JPH08327338A - Three dimensional shape measuring apparatus - Google Patents

Abstract

PURPOSE: To a contact a stable and highly accurate measurement of three dimensional shape by detecting whether the position, the width and the maximum luminance of an image of the reflected light image from an object to be measured is within a specified range or not to lower measuring errors attributable to the inclination of measuring surface of the object to be measured. CONSTITUTION: A control/processing section 20 controls operations of a motor control circuit 18 and a sensor drive circuit 19 with a control section 20a" and controls stages 11 and 13-15 with a control section 20a so that the stages take a plurality of relative positions as specified. A signal selecting section 20b detects whether the position, the width and the maximum luminance of a reflected light image from an object to be measured are within a specified range or not by an output signal of a photodetecting part 16b to select an output signal for generating data. A shape data generating section 20c performs a subpixel processing based the output signal selected by the selecting section 20b while producing three dimensional shape data of the object to be measured based on the output signal selected and an output signal from a position detector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape measuring device for measuring a three-dimensional shape of an object to be measured by using an optical distance measuring device (for example, a laser displacement meter) which uses slit-shaped irradiation light. It is a thing.

[0002]

2. Description of the Related Art In recent years, the object of three-dimensional shape measurement is not limited to a combination of conventional one-dimensional measurement such as height measurement and length measurement, but can be extended to a three-dimensional object having a free curved surface. And research on them is also in progress. As the measurement method, in addition to the conventional contact-type measurement method in which the contact-type probe is brought into contact with the object to be measured, non-contact measurement using an optical distance measuring device such as a laser displacement meter, which has recently been remarkably developed. There is a way.

In such a non-contact measuring method, since it is not necessary to bring the probe into contact with the object to be measured, it is possible to accurately measure even a soft object such as rubber. It has an advantage that the measuring time can be shortened as compared with the measuring method. However, even a non-contact measuring method using an optical distance measuring device such as a laser displacement meter has not been able to accurately measure an object having an arbitrary free-form surface over the entire circumference.

The reason is that the inclination of the normal line of a point on the object to be measured (point to be measured) is unknown, and in the measurement performed by irradiating light such as a laser, the light is radiated to the object to be measured. The accuracy of measurement greatly depends on the angle and the angle of the reflected light from the object to be measured (that is, due to the inclination of the surface on which the point to be measured is located), and when the angle exceeds a predetermined value, measurement may not be possible. Because.

As a matter of course, it is impossible to measure the object to be measured in a range where the irradiation light does not reach.

[0006]

In the three-dimensional shape measurement by light projection, for example, slit-shaped irradiation light is projected on the surface to be measured of the object to be measured, and the reflected light is received by a light receiving portion such as a CCD. The reflected image of the irradiation light is detected, and the three-dimensional coordinates are obtained from the center position of the reflected image. However, even if the same measuring device is used, the inclination of the measured surface of the measured object (that is,
There is a problem that the measurement accuracy may be greatly affected by the irradiation angle of light to the object to be measured and the angle of reflected light from the object to be measured.

For example, depending on the inclination of the surface to be measured, the reflected image becomes very wide, the brightness of the reflected image is extremely lowered, and the reflected light does not enter the light receiving portion. As a result, there is a problem that a part of the object to be measured cannot be measured, or even if the measurement is possible, the measurement accuracy is poor and causes a measurement error. In particular, when the inclination of the surface to be measured becomes large and the oblique incidence angle of the irradiation light approaches zero, the entire reflected image may not fit in the light receiving part such as CCD. In this case, the center position of the reflected image may be incorrect. Could not be detected. Therefore, the obtained three-dimensional coordinates are inaccurate, which causes a measurement error.

