JP4962852B2 - Shape measuring method and shape measuring apparatus - Google Patents

Description

  The present invention relates to a shape measuring method for measuring a surface shape (three-dimensional shape) of an industrial product or the like.

  Various techniques for measuring the surface shape of an object such as an industrial product have been proposed, and one of them is an optical three-dimensional shape measuring apparatus. There are various types of optical three-dimensional shape measurement devices and configurations, but a predetermined projection pattern (striped pattern or lattice pattern) is projected onto the test object, and the test object is imaged. There is a technique that calculates the height of each image position by calculating the fringe phase at each image position (each pixel) and measures the three-dimensional shape of the test object (see, for example, Patent Document 1).

  In such an apparatus, for example, a projection pattern consisting of a fringe pattern is projected onto the surface of a test object (measuring object), and a fringe pattern projected onto the test object from an angle different from the projection direction is imaged. The phase distribution of the fringe pattern is calculated using the surveying principle or the like, and the three-dimensional shape of the surface of the test object is obtained.

An example of the configuration is shown in FIG. 8, and the light from the light source 51 is projected onto the surface of the test object 54 through the projection pattern mask 52 having a striped pattern and the projection lens 53. The stripe pattern of the projection pattern mask 52 projected onto the surface of the test object 54 is deformed according to the three-dimensional shape of the surface of the test object 54, and the pattern of the surface of the test object 54 thus deformed An image is picked up by an image pickup device (for example, a CCD sensor) through an image pickup lens 55 from an angle different from the projection direction, and sent to the arithmetic processing device 57, where calculation processing of the picked-up image data is performed. In the arithmetic processing unit 57, the phase distribution of the fringe pattern is calculated using the imaged image data of the surface of the object imaged in this way by using the principle of triangulation, etc., and the three-dimensional shape of the surface of the object to be detected is calculated. Processing is performed.
JP 2000-9444 A

  However, since the fringe pattern on the surface of the test object is deformed and observed according to the three-dimensional shape of the surface of the test object, the interval between the fringe patterns becomes extremely narrow depending on the inclination of the test object. In some cases, the fringe pattern is not sufficiently resolved, or interpolation between pixels may not be sufficiently performed, resulting in a decrease in measurement accuracy.

  The present invention has been made in view of such a problem, and an object thereof is to provide a shape measuring method and a shape measuring device with improved measurement accuracy.

In order to achieve such an object, the shape measuring method according to the present invention projects a predetermined pattern on a test object from a first direction, and the pattern projected on the test object is different from the first direction. A shape measuring method for observing from two directions and measuring the shape of the test object from the observed pattern, and a pattern formed on the test object when a projection pattern of a predetermined interval is projected onto the test object A near net pattern having a shape similar to the above is projected onto the test object.
In the above-described shape measuring method, the near net pattern projected on the test object may be observed, and the shape of the test object may be measured from the observed near net pattern. Further, as the near net pattern projected on the test object, a pattern having the same shape as the projection pattern formed on the test object by projecting the near net pattern may be observed.

In the above-described shape measuring method, the shape of the near net pattern is a stripe shape, and the interval between the stripes may be different for each portion of the near net pattern. Further, the stripe interval may be different as if the size relationship of the stripe interval in the pattern formed on the test object is reversed when the projection pattern is projected onto the test object.
In the above-described shape measuring method, the shape of the pattern formed on the test object when the near net pattern is projected onto the test object may be a pattern shape at equal intervals.

In the above-described shape measurement method, a plurality of near net patterns different from each other are projected onto the test object, and each of the near net patterns projected onto the test object is observed, and the observed near net patterns are observed. The shape of the test object may be measured.
In the shape measurement method described above, the shape of the near net pattern may be different from the shape of the projection pattern.
In the above-described shape measuring method, the predetermined interval may be an equal interval.
In the above-described shape measuring method, the near net pattern is projected onto a calibration member whose shape is known, the near net pattern projected onto the calibration member is observed, and the shape of the calibration member is determined from the observed near net pattern. An error between the measured actual shape of the calibration member and the measured shape of the calibration member may be calculated, and the shape of the object to be measured may be corrected according to the calculated error.

