JPH04142410A - Shape recognizing device - Google Patents

Abstract

PURPOSE:To measure the shape with high precision by focusing the illumination light radiated from the illumination light source of an optical system with a focusing lens. CONSTITUTION:An illuminating optical component 13 and a detecting optical component 20 with fine lines 16, 23 are provided, an optical system 10 and a measured object 4 are relatively moved, the shape of the measured object 4 is obtained from the position where the light intensity detected by a light detector 21 becomes the minimum value, the focal point, i.e., the position of the measured body 4, can be easily detected by the detection of the lowest light intensity, and the three-dimensional shape of the measured object 4 can be recognized by further performing a scan. The illuminating optical component 13 and detecting optical component 20 with fine lines 16, 23 are used, even if the measured object 4 is an object with large forward reflected light, e.g., solder, metal or a mirror, to extremely increase the forward reflected light quantity, the three-dimensional shape can be precisely recognized when dark portions of the fine lines 16, 23 are overlapped, and the three-dimensional shape can be recognized even if copper Cu and aluminum Al are mixed on the surface and the reflection coefficient distribution on the surface differs.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a shape recognition device.

(Prior art) Methods for recognizing shapes include a stereo method using two cameras, a photometric stereo method that calculates the inclination of a surface from the intensity of scattered light from multiple lights, and a method that projects a slit light and calculates its optical cutting line. There are ways to recognize shapes from

Further, a scanning laser microscope is a typical example of recognizing the shape of an object using confocal light. This scanning laser microscope was developed to perform tomographic observation of objects to be measured, such as animals and plants, using an optical system with an extremely shallow depth of focus. This is because when a spot light with a minute diameter is irradiated onto the object to be measured, the light intensity decreases and becomes dark in areas other than the spot where the spot light is condensed, so the focal position of the spot light and the focal position of the aspect ratio system are in focus. Otherwise, the image would not form. This fact is used to detect the shape of very fine irregularities such as surface roughness.

(Problems to be Solved by the Invention) Shape recognition using the stereo method, photometric stereo method, or optical section method requires precision in the position of the cameras or the positional relationship between the camera and the light source, and is limited to the detection target. It takes a while,
The time required for image processing is also enormous. In addition, since the measurement light is irradiated onto the object to be measured, if the object to be measured has a large specular reflection, for example a metal, the intensity of the reflected light from the object to be measured will be very large. The shape becomes unmeasurable.

Since a scanning laser microscope uses a minute spot, it must be scanned, and it takes a lot of time to detect a wide area. In addition, as in the other measurement detection methods mentioned above, the measurement light is irradiated onto the object to be measured, so the intensity of the reflected laser beam is extremely high for objects to be measured that have large specular reflections, such as metals. Therefore, the shape of the object to be measured could not be measured.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a shape recognition device that can measure the shape of an object to be measured with high precision even if it has a large specular reflection, and can shorten the inspection time.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes an illumination light source, a focusing lens that focuses illumination light emitted from the illumination light source, and a focusing lens arranged at a position where the illumination light is focused by the focusing lens. , and a part of the illumination optical component has a light shielding part of a predetermined shape, and a light shielding part of the illumination optical component that irradiates the object to be measured with the light that has passed through the illumination optical component and is reflected on the object to be measured. an imaging lens that captures an image of the shadow of an optical system having a detection optical component formed with a detection optical component, a photodetector that detects the intensity of light that has passed through the detection optical component, a moving mechanism capable of moving the object to be measured in the XYZ directions, an optical system and The shape recognition apparatus includes a measuring means for determining the shape of the object to be measured from a position where the light intensity detected by a photodetector is a minimum value by mutually moving a moving mechanism. In this case, the light shielding portions of the illumination optical component and the detection optical component are formed of at least one thin wire.

The present invention also provides an illumination light source, a focusing lens that focuses the illumination light emitted from the illumination light source, and a slit that is disposed at a position where the illumination light is focused by the focusing lens and has a slit of a predetermined shape in a part. An illumination optical component, an imaging lens that irradiates the object to be measured with the light that has passed through the illumination optical component and captures an image of the shadow of the light-shielding portion of the illumination optical component reflected on the object to be measured, and the imaging lens. A detection optical component disposed at the image formation position of the illumination optical component captured by the lens and having a slit formed in the same shape and optically conjugate position as the slit of the illumination optical component; and this detection optical component. an optical system having a photodetector that detects the intensity of light that has passed through the object, a moving mechanism that can move the object to be measured in the XYZ directions, and a moving mechanism that moves the optical system and the moving mechanism mutually to detect the intensity of light that is detected by the photodetector. The present invention is a shape recognition device that includes a measuring means for determining the shape of an object to be measured from a position where the light intensity is at a minimum value. In this case, the slits of the illumination optical component and the detection optical component are configured with at least one thin linear shape.