The present invention has been made in view of the above problems, and reduces the measurement error caused by the inclination of the surface of the object to be measured, and enables stable and highly accurate three-dimensional shape of the object to be measured. An object of the present invention is to provide a three-dimensional shape measuring apparatus capable of measuring

[0009]

Therefore, firstly, the present invention relates to "at least an irradiation section for irradiating an object to be measured with slit-shaped irradiation light and a plurality of two-dimensionally arranged light receiving elements. A light receiving unit having a three-dimensional light receiving sensor, the light distance measuring device including a light receiving unit for receiving reflected light from the object to be measured by the irradiation light on the two-dimensional light receiving sensor, and the light distance measuring device. A position setting changing mechanism for setting and changing a relative position between the object and the object to be measured, and a first control unit for controlling the position setting changing mechanism so that the relative position becomes a plurality of predetermined relative positions. , An output for data creation by detecting whether or not the width and the maximum brightness of the reflected light image from the object to be measured are within a predetermined range by using the output signal of the two-dimensional light receiving sensor at each relative position In the signal selection section to select the signal The position relative to the relative position where the signal indicating the measurement failure is output from the signal selection section having the function of outputting the signal indicating the measurement failure when the output signal for data creation cannot be selected. Of the three-dimensional object to be measured based on the output signal selected by the second control unit that controls the position setting change mechanism so that the corrected relative position is obtained and the signal selection unit. A three-dimensional shape measuring apparatus (claim 1) provided with a shape data creation unit for creating shape data.

The present invention secondly provides "at least an irradiation section for irradiating a measured object with slit-shaped irradiation light,
A light receiving unit having a two-dimensional light receiving sensor composed of a plurality of light receiving elements arranged two-dimensionally, the light receiving unit receiving the reflected light from the object to be measured by the irradiation light on the two-dimensional light receiving sensor. Optical distance measuring device, a position setting changing mechanism for setting and changing the relative position between the optical distance measuring device and the object to be measured, and the position so that the relative position becomes a plurality of predetermined relative positions. The position, width and maximum brightness of the reflected light image from the object to be measured are within a predetermined range by using the output signal of the two-dimensional light receiving sensor at each relative position and the first control unit that controls the setting change mechanism. A signal selection unit that selects an output signal for data creation by detecting whether or not the output signal for data creation cannot be selected, and a signal selection unit having a function of outputting a signal indicating that measurement is impossible. And the signal selection Selected by the second control unit that controls the position setting change mechanism so that the relative position is corrected and the relative position at which the signal indicating that measurement is impossible is output, and the signal selection unit is performed. A three-dimensional shape measuring apparatus (claim 2) including a shape data creating unit for creating three-dimensional shape data of the object to be measured based on the output signal thus obtained.

Further, a third aspect of the present invention is to provide a "third control section for controlling the operation of the position setting changing mechanism and the irradiation section and a position detecting mechanism for detecting a position or a driving amount of the position setting changing mechanism. The three-dimensional shape measuring apparatus (claim 3) according to claim 1 or 2 is further provided. In a fourth aspect of the present invention, "the slit-shaped irradiation light is irradiation light obtained by forming semiconductor laser light into slits by a cylindrical lens.
The three-dimensional shape measuring device according to claim 3 is provided.

[0012]

In the three-dimensional shape measuring apparatus of the present invention, by detecting whether the width and the maximum brightness of the reflected light image from the object to be measured are within a predetermined range, or by the reflected light from the object to be measured. An output signal for data creation is selected by detecting whether the position, width, and maximum brightness of the image are within a predetermined range, and based on the selected output signal, three-dimensional shape data of the measured object. To create.

When the output signal for data creation cannot be selected, a signal indicating that measurement is impossible is output, and the positional relationship is corrected with respect to the relative position at which the signal indicating that measurement is impossible is output. Therefore, erroneous shape measurement data is not created, and it is possible to know the measurement points that require remeasurement. Alternatively, it is possible to know the measurement point that needs re-measurement and change the relative position to the measurement point that needs re-measurement and perform the re-measurement so that the output signal for data creation can be obtained. Therefore, more accurate shape measurement data can be obtained.