In addition, the shape measuring apparatus according to the present invention includes a pattern projection system that projects a predetermined pattern on the test object from the first direction, and a second pattern that is different from the first direction on the pattern projected on the test object. A shape measuring device for measuring a shape of a test object from a pattern detected by the pattern detection unit, wherein the pattern projection system applies a projection pattern at a predetermined interval to the test object. A near net pattern having a shape similar to the pattern formed on the test object when projected is projected onto the test object.
In the above-described shape measuring apparatus, the pattern detection unit further includes an arithmetic processing unit that detects the near net pattern projected on the test object and obtains the shape of the test object from the near net pattern detected by the pattern detection unit. May be. Further, the pattern detection unit may detect a pattern having the same shape as the projected pattern formed on the test object by projecting the near net pattern as the near net pattern projected on the test object.

In the above-described shape measuring apparatus, the shape of the near net pattern is a stripe shape, and the interval between the stripes may be different for each portion of the near net pattern. Further, the fringe spacing may be different as when the pattern projection system projects the projection pattern onto the test object, and reverses the magnitude relation of the stripe pattern spacing in the pattern formed on the test object.
In the above-described shape measuring apparatus, the pattern shape formed on the test object when the pattern projection system projects the near net pattern onto the test object may be a pattern shape with equal intervals.

In the above-described shape measuring apparatus, the pattern projection system projects a plurality of different near net patterns onto the test object, and the pattern detection unit detects the plurality of near net patterns projected onto the test object, respectively. And you may further provide the arithmetic processing part which calculates | requires the shape of a test object from the some near net pattern detected by the pattern detection part.
In the above-described shape measuring apparatus, the shape of the near net pattern may be different from the shape of the projection pattern.
In the above-described shape measuring apparatus, the predetermined intervals may be equal intervals.
In the above-described shape measuring apparatus, the pattern projection system causes the near net pattern to be projected onto the calibration member having a known shape, causes the pattern detection unit to detect the near net pattern projected onto the calibration member, and the pattern detection unit. Calculates the error between the calibration calculation unit that calculates the shape of the calibration member from the near net pattern detected by the above and the actual calibration member shape that is known and the shape of the calibration member calculated by the calibration calculation unit An error calculation unit that performs correction, and the arithmetic processing unit may correct the shape of the object to be obtained in accordance with the error calculated by the error calculation unit.

  According to the present invention, measurement accuracy can be improved.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 shows a schematic configuration of a three-dimensional shape measuring apparatus in which the shape measuring method according to the first embodiment is used. First, the shape measuring apparatus will be described with reference to FIG. In FIG. 1, the shape measuring device M1 is shown in FIGS. 1 (a) and 1 (b). However, this is the same, and for the sake of convenience of description, the projection pattern mask 2 is striped at equal intervals. FIG. 1A shows a projection pattern PP1 having a pattern, and FIG. 1B shows a projection pattern mask 2 on which a near net pattern NP1 is formed.

  The shape measuring apparatus M1 projects the light from the light source 1, the projection pattern mask 2 for giving a stripe pattern to the light from the light source 1, and the light from the light source 1 that has passed through the projection pattern mask 2 on the surface of the test object 10. A pattern projection system MA1 composed of the projection lens 3 to be imaged, and an imaging optical system MB1 composed of the imaging device 7 that captures the reflected light from the test object 10 via the imaging lens 6.

  In the pattern projection system MA1, the projection pattern mask 2 is composed of a liquid crystal element or the like, receives a control signal from the display control unit 8 electrically connected to the liquid crystal element, and receives a pattern of any shape and pitch (for example, It is possible to form a stripe pattern or a lattice pattern whose luminance distribution is a sine wave function. As a result, the light from the light source 1 passes through the projection pattern mask 2 and is condensed by the projection lens 3, thereby projecting a desired projection pattern formed by the projection pattern mask 2 onto the surface of the test object 10. be able to.

