JP2009139176A - Measuring device and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of a measuring method of a hollow shape by a conventional technology wherein the hollow shape of an object is not obtained at once, the object and a light source are required to be rotated, the device becomes complicated, and there is a problem in accuracy. <P>SOLUTION: This measuring device includes a light transmitting section for transmitting light in the first direction which is the axial direction of a hollow cylindrical shape, a converting section for converting the light direction to the direction orthogonal to the first direction, a detecting section for detecting the light reflected inside a measuring object of the light whose direction is converted by the converting section, a shape measuring section for measuring the inside shape of the measuring object by determining the shift from a predetermined reference position based on the detection result of the detecting section, and a position adjusting section for reducing the deviation of the shift over the full circumference inside the measuring object. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a measuring apparatus and method for measuring a hollow shape of an object.

Conventionally, a distance sensor method, an oblique incidence optical system method, and the like are known as methods for measuring the hollow shape of an object without contact. For example, the distance sensor method is a method of measuring the hollow shape of an object by projecting laser light inside the hollow and measuring the displacement of reflected light while rotating the object (see, for example, Patent Document 1).
JP 2006-38820 A

  The distance sensor method according to the prior art cannot obtain a hollow shape of an object at a time, and it is necessary to rotate the object and the light source, which not only complicates the apparatus but also has a problem in accuracy.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a high-precision hollow shape measuring apparatus and a method therefor with less errors and without performing complicated calculations with a simple configuration.

  A measuring apparatus according to the present invention is a measuring apparatus that measures an inner shape of a hollow cylindrical object to be measured, and a light transmitting unit that transmits light in a first direction that is an axial direction of the hollow cylindrical object; A conversion unit that converts the direction of the light in a direction substantially orthogonal to the first direction, and a detection unit that detects light reflected on the inside of the object to be measured among the light whose direction is converted by the conversion unit. And a shape measuring unit for measuring an inner shape of the object to be measured by obtaining a deviation from a predetermined reference position based on a detection result of the detecting unit, and the deviation over the entire inner periphery of the object to be measured. And a position adjusting unit that reduces the bias of the apparatus.

  In particular, the position adjustment unit detects a Z coordinate detection unit that detects a Z coordinate when the first direction is the Z axis, and detects a deviation of the deviation in an XY coordinate orthogonal to the Z axis at a predetermined Z coordinate. An XY coordinate deviation detection unit, a measurement optical system including the light transmission unit, the conversion unit, and the detection unit in a direction in which the deviation of the deviation detected by the XY coordinate deviation detection unit is reduced, and the object to be measured. It is characterized by comprising an XY coordinate moving unit that relatively moves on the XY coordinates.

  Further, the position adjusting unit detects an XY coordinate deviation bias with a plurality of Z coordinates by the XY coordinate deviation detection unit, and calculates a deviation correction amount by calculating the deviation deviations with the plurality of Z coordinates. The position adjusting unit relatively moves the measurement optical system and the object to be measured by the XY coordinate moving unit by the amount of the bias correction obtained by the calculation unit before measurement. And

  In particular, the arithmetic unit is characterized in that the deviation correction amount is obtained by averaging deviation deviations at the plurality of Z coordinates.

  Further, the apparatus further includes a Z coordinate moving unit that relatively moves the measurement optical system and the object to be measured in the first direction, and the position adjustment unit is configured so that the Z coordinate moving unit is the measurement optical system during measurement. And the object to be measured are moved relative to each other at a predetermined interval, the deviation of the deviation is detected by the XY coordinate deviation detection unit, and the measurement optical system and the object to be measured are moved by the XY coordinate movement unit. Relative movement is performed only by bias.

  A measuring method according to the present invention is a measuring method for measuring an inner shape of a hollow cylindrical object to be measured, wherein a direction of light transmitted in a first direction that is an axial direction of the hollow cylindrical shape is the first direction. The light image is converted into a direction substantially orthogonal to the direction 1 and irradiated on the inside of the object to be measured, and the light image is detected based on a measurement result of a measuring optical system that detects an image of light reflected on the inside of the object to be measured. When measuring the inner shape of the object to be measured by obtaining the deviation from the predetermined reference position, the deviation of the deviation over the entire inner circumference of the object to be measured is detected, and the deviation of the deviation is small. The measuring optical system and the object to be measured are moved relative to each other on an XY coordinate orthogonal to the first direction.

  According to the present invention, the inner shape of a hollow cylindrical object to be measured can be measured with high accuracy with a simple configuration and without performing complicated calculations.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram of a hollow shape measuring apparatus 101 according to the first embodiment. The hollow shape measuring device 101 obtains a cross-sectional shape by measuring the inner shape of a hollow cylindrical object at a predetermined height, and synthesizes the obtained cross-sectional shape in the height direction, thereby obtaining the hollow shape of the object. It is a three-dimensional construction device.

  The hollow shape measuring apparatus 101 includes a light transmitting unit 102, a circular slit 103, a light limiting slit 104, an illumination lens 105, a half mirror 106, an objective lens 107, a conical mirror 108, and an imaging lens 110. The imaging unit 111, the image processing unit 112, the Z-axis drive unit main body 113, the moving unit 114, the personal computer 115, the Z-axis position detecting unit 119, and the XY coordinate moving unit 120.