Therefore, in the three-dimensional shape measuring apparatus of the present invention, the measurement error due to the inclination of the surface of the object to be measured can be reduced, and the three-dimensional shape of the object to be measured can be stably and highly accurately measured. You can The three-dimensional shape measuring apparatus of the present invention further includes a position setting change mechanism, a third control unit that controls the operation of the irradiation unit, and a position detection mechanism that detects the position or drive amount of the position setting change mechanism. Preferably (claim 3).

The slit-shaped irradiation light applied to the three-dimensional shape measuring apparatus of the present invention is a semiconductor laser light which is slit-shaped irradiation light by a cylindrical lens in order to suppress a decrease in brightness and an increase in size of the apparatus. Is preferred (Claim 4). Hereinafter, the measurement principle according to the present invention will be described with reference to the drawings, but the present invention is not limited to the example of this drawing.

The measuring method is based on the light section method. First, the slit-shaped laser irradiation light 2 emits the DUT 1
The irradiation unit 3 irradiates the surface to be measured. Part of the light reflected by the surface to be measured is received by each of the light receiving sections 4 and 5 (see FIG. 1). In the example of FIG. 1, the positional relationship around the optical axes 4a and 5a of the light receiving units 4 and 5 is such that when the measured surface of the measured object is a plane perpendicular to the optical axis of the irradiation light 2, The image of the reflected light from the object to be measured is set to be perpendicular to the scanning line 8 on the light receiving surface 7 of the two-dimensional light receiving element (sensor) of each of the light receiving portions 4 and 5.

If the surface to be measured is a flat surface and is perpendicular to the optical axis 3a of the irradiation light 2, the image 6 of the reflected light received becomes a linear band, and the light receiving surface 7 of the two-dimensional light receiving element 7 is formed.
Will be located in the central part of (see FIG. 2 (a)),
An image 6'of the reflected light when the surface to be measured is a curved surface like the object 17 to be measured in FIG. 4 has a distorted strip shape (FIG. 2B).
reference).

The widths (X1 direction) of the images 6 and 6'of the reflected light are
Although it varies depending on the width of the irradiation light, the shape of the surface to be measured, the distance of the surface to be measured from the focal plane, etc., it is approximately several pixels (elements) to several tens of pixels. The image of the reflected light is projected on the light receiving surface of the light receiving portion. For example, when there are a plurality of light receiving portions as shown in FIG. 1, the images are projected on the respective light receiving surfaces of the light receiving portions 4 and 5. A plurality of images are obtained for each measured point of the measured object.

As shown in FIG. 1, the angle θ ₁ formed by the two light receiving portions 4 and 5 between their optical axes 4a and 5a and the optical axis 3a of the irradiation portion 3,
When the surfaces to be measured are flat when they are arranged so that θ ₂ becomes equal, the same (or substantially the same) image is projected on the light receiving surfaces of the respective light receiving units 4 and 5. However, when the measured surface is a three-dimensional free-form surface, even if the images are from the same measured point, the surface with the measured point (measured surface) is inclined, so that Different images are projected. The notable difference is the image width and maximum brightness.

For example, when the surface to be measured is inclined downward to the right, the reflected light is more likely to be directed toward the light receiving section 4 than to the light receiving section 5. Therefore, while the light-receiving unit 4 can obtain a high-luminance image, the light-receiving unit 5 can obtain only a low-luminance image, so that it is easily affected by noise and the reliability of measurement is lowered.
Also, in the case of a high-intensity image obtained by the light-receiving unit 4, if the inclination is particularly large, the width of the image becomes too large, and it becomes difficult to obtain the center position of the image, and the reliability of measurement decreases. There is also.

When obtaining the center position of the image, the center of the figure of the luminance distribution is obtained by sub-pixel processing. However, when the image is located close to the end on the light receiving surface 7 and the width of the image is enlarged, It may happen that part of the image hits the edge of the light receiving surface. For example, when the brightness of several pixels at the end of the light receiving surface in each scanning line 8 on the light receiving surface 7 is equal to or higher than a predetermined value, it is determined that the image position is at the end of the light receiving surface 7. be able to.