  In the imaging optical system MB1, the imaging device 7 is composed of a CCD camera or the like that receives light from the test object 10 and images the test object 10, and uses a projected pattern image reflected by the test object 10 as a detection pattern. It can be detected. Further, the image data of the test object 10 imaged by the imaging device 7 is sent to the arithmetic processing device 9, where predetermined image calculation processing is performed to calculate the height of the surface of the test object 10, and The three-dimensional shape (surface shape) of the specimen 10 is obtained.

  Next, the shape measuring method of the test object 10 by the shape measuring apparatus M1 configured as described above will be described below with reference to the flowchart shown in FIG. First, in step S101, the test object 10 is irradiated with light from the light source 1 through the projection pattern mask 2 and the projection lens 3, and the projection pattern PP1 (see FIG. 1 (see (a)). Note that the pitch (interval of the stripe pattern) of the projection pattern PP1 is relatively wide, and the measurement accuracy is relatively coarse. The light thus projected and reflected from the test object 10 is collected through the imaging lens 6 and enters the imaging device 7.

  Next, in step S102, the image of the projection pattern reflected by the test object 10 (see FIG. 1A) is captured by the imaging device 7 as a detection pattern. Image data obtained by imaging is sent from the imaging device 7 to the arithmetic processing device 9. When the principle of triangulation is used, because of the phase connection, imaging by the imaging device 7 is performed a plurality of times with the projection pattern mask 2 changing the pitch of the projection pattern (striped pattern interval), and a set of image data. A group is acquired.

  When the image data is sent in this manner, in step S103, a predetermined calculation process is performed by the calculation processing device 9, whereby the image of the projection pattern reflected by the test object 10, that is, the detection pattern captured in step S102. Specifically, the stripe pattern shape correction is performed on the projection pattern PP1 so that the detection pattern has a substantially uniform distribution so that the detection pattern has a uniform stripe pattern. Create a net pattern.

  At this time, for example, as shown in FIG. 1A, the projected pattern image (detection pattern) reflected by the test object 10 is a striped pattern bent according to the surface shape of the test object 10. On the other hand, for example, in the case of a fringe pattern in which the luminance distribution is a sine wave function, by changing the phase of the sine wave function (luminance distribution), as shown in FIG. Stripe pattern shape correction is performed on the projection pattern PP1 so as to form a stripe pattern. In this case, the shape of the near net pattern is a pattern shape in which the magnitude relation of the pitch (striped pattern interval) in the detection pattern is reversed. When the near net pattern is created in this way, the near net pattern data is sent from the arithmetic processing unit 9 to the display control unit 8, receives a control signal from the display control unit 8, and is applied to the projection pattern mask 2. A pattern NP1 (see FIG. 1B) is formed.

  Next, in step S104, the test object 10 is irradiated with light from the light source 1 via the projection pattern mask 2 and the projection lens 3, and the near net pattern NP1 is projected onto the surface of the test object 10. The light thus projected and reflected from the test object 10 is collected through the imaging lens 6 and enters the imaging device 7.

  Next, in step S105, the imaging device 7 captures an image of the near net pattern reflected by the test object 10 as a detection pattern. At this time, the image (detection pattern) of the near net pattern reflected by the test object 10 becomes a striped pattern with substantially equal intervals, as shown in FIG. Image data obtained by imaging is sent from the imaging device 7 to the arithmetic processing device 9. When using the principle of triangulation, because of phase connection, imaging by the imaging device 7 is performed a plurality of times using a plurality of near net patterns created according to projection patterns having different pitches, and a set of images. Data groups are acquired.

  In step S106, the height of the surface of the test object 10 is determined using the triangulation principle or the like based on the image data imaged in step S105, that is, the detection pattern that is a striped pattern at substantially equal intervals. calculate.