  The moving unit 114 includes a portion where the light of the light transmitting unit 102 is incident on the half mirror 106, and a tip portion 114a of the moving unit 114 inserted in the measurement target 109 in the circumferential direction of the conical mirror 108. Made of transparent material. The moving unit 114 is driven up and down in the direction of the central axis C1 by a Z-axis driving unit main body 113 fixed to a base (not shown), and the tip portion 114a of the moving unit 114 is placed in the hollow portion of the object to be measured 109. Enters and exits and measures the inner shape of the DUT 109. The light transmitting unit 102, the circular slit 103, the light limiting slit 104, the illumination lens 105, the half mirror 106, the objective lens 107, the conical mirror 108, the imaging lens 110, and the imaging unit 111 are supported and integrated by the moving unit 114. This constitutes the measurement optical system and moves up and down. In addition, the Z-axis position detection unit 119 detects the position of the moving unit 114 in the Z-axis direction and outputs it to the image processing unit 112 via the cable 121. Further, the XY coordinate moving unit 120 constitutes a pedestal on which the object 109 to be measured is placed, and moves to a position on the XY coordinate instructed from the image processing unit 112 via the cable 122. In particular, the XY coordinate moving unit 120 includes an X direction position detection sensor 120a and a Y direction position detection sensor 120b, and can accurately move the object 109 to be measured to the XY coordinates instructed from the image processing unit 112.

  The light emitted from the light transmitting unit 102 enters the light limiting slit 104 through the slit 103a of the circular slit 103 corresponding to the field stop. When the light beam passes through the light restricting slit 104, half of the light beam (for example, the light beam 151 at the inner portion centering on the one-dot chain line 154 indicating the center of the light beam) is blocked and is not output to the illumination lens 105 side.

  Here, the shapes of the circular slit 103 and the light limiting slit 104 will be described in detail with reference to FIG. The circular slit 103 shown in FIG. 2A is provided with a slit 103a that transmits light emitted from the light transmitting unit 102 in a ring shape. Here, the ring-shaped slit 103 a is arranged so that the alternate long and short dash line 154 indicating the center of the light beam in FIG. 1 is located at the center of the circular slit 103.

  On the other hand, the light limiting slit 104 shown in FIG. 2B is provided with a ring-shaped slit 104a that shields half of the light beam transmitted through the circular slit 103 and transmits the other half. The light limiting slit 104 is characterized by the fact that the inner diameter of the ring-shaped slit 104a corresponds to the position of the one-dot chain line 154 indicating the center of the light beam, as indicated by the one-dot chain lines C2 and C3. Only the outer half of the light beam is transmitted. The circular slit 103 and the light limiting slit 104 can be realized by controlling the liquid crystal so as to transmit light in a ring shape using a liquid crystal plate, for example. Alternatively, a method such as vapor-depositing a light shielding part on a glass plate or the like or etching a transmissive part may be used. Further, the sensitivity of the imaging unit 111 changes depending on the shielding rate.

  The light whose half of the light beam is blocked by the light limiting slit 104 enters the half mirror 106 through the illumination lens 105. The half mirror 106 changes the direction of incident light and reflects it to the objective lens 107 side. Here, if the direction of light reflected by the half mirror 106 is defined as the first direction, the light reflected in the first direction by the half mirror 106 is transmitted to the conical mirror 108 via the objective lens 107. The conical mirror 108 irradiates horizontally toward the inside of the object 109 to be measured in the entire circumferential direction substantially orthogonal to the first direction. The horizontally irradiated light is reflected on the inside of the object to be measured 109, is incident again on the conical mirror 108, is reflected on the objective lens 107 side, and then passes through the half mirror 106 and the imaging lens 110 to capture an image. An image is formed on the light receiving surface of the unit 111. Note that the light receiving surface of the imaging unit 111, the circular slit 103 that forms the field stop, and the reference position where the DUT 109 is placed are optically conjugate positions, and these three places are in focus. It has become. Further, the ring center of the ring-shaped light beam reflected by the half mirror 106 is coincident with the center of the conical mirror 108.

  Here, the shape of the conical mirror 108 will be described with reference to FIG. 3A is a perspective view of the conical mirror 108, FIG. 3B is a top view, and FIG. 3C is a side view. An alternate long and short dash line 154 indicating the center of the light beam reflected in the first direction through the half mirror 106 is reflected in a direction substantially orthogonal to the first direction by the mirror portion 108a inclined outward from the conical mirror 108, Irradiates the inside of the measurement object 109. FIG. 1A illustrates this state in detail. The light beam transmitted without being blocked by the light limiting slit 104 is, for example, between a dashed line 154 indicating the center of the light beam and a dotted line 152 indicating the outside of the light beam, and reflected by the mirror portion 108 a of the conical mirror 108. Further, a dotted line 152 indicating the outside of the light beam is reflected by the object to be measured 109 and again reflected by the conical mirror 108 toward the objective lens 107 as indicated by a solid line 153. That is, half of the light beam reflected and returned from the inside of the object to be measured 109 is still shielded, and is between the alternate long and short dash line 154 indicating the center of the light beam and the solid line 153 indicating the outside of the light beam.

  This will be described with reference to FIG. FIG. 4 is a diagram depicting the optical configuration of the hollow shape measuring apparatus 101 of FIG. 1, and the same reference numerals as those in FIG. 1 denote the same components. The light transmitting unit 102 includes a light source 130, an aperture stop 131 that determines the illumination NA, a lens 132 that condenses the light from the light source 130, and an imaging aperture 133 that determines the NA on the light receiving side. As described above, the light receiving surface of the imaging unit 111, the circular slit 103 constituting the field stop, and the area of the object 109 to be measured at the reference position are optically conjugate positions. It can be seen that the camera is in focus at several locations. In FIG. 4, since half of the light beam is shielded by the light limiting slit 104, half of the light beam returning from the object to be measured 109 is also shielded, and half of the light beam 160 indicated by hatching is not incident on the imaging unit 111. .