In this case, even if the center position is obtained by the sub-pixel processing, the value does not become an accurate value, and the reliability of measurement decreases. Therefore, it can be said that the reliability of the measurement is high when the width and the maximum brightness of the reflected light image are in the proper range, or when the position, the width and the maximum brightness are in the proper range.

Therefore, in the present invention, the reliability of the measurement is judged by using the width and the maximum brightness of the reflected light image projected on the light receiving portion as a guide, or the position of the reflected light image projected on the light receiving portion, By determining the reliability of the measurement by using the width and the maximum brightness as a guide, a signal with high reliability is selected from the output signals from the light receiving unit and used as the shape data.

When the output signal for data creation cannot be selected, a signal indicating that measurement is impossible is output, and the positional relationship is corrected with respect to the relative position at which the signal indicating that measurement is impossible is output. Therefore, erroneous shape measurement data is not created, and it is possible to know the measurement points that require remeasurement. Alternatively, it is possible to know the measurement point that needs re-measurement and change the relative position to the measurement point that needs re-measurement and perform the re-measurement so that the output signal for data creation can be obtained. Therefore, more accurate shape measurement data can be obtained.

By the way, since the luminance distribution of the images 6 and 6'of the reflected light is a Gaussian distribution, the central portion has high luminance and the peripheral portion has low luminance. The center position (X1 direction) of the images 6 and 6'of the reflected light is estimated by the sub-pixel processing to obtain the distance to the measured point. Here, the sub-pixel processing will be described with reference to the drawings. Irradiation part 16 to DUT 17
When the slit-shaped irradiation light is emitted from a, the DUT 1
A cutting line along the shape of 7 is formed, and the cutting line is imaged by the light receiving unit 16b. That is, for example, as shown in FIG. 2B, the light receiving surface 7 of the two-dimensional light receiving element of the light receiving portion 16b is formed.
An image 6'of the cutting line is projected on the top.

2A and 2B, the vertical axis represents the position on the light receiving surface in the Y1 direction corresponding to the Y direction in FIG. 1 (that is, the spreading direction of the slit-shaped irradiation light). ing. The horizontal axis in FIGS. 2A and 2B is X perpendicular to the Y1 direction.
The position in one direction is shown. Width of image 6 '(X1 direction)
Is usually longer than the length of one light receiving element in the X1 direction, and is, for example, about 10 elements (pixels). X1 at a certain position in the Y1 direction in FIG.
The distribution of the output levels of the two-dimensional light-receiving elements corresponding to the one-row light-receiving elements arranged in the direction
The distribution of the amount of received light along the X1 direction at a certain position in the Y1 direction) is as shown in FIG.

X1 of the image 6'at this position in the Y1 direction
The position in the direction corresponds to the position where the output level in FIG. 2C is high. The process of estimating the center position of the image 6 ′ in the X1 direction from the distribution shape shown in FIG. 2C is what is called sub-pixel process. Specifically, the center position of the image 6 ′ in the X1 direction is determined by using the weighted average of the portion having a predetermined threshold value (light receiving amount) or more in FIG. This center position indicates the distance to the measurement point of the DUT 17 corresponding to a certain position in the Y1 direction.

In the present invention, the sub-pixel processing is performed by the shape data creation unit that creates the three-dimensional shape data of the object to be measured based on the output signal selected by the signal selection unit. That is, in the present invention, by the signal selection unit,
By detecting whether or not the width and maximum brightness of the reflected light image are within a predetermined range from the output signals of the two-dimensional light receiving element of the light receiving unit, or by detecting the position, width and maximum brightness of the reflected light image. By detecting whether or not it is within a predetermined range, an output signal for data creation is selected, and then the subpixel processing is performed by the three-dimensional shape data creation unit to obtain each distance data.