  If the amount of deviation of the detection pattern with respect to the projection pattern at a certain measurement point is a (see, for example, FIG. 1A), the projection pattern is taken from a direction that forms an angle of 30 ° with respect to the height direction of the test object. When projecting and imaging a detection pattern from a direction that forms an angle of 30 ° opposite to the projection direction, the height t of the test object is expressed by the following equation (1).

  t = (a / 2) / sin30 ° (1)

  In addition, as shown in FIG. 3, the angle of the inclined portion of the test object 10 with respect to the plane perpendicular to the optical axis of the pattern projection system is θ1, and the angle of the inclined portion of the test object 10 with respect to the optical axis of the imaging optical system is Assuming that θ2 is the pitch of the projection pattern (striped pattern interval) is p1, the pitch p2 of the detection pattern is expressed by the following equation (2).

  p2 = (sin θ2 / cos θ1) × p1 (2)

  As can be seen from the equation (2), when θ2 approaches zero, the pitch p2 of the detection pattern decreases and approaches the pixel size of the imaging device, and interpolation between pixels cannot be sufficiently performed.

  On the other hand, according to the shape measuring method and the shape measuring apparatus M1 of the first embodiment, the near net pattern NP1 is projected onto the test object 10, and the test is performed on the basis of the detection pattern that is a striped pattern at substantially equal intervals. Since the height of the surface of the object 10 is measured, the detection pattern pitch (striped pattern interval) can be set to an appropriate value, so that the measurement accuracy can be improved.

  In the first embodiment described above, after step S103, as shown in FIG. 4, the near-net pattern NP1 is used to calculate the surface height of the calibration member 15 whose surface height is known, Depending on the error between the actual surface height of the calibration member 15 and the calculated surface height of the calibration member 15, the height of the surface of the test object 10 calculated in step S104 and subsequent steps may be corrected. Good. In this way, measurement accuracy can be further improved.

  Specifically, as shown in FIG. 5, first, the near net pattern NP1 is projected onto the surface of the calibration member 15 whose surface height is known in the same manner as in step S104 (step S151). Next, similarly to step S105, an image of the near net pattern reflected by the calibration member 15 is captured as a detection pattern (step S152). Next, similarly to step S106, the height of the surface of the calibration member 15 is calculated based on the captured detection pattern (step S153). Next, an error between the actual surface height of the calibration member 15 and the calculated surface height of the calibration member 15 is calculated (step S154).

  Then, the height of the surface of the test object 10 calculated in and after step S104 may be corrected according to the error calculated in step S154. At this time, for example, the height of the surface of the test object 10 is calculated by multiplying the correction coefficient proportional to or inversely proportional to the error rate by the surface height (calculated value) of the test object 10 calculated in step S106. It can be corrected. At this time, the calculation of the height of the surface of the calibration member 15 and the calculation of the error are performed by the arithmetic processing unit 9, but the calibration calculation unit for calculating the height of the surface of the calibration member 15 and the error are calculated. An error calculation unit that calculates the above may be provided separately from the arithmetic processing unit. Further, when the design shape of the test object 10 is known as in the mass-produced product inspection, the near net pattern NP1 can be obtained from the design data.

  Next, a second embodiment of the shape measuring apparatus will be described with reference to FIG. 6A and 6B, the shape measuring device M2 is shown, but this is the same, and the projection pattern PP2 is provided on the projection pattern mask 23 for convenience of explanation. FIG. 6A shows the formed pattern, and FIG. 6B shows the projection pattern mask 23 with the near net pattern NP2 formed.

  The shape measuring apparatus M2 of the second embodiment includes a light source 21, a condenser lens 22 that condenses the light from the light source 21, a projection pattern mask 23 for giving a stripe pattern to the light from the light source 21, and a projection pattern mask. The pattern projection system MA2 including a projection lens 25 that projects the light from the light source 21 that has passed through 23 onto the surface of the test object 30 and the reflected light from the test object 30 are imaged via the mirror 24 and the imaging lens 26. And an imaging optical system MB2 including the imaging device 27. The test object 30 is placed in a transparent water tank 31 filled with a predetermined medium 32 (for example, colored water).

  In the pattern projection system MA2, the projection pattern mask 23 is composed of a liquid crystal element or the like, receives a control signal from the display control unit 28 electrically connected to the liquid crystal element, and has a pattern (for example, an arbitrary shape and pitch). A striped pattern, a lattice pattern, etc.) can be formed. As a result, the light from the light source 21 is passed through the projection pattern mask 23 via the condenser lens 22 and is condensed by the projection lens 25, whereby a desired projection pattern formed by the projection pattern mask 23 is obtained as the test object 30. Can be projected onto the surface.

