JPH08233518A - Three-dimensional shape measuring apparatus - Google Patents

Abstract

PURPOSE: To measure a three-dimensional shape, which is different for every material to be measured, respectively, without performing at all or scarcely performing cumbersome working. CONSTITUTION: An operation/control part 20 performs the control so that the relative positions of a laser displacement gage 16 and a material to be measured 17 are located at a plurality of specified positions, receives the output of the laser displacement gage 16 and performs the preliminary measurement. Then, the operation/control part 20 obtains the position information indicating a plurality of the relative positions of the laser displacement gage 16 and the material to be measured 17 required for obtaining the shape data of a plurality of intended points of the material to be measured 17 based on the three-dimensional shape data obtained by the preliminary measurement. Finaly, the operation/ control part 20 performs the control so that the relative positions of the laser displacement gage 16 and the material to be measured 17 become the relative positions indicated by the position information, receives the output of the laser displacement gage 16 and performs the main measurement.

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 the three-dimensional shape of an object to be measured by using an optical distance sensor such as a laser displacement meter.

[0002]

2. Description of the Related Art An optical distance sensor provided with an irradiating section for irradiating an object to be measured with irradiation light and a light receiving section for receiving reflected light from the object to be measured is used to non-contact the third order of the object to be measured. Conventionally, measuring the original shape has been widely performed. This method is widely known as a method that is simple and relatively good in accuracy, since it does not involve deformation of the object to be measured due to the contact pressure of the probe that is necessarily accompanied by measurement with the contact probe, correction of the radius of the contact sphere at the probe tip, etc. ing.

As one of such optical distance sensors, there is a triangulation type laser displacement meter which utilizes the principle of triangulation and uses laser light.

FIG. 7 is an explanatory view showing the measurement principle of a general triangulation type laser displacement meter 1.

As shown in FIG. 7, this laser displacement meter 1
Is provided with an irradiation unit 2 that irradiates the DUT 6 with spot-shaped laser light (a laser beam that does not spread) and a light receiving unit 3 that receives reflected light from the DUT 6. The light receiving unit 3 outputs a signal PS corresponding to the light receiving position.
D (position sensitive device, semiconductor position detector)
A one-dimensional light receiving sensor 4 such as a CCD or CCD, and a light receiving lens 5 for projecting the reflected light (an image formed by the irradiation light on the DUT 6) onto the light receiving surface of the one-dimensional light receiving sensor 4.

According to this laser displacement meter 1, the irradiation unit 2
The laser light emitted from the device is irradiated on the DUT 6, and the reflected light is received by the light receiving sensor 4 via the light receiving lens 5. At this time, as shown in FIG. 7, the position of the reflected light entering the light receiving sensor 4 changes according to the position of the surface of the DUT 6. Therefore, an output indicating the distance from the light receiving sensor 4 to the laser light irradiation position on the DUT 6 is obtained.

In the laser displacement meter 1, there is also known a laser displacement meter which uses a slit-shaped laser beam as the irradiation unit 2 and a two-dimensional light receiving sensor as the light receiving sensor. . This laser displacement meter is based on the same principle as that of the laser displacement meter 1, except that the linear irradiation position (the position of the light cutting line) on the DUT 6 irradiated with the slit-shaped laser light is measured. The distance is collectively obtained as the output of the two-dimensional light receiving sensor.

In the conventional three-dimensional shape measuring apparatus using the optical distance sensor such as the laser displacement meter as described above, the relative distance between the optical distance sensor and the measured object is irrespective of the shape of the measured object. While constantly changing the position to be a predetermined plurality of relative positions, based on the output of the optical distance sensor according to the predetermined plurality of relative positions between the optical distance sensor and the object to be measured, The three-dimensional shape data of the measured object was created.

[0009]

However, in the above-described conventional three-dimensional shape measuring apparatus, when there is a point where measurement cannot be performed (a point where shape data cannot be obtained) due to the inclination of the surface of the object to be measured. There were many

This is because in the optical distance sensor, measurement may not be possible depending on the relationship between the irradiation direction of light and the receiving direction of reflected light from the object to be measured and the inclination of the surface of the object to be measured. Because there is.

For example, when the laser displacement meter 1 shown in FIG. 7 is used, as shown in FIG. 7, the normal line of the surface of the DUT 6 with respect to the irradiation optical axis and the received optical axis of the laser displacement meter 1 is measured. When the inclination is small, the light receiving unit 3 of the laser displacement meter 1 can receive a sufficient amount of reflected light from the DUT 6, and the measurement point (the point where the light from the irradiation unit 2 is irradiated) is measured. Is possible.

On the other hand, as shown in FIG. 8, when the inclination of the normal line of the surface of the object 6 to be measured is large with respect to the irradiation optical axis and the receiving optical axis of the laser displacement meter 1, the light receiving section 3 of the laser displacement meter 1 is shown. Cannot receive a sufficient amount of reflected light from the DUT 6, and the measurement point (the point where the light from the irradiation unit 2 is irradiated) cannot be measured. Specifically, as shown in FIG. 8, when the light receiving unit 3 is located on the right side with respect to the irradiation unit 2 and the surface of the DUT 6 is largely inclined to the left side, the DUT 6 is measured.
The reflected light from is almost offset to the left side with respect to the irradiation unit 2, and the light receiving unit 3 cannot receive a sufficient amount of reflected light to acquire the shape data.

Therefore, in the conventional three-dimensional shape measuring apparatus, when a measurement impossible portion occurs, the position, angle, etc. on which the object to be measured is placed when the object to be measured is placed on a stage or the like, It was done to repeat the measurement and repeat this work until the measurement was accurate. Alternatively, if there is a point where measurement is still impossible, the measurement had to be abandoned.

The present invention has been made in view of such conventional problems, and three-dimensional shape measurement capable of measuring different three-dimensional shapes depending on an object to be measured without performing complicated work completely or almost. The purpose is to provide a device.