When the output signal for data creation cannot be selected, the signal selection section outputs a signal indicating that measurement is impossible, and the second control section outputs the signal indicating that measurement is impossible with respect to the relative position. The positional relationship is being corrected. Therefore, erroneous shape measurement data is not created, and it is possible to know the measurement points that require remeasurement. Alternatively,
To be able to know the measurement point that needs re-measurement and to obtain the output signal for data creation by changing the relative position to the measurement point that needs re-measurement and performing the re-measurement. Therefore, more accurate shape measurement data can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0031]

EXAMPLE FIG. 4 is a diagram schematically showing the overall configuration of the three-dimensional shape measuring apparatus of this example. As shown in FIG. 4, the three-dimensional shape measuring apparatus of this embodiment has an X stage 11 mounted on a main body substrate (not shown) and movable in the X direction.
And a rotary stage 13 mounted on the X stage 11 and rotatable about a rotary shaft 13c extending in the X direction,
A Z stage 14 attached to the main body substrate above the rotary stage 13 and movable in the Z direction perpendicular to the surface of the X stage 11, and a Y stage attached to the Z stage 14.
A rotary stage 15 rotatable about a rotary shaft 15c extending in the direction, and a laser displacement meter 16 as an optical distance measuring device attached to the rotary stage 15 are provided.

The object to be measured 17 is placed on the rotary stage 13. In this embodiment, these stages 11, 1
3 to 15 constitute a position setting changing mechanism for setting and changing the relative position between the laser displacement meter 16 and the object to be measured 17. In FIG. 4, each stage 11, 13
X stage 11 to facilitate understanding of the movement of
11a for the fixed part of the X stage, 11b for the movable part of the X stage 11,
The fixed part of the rotary stage 13 is 13a, and the rotary stage 13 is
13b is a movable part of the Z stage 14, 14a is a fixed part of the Z stage 14,
The movable part of the Z stage 14 is 14b, the fixed part of the rotary stage 15 is 15a, and the movable part of the rotary stage 15 is 15b.
, Respectively.

The laser displacement meter 16 receives the reflected light from the object to be measured 17 and the irradiation section 16a which irradiates the object to be measured 17 with slit-shaped irradiation light spread in the Y direction perpendicular to the X direction. It has a light receiving portion 16b. Irradiator 16a
The laser light emitted from the semiconductor laser light is a 670 nm semiconductor laser light, but by using the light receiving portion 16b having a large sensitivity characteristic, a laser having another wavelength can be used.

In this embodiment, a semiconductor lens light is used as slit-shaped irradiation light by using a cylindrical lens. Therefore, the brightness does not decrease as in the case of using a slit to form a slit, and the size of the device does not increase as in the case of using a polygon mirror. Although not shown in the figure, the light receiving unit 16b has a two-dimensional light receiving sensor such as a two-dimensional CCD including a plurality of two-dimensionally arranged light receiving elements, and the light receiving unit 16b may be, for example, C
A CD camera can be used.

The positional relationship of the light receiving portion 16b around the optical axis is
When the measured surface of the DUT 17 is a plane perpendicular to the optical axis of the irradiation light, the image of the reflected light from the DUT is displayed on the scanning line 8 of the two-dimensional light receiving sensor surface 7 of the light receiving unit 16b. It is set to be vertical. Further, the three-dimensional shape measuring apparatus of the present embodiment, as shown in FIG.
A motor drive circuit 18 for driving a drive motor (not shown) 15; a sensor drive circuit 19 for driving the laser displacement meter 16; a control / processing unit 20; and a measurer controlling / processing unit 2
An input unit (e.g., keyboard) 21 for giving various commands to 0, and a position detector (e.g., encoder, not shown) for detecting the position (or drive amount) of each stage 11, 13-15. ing.

