 17 _b, it is installed displacement gauge probe ₁₇ c, 17 _d for detecting the horizontal displacement. As shown in equation (4), the stage motion error is calculated based on the output of one displacement meter for straightness measurement and two displacement meters for angle measurement. The number required for the type of motion error to be detected is calculated. It is also possible to adopt a configuration in which one or more devices are installed. That is, two or more displacement meter probes are installed in the case of straightness error detection, and three or more displacement meter probes are installed in the direction in which the inclination angle is to be detected in the case of angle error detection.
Even when the straightness error and the angle error are detected at the same time, 3
A configuration in which more than one displacement meter probe is installed.

The one shown in FIG. 5 straightness error, the configuration of the case of detecting the angle error simultaneously _and 17 e, 17 _f 4
Is a displacement meter probe newly added to the configuration of FIG. With the device having this configuration, the displacement output in the direction perpendicular to the moving direction accompanying the stage movement of the reference plane is separated in real time into the stage motion error component and the shape component of the reference plane.
The basic principle of this measurement is a three-point method which is a known technique. The three-point method is described in “Precision Machinery” 48, 2 (1982) P2
This is one of the multipoint methods for separating and extracting the motion error of the moving object and the shape error of the surface of the measuring object as shown in 39 etc., and is arranged on the same straight line in the moving direction of the moving object. This is a method using three displacement meters.

[0027] In the configuration of FIG. 5, the position on the reference plane 18 side of the displacement sensor 17a as x, the displacement meter ₁₇ a, 17
_e, 17 _b of the displacement output respectively _{h a (x), h e} (x),
and h b _(x), also a vertical straightness error in position of the displacement meter 17 _a T (x), the shape of the reference plane S (x), when the angular error and theta (x), each displacement meter The output can be expressed by the following equation. However _{M 1} is displacement meter 17 _a and 17 _e
Intervals, _{M 2} is the spacing 17 _a and 17 _b.

[Equation 8] _{h a (x) = T (} x) + S (x) h e (x) = T (x) + S (x-M 1) -M 1 · tan Θ (x) hb (x) = T (X) + S (x + M ₂ ) + M ₂ · tan Θ (x) (8)

[0028] _{Here, h a (x), h} e (x), is calculated the following equation H (x) using a _{h b} (x),

[Equation 9] ... (9), which does not include the motion error, and has the shape error S (x) of the reference plane.
Is obtained. Shape error S (x) and H
When (x) is represented by a Fourier series, the Fourier coefficients of the two correspond one-to-one, and therefore H (x) obtained from the output of each displacement meter.
, The reference plane shape error S (x) can be calculated. Thereafter, by subtracting the shape error S (x) from the displacement meter output, the vertical straightness and the angle error can be obtained. Horizontal straightness,
Similarly, the rotation error obtained by removing the reference plane shape is obtained.

As shown in FIG. 1, the mold is constructed by assembling the mirror frame with the mold frame, but the reference plane is the surface (the side surface and the mirror surface frame on the upper surface) constituting the mold frame. Surfaces other than the assembly part) can also be used. Although the configuration surface of the mold frame is not very accurate, the above-mentioned method can be used as a reference plane for correcting the stage motion error in the eccentricity measurement because the shape component of the reference plane can be removed. Becomes

[0030]

According to the first aspect of the present invention, the motion error of the moving stage is measured in advance and stored as moving motion error data, and the center of curvature of the lens piece or the center of paraxial curvature detected at the time of the eccentricity measurement. By subtracting (correcting) from the displacement data, the effect of the movement error on the eccentricity measurement can be removed, so that highly accurate eccentricity measurement can be performed. According to the configuration of claim 2, the motion error of the moving stage in the eccentricity measurement can be detected in real time, and the temperature difference between the measurement of the moving motion error and the eccentricity measurement,
Measurement conditions such as a humidity difference can be completely matched, and a correction error of the movement can be reduced. Therefore, a measuring device capable of performing highly accurate eccentricity measurement can be provided. According to the configuration of claim 3, the lens array mold is displaced in a plane having a length equal to or longer than the movement stroke in the lens arrangement direction (a reference plane for the movement) or in a direction substantially perpendicular to the lens array arrangement direction. The displacement of the surface in a direction substantially perpendicular to the moving direction of the surface when one of the displacement meters for detecting the displacement is moved along with the movement of the lens array mold in the lens array arranging direction is referred to as the displacement. The movement of the lens array mold is observed in real time by detecting with a meter. This makes it possible to faithfully detect the movement motion during eccentricity measurement, enabling real-time detection of the movement stage movement error in eccentricity measurement.The measurement conditions such as temperature difference and humidity difference between the measurement of the movement movement error and the eccentricity measurement can be determined. It is possible to completely match them. Therefore, the correction error of the moving motion can be reduced, and more accurate eccentricity measurement can be performed. According to the configuration of the fourth aspect, the displacement data detected by the displacement meter is separated into the shape component of the reference plane and the motion error component of the moving stage, and only the motion error component of the moving stage is located at the center of the lens gold piece curvature or near. By subtracting from the position data of the axis curvature center, it is possible to correct the movement error of the moving means which is not affected by the shape error of the reference plane, and it is possible to perform highly accurate eccentricity measurement without increasing the cost. According to the configuration of claim 5, when measuring the reference plane displacement in the eccentricity measurement, the displacement output is separated in real time into the reference plane shape and the stage motion error, thereby enabling high-accuracy eccentricity measurement without cost. A measuring device that realizes the measuring method described above can be provided. According to the configuration of claim 6, by utilizing the configuration surface of the lens array mold frame as the reference plane, it is possible to accurately correct the movement error of the lens array mold without adding a special reference plane component to the apparatus. Make it possible. Therefore, it is possible to provide a device capable of performing highly accurate eccentricity measurement without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a plan view of a mold.