[0015]

In order to solve the above-mentioned problems, the three-dimensional shape measuring apparatus according to the first aspect of the present invention comprises:
An optical distance sensor, a position changing unit that changes a relative position between the optical distance sensor and the object to be measured, and a relative position between the optical distance sensor and the object to be measured are a plurality of predetermined relative positions. A first control means for controlling the position changing means so that the position is changed, and an output of the optical distance sensor according to the predetermined plurality of relative positions between the optical distance sensor and the object to be measured. Based on the first three-dimensional shape data creating means for creating first three-dimensional shape data of the object to be measured, and a desired plurality of desired objects to be measured based on the first three-dimensional shape data. Means for obtaining positional information indicating a plurality of relative positions between the optical distance sensor and the object to be measured, which are necessary for obtaining shape data of a location, and based on the positional information, the optical distance sensor and the The relative position between the object and Based on the output of the optical distance sensor according to the plurality of relative positions indicated by the position information, and the second control unit for controlling the position changing unit so that the plurality of relative positions are indicated. Second three-dimensional shape data creating means for creating two three-dimensional shape data.

Further, in the three-dimensional shape measuring apparatus according to the second aspect of the present invention, in the three-dimensional shape measuring apparatus according to the first aspect, the density of the predetermined plurality of relative positions is indicated by the position information. It is coarser than the density of a plurality of relative positions.

A three-dimensional shape measuring apparatus according to a third aspect of the present invention is an optical distance sensor, position changing means for changing a relative position between the optical distance sensor and the object to be measured, and the optical distance sensor. Between the optical distance sensor and the object to be measured, the first control means for controlling the position changing means so that the relative position between the object and the object to be measured becomes a plurality of predetermined relative positions. First three-dimensional shape data creating means for creating first three-dimensional shape data of the object to be measured based on the output of the optical distance sensor according to the predetermined plurality of relative positions of With respect to the three-dimensional shape data of, the determination means for determining whether or not there was a location where the shape data could not be obtained among the locations where the shape data in the measured object should have been obtained, by the determination means,
If it is determined that there was a location where the shape data could not be obtained among the locations where the shape data was to be obtained in the measured object, the location is determined based on the first three-dimensional shape data. Means for obtaining the positional information indicating the relative position between the optical distance sensor and the object to be measured necessary for obtaining the shape data of the optical distance sensor and the object to be measured based on the position information. So that the relative position between and becomes the relative position indicated by the position information,
The second control means for controlling the position changing means, the shape data based on the output of the optical distance sensor according to the relative position indicated by the position information, and the first three-dimensional shape data are combined, Second three-dimensional shape data creating means for creating second three-dimensional shape data.

[0018]

According to the first aspect, the so-called preliminary measurement of the three-dimensional shape of the object to be measured is performed by the first control means and the first three-dimensional shape data creating means.

During this preliminary measurement, the relative position between the optical distance sensor and the object to be measured becomes a predetermined plurality of relative positions by the first control means regardless of the shape of the object to be measured. Since it is changed, there are cases where measurement is impossible, like the three-dimensional shape data obtained by the conventional three-dimensional shape measuring apparatus. However, the unmeasurable point does not extend to the entire measured object, and normally only a part of the measured object becomes unmeasurable. Therefore, even if there are unmeasurable points, the three-dimensional shape data obtained by preliminary measurement
Since the shape near the unmeasurable point is known, the tilt direction of the surface near the unmeasurable point can be known. As described above, the reason why measurement at a certain point is impossible is the inclination of the surface at that point.Therefore, the angle with respect to the surface of the measurement point of the object to be irradiated and received by the optical distance sensor is changed. As described above, if the relative position between the optical distance sensor and the object to be measured is changed, it is possible to measure the unmeasurable point. Therefore, based on the first three-dimensional shape data obtained by the preliminary measurement, between the optical distance sensor and the object to be measured, which are necessary to obtain the shape data of a desired plurality of points of the object to be measured. It is possible to obtain position information indicating a plurality of relative positions.

According to the first aspect, such position information is obtained, and based on the position information, the second control means and the second three-dimensional shape data creating means are, so to speak, measured. The actual measurement of the three-dimensional shape of the object will be performed.

Therefore, according to the first aspect, no unmeasurable points may appear at the time of the main measurement of the three-dimensional shape of the object to be measured, or even if unmeasurable points may appear. The cause is due to an error in estimating the inclination of the surface of the object to be measured based on the first three-dimensional shape data obtained by the preliminary measurement. For this reason, is it possible to completely eliminate the troublesome work that is frequently required in the conventional three-dimensional shape measuring apparatus, that is, the object to be measured is changed in position and angle, remounted on the stage and then measured again? Or it can be extremely small.

By the way, in the first aspect, since the preliminary measurement is performed only to obtain the position information, it is not necessary to measure the measurement points at the same density as the main measurement in the preliminary measurement. . Then, in the preliminary measurement, when measuring points at the same density as the main measurement,
Measurement time becomes long. Therefore, as in the second aspect, the density of the predetermined plurality of relative positions related to the production of the first three-dimensional shape data is made coarser than the density of the plurality of relative positions indicated by the position information, that is, ,
In order to shorten the measurement time, making the density of the measurement points in the preliminary measurement rougher than the density of the measurement points in the main measurement
preferable. However, if the density of the measurement points in the preliminary measurement is made too rough, the error in estimating the inclination of the surface of the object to be measured becomes too large, and there is a high possibility that unmeasurable points will appear during the main measurement. Therefore, it is preferable to make the density of the measurement points in the preliminary measurement coarse so that the error in estimating the inclination of the surface of the measured object does not increase.

Further, according to the third aspect, the first control means and the first three-dimensional shape data creating means, so to speak, perform the first main measurement of the three-dimensional shape of the object to be measured. . This first main measurement itself is the same as the preliminary measurement according to the first aspect, but the first measurement result is the first measurement.
Since the three-dimensional shape data of is used as all or part of the final measurement result, it can be said to be the first main measurement.

Then, the determining means determines whether or not there is an unmeasurable portion during the first main measurement, and if there is no unmeasurable portion, the first three-dimensional obtained by the first main measurement is obtained. The shape data is the final measurement result.

