JP2633718B2 - Shape recognition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a shape recognition device.

(Prior Art) As a method of recognizing a shape, a stereo method using two cameras, a photometric stereo method for obtaining a surface inclination from scattered light intensities of a plurality of illuminations, a slit light projection, and a light cutting line thereof There is a method of recognizing the shape from the object.

A scanning laser microscope is a typical example of recognizing the shape of an object using confocal. This scanning laser microscope has been developed for performing tomographic fluoroscopy of an object to be measured such as animals and plants using an optical system having an extremely shallow depth of focus. This is because when spot light with a small diameter is irradiated on the object to be measured, the amount of light decreases and darkens at positions other than the position where the spot light is condensed, so that the focus position of the spot light and the focus position of the detection system are focused. Without it, no image was formed. Utilizing this fact, it is used for detecting the shape of very fine irregularities such as surface roughness.

(Problems to be solved by the invention) Shape recognition by the stereo method, the photometric stereo method or the light section method requires precision in the position between cameras or the positional relationship between the camera and the light source, and is limited to the detection target. And the time required for image processing is enormous. Also,
Since the measurement light is applied to the measurement object, if the measurement object has a large specular reflection, for example, a metal, the intensity of the reflected light from the measurement object is extremely large, and the shape of the measurement object is reduced. Measurement becomes impossible.

Since scanning laser microscopes use small spots,
This must be scanned, and a large amount of time is required to detect a wide range. In addition, since the measurement light is applied to the measurement target similarly to the other measurement and detection methods described above, the intensity of the reflected laser light is extremely large for the measurement target having a large regular reflection light such as a metal. As a result, the shape of the object to be measured could not be measured.

Therefore, an object of the present invention is to provide a shape recognition device that can measure a shape with high accuracy even if a measured object has a large regular reflection, and that can shorten the inspection time.

[Constitution of the Invention] (Means for Solving the Problems) The present invention is arranged at an illumination light source, a focusing lens for focusing illumination light emitted from the illumination light source, and a focusing position of the illumination light by the focusing lens. A lighting optical component having a light-shielding portion having a predetermined shape in part, and a light-shielding portion of the illumination optical component that irradiates the measurement object with light that has passed through the illumination optical component and is reflected on the measurement object. An imaging lens that captures an image of the shadow of the illumination optical component, which is arranged at an image forming position of the optical component for illumination captured by the imaging lens, has a light shielding portion having the same shape as the light shielding portion of the optical component for illumination, and A detection optical component disposed at an optically conjugate position with the light-shielding portion of the illumination optical component so as to overlap an image of the light-shielding portion of the illumination optical component; and detecting a light intensity passing through the detection optical component. With multiple photodetectors An optical system, the object to be measured XYZ
A moving mechanism capable of moving in the direction, and measuring means for moving the optical system and the moving mechanism with respect to each other to determine the shape of the object to be measured from a position where the light intensity detected by the photodetector is a minimum value. It is a recognition device.

(Operation) By providing such means, the illumination light emitted from the illumination light source of the optical system is focused by the focusing lens,
The object to be measured is illuminated by the imaging lens through the illumination optical component, and the image of the light-shielding portion of the illumination optical component reflected on the object to be measured is captured by the imaging lens, passes through the detection optical component, and is illuminated. Light is received by the detector.

At this time, the shape of the measured object is obtained from the position where the optical system and the measured object are moved relative to each other and the light intensity detected by the photodetector becomes a minimum value.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a shape recognition device. The XYZ table 1 is composed of an XY table 2 and a Z table 3, and an object 4 to be measured is placed on the Z table 3.

An optical system 10 is arranged above the XYZ table 1. The optical system 10 includes an illumination light source 11.
This illumination light source 11 is composed of a semiconductor laser. On the optical axis of the illumination light emitted from the illumination light source 11, that is, the semiconductor laser light, a cylindrical lens 12 and an illumination optical component 13 are arranged. The illumination optical component 13 is arranged at a focusing position of the focusing lens 12.

As shown in FIG. 2, the illumination optical component 13 is formed by forming a rectangular window 15 in an optical component plate 14 and extending a thin line 16 in the longitudinal direction of the window 15. The illumination optical component 13
As shown in FIG. 3, a plurality of, for example, three fine wires 17 may be stretched in parallel.