  In the imaging optical system MB2, the imaging device 27 is configured by a CCD camera or the like that receives light from the test object 30 and images the test object 30, and is reflected by the test object 30 and transmitted through the medium 32. This image can be detected as a detection pattern. The image data of the test object 30 imaged by the imaging device 27 is sent to the arithmetic processing device 29, where a predetermined image calculation process is performed to calculate the height of the surface of the test object 30, The three-dimensional shape (surface shape) of the specimen 30 is obtained. The mirror 24 is provided between the projection pattern mask 23 and the projection lens 25, transmits light from the projection pattern mask 23 toward the projection lens 25 and the test object 30, and from the test object 30. Light is reflected toward the imaging lens 26 and the imaging device 27.

  Next, a method for measuring the shape of the test object 30 by the shape measuring apparatus M2 of the second embodiment will be described below with reference to the flowchart shown in FIG. First, in step S <b> 201, the light from the light source 21 is irradiated onto the test object 30 through the condenser lens 22, the projection pattern mask 23, the mirror 24, the projection lens 25, and the medium 32, and the surface of the test object 30 is irradiated. A patternless projection pattern PP2 (see the inside of the circle A in FIG. 6A) is projected. That is, the projection pattern mask 23 is in a state where light is totally transmitted.

  At this time, the wavelength of light emitted from the light source 21 is selected such that the attenuation of light (luminance) in the medium 32 (reflected by the test object 30) is about 1/100. Thereby, about 1/300 of the total height of the test object 30 can be specified. The light thus projected and reflected from the test object 30 enters the imaging device 27 via the medium 32, the projection lens 25, the mirror 24, and the imaging lens 26.

  Next, in step S <b> 202, the image of the projection pattern reflected by the test object 30 and transmitted through the medium 32 is captured by the imaging device 27 as a detection pattern. Image data obtained by imaging is sent from the imaging device 27 to the arithmetic processing device 29.

  When the image data is sent in this way, in step S203, the arithmetic processing unit 29 performs predetermined arithmetic processing, so that the shape distribution of the detection pattern is substantially uniform based on the detection pattern imaged in step S202. Specifically, a near net pattern is generated by correcting the shape of the projection pattern PP2 so that the brightness (luminance) of the detection pattern is substantially uniform.

  At this time, since the projection pattern PP2 is blank, an image (detection pattern) of the projection pattern reflected by the test object 30 and transmitted through the medium 32 is shown inside the circle B in FIG. In this embodiment, the height of the upper half of the test object 30 is relatively low, resulting in a pattern in which light and dark appear according to the surface shape (unevenness) of the test object 30. The upper half of the detection pattern is relatively dark). On the other hand, as shown inside the circle D in FIG. 6B, the light / dark positional relationship in the detection pattern is reversed so that the brightness (luminance) of the detection pattern is substantially uniform ( In the present embodiment, a near net pattern NP2 (see the inside of a circle C in FIG. 6B) having a pattern shape in which the lower half of the pattern is relatively darkened is created. When the near net pattern is created in this way, the data of the near net pattern is sent from the arithmetic processing unit 29 to the display control unit 28, receives the control signal from the display control unit 28, and receives the near net pattern on the projection pattern mask 23. A pattern NP2 is formed.

  Next, in step S <b> 204, the object 30 is irradiated with light from the light source 21 via the condenser lens 22, the projection pattern mask 23, the mirror 24, the projection lens 25, and the medium 32, and the surface of the object 30. Project a near net pattern NP2. At this time, the wavelength of the light emitted from the light source 21 is selected such that the attenuation of the light (luminance) in the medium 32 (reflected by the test object 30) is about 1/30000. The light thus projected and reflected from the test object 30 enters the imaging device 27 via the medium 32, the projection lens 25, the mirror 24, and the imaging lens 26.