On the other hand, if there is an unmeasurable portion during the first main measurement, the optical distance sensor and the object to be measured necessary to obtain the unmeasurable portion based on the first three-dimensional shape data. Position information indicating a relative position with an object is obtained. The reason why such position information is obtained is the same as the reason why the position information can be obtained in the first mode.
Then, on the basis of the obtained position information, the second control means and the second three-dimensional shape data creating means carry out a so-called supplementary main measurement to obtain the shape data of the unmeasurable portion. And the first shape data are second
The three-dimensional shape data creating means of (1) creates the second three-dimensional shape data that is the final measurement result.

Therefore, according to the third aspect as well,
It is possible to completely eliminate or extremely reduce the troublesome work of changing the position and angle of the object to be measured, remounting the object on the stage, and measuring again.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-dimensional shape measuring apparatus according to various embodiments of the present invention will be described below with reference to the drawings. In addition,
In the following examples, the object to be measured is a dental work model. However, the object to be measured is not limited to this, and the three-dimensional shape measuring apparatus according to the present invention can measure any other object.

First, a three-dimensional shape measuring apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram schematically showing the overall structure of a three-dimensional shape measuring apparatus according to the first embodiment of the present invention.

As shown in FIG. 1, the three-dimensional shape measuring apparatus according to the present embodiment is mounted on a main body substrate (not shown) and is movable in the X direction, and an X stage 11 mounted on the X stage 11. The Y stage 12 movable in the Y direction perpendicular to the X direction, the rotary stage 13 mounted on the Y stage 12 and rotatable about a rotary shaft 13c extending in the X direction, and above the rotary stage 13 above the rotary stage 13. A Z stage 14 attached to the main body base and movable in the Z direction perpendicular to the XY plane; a rotary stage 15 attached to the Z stage 14 and rotatable about a rotary shaft 15c extending in the Y direction; And a laser displacement meter 16 as an optical distance sensor attached to 15. The DUT 17 is placed on the rotary stage 13.
In the present embodiment, these stages 11 to 15 constitute position changing means for changing the relative position between the laser displacement meter 16 and the object to be measured 17.

Incidentally, in FIG. 1, each of the stages 11 to 1
5, the fixed part of the X stage 11 is 11a, the movable part of the X stage 11 is 11b, the fixed part of the Y stage 12 is 12a, the movable part of the Y stage 12 is 12b, and the rotary stage 13 is 13a, the movable part of the rotary stage 13 is 13b, the fixed part of the Z stage 14 is 14a, 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 has the same structure as the displacement meter 1 shown in FIG. That is, the laser displacement meter 16 has an irradiation unit 16 a that irradiates the DUT 17 with spot-shaped laser light, and a light receiving unit 16 b that receives the reflected light from the DUT 17.

Further, as shown in FIG. 1, the three-dimensional shape measuring apparatus according to this embodiment includes a motor drive circuit 18 for driving a drive motor (not shown) of each of the stages 11 to 15, and a laser displacement meter 16. A sensor drive circuit 19 to be driven, a calculation / control unit 20 for performing various calculations and controls, an input device 21 such as a keyboard for a measurer to give various commands to the calculation / control unit 20, and each stage 11 to 11. And a position detector (not shown) such as an encoder for detecting the 15 positions (or the drive amount).

The arithmetic / control unit 20 is composed of a microcomputer having a storage device, a CPU and the like (not shown) built therein, and has a function as a drive control unit for controlling the operation of the motor drive circuit 18 and the sensor drive circuit 19 and a laser. Functions as a three-dimensional shape data creating unit that creates three-dimensional shape data based on the output from the displacement gauge 16 and the output from the position detector (position detection signal of each stage) and various functions described later. .

In the present embodiment, the three-dimensional shape data finally produced by the arithmetic / control unit 20 is supplied to the CAD device 22 utilizing this.

Next, an example of the operation of the three-dimensional shape measuring apparatus according to this embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing the main operation of the arithmetic / control unit 20.

First, since the measurement points necessary for the measurement of the dental model, which is the object to be measured 17, are the mating surfaces and side surfaces of the teeth, the measurer places the object to be measured so that the surface not to be measured is facing down. 17 is temporarily fixed to the rotary stage 13 with an adhesive (not shown).

Next, the measurer gives an instruction to the calculation / control section 20 by means of the input device 21 to perform the initial setting. That is, the arithmetic / control unit 20 controls the respective stages 11 to 15 via the motor drive circuit 18 in accordance with a command from the input device 21, the rotary stage 13 remains in the horizontal position, and the rotary stage 15 uses the laser displacement meter 16. The origin position at which the laser irradiation light from the irradiation unit 16a of is perpendicular to the XY plane, the Z stage 14 is a light receiving lens (not shown) of the light receiving unit 16b of the laser displacement meter 16 as a standard measured object.
Set it at the origin position within the depth of focus of. Also,
The object to be measured 17 is moved by using the X stage 11 and the Y stage 12 so that the laser irradiation light from the irradiation unit 16a of the laser displacement meter 16 is in a range where the object to be measured 17 is irradiated.

Next, the measurer gives a measurement start command to the calculation / control section 20 by means of the input device 21.

In response to the measurement start command, the arithmetic / control unit 20 first performs preliminary measurement in step 31 in FIG.
That is, the calculation / control unit 20 gives a drive control signal to the motor drive circuit 18 to move the laser displacement meter 16 and the object to be measured 17 (in the present embodiment, the rotary stage 13 on which the object to be measured 17 is placed is movable). While controlling the respective stages 11 to 15 (first control) so that the relative position to the portion 13b) becomes a predetermined plurality of relative positions, a laser displacement meter according to the predetermined plurality of relative positions. The output of 16 is taken in and the 1st three-dimensional shape data of the to-be-measured object 17 are produced. In addition,
In response to the measurement start command, the calculation / control unit 20 gives a drive control signal to the sensor drive circuit 19 so that the laser beam is emitted from the irradiation unit 16a of the laser displacement meter 16 until the measurement is completed. To do.