  Next, an image of points constituting an image formed on the light receiving surface of the imaging unit 111 will be described with reference to FIG. FIG. 6A is a diagram showing a state when a certain point inside the object to be measured 109 is photographed by the imaging unit 111 when there is no light limiting slit 104, and in the case where the hole diameters are different at the measurement position. A change in the spread of the light beam, that is, a change in focus (blurred image) in the imaging unit 111 is depicted. Here, the focus is shifted depending on the inner diameter of the object 109 to be measured, but the inner diameter at the in-focus position is defined as the reference hole diameter, and the optical system of the hollow shape measuring apparatus 101 is preliminarily adjusted so that the focus is exactly at this reference hole diameter. It shall be calibrated.

  451 and 451a to 451f in FIG. 5A show images picked up by the image pickup unit 111, where the portion indicated by the straight line 401 is the reference hole diameter, and the hole diameter from the straight line 401 toward the upper side of the paper surface. On the contrary, the hole diameter decreases toward the lower side of the drawing. For example, when the reference hole diameter is photographed, the image is not blurred as the light beam 451, but the light beam spreads as the light beams 451a, 451b, and 451c as the hole diameter becomes larger than the reference hole diameter. Similarly, as the hole diameter becomes smaller than the reference hole diameter, the light beam spreads as light beams 451d, 451e, and 451f. That is, the magnitude of deviation from the reference hole diameter can be measured from the amount of spread of the light beam. However, at this time, the light beam spreads in the same way on both sides of the axis C4 passing through the focus position of the reference hole diameter regardless of whether the hole diameter is increased or decreased. Cannot determine whether it has become smaller or smaller.

  On the other hand, in the case of the present embodiment, half of the light beam irradiated to the object to be measured 109 is shielded by the light limiting slit 104, so the change in the spread of the light beam when the hole diameter is different is shown in FIG. become that way. In the figure, when the reference hole diameter is photographed, there is no blur of the image like the light beam 452, but the light beam spreads as the light beams 452a, 452b and 452c as the hole diameter becomes larger than the reference hole diameter. . Similarly, as the hole diameter becomes smaller than the reference hole diameter, the light beam spreads like light beams 452d, 452e and 452f. However, unlike the case of FIG. 5 (a), the light beams 452a, 452b and 452c spread only in the right direction of the plane of the axis C4. Similarly, the light beams 452d, 452e and 452f spread This is only in the left direction of the paper surface of the axis C4. That is, it can be determined whether the hole diameter of the DUT 109 is larger or smaller than the reference hole diameter depending on whether the axis C4 is shifted to the right or left of the paper surface. The image processing unit 112 measures the magnitude of the deviation from the reference hole diameter from the determination result and the amount of spread of the light beam, and determines how large or small the inner shape of the DUT 109 is with respect to the reference hole diameter. Can be sought.

  Although the state of the light beam imaged on the light receiving surface of the imaging unit 111 has been described with reference to FIG. 5, how the captured image changes depending on the shape of the hole of the object to be measured 109 will be described with reference to FIG. This figure shows the overall state of the image formed on the light receiving surface 501 of the imaging unit 111. FIG. 10A shows an image when the reference hole diameter is measured, and is connected to the reference hole diameter position C6. Imaged. FIG. 7B shows an image obtained when a hole larger than the reference hole diameter is measured, and an image blurred on the outside of the reference hole diameter position C6 is obtained. On the other hand, FIG. 5C shows an image obtained when a hole smaller than the reference hole diameter is measured, and an image blurred inside the reference hole diameter position C6 is obtained. In FIGS. 6A, 6B, and 6C, hatched portions showing images are drawn slightly apart on both sides of the reference hole diameter position C6 for easy understanding, but in actuality, the reference hole diameter position C6 is shown. Overlapping parts. For example, when the object to be measured 109 having a square inner shape that is larger or smaller than the reference hole diameter position C6 is measured, an image as shown in FIG.

  As described above, when the image processing unit 112 receives the image data imaged on the light receiving surface of the imaging unit 111, the image processing unit 112 determines whether the inner shape of the DUT 109 is larger or smaller than the reference hole diameter from the direction in which the light beam spreads. It is possible to determine the inner diameter (shape) of the measured object 109 from the distance between the center or peak position of the further expanded light beam and the reference hole diameter position C6. For example, in the case of FIG. 6B, the distance Δx1 between the peak position of the spread light beam and the reference hole diameter position C6 is measured, and in the case of FIG. Find the hole diameter. Further, a complicated shape can be measured by subdividing the entire circumference range (for example, every 1 ° to 2 °) and obtaining and synthesizing each diameter (shape). In actual measurement, using a calibration tool whose hole diameter is different from the reference hole diameter, the distance Δx between the peak position of the spread light beam and the reference hole diameter position C6 and the actual hole are measured. It is preferable to measure the difference in diameter in advance and prepare a conversion table for the difference between the distance Δx and the actual hole diameter.

  Next, a method for measuring a cross section will be described. FIG. 7A shows an optical ring imaged on the light receiving surface. First, a temporary center is set at the center of the light receiving surface. Next, from the temporary center, the light intensity in the radial direction is measured for each set angle. The light intensity is high at the portion where the light ring is imaged. A portion defined as the circumference of the ring is calculated from the light amount distribution of the ring image.

There are several definition methods. For example, the following methods can be used.
1) Light quantity peak method: A method of calculating the peak position by fitting discrete data of the light quantity distribution around the peak position of the ring profile to an approximate expression.
2) Light intensity centroid method: A method of calculating the centroid position of the light intensity distribution around the peak position of the ring profile.
3) Threshold method: A method in which a threshold is set, for example, at a position 30% darker than the peak position of the ring profile, and an intermediate position between the positions intersecting the profile is calculated.