Here, the control / processing section 20 is composed of a microcomputer or the like having a built-in storage device, CPU, etc., not shown, and a third control section for controlling the operation of the motor drive circuit 18 and the sensor drive circuit 19. 20a '', a function as a first control unit 20a for controlling the position setting change mechanism (each stage 11, 13 to 15) so that the relative position becomes a plurality of predetermined relative positions, and a light receiving unit 16b. By detecting whether or not the width and maximum brightness of the reflected light image from the object to be measured are within a predetermined range by using the output signal of the constituting two-dimensional light receiving element, or
A function to select the output signal for data creation by detecting whether the position, width and maximum brightness of the reflected light image from the DUT are within the specified range, and the output signal for data creation cannot be selected At this time, the function of outputting a signal indicating that measurement is impossible (function as the signal selection unit 20b) is performed so that the relative position is corrected with respect to the relative position at which the signal indicating that measurement is not possible, and the corrected relative position is obtained. And a second controller 20 for controlling the position setting change mechanism.
The function as a ', the sub-pixel processing is performed based on the output signal selected by the signal selection unit 20b, and the output signal selected by the signal selection unit 20b and the output signal from the position detector (each stage 11 , 13 to 15 position detection signals)
Based on the above, various functions such as a function as the shape data creating unit 20c for creating three-dimensional shape data of the object to be measured are performed.

In the present embodiment, the shape data creation unit 2
The three-dimensional shape data created at 0c is supplied to the CAD device 22 using this. Hereinafter, an example of the operation of the three-dimensional shape measuring apparatus of this embodiment will be described. First, since the measurement points necessary for the measurement of the dental model (see FIG. 3), which is the object to be measured, are the occlusal surface and the side surface of the tooth, the object to be measured 1 is placed so that the surface not requiring measurement is facing downward.
7 is temporarily fixed to the rotary stage 13. Note that, in FIG. 4, only one tooth forming the dental model (see FIG. 3) is illustrated as the object to be measured 17.

Next, the measurer controls the input unit 21.
Initialization is performed by giving a command to the processing unit 20. That is, the control / processing unit 20 follows the instruction from the input unit 21 and outputs each stage 1 via the motor drive circuit 18.
1, 13 to 15 are controlled, while the rotary stage 13 remains in the horizontal position, the rotary stage 15 has the origin position at which the laser irradiation light from the irradiation unit 16a of the laser displacement meter 16 is perpendicular to the surface of the X stage 11, the Z stage 14. Is set to the origin position where the standard object to be measured is within the depth of focus of the light receiving lens (not shown) of the light receiving portion 16b of the laser displacement meter 16. Further, the object 17 to be measured is moved by using the X stage 11 so that the slit-shaped laser irradiation light from the irradiation unit 16 a of the laser displacement meter 16 is in a range where the object 17 is irradiated.

Next, the measurer gives a measurement start command to the control / processing unit 20 through the input unit 21. In this state, the third control unit 20a ″ in the control / processing unit 20 responds to the measurement start command given from the input device 21 by the measurer and gives a control signal to the sensor drive circuit 19. The slit light is emitted from the irradiation unit 16a to the DUT 17.
Then, a cutting line along the shape of the DUT 17 is formed.

The cutting line is obliquely imaged by the light receiving section 16b. That is, as shown in FIG.
An image 6 ′ of the cutting line is projected on the light receiving surface 7 of the two-dimensional light receiving sensor 6b. As a result, an output signal corresponding to the image is obtained from the two-dimensional light receiving sensor of the light receiving unit 16b. The signal selection unit 20b in the control / processing unit 20 is the light receiving unit 16b.
From the output from the two-dimensional light receiving sensor, it is possible to detect whether the width and the maximum brightness of the reflected light image are within a predetermined range, or the position, the width and the maximum brightness of the reflected light image are within the predetermined range. The output signal for data creation is selected by detecting whether or not the output signal is within.

When the output signal for data creation cannot be selected, the signal selection section 20b outputs a signal indicating that measurement is impossible. The shape data creation unit 20c in the control / processing unit 20 temporarily stores the output signal selected by the signal selection unit 20b in a frame memory (not shown). And
By performing the sub-pixel processing on the image data as the output signal, the center position of the image 6'of the cutting line in the X1 direction is obtained at each position in the Y1 direction, and the data is stored in each of the stages 11, 13 to. It is stored in a memory (not shown) in association with the 15 position data.