Specifically, for example, preliminary measurement is performed as follows.

First, the upper surface of the object to be measured 17 is measured in the initial setting state. That is, the X-stage 11 and the Y-stage 12 are moved in a width of about 1 mm from the initial setting state, and the upper surface of the DUT 17 is measured over the entire area in a grid pattern. Next, in order to measure the front surface of the DUT 17, the rotary stage 13 is rotated by a predetermined amount so that the front surface of the DUT 17 is located above. Then, similarly,
The measurement is performed while moving the X stage 11 and the Y stage 12, and when the measurement of the entire front surface of the DUT 17 is completed, the measurement of the back surface of the DUT 17 is started. The rotary stage 13 is rotated by a predetermined amount so that the back surface faces upward, and in this state, measurement is performed while moving the X stage 11 and the Y stage 12 in the same manner. Next, in order to measure the right side surface of the object to be measured 17, first, the rotary stage 15 is rotated, and the angle is set so that the irradiation laser light strikes the right side surface of the object to be measured 17 at an angle close to vertical. In this state, X stage 11, Y
Laser light is emitted from the stage 12 and the Z stage 14 to be measured 1
7 is moved, and the Z stage 14 and the Y stage 12 are moved with a width of about 1 mm for measurement. Finally, in order to measure the left side surface of the object to be measured 17, first, the rotary stage 15 is rotated so that the irradiation laser light is irradiated onto the object to be measured 17.
Set the angle so that it hits the left side of the at an angle close to vertical. In this state, X stage 11, Y stage 12, Z
The stage 14 is moved so that the laser beam hits the object to be measured 17, and the Z stage 14 and the Y stage 12 are moved by a width of about 1 mm for measurement. As a result, the DUT 1
The preliminary measurement of 7 is completed.

With this, the preliminary measurement of the object to be measured 17 is completed, and the first three-dimensional shape data of the object to be measured 17 is obtained.
This means that the shape of the DUT 17 is known.

Next, in step 32 in FIG. 2, the arithmetic / control unit 20 determines a desired plurality of locations on the object to be measured 17 based on the first three-dimensional shape data obtained by the preliminary measurement. Laser displacement gauge 16 required to obtain shape data
And position information indicating a plurality of relative positions between the object 17 and the object to be measured 17 are obtained.

In the preliminary measurement, depending on the shape of the object to be measured 17, the reflected light may not be returned to the light receiving portion 16b of the laser displacement meter 16 in a sufficient amount for measurement due to the inclination of the surface of the measurement point. The measuring point becomes unmeasurable because the quantity is significantly reduced. However, the point that cannot be measured is 17
It does not cover the whole, and normally only a part of the measured object becomes unmeasurable. Therefore, even if there is an unmeasurable point, the shape in the vicinity thereof is known, and naturally, the inclination direction of the surface near the unmeasurable point is also known, and the inclination of the surface near the unmeasurable point can be known. Since the cause of making the measurement at a certain point impossible is the inclination of the surface at that point, it is possible to change the angle of the DUT 16 for irradiating and receiving the laser light by the laser displacement meter 16 with respect to the surface of the relevant measuring point. For example, it is possible to measure the unmeasurable point. For this reason,
Based on the first three-dimensional shape data obtained by the preliminary measurement, between the laser displacement meter 16 and the object to be measured 17 necessary for obtaining the shape data of a desired plurality of points of the object to be measured 17. It is possible to obtain position information indicating a plurality of relative positions.

Specifically, for example, the arithmetic / control unit 20
Can obtain the position information as follows.

First, the angle of the surface of the unmeasurable point in the preliminary measurement (including the point around which the main measurement is to be performed, if necessary) is set to the measurement point in the vicinity of the unmeasurable point. It is calculated from the shape data, and the laser displacement gauge 16
The positions of the respective stages 11 to 15 are calculated so that the inclinations of the irradiation optical axis and the received optical axis are reduced. Except for this non-measurable point (including the point around which the main measurement is to be performed if necessary), it was possible to measure in the preliminary measurement. Measurement can be performed by moving the stages 11 to 15. Then, the information indicating such a movement pattern (this corresponds to the information indicating the relative position between the laser displacement meter 16 and the DUT 17),
It is stored in advance in a storage device in the arithmetic / control unit 20.
Therefore, in the present embodiment, the positions of the stages 11 to 15 calculated as described above and the movement patterns other than the unmeasurable points are used as the position information. If there are no unmeasurable points during the preliminary measurement, the calculation / control unit 2
The movement pattern previously stored in the storage device in 0 is set as the position information.

However, based on the first three-dimensional shape data obtained by the preliminary measurement, the angles of the surfaces of the measurement points are calculated for all the desired measurement points of the object to be measured,
According to this angle, the positions of the respective stages 11 to 15 are calculated so that the inclinations of the irradiation optical axis and the light receiving optical axis of the laser displacement meter 16 are as small as possible with respect to the normal line of the surface of the measurement point, and these are calculated. The calculation result of may be used as the position information. In this case, at the time of main measurement described later, with respect to all desired measurement points of the object to be measured, the angles of the irradiation optical axis and the reception optical axis of the laser displacement meter 16 with respect to the surface of the measurement impossible point are optimized, Since the amount of light received by the light receiving unit 16a of the laser displacement meter 16 can be increased, there is an advantage that the measurement accuracy can be improved.

Next, the calculation / control section 20 performs the main measurement in step 33 in FIG. That is, the arithmetic / control unit 20
Gives a drive control signal to the motor drive circuit 18 based on the position information obtained in step 32, and the laser displacement meter 1
6 so that the relative position between the object 6 and the object to be measured 17 becomes a plurality of relative positions indicated by the position information.
While controlling 1 to 15 (second control), the output of the laser displacement meter 16 corresponding to the plurality of relative positions is taken in to produce second three-dimensional shape data of the object to be measured 17.

Specifically, for example, the main measurement is performed as follows.