  For example, the circumferential position in each direction is obtained by the above optical center of gravity method. FIG. 7A shows a case where calculation is performed every 45 degrees, and 8 points are obtained as the circumferential points of the optical ring shown in FIG. 7B. Thereafter, the size of the optical ring and the center of the ring are obtained from these points using a mathematical method such as a least square method. Furthermore, the inner diameter of the object to be measured can be directly calculated from the size of the optical ring. Further, as described above, the difference from the reference ring dimension can also be calculated.

  However, as shown in FIG. 8A, the center axis CA1 of the moving unit 114 and the center axis CA2 of the DUT 109 are shifted on the XY plane, or FIGS. 8B and 8C. When the center axis CA3 of the measured object 109 is inclined with respect to the Z-axis direction as shown in FIG. 8, or when the inner shape of the measured object 109 is relative to the Z-axis direction as shown in FIG. In the case of a zigzag inclination, the direction in which the light beam spreads is not symmetrical with respect to the reference hole diameter position C6 as described with reference to FIG. This will be described with reference to FIG.

  FIG. 9 shows the spread of the luminous flux when measuring the measured object 109 having the same hole diameter as the reference hole diameter position C6. The central axis CA1 of the moving unit 114 and the central axis of the measured object 109 are shown. Since CA2 is displaced on the XY plane, the image spreads as if the center coordinate Pnxy of the inner shape of the DUT 109 is decentered with respect to the center coordinate Rxy of the reference hole diameter position C6. When the center coordinate Pnxy of the inner shape of the object to be measured 109 is not deviated from the center coordinate Rxy of the reference hole diameter position C6, as described with reference to FIGS. When the image spreads uniformly on the circumference according to the size of the inner shape, the center coordinate Pnxy of the inner shape of the DUT 109 is shifted from the center coordinate Rxy of the reference hole diameter position C6. As shown by the hatched portion in FIG. 9, the image does not spread uniformly on the circumference, and deviation of deviation occurs. In this case, at the points Q1 and Q2, the inner diameter of the reference hole diameter position C6 and the measured object 109 are exactly the same, so that the brightness QB of the formed image is increased, but the image is cut at the cross section S1-S2. It is spread and distributed like the luminances SB1 and SB2 of the image.

  As described above, when the center axis CA1 of the moving unit 114 and the center axis CA2 of the measured object 109 are shifted on the XY plane, the measurement accuracy varies depending on the position of the measured object 109 on the circumference. Therefore, accurate measurement cannot be performed. Note that the same applies to the case where the center axes CA3 and CA4 of the DUT 109 are inclined with respect to the center axis CA1 of the moving unit 114, as shown in FIGS.

  Therefore, in the present embodiment, the deviation on the XY plane between the center of the moving unit 114 and the center of the DUT 109 is corrected. Next, the shift on the XY plane between the center of the moving unit 114 and the center of the DUT 109 will be described with reference to FIG.

  FIG. 10 shows a state in which the central axis CA3 of the DUT 109 is tilted with respect to the central axis CA1 (referred to as the Z-axis direction) of the moving unit 114 as described with reference to FIG. Yes. In FIG. 10, the displacement of the center axis CA3 of the DUT 109 with respect to the center axis CA1 of the moving unit 114 changes according to the position in the Z-axis direction. For example, the center coordinate on the XY plane orthogonal to the Z-axis of the inner shape 601 of the object to be measured 109 is P1xy at the position Z1, but the center coordinate of the inner shape 602 of the object to be measured 109 is P2xy at the position Z2. The deviation of the hole diameter position C6 from the center coordinate Rxy is larger than the position Z1. Similarly, the center coordinate of the inner shape 603 of the object to be measured 109 is P3xy at the position Z3, and the deviation from the center coordinate Rxy of the reference hole diameter position C6 is further larger than the position Z1.

Next, the measurement flow of the hollow shape measuring apparatus 101 when correcting such a displacement will be described with reference to the flowchart of FIG. For easy understanding, processes related to misalignment correction are indicated by step numbers in the 300s, and processes other than misalignment correction are indicated by step numbers in the 200s.
(Step S201) First, the DUT 109 is set under the moving unit 114.
(Step S202) Next, measurement specifications such as a measurement range (movement range) in the Z-axis direction and a measurement pitch (movement pitch) in the Z-axis direction of the moving unit 114 are input from the personal computer 115. The measurement specifications input by the personal computer 115 are output to the image processing unit 112 via the cable 118. The image processing unit 112 sends the moving unit 114 to the Z-axis drive unit main body 113 via the cable 117 together with the light transmitting unit 102 and the like. Command to move to measurement start position.
(Step S301) A process of temporarily measuring the size of the positional deviation is performed. Here, the positional deviation temporary measurement processing that is made into a subroutine will be described in detail with reference to FIG.

FIG. 12 is a process for measuring the center coordinates of the inner shape of the DUT 109 for each Z coordinate in the Z-axis direction as shown in FIG.
(Step S 311) Light is emitted from the light transmitting unit 102 at the current position of the moving unit 114, and an image is captured by the imaging unit 111.
(Step S 312) The image received by the imaging unit 111 is output to the image processing unit 112 via the cable 116.
(Step S313) The image processing unit 112 reads the current position (Z coordinate) of the moving unit 114 from the Z-axis position detecting unit 119 connected via the cable 121.
(Step S314) The image processing unit 112 measures the center coordinates of the inner shape of the DUT 109 from the captured image. As described above with reference to FIGS. 6 and 7, the center coordinates can be obtained by obtaining the inner shape of the DUT 109 and determining the equidistant position or the barycentric position from each side of the inner shape as the center coordinates.
(Step S315) It is determined whether the measurement is completed according to the measurement specification. For example, if the moving unit 114 has not reached the end position of the moving range, the process proceeds to step S316, and if it has reached the end position, the process proceeds to step S317.
(Step S316) The moving unit 114 is moved in the Z-axis direction to the next measurement position in accordance with the set measurement pitch, and the process returns to Step S311 to continue the temporary displacement measurement at the position.
(Step S317) When the moving unit 114 reaches the end position of the set moving range in the Z-axis direction, the temporary displacement measurement process subroutine is terminated and the process returns to the main routine.