On the optical axis of the illumination light source 11, a half mirror 18 is arranged. An imaging lens 19 is arranged in a reflection direction of the half mirror 18, and a detection optical component 20 and a photodetector 21 are arranged in a direction opposite to the reflection direction.

The imaging lens 19 converges the light of the optical component reflected by the half mirror 18 and irradiates the light to the measured object 4, and at this time, captures an image of the illumination optical component reflected on the measured object 4 and detects the image of the optical component for detection 20. Is imaged on the arrangement side of.

As shown in FIG. 4, the detection optical component 20 is an optical component plate 21.
A rectangular window 22 is formed in the
It is the one with As shown in FIG. 5, the detection optical component 20 may have a plurality of, for example, three thin wires 24 stretched in parallel.

By the way, the illumination optical component 13 and the detection optical component
20 is arranged at a conjugate position via an imaging lens 19, and is arranged such that the thin wires 16, 23 of these optical components 13, 20 overlap. That is, when the image of the illumination optical component 13 is reflected on the measured object 4 and this image is captured by the imaging lens 19 and formed on the detection optical component 20, the thin line 16 of the formed image is detected. The illumination optical component 13 and the detection optical component 20 are arranged in a direction in which the thin wire 23 of the optical component 20 overlaps.

The photodetector 21 receives light that has passed through the detection optical component 20 and outputs an electric signal corresponding to the intensity of the received light. Specifically, it is composed of a CCD (solid-state imaging device) line sensor, area sensor, and the like.

The electric signal output from the photodetector 21 is
Has been sent to The measurement circuit 22 issues a scanning command S to the XYZ table 1 to scan and move the XYZ table 1 and issues an elevating command H to move the Z table 3 up and down. This state is detected by the photodetector 21. It has a function of obtaining the three-dimensional shape of the measured object 4 from the position where the received light intensity has the minimum value.

Next, the operation of the apparatus configured as described above will be described.

The illumination light emitted from the illumination light source 11 is converged by the cylindrical lens 12, passes through the illumination optical component 13, and reaches the half mirror 18 as optical component light. The optical component light is reflected by the half mirror 18, is converged by the imaging lens 19, and is irradiated on the measured object 4, and an image of the detection optical component 13 is formed on the measured object 4. The image of the detection optical component 13 passes through the imaging lens 19 and the half mirror 18 and is formed again at the position of the detection optical component 20. And optical components for detection
Light that has passed through 20 is received by photodetector 21.

Here, as shown in FIG. 6, lines a, b, and c indicating the relative position shift between the measured object 4 and the optical system 10 are set,
If line b is in focus, each remaining line a,
Assume that c is out of focus.

The light reflected by the line b reaches the detection optical component 20 through the imaging lens 19 and the half mirror 18. in this case,
Since the image is focused, the image of the illumination optical component 13 is formed on the detection optical component 20, and the thin line 16 of the detection optical component 13 and the thin line 23 of the detection optical component 20 overlap. Therefore, the light detector
The light intensity received by 21 is the lowest,
The level of the electric signal output from is the lowest.

On the other hand, the light reflected by the line a forms an image on the photodetector 21 side of the detection optical component 20. For this reason, the light that goes around the thin wire 23 of the detection optical component 20 enters the photodetector 21. Therefore, the intensity of light received by the photodetector 21 increases.

The light reflected by the line c forms an image on the half lens 18 side of the detection optical component 20. For this reason, as in the case of the line a, the light that has passed around the thin wire 23 of the optical component for detection 20 enters the photodetector 21. Therefore, the intensity of light received by the photodetector 21 increases.

However, as shown in FIG. 7, the relationship between the displacement of the relative position of the object 4 and the optical system 10 and the output of the photodetector 21 is such that when the imaging lens 19 with respect to the object 4 is in focus, Detector
21 has the lowest output level.

Therefore, by changing the relative position between the measured object 4 and the optical system 10, for example, by moving the measured object 4 up and down by the Z table 3, the position at which the output of the photodetector 21 becomes lowest is detected. A position is required.