In the main measurement, a predetermined fine pitch (for example, 0.2
Measurement is performed by moving the X stage 11, the Y stage 12, and the Z stage 14 at a (mm pitch) in the same procedure as in the preliminary measurement. At the unmeasurable point in the preliminary measurement, each stage 11 to 15 is moved so that the amount of light received by the light receiving unit 16b of the laser displacement meter 16 becomes large.

The second three-dimensional shape data obtained by this main measurement becomes the final measurement result, and when the main measurement is completed, the measurement of the three-dimensional shape of the DUT 17 is completed.

According to the present embodiment described above, the preliminary measurement is performed in advance, and the main measurement is performed based on the three-dimensional shape data obtained by the preliminary measurement. Even if there is no possibility or there is a possibility that an unmeasurable point may appear, the cause is the object to be measured 17 based on the first three-dimensional shape data obtained by the preliminary measurement.
This is due to an error in the estimation of the inclination of the plane, and the possibility that an unmeasurable point will appear is extremely low. For this reason, it is possible to completely eliminate or extremely reduce the complicated work of changing the position and the angle of the object to be measured 17 and remounting the object to be measured on the rotary stage 13.

Further, in this embodiment, the density of the measurement points in the preliminary measurement (pitch about 1 mm) is made coarser than the density of the measurement points in the main measurement (pitch 0.2 mm).
The measurement time can be shortened as compared with the case where the density of the measurement points in the preliminary measurement is the same as the density in the main measurement.

Next, a three-dimensional shape measuring apparatus according to a second embodiment of the present invention will be described with reference to FIGS.

The three-dimensional shape measuring apparatus according to this embodiment is the same as the three-dimensional shape measuring apparatus according to the first embodiment except for the operation of the calculation / control section 20. Therefore, FIG.
6 is also a diagram schematically showing the overall configuration of the three-dimensional shape measuring apparatus according to the second embodiment, and a duplicate description will be omitted.

In this embodiment, the arithmetic / control unit 20 is configured as shown in FIG.
The operation is performed as shown in. FIG. 3 shows the calculation in this embodiment.
6 is a flowchart showing a main operation of the control unit 20.

Next, an example of the operation of the three-dimensional shape measuring apparatus according to this embodiment will be described with reference to FIGS.

First, as in the case of the first embodiment, the measurer temporarily fixes the object 17 to be measured on the rotary stage 13 and performs initial setting.

Next, the measurer gives a measurement start command to the calculation / control unit 20 by using the input device 21.

In response to the measurement start command, the arithmetic / control unit 20 first performs the first main measurement in step 41 in FIG. In other words, the arithmetic / control unit 20 uses the motor drive circuit 1
8 by giving a drive control signal to a predetermined relative position between the laser displacement meter 16 and the DUT 17 (in this embodiment, the movable portion 13b of the rotary stage 13 on which the DUT 17 is placed). Each of the stages 11 to 1 is set to have a plurality of relative positions.
While controlling 5 (first control), the output of the laser displacement meter 16 corresponding to the predetermined plurality of relative positions is taken in to prepare first three-dimensional shape data of the object to be measured 17.

Specifically, for example, the first main measurement is performed in the same manner as the preliminary measurement in the first embodiment. However, in the present embodiment, since the first three-dimensional shape data is used as the final measurement result, the measurement pitch is, for example, 0.2 mm instead of about 1 mm.

Next, the calculation / control unit 20 should obtain the shape data of the object to be measured 17 with respect to the first three-dimensional shape data obtained by the first main measurement in step 42 in FIG. It is determined whether or not there was a portion for which the shape data could not be obtained, that is, whether or not there was an unmeasurable point in the first main measurement. Whether or not the measurement cannot be made can be determined by whether or not the output of the laser displacement meter 16 indicates that the reflected light of a predetermined amount or more is not received.

When it is determined in step 42 that there is no unmeasurable point, the first three-dimensional shape data is taken as the final measurement result, and the measurement of the three-dimensional shape of the DUT 17 is completed.

On the other hand, if it is determined in step 42 that there is an unmeasurable point, the arithmetic / control unit 20 determines in step 43 in FIG. 3 the first three-dimensional shape data obtained by the first main measurement. Based on the above, the laser displacement meter 16 and the object to be measured 17 necessary for obtaining the shape data of the unmeasurable point are obtained.
Position information indicating a plurality of relative positions between and is obtained.

Specifically, for example, the angle of the surface of the unmeasurable point in the first measurement is calculated from the shape data of the measurable measuring point near the unmeasurable point, and the angle is calculated according to this angle. The positions of the respective stages 11 to 15 are calculated such that the inclinations of the irradiation optical axis and the received optical axis of the laser displacement meter 16 become small with respect to the normal line of the surface of the unmeasurable point. The position obtained by this calculation corresponds to the position information.

Next, the calculation / control section 20 performs supplementary main measurement at step 44 in FIG. That is, the calculation / control unit 20 determines, based on the position information obtained in step 43,
A drive control signal is applied to the motor drive circuit 18 to control each of the stages 11 to 15 so that the relative position between the laser displacement meter 16 and the DUT 17 becomes a plurality of relative positions indicated by the position information. By taking in the output of the laser displacement meter 16 according to the relative position indicated by the position information while (second control), the shape data of the unmeasurable point in the first main measurement is additionally obtained. Subsequently, in step 44, the arithmetic / control unit 20 synthesizes the supplementally obtained shape data and the first three-dimensional shape data obtained by the first main measurement, and The second three-dimensional shape data is created, and the measurement of the three-dimensional shape of the DUT 17 is completed.

When it is determined in step 42 that there is an unmeasurable point, the second three-dimensional shape data thus obtained becomes the final measurement result.

Therefore, according to the present embodiment as well, similar to the first embodiment, the complicated work of repositioning the object to be measured 17 on the rotary stage 13 while changing the position and angle and performing the measurement again is completely eliminated. Can be done or very low.