  Next, in step S <b> 205, the near-net pattern image reflected by the test object 30 and transmitted through the medium 32 is captured by the imaging device 27 as a detection pattern. At this time, the image (detection pattern) of the near net pattern reflected by the test object 30 and transmitted through the medium 32 has substantially the same brightness (luminance) as shown inside the circle D in FIG. 6B. It becomes like. Image data obtained by imaging is sent from the imaging device 27 to the arithmetic processing device 29.

In step S206, the height of the surface of the test object 30 is calculated based on the image data captured in step S205, that is, the detection pattern in which the brightness (luminance) is substantially uniform. Specifically, first, a distance L between the imaging optical system and the test object 30 is obtained. This distance L is calculated from the relational expression Bp = Ip × a ^L where a is the absorption coefficient of the medium, Bp is the luminance of the detection pattern, and Ip is the luminance of the near net pattern. Then, the height of the surface of the test object 30 is calculated from the difference between the preset distance between the imaging optical system and the predetermined reference position and the calculated distance L.

  Thus, when calculating the height of the surface of the test object using the attenuation of light transmitted through the medium, the height (of the test object) with respect to the luminance of the detection light is required to increase the measurement accuracy. The attenuation of light must be increased so that the sensitivity of the light becomes high. However, if the attenuation of light is increased, if the unevenness of the test object is large, the low-height part becomes extremely dark, the SN ratio of this part is lowered, and the measurement accuracy is lowered.

  On the other hand, according to the shape measuring method and the shape measuring apparatus M2 of the second embodiment, the near net pattern NP2 is projected onto the test object 30, and based on the detection pattern in which the brightness (luminance) is substantially uniform. In order to measure the height of the surface of the test object 30, the brightness (luminance) of the detection pattern is substantially uniform even if the attenuation of light is increased (in this embodiment, about 1/30000). Therefore, since the decrease in the SN ratio can be suppressed, the measurement accuracy can be improved.

  In the second embodiment described above, after step S203, the height of the surface of the calibration member whose surface height is known is calculated using the near net pattern, as in the case of the first embodiment. The surface height of the test object 30 calculated in and after step S204 may be corrected according to the error between the actual surface height of the calibration member and the calculated surface height of the calibration member. . In this way, measurement accuracy can be further improved.

  Further, in each of the embodiments described above, the near net pattern is created by the arithmetic processing device. However, the present invention is not limited to this, and the near net pattern creating unit for creating the near net pattern is referred to as the arithmetic processing device. It may be provided separately.

It is a schematic block diagram of the shape measuring apparatus used for the shape measuring method of 1st Embodiment. It is a flowchart which shows the shape measuring method of 1st Embodiment. It is explanatory drawing which shows the inclination part of a to-be-tested object. It is a schematic block diagram of the shape measuring apparatus which showed the modification of 1st Embodiment. It is a flowchart which shows the modification of 1st Embodiment. It is a schematic block diagram of the shape measuring apparatus used for the shape measuring method of 2nd Embodiment. It is a flowchart which shows the shape measuring method of 2nd Embodiment. It is a schematic block diagram of the conventional shape measuring apparatus.

Explanation of symbols

M1 shape measuring device (first embodiment) M2 shape measuring device (second embodiment)
MA1 pattern projection system (first embodiment) MA2 pattern projection system (second embodiment)
MB1 imaging optical system (first embodiment) MB2 imaging optical system (second embodiment)
PP1 projection pattern (first embodiment) PP2 projection pattern (second embodiment)
PN1 near net pattern (first embodiment)
PN2 near net pattern (second embodiment)
9 Arithmetic processing device (first embodiment) 10 Test object (first embodiment)
29 arithmetic processing unit (second embodiment) 30 test object (second embodiment)

Claims (20)