This completes the measurement for one cutting line. To measure the entire DUT 17, namely,
In order to perform the measurement on the entire surface 1a to be measured (see FIG. 3), the X stage 11 may be moved at a predetermined pitch and then the measurement may be repeated in the same procedure. Each data obtained by the measurement is similarly stored in the memory.

If the entire area of the object to be measured 17 can be measured at a predetermined pitch (if the entire surface of the object to be measured 1a can be measured), the first position relative to the relative position at which the signal indicating that measurement is impossible is output. The second control unit 20a 'corrects the positional relationship and controls the position setting changing mechanism so that the corrected relative position is obtained. The relative position is corrected by, for example, the irradiation unit 16
It may be corrected so that the irradiation angle of the slit light 2 irradiating the object to be measured 17 from a is rotated by 90 ° with respect to the original relative position (referred to as slit light 2a, see FIG. 3). , But is not limited to this.

All necessary measurement data can be obtained by performing each measurement in the corrected relative position in the same manner or repeating the measurement and the relative position change. Each measurement data obtained by the measurement is similarly stored in the memory. Then, using each measurement data stored in the memory, the shape data creation unit 20c creates three-dimensional shape data of the DUT 17.

In the three-dimensional shape measuring apparatus of this embodiment, by detecting whether the width and the maximum brightness of the reflected light image from the object to be measured are within a predetermined range, or by reflecting from the object to be measured. An output signal for data creation is selected by detecting whether the position, width, and maximum brightness of the light image are within a predetermined range, and the three-dimensional shape of the measured object is selected based on the selected output signal. Creating data.

That is, in this embodiment, the signal selection unit 20b detects whether or not the width and the maximum brightness of the reflected light image are within the predetermined range from the output signals of the two-dimensional light receiving element of the light receiving unit 16b. Or by detecting whether or not the position, width and maximum brightness of the reflected light image are within a predetermined range, the output signal for data creation is selected, and then the shape data creation unit 20c The sub-pixel processing is performed to obtain each distance data.

When the output signal for data creation cannot be selected, the signal selector 20b outputs a signal indicating that measurement is impossible, and the second controller 20a 'outputs a signal indicating that measurement is impossible. The positional relationship has been corrected. Therefore, erroneous shape measurement data is not created, and it is possible to know the measurement points that require remeasurement. Alternatively, it is possible to know the measurement point that needs re-measurement and change the relative position to the measurement point that needs re-measurement and perform the re-measurement so that the output signal for data creation can be obtained. Therefore, more accurate shape measurement data can be obtained.

Therefore, in the three-dimensional shape measuring apparatus of this embodiment, the measurement error due to the inclination of the surface of the object to be measured is reduced, and the three-dimensional shape of the object to be measured is stably and accurately measured. be able to. Although the present embodiment has been described above, the present invention is not limited to this embodiment.

For example, although a single laser displacement meter (optical distance measuring device) is used in this embodiment, a plurality of laser displacement meters may be used. Further, in this embodiment, each stage 11, 13 to 15 is used as a position setting changing mechanism for setting and changing the relative position between the laser displacement meter and the object to be measured.
However, if the relative position can be set to a position necessary for obtaining a desired three-dimensional shape, any structure can be adopted as the position setting changing mechanism.

[0050]

As described in detail above, according to the three-dimensional shape measuring apparatus of the present invention, the measurement error caused by the inclination of the surface of the object to be measured is reduced, and the object to be measured can be stably and highly accurately. The three-dimensional shape of can be measured.

[Brief description of drawings]

FIG. 1 is a schematic side view for explaining a measurement principle according to the present invention.

2A and 2B are explanatory views (a) and (b) showing a state of an image projected on a light receiving surface of a light receiving section and an explanatory view (c) showing a luminance distribution in the X1 direction in the image.

FIG. 3 is a plan view showing a dental model that is an object to be measured in the example.

FIG. 4 is a diagram schematically showing an overall configuration of a three-dimensional shape measuring apparatus according to an embodiment.