Next, a three-dimensional shape measuring apparatus according to a third embodiment of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a diagram schematically showing the overall structure of a three-dimensional shape measuring apparatus according to the third embodiment of the present invention.

As shown in FIG. 4, the three-dimensional shape measuring apparatus according to this embodiment is mounted on a main body substrate (not shown) and is movable on the X direction, and is mounted on the X stage 51. And a rotary stage 53 rotatable about a rotary shaft 53c extending in the X direction.
Z stage 54 attached to the main body base above the X stage and movable in the Z direction perpendicular to the surface of the X stage 51.
A rotary stage 55 attached to the Z stage 54 and rotatable about a rotary shaft 55c extending in the Y direction; and a laser displacement meter 56 attached to the rotary stage 55 as an optical distance sensor. The DUT 57 is placed on the rotary stage 53. In the present embodiment, these stages 51, 53 to 55 constitute position changing means for changing the relative position between the laser displacement meter 56 and the object to be measured 57.

In FIG. 4, each stage 51, 5
To make it easier to understand the movement of 3-55, X stage 5
1 is the fixed part 51a, and the movable part of the X stage 51 is 51a.
b, the fixed part of the rotary stage 53 is 53a, the movable part of the rotary stage 53 is 53b, and the fixed part of the Z stage 54 is 54
a, the movable part of the Z stage 54 54b, the rotary stage 5
5 is a fixed part 55a, and the rotary stage 55 is a movable part 55a.
Each is shown by b.

The laser displacement meter 56 has basically the same structure as the displacement meter 1 shown in FIG. 7, but has a slit shape extending in the direction in which the rotary shaft 55c extends with respect to the object 57 to be measured. The irradiation unit 56a for irradiating the laser beam and the light receiving unit 56b for receiving the reflected light from the DUT 57 are included. Although not shown in the drawing, the light receiving unit 56b has a two-dimensional light receiving sensor, and a CCD camera, for example, can be used as the light receiving unit 56b.

Further, in the three-dimensional shape measuring apparatus according to this embodiment, as shown in FIG. 4, a motor drive circuit 58 for driving a drive motor (not shown) for each of the stages 51, 53 to 55.
And a sensor drive circuit 59 for driving the laser displacement meter 56.
A calculation / control unit 60 for performing various calculations and controls, an input device 61 such as a keyboard for a measurer to give various commands to the calculation / control unit 60, and stages 51, 53-
And a position detector (not shown) such as an encoder for detecting the position (or drive amount) of 55.

The arithmetic / control unit 60 is composed of a microcomputer having a storage device, a CPU and the like (not shown) incorporated therein, and has a function as a drive control unit for controlling the operation of the motor drive circuit 58 and the sensor drive circuit 59 and a laser. Functions as a three-dimensional shape data creating unit that creates three-dimensional shape data based on the output from the displacement meter 56 and the output from the position detector (position detection signal of each stage) and various functions described later. .

In the present embodiment, the three-dimensional shape data finally produced by the arithmetic / control unit 60 is supplied to the CAD device 62 which uses the data.

Next, an example of the operation of the three-dimensional shape measuring apparatus according to this embodiment will be described with reference to FIGS. FIG. 5 is a flowchart showing the main operation of the arithmetic / control unit 60.

First, since the measurement points necessary for the measurement of the dental model, which is the object to be measured 57, are the mating surfaces and the side surfaces of the tooth, the measurer places the object to be measured so that the surface not to be measured faces downward. 57 is temporarily fixed to the rotary stage 53 with an adhesive (not shown).

Next, the measurer gives an instruction to the calculation / control section 60 through the input device 61 to perform the initial setting. That is, the arithmetic / control unit 60 controls each stage 51, 53 to 55 via the motor drive circuit 58 in accordance with a command from the input device 61, the rotary stage 53 remains in the horizontal position, and the rotary stage 55 is laser-displaced. The origin position where the laser irradiation light from the irradiation unit 56a of the total 56 is perpendicular to the surface of the X stage 51, and the standard measurement object of the Z stage 54 is a light receiving lens (not shown) of the light receiving unit 56b of the laser displacement meter 56. ) Set the origin position within the depth of focus. Further, the measured object 57 is moved by using the X stage 51 so that the slit-shaped laser irradiation light from the irradiation unit 56a of the laser displacement meter 56 is in a range where the measured object 57 is irradiated.

Next, the measurer gives a measurement start command to the calculation / control unit 60 by using the input device 61.

In response to the measurement start command, the arithmetic / control unit 60 first performs preliminary measurement in step 71 in FIG.
That is, the arithmetic / control unit 60 gives a drive control signal to the motor drive circuit 58 to move the laser displacement meter 56 and the object to be measured 57 (in this embodiment, the rotary stage 53 on which the object to be measured 57 is placed is movable). So that the relative position with respect to the portion 53b) becomes a predetermined plurality of relative positions.
While controlling 55 (first control), the output of the laser displacement meter 56 corresponding to the predetermined plurality of relative positions is taken in to prepare first three-dimensional shape data of the object 57 to be measured.
The calculation / control unit 60 responds to the measurement start command by
A drive control signal is given to the sensor drive circuit 59 so that the laser beam is emitted from the irradiation section 56a of the laser displacement meter 56 until the measurement is completed.

Specifically, for example, preliminary measurement is performed as follows.

First, in the initial setting state, the upper surface of the object 57 to be measured is measured. That is, the upper surface of the DUT 57 is measured over the entire area while moving the X stage 51 in a width of about 1 mm from the initial setting state. Next, in order to measure the front surface of the DUT 57, the rotary stage 53
Is rotated by a predetermined amount so that the front surface of the object to be measured 57 comes up. After that, similarly, the measurement is performed while moving the X stage 51, and when the measurement of the entire front surface of the object to be measured 57 is completed, the measurement is performed to the rear surface of the object to be measured 57. The rotary stage 53 is rotated by a predetermined amount so that the back surface faces upward, and in this state, measurement is performed while moving the X stage 51 as well. Next, in order to measure the right side surface of the object to be measured 57, first, the rotary stage 55 is rotated to set an angle such that the slit-shaped irradiation laser light strikes the right side surface of the object to be measured 57 at an angle close to vertical. To do. In this state, X stage 5
1. The Z stage 54 is moved so that the laser light strikes the object 57 to be measured, and the Z stage 54 is moved by a width of about 1 mm for measurement. Finally, in order to measure the left side surface of the DUT 57, first, the rotary stage 55 is rotated to set an angle such that the slit-shaped irradiation laser light strikes the left side surface of the DUT 57 at an angle close to vertical. To do. In this state,
The X stage 51 and the Z stage 54 are moved so that the laser light strikes the object 57 to be measured, and the Z stage 54 is moved in a width of about 1 mm for measurement. This completes the preliminary measurement of the DUT 57.