Next, the operation of shape recognition using the above-described method of detecting the focal point will be described.

The measurement circuit 22 issues a movement command to the XYZ table 1 to position the measured object 4. That is, XY table 2
Moves in the X and Y directions, and places the measured object 4 below the optical system 10. Next, the XY table 2 is moved, for example, in the Y direction to move the image forming position of the optical system 10 as shown in FIG.
Position at the end points (a) of a and 4b. Next, the measurement circuit 22 issues an elevation command H to the Z table 3. As a result, the Z table 3 moves up and down.

In this state, the illumination light emitted from the illumination light source 11 is converged by the cylindrical lens 12, reaches the half mirror 18 through the illumination optical component 13, is reflected by the half mirror 18, is converged by the imaging lens 19, and is received. The measurement object 4 is irradiated. Then, the reflected light from the measured object 4 reaches the detection optical component 20 through the imaging lens 19 and the half mirror 18 again. Then, when the focal point is reached by elevating and lowering the measured object 4, the output level of the photodetector 21 becomes the lowest. Then the measurement circuit
22 issues an X-direction scanning command S to the XY table 2. Thus, when the object 4 moves in the X direction, the measuring circuit 22 moves up and down the Z table 3 to find a position where the output of the photodetector 21 becomes minimum. As a result, the measurement circuit
22 recognizes the shape at the end point (a) as shown in FIG.

Next, the measurement circuit 22 moves the XY table 2 at a constant pitch in the Y direction and positions it at the position (b). Next, the measuring circuit 22
An elevation command H is issued to the table 3. As a result, the Z table 3 moves up and down. However, similarly to the operation in the case of the end point (a), the measured object 4 moves up and down, and when the object 4 comes to a focal point, the output level of the photodetector 21 becomes the lowest. Then, the measurement circuit 22 issues a scan command S in the X direction to the XY table 2. Thus, when the object 4 moves in the X direction, the measuring circuit 22 moves up and down the Z table 3 to find a position where the output of the photodetector 21 becomes minimum. As a result, the measuring circuit 22 recognizes the shape at the position (b) as shown in FIG.

Next, the measuring circuit 22 moves the XY table 2 at a constant pitch in the Y direction and positions it at the position (c), and the measuring circuit 22 operates as shown in FIG. Recognize the shape at the position (c).

Thus, the measurement circuit 22 recognizes the three-dimensional shape of each of the measured objects 4a and 4b.

As described above, the illumination optical component 13 and the detection optical component 20 having the fine lines 16 and 23 are provided, and the optical system 10 and the object 4 are moved with respect to each other to detect the light detected by the photodetector 21. Since the shape of the measured object 4 is obtained from the position where the intensity becomes the minimum value, the focus is easily detected by detecting the lowest light intensity, that is, the position of the measured object 4 can be easily detected, and further scanning is performed. Thereby, the three-dimensional shape of the measured object 4 can be recognized. Further, since the illumination optical component 13 and the detection optical component 20 having the fine wires 16 and 23 are used, the measured object 4 has a large specular reflection light, for example, a solder, a metal, or a mirror surface. Even when the dark portions of the fine lines 16 and 23 are superimposed, the three-dimensional shape can be recognized with high accuracy. Can be recognized.

Next, a modified example of the present invention will be described with reference to FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

On the optical axis of the illumination light source 11, an optical lens 30 and a cylindrical lens 31 are provided.
And an illumination optical component 13, and an optical scanner 32 is arranged on the optical path of the light passing through the illumination optical component 13. The optical scanner 32 rotates in the direction of the arrow (d) to scan the illumination light on the surface of the measured object 4. An optical scanner is located on the reflected light path of the half mirror 18.
A detection optical component 20 and a photodetector 34 are disposed on the reflected light path of the optical scanner 33. The optical scanner 33 rotates in the direction of the arrow (e) in synchronization with the optical scanner 32. The light detector 34 is a CCD one-dimensional sensor in which a plurality of light detectors are arranged.