[Explanation of symbols for main parts]

 1 ... Object to be measured 1a '... Surface to be measured of dental model which is object to be measured 2 ... Slit-shaped irradiation light 2a ... Slit-shaped irradiation light 3 ... Irradiation section 3a ... Optical axis 4 of light 2 ... Light receiving section 4a ... Optical axis of light receiving section 5 ... Light receiving section 5a ... Optical axis of light receiving section 6 ... Reflected light image 6 '.・ Image of reflected light from the object to be measured 7 ・ ・ ・ Light receiving surface of two-dimensional light receiving element 8 ・ ・ ・ Scanning line 11 ・ ・ X stage 13 ・ ・ Rotating stage 14 ・ ・ Z stage 15 ・ ・ Rotating stage 16 ・ ・ Light Distance measuring device 16a ... Irradiation unit 16b ... Light receiving unit 17 ... Object to be measured 18 ... Motor drive circuit 19 ... Sensor drive circuit 20 ... Control processing unit 20a ... First control unit 20a '... 2 control unit 20a '' ... third control unit 20b ... signal selection unit 20c ... shape data creation 21 ... input section 22 ·· CAD system than on the

Claims (4)

[Claims] 1. A light receiving unit having at least an irradiation unit for irradiating an object to be measured with slit-shaped irradiation light and a two-dimensional light receiving sensor including a plurality of light receiving elements arranged two-dimensionally, the irradiation unit comprising: An optical distance measuring device including a light receiving section that receives reflected light from the object to be measured by light on the two-dimensional light receiving sensor, and a relative position between the optical distance measuring device and the object to be measured is set. And a position setting changing mechanism to be changed, a first control unit for controlling the position setting changing mechanism so that the relative position becomes a plurality of predetermined relative positions, and an output signal of the two-dimensional light receiving sensor at each relative position. Is a signal selection unit that selects an output signal for data creation by detecting whether or not the width and maximum brightness of the reflected light image from the DUT are within a predetermined range. Output signal can be selected When there is no signal, the signal selecting unit having a function of outputting a signal indicating that measurement is impossible, and the relative position at which the signal indicating that measurement is impossible are output from the signal selecting unit, and the corrected relative position is obtained. Based on the output signal selected by the second control unit for controlling the position setting change mechanism, and the signal selection unit,
A three-dimensional shape measuring apparatus comprising: a shape data creating unit that creates three-dimensional shape data of the object to be measured. 2. A light receiving unit having at least an irradiation unit for irradiating an object to be measured with slit-shaped irradiation light and a two-dimensional light receiving sensor including a plurality of light receiving elements arranged two-dimensionally, An optical distance measuring device including a light receiving section that receives reflected light from the object to be measured by light on the two-dimensional light receiving sensor, and a relative position between the optical distance measuring device and the object to be measured is set. And a position setting changing mechanism to be changed, a first control unit for controlling the position setting changing mechanism so that the relative position becomes a plurality of predetermined relative positions, and an output signal of the two-dimensional light receiving sensor at each relative position. Is a signal selection unit that selects an output signal for data creation by detecting whether or not the position, width and maximum brightness of the reflected light image from the DUT are within a predetermined range. Select the output signal for creation When not possible, a signal selecting unit having a function of outputting a signal indicating that measurement is impossible, and performing a position correction with respect to the relative position at which a signal indicating that measurement is impossible is output from the signal selecting unit, and the corrected relative position Second for controlling the position setting changing mechanism so that
Based on the output signal selected by the control unit and the signal selection unit,
A three-dimensional shape measuring apparatus comprising: a shape data creating unit that creates three-dimensional shape data of the object to be measured. 3. A third control unit for controlling operations of the position setting changing mechanism and the irradiation unit, and a position detecting mechanism for detecting a position or a driving amount of the position setting changing mechanism. The three-dimensional shape measuring device according to claim 1 or 2. 4. The three-dimensional shape measuring apparatus according to claim 1, wherein the slit-shaped irradiation light is irradiation light in which a semiconductor laser light is slit-shaped by a cylindrical lens.