This completes the preliminary measurement of the object to be measured 57 and obtains the first three-dimensional shape data of the object to be measured 57.
This means that the shape of the DUT 57 is known.

Next, in step 72 in FIG. 5, the calculation / control section 60 determines a plurality of desired locations of the object 57 to be measured based on the first three-dimensional shape data obtained by the preliminary measurement. Laser displacement meter 56 required to obtain shape data
And position information indicating a plurality of relative positions between the object 57 and the object to be measured 57 are obtained. Specifically, the arithmetic / control unit 60 obtains the position information in the same manner as the arithmetic / control unit 60 obtained the position information in step 32 in the first embodiment.

Next, the calculation / control section 60 performs the main measurement in step 73 in FIG. That is, the arithmetic / control unit 60
Supplies a drive control signal to the motor drive circuit 58 based on the position information obtained in step 72, and the laser displacement meter 5
6 so that the relative position between the object 6 and the object to be measured 57 becomes a plurality of relative positions indicated by the position information.
While controlling 1, 53 to 55 (second control), the output of the laser displacement meter 56 corresponding to the plurality of relative positions is taken in and the second three-dimensional shape data of the measured object 57 is produced.

Specifically, for example, the main measurement is performed as follows.

In the main measurement, a predetermined fine pitch (for example, 0.2
While moving the X stage 51 and the Z stage 54 at (mm pitch), measurement is performed in the same procedure as in the preliminary measurement. At the unmeasurable point in the preliminary measurement, each stage 5 is adjusted so that the amount of light received by the light receiving section 56b of the laser displacement meter 56 becomes large.
1,53-55 will be moved and it will measure.

The second three-dimensional shape data obtained by the main measurement becomes the final measurement result, and when the main measurement is completed, the measurement of the three-dimensional shape of the object 57 to be measured is completed.

According to the present embodiment described above, the measurement is performed by using the slit-shaped laser beam. However, as in the first embodiment, the object 57 to be measured is changed in position and angle to rotate the rotary stage. It is possible to completely eliminate or extremely reduce the complicated work of remounting on 53 and measuring again.

Further, in the present embodiment, similarly to the first embodiment, the density of the measurement points in the preliminary measurement (pitch of about 1 m
m is the density of the measurement points in this measurement (pitch 0.2 m
Since it is rougher than m), the measurement time can be shortened as compared with the case where the density of the measurement points in the preliminary measurement is the same as the density in the main measurement.

Next, a three-dimensional shape measuring apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS. 4 and 6.

The three-dimensional shape measuring apparatus according to this embodiment is the same as the three-dimensional shape measuring apparatus according to the third embodiment except for the operation of the calculation / control section 60. Therefore, FIG.
6 is also a diagram schematically showing the overall configuration of the three-dimensional shape measuring apparatus according to the fourth embodiment, and a duplicate description will be omitted.

In this embodiment, the arithmetic / control unit 60 is configured as shown in FIG.
The operation is performed as shown in. FIG. 6 shows the calculation in this embodiment.
6 is a flowchart showing a main operation of the control unit 60.

Next, an example of the operation of the three-dimensional shape measuring apparatus according to this embodiment will be described with reference to FIGS. 4 and 6.

First, similarly to the case of the first embodiment, the measurer temporarily fixes the object 57 to be measured on the rotary stage 53 and performs the initial setting.

Next, the measurer gives a measurement start command to the arithmetic / control unit 60 by using the input device 61.

In response to the measurement start command, the arithmetic / control unit 60 first performs the first main measurement in step 81 in FIG. That is, the arithmetic / control unit 60 controls the motor drive circuit 5
A drive control signal is given to 8 to set the relative position between the laser displacement meter 56 and the object to be measured 57 (in this embodiment, the movable portion 53b of the rotary stage 53 on which the object to be measured 57 is placed) to a predetermined value. Each stage 51, 5 is arranged so as to have a plurality of relative positions.
While controlling 3 to 55 (first control), the output of the laser displacement meter 56 corresponding to the predetermined plurality of relative positions is taken in to prepare the first three-dimensional shape data of the object 57 to be measured.

Specifically, for example, this first main measurement is performed in the same manner as the preliminary measurement in the third embodiment. However, in the present embodiment, since the first three-dimensional shape data is used as the final measurement result, the measurement pitch is, for example, 0.2 mm instead of about 1 mm.

Next, in step 82 in FIG. 6, the arithmetic / control unit 60 should obtain the shape data of the object 57 to be measured with respect to the first three-dimensional shape data obtained by the first main measurement. It is determined whether or not there was a portion for which the shape data could not be obtained, that is, whether or not there was an unmeasurable point in the first main measurement. Whether or not the measurement is impossible can be determined by whether or not the output of the laser displacement meter 56 indicates that the reflected light of a predetermined amount or more is not received.

When it is determined in step 82 that there is no measurement impossible point, the first three-dimensional shape data is taken as the final measurement result, and the measurement of the three-dimensional shape of the object 57 is completed.

On the other hand, if it is determined in step 82 that there is an unmeasurable point, the arithmetic / control unit 60 determines in step 83 in FIG. 6 the first three-dimensional shape data obtained by the first main measurement. The laser displacement meter 56 and the object to be measured 57 required to obtain the shape data of the unmeasurable point based on
Position information indicating a plurality of relative positions between and is obtained.