A predetermined pattern is projected on the test object from a first direction, the pattern projected on the test object is observed from a second direction different from the first direction, and the pattern is observed from the observed pattern. A shape measuring method for measuring the shape of a test object,
A shape measuring method , wherein a near net pattern having a shape similar to a pattern formed on the test object is projected onto the test object when projected patterns of a predetermined interval are projected onto the test object. . Observe the near net pattern projected on the test object,
The shape measuring method according to claim 1, wherein the shape of the test object is measured from the observed near net pattern . The near-net pattern projected on the test object is characterized by observing a pattern having the same shape as the projection pattern formed on the test object by projecting the near-net pattern. Item 3. The shape measuring method according to Item 2. The shape of the near net pattern is a stripe shape,
The shape measuring method according to any one of claims 1 to 3, wherein an interval of the stripes is different for each portion of the near net pattern. The spacing between the fringes is different as if the size relation of the spacing between the striped patterns in the pattern formed on the test object is reversed when the projection pattern is projected onto the test object. Item 5. The shape measuring method according to Item 4. The shape of the pattern formed on the test object when the near net pattern is projected onto the test object is an equally spaced pattern shape. The shape measuring method described in 1. A plurality of near net patterns different from each other are projected onto the test object,
Observing each of the plurality of near net patterns projected on the test object,
The shape measurement method according to claim 1, wherein the shape of the test object is measured from the observed plurality of near net patterns. The shape measurement method according to claim 1, wherein a shape of the near net pattern is different from a shape of the projection pattern. The shape measuring method according to claim 1, wherein the predetermined interval is an equal interval. Projecting the near net pattern onto a calibration member having a known shape, observing the near net pattern projected onto the calibration member, and measuring the shape of the calibration member from the observed near net pattern ,
Calculate the error between the known actual shape of the calibration member and the measured shape of the calibration member,
The shape measuring method according to claim 2, wherein the shape of the object to be measured is corrected in accordance with the calculated error. A pattern projection system that projects a predetermined pattern onto the test object from a first direction; and a pattern detection unit that detects the pattern projected onto the test object from a second direction different from the first direction; A shape measuring device for measuring the shape of the test object from the pattern detected by the pattern detection unit,
The pattern projection system projects a near net pattern having a shape similar to a pattern formed on the test object when a projection pattern of a predetermined interval is projected onto the test object. A feature measuring device. The pattern detection unit detects the near net pattern projected on the test object,
The shape measuring apparatus according to claim 11, further comprising an arithmetic processing unit that obtains the shape of the test object from the near net pattern detected by the pattern detection unit. The pattern detection unit detects, as the near net pattern projected onto the test object, a pattern having the same shape as the projection pattern formed on the test object by projecting the near net pattern. The shape measuring apparatus according to claim 12. The shape of the near net pattern is a stripe shape,
The shape measuring apparatus according to claim 11, wherein an interval between the stripes is different for each portion of the near net pattern. The fringe spacing is different as if the pattern projection system reversed the magnitude relation of the fringe spacing in the pattern formed on the test object when the projection pattern was projected onto the test object. The shape measuring apparatus according to claim 14. 16. The shape of a pattern formed on the test object when the pattern projection system projects the near net pattern onto the test object is an equally spaced pattern shape. The shape measuring device according to any one of the above. The pattern projection system projects a plurality of near net patterns different from each other onto the test object,
The pattern detection unit detects the plurality of near net patterns respectively projected on the test object,
The shape measurement according to claim 11, further comprising an arithmetic processing unit that obtains the shape of the test object from the plurality of near net patterns detected by the pattern detection unit. apparatus. The shape measurement apparatus according to claim 11, wherein the shape of the near net pattern is different from the shape of the projection pattern. The shape measuring apparatus according to claim 11, wherein the predetermined interval is an equal interval. The pattern projection system projects the near net pattern onto a calibration member having a known shape, causes the pattern detection unit to detect the near net pattern projected onto the calibration member, and the pattern detection unit A calibration calculation unit for obtaining the shape of the calibration member from the detected near net pattern;
An error calculating unit that calculates an error between the known shape of the actual calibration member and the shape of the calibration member obtained by the calibration calculating unit;
The said arithmetic processing part correct | amends the shape of the said to-be-examined test object calculated | required according to the error calculated by the said error calculation part, It is any one of Claim 12, 13 and 17 characterized by the above-mentioned. Shape measuring device.

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