When the temporary displacement measurement process in step S301 in FIG. 11 is completed, the process in step S302 is performed.
(Step S302) The image processing unit 112 calculates the amount of positional deviation from the center coordinates of the inner shape of the measured object 109 for each Z coordinate measured in the temporary positional deviation measurement process of Step S301. For example, if the temporarily measured Z coordinates are n of Z1, Z2... Zn, the center coordinates of the inner shape of each object 109 to be measured are P1xy, P2xy. In this case, an average value of n center coordinates is calculated, and this is set as an average center coordinate Pavexy. Further, the difference Δxy between the obtained average center coordinate Pavexy and the center coordinate Rxy of the reference hole diameter position C6 can be calculated as a positional deviation amount on the XY coordinates. Here, for easy understanding, the average value of the center coordinates for each of the n Z coordinates is simply obtained, but a method such as a least square method may be used, and the Z coordinate (height position) may be used. You may make it weight by. For example, by increasing the weighting at the height position where measurement is desired with high accuracy, the measurement accuracy of the part can be improved.
(Step S303) The image processing unit 112 adjusts the positional deviation on the XY coordinates by a difference Δxy from the center coordinate Rxy of the reference hole diameter position C6 obtained in Step S302. For example, if the difference is Δxy (Δx, Δy), the image processing unit 112 instructs the XY coordinate moving unit 120 to perform Δx in the X-axis direction and Δy in the Y-axis direction with respect to the current XY coordinate position. Just move each one.

Through the processing so far, the DUT 109 is arranged at a position where the average center coordinate Pavexy obtained in step S302 matches the center coordinate Rxy of the reference hole diameter position C6. Thereafter, the inner shape of the hollow shape measuring apparatus 101 is measured in a state in which the positional deviation is adjusted.
(Step S <b> 203) Light is emitted from the light transmitting unit 102 at the current position of the moving unit 114, and an image is captured by the imaging unit 111.
(Step S <b> 204) The image received by the imaging unit 111 is output to the image processing unit 112 via the cable 116.
(Step S205) As described with reference to FIGS. 5 and 6, the image processing unit 112 obtains the inner diameter (shape) of the DUT 109.
(Step S206) It is determined whether the measurement is completed according to the measurement specification. For example, if the moving unit 114 in the Z-axis direction has not reached the end position of the moving range, the process proceeds to step S207, and if it has reached the end position, the process proceeds to step S208.
(Step S207) The moving unit 114 is moved in the Z-axis direction to the next measurement position according to the set measurement pitch, and returns to Step S203 to perform measurement at the position.
(Step S208) When the movement unit 114 reaches the end position of the set movement range in the Z-axis direction and finishes the measurement, the inner height of the object to be measured 109 (relative position with respect to the measurement optical system) Shapes are obtained, and these shapes are synthesized to create hollow shape data.

  Here, a method for synthesizing hollow shape data will be described with reference to FIG. In FIG. 13, reference numerals 701 to 706 denote inner shapes of the DUT 109 when the height is varied from the height (n) to (n + 5) by a predetermined pitch in the Z-axis direction (height direction). In FIG. 10, the inner shape is shown as a circle for easy understanding. However, depending on the object to be measured 109, there may be an inner shape with irregularities having different radii. By synthesizing the inner shapes 701 to 706 for each height, the hollow shape data of the DUT 109 can be obtained, and the three-dimensional hollow shape 109a can be constructed from the hollow shape data.

Returning to the flowchart of FIG.
(Step S209) The hollow shape data created by the image processing unit 112 is output to the personal computer 115 via the cable 118 and displayed on the screen of the personal computer 115.
(Step S210) If necessary, the personal computer 115 operates the keyboard or mouse to specify an arbitrary position of the device 109 displayed on the screen, and the device under test received from the image processing unit 112. The size and length of each part designated from 109 hollow shape data are displayed.
(Step S211) All measurements are terminated.

  As described above, the hollow shape measuring apparatus 101 according to the present embodiment obtains the inner shape from the deviation from the reference hole diameter for each predetermined height of the measured object 109 while moving the moving unit 114 up and down at a predetermined pitch. The hollow shape of the object can be three-dimensionally constructed by synthesizing the inner shape for each height. In particular, even when the inside of the measured object 109 is inclined with respect to the Z-axis direction, the measured object 109 is arranged at a position where the average center coordinate Pavexy of the inclination coincides with the central coordinate Rxy of the reference hole diameter position C6. Therefore, the hollow shape of the DUT 109 can be measured with high accuracy.

(Second Embodiment)
Next, the hollow shape measuring apparatus 101 according to the second embodiment will be described. The configuration of the hollow shape measuring apparatus 101 according to this embodiment is the same as that of the hollow shape measuring apparatus 101 according to the first embodiment shown in FIG. The difference between the present embodiment and the first embodiment is that the correction method of the positional deviation between the center coordinate Pnxy of the inner shape of the DUT 109 and the center coordinate Rxy of the reference hole diameter position C6 is different. Here, only a different part from 1st Embodiment is demonstrated.