Specifically, for example, the angle of the surface of the unmeasurable point in the first measurement is calculated from the shape data of the measurable measuring point near the unmeasurable point, and the angle is calculated according to this angle. The positions of the respective stages 51, 53 to 55 are calculated so that the inclinations of the irradiation optical axis and the light receiving optical axis of the laser displacement meter 56 become small with respect to the normal line of the surface of the unmeasurable point.
The position obtained by this calculation corresponds to the position information.

Next, the calculation / control section 60 performs a supplementary main measurement at step 84 in FIG. That is, the calculation / control unit 60, based on the position information obtained in step 83,
A drive control signal is given to the motor drive circuit 58 so that the relative position between the laser displacement meter 56 and the object to be measured 57 becomes a plurality of relative positions indicated by the position information, and each of the stages 51, 53 to 55. While controlling (second control), the output of the laser displacement meter 56 corresponding to the relative position indicated by the position information is taken in, and the shape data of the unmeasurable point in the first main measurement is additionally obtained. Subsequently, in step 84, the calculation / control unit 60 combines the supplementally obtained shape data and the first three-dimensional shape data obtained by the first main measurement, and Create the second three-dimensional shape data and measure
The measurement of the three-dimensional shape of 7 is completed.

If it is determined in step 82 that there is an unmeasurable point, the second three-dimensional shape data thus obtained becomes the final measurement result.

Therefore, according to the present embodiment as well, similar to the third embodiment, the complicated work of repositioning the object 57 to be measured on the rotary stage 53 by changing the position and angle and re-measurement is completely eliminated. Can be done or very low.

Although the respective embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

For example, although a single optical distance sensor is used in each of the above embodiments, a plurality of optical distance sensors may be used.

Further, in each of the above embodiments, the stages 11 to 15 or 51, 53 to 55 are adopted as the position changing means for changing the relative position between the optical distance sensor and the object to be measured. If the position can be set to a position required to obtain a desired three-dimensional shape, any structure can be adopted as the position changing means.

[0111]

As described above, according to the present invention,
It is possible to measure the three-dimensional shape of the object to be measured completely or almost without performing the complicated work of changing the position or angle of the object to be measured, remounting the object on a stage or the like, and measuring again.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an overall configuration of a three-dimensional shape measuring apparatus according to first and second embodiments of the present invention.

FIG. 2 is a flowchart showing a main operation of a calculation / control unit in the first exemplary embodiment of the present invention.

FIG. 3 is a flowchart showing a main operation of a calculation / control unit in the second exemplary embodiment of the present invention.

FIG. 4 is a diagram schematically showing an overall configuration of a three-dimensional shape measuring apparatus according to third and fourth embodiments of the present invention.

FIG. 5 is a flow chart showing the main operation of the arithmetic / control unit in the third embodiment of the present invention.

FIG. 6 is a flow chart showing main operations of a calculation / control unit in the fourth exemplary embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a measurement principle of a general triangulation type laser displacement meter.

FIG. 8 is an explanatory diagram showing a situation in which measurement is impossible due to deviation of reflected light from an object to be measured.

[Explanation of symbols]

 11,51 X stage 12 Y stage 13,53 rotary stage 13c, 53c rotary shaft 14,54 Z stage 15,55 rotary stage 15c, 55c rotary shaft 16,56 laser displacement meter 16a, 56a irradiation unit 16b, 56b light receiving unit 17 , 57 DUT 18, 58 Motor drive circuit 19, 59 Sensor drive circuit 20, 60 Arithmetic / control unit

Claims (3)

[Claims] 1. An optical distance sensor, position changing means for changing a relative position between the optical distance sensor and the object to be measured, and a relative position between the optical distance sensor and the object to be measured,
First control means for controlling the position changing means so as to have a plurality of predetermined relative positions, and the light according to the predetermined plurality of relative positions between the optical distance sensor and the object to be measured. First three-dimensional shape data creating means for creating first three-dimensional shape data of the object to be measured based on the output of a distance sensor; and the object to be measured based on the first three-dimensional shape data. Required to obtain the shape data of the desired plurality of locations, means for obtaining position information indicating a plurality of relative positions between the optical distance sensor and the object to be measured, based on the position information, A second control unit that controls the position changing unit so that the relative position between the optical distance sensor and the object to be measured becomes a plurality of relative positions indicated by the position information, and is indicated by the position information. The light according to a plurality of relative positions A three-dimensional shape measuring apparatus comprising: a second three-dimensional shape data creating unit that creates second three-dimensional shape data based on the output of the distance sensor. 2. The three-dimensional shape measuring apparatus according to claim 1, wherein the density of the predetermined plurality of relative positions is coarser than the density of the plurality of relative positions indicated by the position information. 3. An optical distance sensor, position changing means for changing a relative position between the optical distance sensor and the object to be measured, and a relative position between the optical distance sensor and the object to be measured,
First control means for controlling the position changing means so as to have a plurality of predetermined relative positions, and the light according to the predetermined plurality of relative positions between the optical distance sensor and the object to be measured. First three-dimensional shape data creating means for creating first three-dimensional shape data of the object to be measured based on the output of the distance sensor; and the shape of the object to be measured with respect to the first three-dimensional shape data. A determination means for determining whether or not there was a portion for which the shape data could not be obtained among the portions for which the data should have been obtained, and the shape data for the object to be measured should be obtained by the determination means. When it is determined that there is a part for which the shape data cannot be obtained, the optical distance required to obtain the shape data of the part based on the first three-dimensional shape data. Sensor for obtaining position information indicating a relative position between the sensor and the object to be measured, and the relative position between the optical distance sensor and the object to be measured is indicated by the position information based on the position information. Second for controlling the position changing means so as to be a relative position
And the shape data based on the output of the optical distance sensor corresponding to the relative position indicated by the position information and the first three-dimensional shape data are combined to produce the second three-dimensional shape data. And a second three-dimensional shape data producing means for performing the three-dimensional shape measuring apparatus.