FIG. 2 is a front view of the mirror surface piece alignment accuracy measuring device.

FIG. 3 is a conceptual diagram of a position shift measurement result.

FIG. 4 is a front view of the motion error measuring device.

FIG. 5 is a front view of another motion error measuring device. Description of reference numerals in FIGS. 1 to 5 1... Mold frame 1a... Groove 2... Mirror surface piece (gold piece) 3. ······························································· Light source Beam splitter 8 ······· Lens 9 ········· Lens 10 ······· CCD camera 11 ······· Image input device 12 ·····・ PC 13 ・ ・ ・ ・ ・ Stage 14 ・ ・ ・ ・ ・ ・ Stepping motor 15 ・ ・ ・ ・ ・ ・ ・ Driver 16 ・ ・ ・ ・ ・ ・ Pulse controller 17a ~ 17f ・ ・ ・ ・ ・ ・ ・ ・ ・Displacement probe 18 Reference plane

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA06 AA11 AA17 AA27 AA46 AA52 BB18 BB25 CC00 DD00 EE00 EE01 FF01 FF04 FF10 FF17 GG12 HH04 HH13 JJ03 JJ26 LL04 LL46 MM03 PP02 PP12 AQA A2AA2 BB38 BB40 DD12 DD30 EE02 EE12 EE23 GG04 GG07 GG52 GG58 GG62 GG65 HH15 HH30 JJ13 JJ22 MM02 MM34 NN26

Claims (6)

[Claims] 1. A lens array mold is moved in a lens array direction while detecting the position of the center of curvature of each lens piece forming the lens array mold or the position of the center of paraxial curvature. In the lens array mold eccentricity measuring method for measuring the relative displacement between the centers of curvature of lens mold pieces or the centers of paraxial curvatures, the movement movement is measured in advance in the movement direction of the lens array mold in the lens array direction. By storing the data as error data and subtracting the movement error data from the detected position data of the center of the lens piece curvature or the center of the paraxial curvature, the effect of the movement error on the eccentricity measurement is removed. Lens mold eccentricity measurement method. 2. The method according to claim 1, wherein the lens array molds are moved in the lens array direction while detecting the position of the center of curvature of each lens piece forming the lens array mold or the center of the paraxial curvature center. In a lens array mold eccentricity measuring device for measuring a relative positional deviation between lens gold piece curvature centers or paraxial curvature centers, means for detecting a position of a lens gold piece curvature center or a paraxial curvature center, and a lens array A stage for moving the mold in the lens array direction, means for detecting the position of the stage in the lens array direction, data detected by the center-of-curvature detecting means, and detection of the lens array position to be measured Calculating means for determining the eccentricity of the lens array to be measured based on the data detected by the means, and a moving direction of the moving stage A lens array mold having a surface parallel to and having a length equal to or greater than the stage stroke with respect to the moving direction of the moving stage, and a displacement meter for detecting displacement in a direction substantially perpendicular to the moving direction of the surface. Eccentricity measuring device. 3. A lens array mold eccentricity measuring apparatus according to claim 2, wherein said lens array mold has a surface having a length equal to or longer than a movement stroke of said lens array mold in a lens arrangement direction, or substantially perpendicular to said lens array arrangement direction. One of the displacement gauges for detecting displacements in different directions is moved in accordance with the movement of the lens array mold in the lens array arrangement direction, the direction of movement of the surface in a direction substantially perpendicular to the movement direction. Displacement is detected by the displacement meter, and the displacement data is subtracted from the position data of the center of curvature of the lens gold piece or the center of paraxial curvature to remove an error caused by a movement stage movement error in the eccentricity measurement. Lens array mold eccentricity measuring device. 4. A lens array mold eccentricity measuring apparatus according to claim 3, wherein the displacement data detected by said displacement meter is separated into a shape component of said surface and a motion error component of said moving stage. A lens array mold eccentricity measuring device characterized in that an error given to an eccentricity measurement by a moving stage motion error is removed by subtracting only a motion error component from a position data of a center of curvature of a lens metal piece or a center of paraxial curvature. 5. A lens array mold eccentricity measuring apparatus according to claim 2, wherein one or more measuring elements of said displacement meter are provided more than the number required for the kind of motion error to be detected. Mold eccentricity measuring device. 6. A lens array mold eccentricity measuring apparatus according to claim 2, wherein said surface is a constituent surface of a lens array mold frame.