(Function) By providing such a means, the illumination light emitted from the illumination light source of the optical system is focused by the focusing lens, passes through the illumination optical component, and is irradiated onto the object to be measured by the imaging lens. An image of the light blocking portion or slit of the illumination optical component reflected on the object to be measured is captured by an imaging lens, passes through the detection optical component, and is received by a photodetector. At this time, the optical system and the object to be measured are moved relative to each other, and the shape of the object to be measured is determined from the position where the light intensity detected by the photodetector has a minimum value.

(Example) Hereinafter, a first example of the present invention will be described with reference to the drawings.

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

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

As shown in FIG. 2, this illumination optical component 13 has a rectangular window 15 formed on an optical component plate 14, and a thin wire 16 stretched in the longitudinal direction of the window 15.

Note that this illumination optical component 13 may include a plurality of thin wires 17, for example, three thin wires 17 stretched in parallel as shown in FIG.

A half mirror 18 is arranged on the optical axis of the illumination light source 11. An imaging lens 19 is arranged in the reflection direction of the half mirror 18, and a detection optical component 2o and a photodetector 21 are arranged in a direction opposite to the reflection direction of the parentheses.

The imaging lens 19 focuses the optical component light reflected by the half mirror 18 and irradiates it onto the object to be measured 4 , and at the same time captures an image of the illumination optical component reflected on the object to be measured 4 and sends it to the detection optical component 20 . The image is formed on the side where the

The detection optical component 20 is mounted on an optical component plate 2 as shown in FIG.
A rectangular window 22 is formed in 1, and a thin wire 23 is stretched in the longitudinal direction of this window 22.

Note that this detection optical component 20 may include a plurality of thin wires 24, for example, three thin wires 24 stretched in parallel as shown in FIG.

By the way, the illumination optical component 13 and the detection optical component 14 are arranged at a conjugate position via the imaging lens 19,
In addition, these optical components 13, 14 are arranged so that each of the thin lines 16, 23 overlaps with each other. That is, an image of the illumination optical component 13 is reflected on the object to be measured 4, and this image is reflected on the imaging lens 19.
When the image is captured by and formed on the detection optical component 20, the illumination optical component 13 and the detection optical component 20 are moved in the direction in which the thin line 16 of this imaged image and the thin line 23 of the detection optical component 20 overlap. is located.

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

The electrical signal output from this photodetector 21 is transmitted to the measuring circuit 2.
It's happening on 2. This measurement circuit 22 issues a scan command S to the XYZ table 1 to scan and move the XYZ table 1, and issues a lift command H to move the Z table 3 up and down, and this state is detected by the photodetector 21. It has a function of determining the three-dimensional shape of the object to be measured 4 from the position where the received light intensity is the minimum value.

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

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

Here, as shown in FIG. 6, each line aSb indicates a deviation in relative position between the object to be measured 4 and the optical system 10.

C is set, and when line b is in focus, the remaining lines a and C are out of focus.

The light reflected on line b passes through the imaging lens 19 and the half mirror 18 and reaches the detection optical component 20. In this case, since the focus is correct, 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 intensity of the light received by the photodetector 21 is the lowest, and the level of the electrical signal output from the photodetector 21 is the lowest.

On the other hand, the light reflected from line a forms an image on the photodetector 21 side of the detection optical component 20. For this reason, the detection optical component 2
The light that has passed around the zero thin wire 23 is incident on the photodetector 21. Therefore, the intensity of light received by the photodetector 21 becomes high.

Further, the light reflected on the line C forms an image on the half lens 18 side of the detection optical component 20. Therefore, as in the case of line a, the light that has gone around the thin wire 23 of the detection optical component 20 is incident on the photodetector 21.

Therefore 1. The intensity of light received by the photodetector 21 increases.

However, the relationship between the relative positional deviation of the object to be measured 4 and the optical system 10 and the output of the photodetector 21 is as shown in FIG. The output level of the detector 21 becomes the lowest.

Therefore, by changing the relative position between the object to be measured 4 and the optical system 10, for example by moving the object to be measured 4 up and down by the Z table 3, and by detecting the position where the output of the photodetector 21 is the lowest, the in-focus point can be determined. location is required.

Next, the effect of shape recognition using the above-described in-focus point position detection method will be explained.