With such a configuration, the illumination light emitted from the illumination light source 11 passes through the optical lens, the cylindrical lens, and the illumination optical component 13, reaches the optical scanner 32 as optical component light, and is scanned by the optical scanner 32. . This scanned optical component light is transmitted through the half mirror 18 and the imaging lens
The light is converged by 19 and radiated onto the measured object 4. The reflected light from the object 4 is reflected by the half mirror 18 and scanned by the optical scanner 33. Then, the scanned light is incident on the photodetector 34. On the other hand, the measured object 4 is moved up and down together with the scanning of the optical component light. Therefore, the three-dimensional shape of the measured object 4 is obtained by detecting the position where the output of the photodetector 34 is maximum.

As described above, according to the second embodiment, the speed of shape recognition can be increased.

The present invention is not limited to the above embodiments, and may be modified without departing from the gist thereof. For example,
The illumination light source 11 is not limited to a semiconductor laser, but may be a laser diode. When the shape is recognized, the optical system 10 may be moved up and down instead of moving the object 4 up and down in the Z direction.

A third embodiment will be described below. The configuration of the apparatus is the same as that of FIG. The difference between the third embodiment and the first embodiment lies in the configuration of the illumination optical component 13 and the detection optical component 20. In contrast to the first embodiment in which a light shielding portion is provided for both optical components, in the third embodiment, instead of this, FIGS.
Each slit is provided as shown in the figure. The effect of this is that the same effect as in the first embodiment can be obtained only by inverting the brightness of the image. Of course, FIG.
As shown in FIG. 16, a plurality of slits may be received.

[Effects of the Invention] As described above in detail, according to the present invention, a detection optical component having a light-shielding portion having the same shape as the light-shielding portion of the illumination optical component is optically connected to the light-shielding portion of the illumination optical component. With a simple configuration in which it is arranged at the conjugate position so as to overlap the image of the light-shielding part of the illumination optical component, even if the measured object has a large regular reflection, the three-dimensional shape can be recognized with high accuracy, and this three-dimensional shape can be recognized. And a shape recognition device that can speed up recognition of the object.

[Brief description of the drawings]

1 to 11 show a first embodiment of a shape recognition device according to the present invention.
FIG. 1 is a diagram for explaining an embodiment, FIG. 1 is a configuration diagram,
2 and 3 are configuration diagrams of optical components for illumination, FIGS. 4 and 5 are configuration diagrams of optical components for detection, FIG. 6 is a schematic diagram showing a focal point, and FIG. 7 is a photodetector. 8 to 11 are diagrams for explaining the operation of shape recognition, and FIGS.
FIG. 13 is a block diagram showing a second embodiment of the present invention, and FIGS.
The figure is an external view of the slit. 1 ... XYZ table, 4 ... Measurement object, 10 ... Optical system, 1
1 ... Illumination light source, 12 ... Cylindrical lens, 13 ... Optical parts for illumination, 15 ... Window, 16 ... Fine wire, 18 ... Half mirror, 19
... Imaging lens, 20 optical components for detection, 21 photodetector, 22 measurement circuit.

Claims (2)

(57) [Claims] An illumination light source, a converging lens for converging illumination light emitted from the illumination light source, and a light-shielding portion of a predetermined shape arranged at a position where the illumination light is converged by the converging lens and partially provided An illumination optical component, and an imaging lens that irradiates the object to be measured with light that has passed through the illumination optical component and captures an image of a shadow of a light-shielding portion of the illumination optical component reflected on the object to be measured. A light-shielding portion having the same shape as a light-shielding portion of the illumination optical component is formed at an image forming position of the illumination optical component imaged by an imaging lens, and the light-shielding portion of the illumination optical component is optically connected to the optical component. And a plurality of photodetectors for detecting the intensity of light passing through the detection optical component, the detection optical component being disposed at a conjugate position so as to overlap the image of the light shielding portion of the illumination optical component. An optical system; A moving mechanism capable of moving the fixed object in the XYZ directions, and moving the optical system and the moving mechanism to each other to change the shape of the measured object from a position where the light intensity detected by the photodetector is a minimum value. A shape recognizing device, comprising: a measuring unit to be obtained; 2. The shape recognition apparatus according to claim 1, wherein each of the light-shielding portions of the illumination optical component and the detection optical component is formed of at least one thin line.