  The flowchart of FIG. 14 shows a measurement flow of the hollow shape measuring apparatus 101 in the present embodiment. The same processes as those in the first embodiment are indicated by the same step numbers. Further, different processes in this embodiment are indicated by step numbers in the 400s. The processes up to step S201, step S202, and step S301 are the same as those in the flowchart of FIG. 11 of the first embodiment. That is, the measurement object 109 is set under the moving unit 114, and measurement specifications such as a measurement range (moving range) and a measurement pitch (moving pitch) of the moving unit 114 are input from the personal computer 115. Further, a process for temporarily measuring the size of the displacement is performed, and the center coordinates of the inner shape of the DUT 109 are measured for each Z coordinate.

(Step S401) The image processing unit 112 uses a function (position shift function f (z) with the Z coordinate as a variable from the center coordinate of the inner shape of the DUT 109 measured by the position shift temporary measurement process in step S301. )). For example, the difference Δxy from the center coordinate Rxy of the reference hole diameter position C6 at an arbitrary Z-axis position (height z) is
Difference Δxy = Rxy−f (z) (Formula 1)
It can be calculated by the following formula. Note that the displacement function f (z) is not necessarily a linear function. In addition, when it cannot obtain | require with a linear function, it is good also as a high-order function, and it is good also as a linear function for every divided area by dividing | segmenting a Z direction.

  (Step S402) In accordance with the measurement specification set in Step S202, the image processing unit 112 moves the moving unit 114 to the Z-axis drive unit main body 113 via the cable 117 together with the light transmission unit 102 and the like to the measurement start position (initial position). Command to move.

  (Step S <b> 403) The image processing unit 112 reads the current position (Z coordinate) of the moving unit 114 from the Z-axis position detection unit 119 connected via the cable 121. The read Z coordinate is substituted into the positional deviation function f (z) obtained in step S401 to calculate the positional deviation amount at the current position. That is, the difference Δxy (Δx, Δy) is obtained by (Equation 1).

  (Step S404) If the difference is Δxy (Δx, Δy), the image processing unit 112 instructs the XY coordinate moving unit 120 to move in the X-axis direction with respect to the current XY coordinate position. Move by Δx and Δy in the Y-axis direction. As a result, the center coordinate Rxy of the reference hole diameter position C6 coincides with the center coordinate of the inner shape of the DUT 109 at the height z (position shift adjustment). Note that the image processing unit 112 stores the difference Δxy (Δx, Δy) adjusted for positional deviation in correspondence with the Z coordinate (height).

  The processing from the next step S203 to step S205 is the same as the flowchart of FIG. 11 of the first embodiment.

  (Step S405) Similar to step S206 in FIG. 11, it is determined whether the measurement is completed according to the measurement specification. If the moving unit 114 has not reached the end position of the set movement range in the Z-axis direction, the process proceeds to step S406, and if it has reached the end position, the process proceeds to step S407.

  (Step S406) Similar to step S207 in FIG. 11, the moving unit 114 is moved in the Z-axis direction to the next measurement position in accordance with the set measurement pitch. After the processing, the process returns to step S403, and the amount of positional deviation at that position is calculated.

  (Step S407) When the movement unit 114 reaches the end position of the set movement range in the Z-axis direction and completes the measurement, the inner height of the object to be measured 109 (relative position with respect to the measurement optical system) is set. Shapes are obtained, and these shapes are synthesized to create hollow shape data.

  Here, a method for synthesizing hollow shape data in the present embodiment will be described with reference to FIG. In FIG. 15A, reference numerals 711 to 716 denote the inner shape of the DUT 109 when it is varied at predetermined pitches from the height (n) to (n + 5) in the Z-axis direction (height direction). Yes. In FIG. 13 of the first embodiment, the inner shape of the DUT 109 is measured while being inclined obliquely. However, in this embodiment, the deviation from the center coordinate Rxy of the reference hole diameter position C6 for each height. Therefore, as shown in FIG. 15A, the inclination of the inner shape of the object to be measured 109 is corrected, and the hollow shape data in an untilted state is synthesized. Therefore, in this embodiment, the shift amount is corrected and synthesized. Since the image processing unit 112 stores the difference Δxy (Δx, Δy) adjusted in positional deviation in step S404 in correspondence with the Z coordinate (height), the XY of the inner shapes 711 to 715 in FIG. The position on the coordinate is corrected for each Z coordinate, and as shown in FIG. 15 (b), it is synthesized and displayed so as to be the same as the actual object to be measured 109, as in the inner shapes 721 to 725. In FIG. 15, the center coordinates of the inner shape 706 are drawn so as to coincide with the center coordinates Rxy of the reference hole diameter position C6.

  The processing from the next step S209 to step S211 is the same as the flowchart of FIG. 11 of the first embodiment, and the hollow shape data synthesized in step S407 is displayed on the screen of the personal computer 115 as shown in FIG. 15B. Is done.

  As described above, the hollow shape measuring apparatus 101 according to the present embodiment obtains the inner shape from the deviation from the reference hole diameter for each predetermined height of the measured object 109 while moving the moving unit 114 up and down at a predetermined pitch. The hollow shape of the object can be three-dimensionally constructed by synthesizing the inner shape for each height. In particular, even when the inside of the object to be measured 109 is inclined with respect to the Z-axis direction, the positional deviation between the center coordinate Pnxy of the object to be measured 109 and the center coordinate Rxy of the reference hole diameter position C6 at the time of every height measurement. Since the position on the XY coordinate of the object to be measured 109 is adjusted so as to match, the hollow shape of the object to be measured 109 can always be measured with high accuracy regardless of the height.

(Third embodiment)
Next, a hollow shape measuring apparatus 101 according to the third embodiment will be described. The configuration of the hollow shape measuring apparatus 101 according to this embodiment is the same as that of the hollow shape measuring apparatus 101 according to the first embodiment shown in FIG. The difference between the present embodiment, the first embodiment, and the second embodiment is that a method for correcting the positional deviation between the center coordinate Pnxy of the inner shape of the DUT 109 and the center coordinate Rxy of the reference hole diameter position C6. Is different. Here, only parts different from the first embodiment and the second embodiment will be described.

  The flowchart of FIG. 16 shows a measurement flow of the hollow shape measuring apparatus 101 in the present embodiment. The same processes as those in the first embodiment are indicated by the same step numbers. Further, different processes in this embodiment are indicated by step numbers in the 500s. The processing up to step S201 and step S202 is the same as the flowchart of FIG. 11 of the first embodiment. That is, the measurement object 109 is set under the moving unit 114, and measurement specifications such as a measurement range (moving range) and a measurement pitch (moving pitch) of the moving unit 114 are input from the personal computer 115.

  (Step S501) Similar to step S402 in FIG. 14, according to the measurement specification set in step S202, the image processing unit 112 sends the moving unit 114 to the Z-axis drive unit main body 113 via the cable 117, etc. At the same time, command to move to the measurement start position (initial position).

  (Step S502) Similar to step S314 in FIG. 12, the image processing unit 112 measures the center coordinates of the inner shape of the DUT 109 from the captured image.

  (Step S503) Similar to step S302 in FIG. 12, the image processing unit 112 calculates a positional deviation amount from the center coordinates of the inner shape of the DUT 109 obtained in step S502.

  (Step S504) Similar to step S303 in FIG. 12, the image processing unit 112 instructs the XY coordinate moving unit 120 to set the XY coordinates by the difference Δxy from the center coordinate Rxy of the reference hole diameter position C6 obtained in step S502. Adjust the upper misalignment. At this time, the DUT 109 is arranged at a position where the center coordinates of the inner shape of the DUT 109 obtained in Step S502 coincide with the center coordinates Rxy of the reference hole diameter position C6. Note that the image processing unit 112 stores the difference Δxy (Δx, Δy) adjusted for positional deviation in correspondence with the Z coordinate (height) at the time of adjustment.

  The processing from the next step S203 to step S205 is the same as the flowchart of FIG. 11 of the first embodiment.

  (Step S505) Similar to step S206 in FIG. 11, it is determined whether the measurement is completed according to the measurement specification. If the moving unit 114 has not reached the end position of the set movement range in the Z-axis direction, the process proceeds to step S506, and if it has reached the end position, the process proceeds to step S507.

  (Step S506) Similar to step S207 of FIG. 11, the moving unit 114 is moved in the Z-axis direction to the next measurement position according to the set measurement pitch. After the processing, the process returns to step S502, and the center coordinates of the inner shape of the DUT 109 at the position are measured.

  (Step S507) When the movement unit 114 reaches the end position of the set movement range in the Z-axis direction and finishes the measurement, the inner height of the object to be measured 109 (relative position with respect to the measurement optical system) Shapes are obtained, and these shapes are synthesized to create hollow shape data. At this time, as in step S407 of FIG. 14, the generated hollow shape data is corrected for the deviation of the center coordinate of the inner shape of the DUT 109 for each height in step S504. ), The hollow shape data in an untilted state is synthesized. Therefore, as in the second embodiment, the shift amount is corrected and synthesized. Since the image processing unit 112 stores the difference Δxy (Δx, Δy) adjusted in position deviation in step S504 in correspondence with the Z coordinate (height) at the time of adjustment, from the inner shape 711 in FIG. The position of 715 on the XY coordinates is corrected for each Z coordinate, and as shown in FIG. 15B, the hollow shape data is set so as to be the same as the actual measured object 109, as shown in the inner shapes 721 to 725. Synthesize.

  The processing from the next step S209 to step S211 is the same as the flowchart of FIG. 11 of the first embodiment, and the hollow shape data synthesized in step S507 is displayed on the screen of the personal computer 115 as shown in FIG. 15B. Is done.

  In the third embodiment, provisional measurement for misalignment adjustment is performed in step S502 to obtain the center coordinates, and then the misalignment is adjusted, and then the inner shape of the DUT 109 is measured in step S203. However, the provisional measurement and the main measurement may be performed at the same time to predict the positional deviation adjustment amount of the next measurement. For example, at the time of measurement at the position Z1 in FIG. 10, the center coordinate of the position Z2 to be measured next is predicted, the XY coordinate is moved simultaneously with the movement of the Z axis, and the main measurement is performed at the next measurement position Z2. As a prediction method, for example, the first few points are measured, and the next center coordinate can be predicted from the inclination. By performing the prediction process, provisional measurement becomes unnecessary, and the displacement is adjusted by the XY coordinate moving unit 120 at the same time as the moving unit 114 is moved in the Z-axis direction, so that the measurement time can be shortened.

  As described above, the hollow shape measuring apparatus 101 according to the present embodiment corrects a deviation from the reference hole diameter for each predetermined height of the object 109 to be measured while moving the moving unit 114 up and down at a predetermined pitch. The hollow shape of the object can be three-dimensionally constructed by obtaining the inner shape for each height. In particular, even when the inside of the object to be measured 109 is inclined with respect to the Z-axis direction, the positional deviation between the center coordinate Pnxy of the object to be measured 109 and the center coordinate Rxy of the reference hole diameter position C6 at the time of every height measurement. Since the position on the XY coordinate of the object to be measured 109 is adjusted so as to match, the hollow shape of the object to be measured 109 can always be measured with high accuracy regardless of the height.

  In each embodiment, the image processing unit 112 that performs image processing and the personal computer 115 that displays the entire operation of the hollow shape measuring apparatus 101 and the display of measurement results are provided separately. You may make it incorporate hardware and software. Or, conversely, an operation unit or a display unit may be provided in the image processing unit 112 to be a control unit dedicated to the hollow shape measuring apparatus 101.

  Moreover, in each embodiment, although the to-be-measured object 109 was moved by the XY coordinate moving part 120, you may make it move the moving part 114 side, and the to-be-measured object 109 may be made into an X coordinate direction or a Y coordinate. The moving unit 114 may be moved in the Y coordinate direction or the X coordinate direction. That is, any mechanism that relatively moves the DUT 109 side and the moving unit 114 side on the XY coordinates may be used.

It is a block diagram of the hollow shape measuring apparatus 101 which concerns on 1st, 2nd, 3rd embodiment. It is a block diagram of the circular slit 103 and the light limiting slit 104 of the hollow shape measuring apparatus 101. 2 is a configuration diagram of a conical mirror 108 of the hollow shape measuring apparatus 101. FIG. 3 is an auxiliary diagram showing an optical system of the hollow shape measuring apparatus 101. FIG. It is an auxiliary figure for demonstrating the principle of the hollow shape measuring apparatus 101. FIG. It is an auxiliary figure for demonstrating the principle of the hollow shape measuring apparatus 101. FIG. It is an auxiliary figure for demonstrating a measurement principle. FIG. 5 is an auxiliary diagram for explaining the positional relationship between an object to be measured 109 and a moving unit 114. It is explanatory drawing which shows the mode of the image formed when there exists a position shift. It is explanatory drawing which shows a mode when the inner side shape of the to-be-measured object 109 inclines. It is a flowchart which shows the measurement procedure of the hollow shape measuring apparatus 101 which concerns on 1st Embodiment. It is a flowchart which shows a position shift temporary measurement process. It is explanatory drawing which shows the synthesis | combination of the hollow shape data formed with the hollow shape measuring apparatus 101 which concerns on 1st Embodiment. It is a flowchart which shows the measurement procedure of the hollow shape measuring apparatus 101 which concerns on 2nd Embodiment. It is explanatory drawing which shows the synthesis | combination of the hollow shape data formed with the hollow shape measuring apparatus 101 which concerns on 2nd, 3rd embodiment. It is a flowchart which shows the measurement procedure of the hollow shape measuring apparatus 101 which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Hollow shape measuring apparatus; 102 ... Light transmission part; 103 ... Circular slit; 104 ... Light limiting slit; 105 ... Illumination lens; 106 ... Half mirror; Objective lens; 108 ... Conical mirror; 109 ... Object to be measured; 110 ... Imaging lens; 111 ... Imaging unit; 112 ... Image processing unit; Main body; 114 ... moving unit; 115 ... personal computer; 119 ... Z-axis position detecting unit; 120 ... XY coordinate moving unit

Claims (6)

A measuring device for measuring the inner shape of a hollow cylindrical object to be measured,
A light transmitting section for transmitting light in a first direction which is the axial direction of the hollow cylinder;
A converter that converts the direction of the light into a direction substantially orthogonal to the first direction;
A detection unit for detecting light reflected on the inside of the object to be measured among the light whose direction is converted by the conversion unit;
Based on the detection result of the detection unit, a shape measuring unit that measures the inner shape of the object to be measured by obtaining a deviation from a predetermined reference position;
A position adjusting unit that reduces the deviation of the deviation over the entire inner circumference of the object to be measured. The measuring apparatus according to claim 1,
The position adjusting unit detects a Z coordinate when the first direction is the Z axis, and detects an offset of the deviation in an XY coordinate perpendicular to the Z axis with a predetermined Z coordinate. XY coordinates of the measurement optical system including the light transmission unit, the conversion unit, and the detection unit in the direction in which the deviation of the deviation detected by the coordinate deviation detection unit, the XY coordinate deviation detection unit is reduced, and the object to be measured A measuring apparatus comprising: an XY coordinate moving unit that relatively moves above. The measuring apparatus according to claim 2,
A calculating unit for detecting a bias deviation of XY coordinates at a plurality of Z coordinates by the XY coordinate shift detection unit and calculating a bias correction amount by calculating a bias of the shifts at the plurality of Z coordinates; In addition,
The position adjusting unit relatively moves the measurement optical system and the object to be measured by the XY coordinate moving unit by the bias correction amount obtained by the calculation unit before measurement. The measuring device according to claim 3,
The computing unit obtains the bias correction amount by averaging the bias of deviations at the plurality of Z coordinates. The measuring apparatus according to claim 2,
A Z coordinate moving unit that relatively moves the measuring optical system and the object to be measured in the first direction;
The position adjustment unit detects deviation of deviation by the XY coordinate deviation detection unit every time the Z coordinate movement unit relatively moves the measurement optical system and the object to be measured at a predetermined interval during measurement. The measurement apparatus characterized in that the measurement optical system and the object to be measured are relatively moved by the deviation deviation by the XY coordinate moving unit. A measuring method for measuring the inner shape of a hollow cylindrical object to be measured,
The direction of light transmitted in the first direction which is the axial direction of the hollow cylinder is converted into a direction substantially orthogonal to the first direction and irradiated to the inside of the object to be measured. When measuring the inner shape of the object to be measured by determining the deviation of the light image from a predetermined reference position based on the measurement result of the measuring optical system that detects the image of the light reflected on the inside, the measured object The deviation of the deviation over the entire inner circumference of the object is detected, and the measurement optical system and the object to be measured are relative to each other on the XY coordinates orthogonal to the first direction in a direction in which the deviation of the deviation is reduced. A measuring method characterized by moving.

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