The measurement circuit 22 issues a movement command to the XYZ table 1 to position the object 4 to be measured. That is, the XY child table moves in the X and Y directions, and the object to be measured 4 is moved into the optical system 10.
Place it below. Next, the XY child table is moved, for example, in the Y direction to position the imaging position of the optical system 10 at the end point (A) of the object to be measured 4a, 4b, as shown in FIG. Next, the measurement circuit 22 issues a lift 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 focused by the cylindrical lens 12, passes through the illumination optical component 13, reaches the half mirror 18, is reflected by the half mirror 18, is focused by the imaging lens 19, and is focused by the imaging lens 19. The measurement object 4 is irradiated. Then, the reflected light from the object to be measured 4 passes through the imaging lens 19 and the nozzle mirror 18 again, and then passes through the detection optical component 2.
Reach 0. Then, when the object to be measured 4 moves up and down to reach a focused point, the output level of the photodetector 21 becomes the lowest.

Then, the measurement circuit 22 issues a scanning command S in the X direction to the XY child table. Thus, when the object to be measured 4 moves in the X direction, the measurement circuit 22 moves the Z table 3 up and down to find the position where the output of the photodetector 21 is the smallest. As a result, the measuring circuit 22 recognizes the shape at the end point (a) as shown in FIG.

Next, the measuring circuit 22 moves the XY child table by a fixed pitch in the Y direction and positions it at position (B). Next, the measurement circuit 22
issues a lift command H to the second table 3. This allows Z
Table 3 moves up and down.

However, the object to be measured 4 moves up and down in the same way as in the case of the above-mentioned end point (a), and when it comes to a focused point, the output level of the photodetector 21 becomes the lowest. Then, the measurement circuit 22 issues a scanning command S in the X direction to the XY child table. Thus, when the object to be measured 4 moves in the X direction, the measuring circuit 22 moves the two tables 3 up and down to find the position where the output of the photodetector 21 is the smallest. As a result, the measuring circuit 22 recognizes the shape at position (b) as shown in FIG.

Next, the measuring circuit 22 moves the XY child table a fixed pitch in the Y direction to determine the position (C), and the measuring circuit 22 operates in the same manner as in the case of the above-mentioned end point (B) as shown in FIG. Yonii place! Recognize the shape in (c).

Thus, the measurement circuit 22 is connected to each measured object 4a.

Recognize the three-dimensional shape of 4b.

In this way, in the first embodiment, the thin wire 16.23
An illumination optical component 13 and a detection optical component 20 are provided, and the optical system 1o and the object to be measured 4 are moved relative to each other, and the object to be measured is moved from the position where the light intensity detected by the photodetector 21 is the minimum value. Since the shape of the object 4 is determined, the focused point, that is, the position of the object 4 to be measured, can be easily detected by detecting the lowest light intensity, and by further scanning, the three-dimensional shape of the object 4 to be measured can be determined. can be recognized. Also, thin line 16.
An illumination optical component 13 and a detection optical component 2 having 23
Since 0 is used, the object to be measured 4 or one with large specular reflection light,
For example, even if the amount of specularly reflected light is extremely large on solder, metal, or mirror surfaces, three-dimensional shapes can be recognized with high precision by overlapping the dark parts of thin lines 16. A three-dimensional shape can be recognized even if the surface reflectance distribution is different.

Next, a second embodiment of the present invention will be described with reference to a configuration diagram of a shape recognition device shown in FIG. Note that the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

An optical lens 30, a cylindrical lens 31, and an illumination optical component 13 are arranged on the optical axis of the illumination light source 11, and an optical scanner 32 is placed on the optical path of the light that has passed through the illumination optical component 13.
is located. This optical scanner 32 is indicated by the arrow (d)
The illumination light is rotated in the direction to scan the surface of the object 4 to be measured.

Further, an optical scanner 3 is installed on the reflected optical path of the half mirror 18.
3 are arranged, and a detection optical component 2o and a photodetector 34 are arranged on the reflected optical path of this optical scanner 33.

The optical scanner 33 synchronizes with the optical scanner 32 and moves the arrow (
It is designed to rotate in the (po) direction. The photodetector 34 is a one-dimensional CCD sensor.

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, and reaches the optical scanner 32 as optical component light,
This optical scanner 32 scans. This scanned optical component light passes through the half mirror 18, is focused by the imaging lens 19, and is irradiated onto the object 4 to be measured. This reflected light from the object to be measured 4 is reflected by the half mirror 18 and scanned by the optical scanner 33.

This scanned light then enters the photodetector 34. On the other hand, the object to be measured 4 is raised and lowered as the optical component light scans. Therefore, the three-dimensional shape of the object to be measured 4 can be determined by detecting the position where the output of the photodetector 34 is minimum.

In this way, according to the second embodiment, shape recognition can be speeded up.

Note that the present invention is not limited to the above embodiments, and may be modified without departing from the spirit thereof. For example, the illumination light source 11 may be a laser diode instead of a semiconductor laser. Further, when recognizing the shape, the object to be measured 4 is not limited to being raised and lowered to zz5r8, but the optical system 10 may be raised and lowered.

Further, a third embodiment will be shown below. The configuration of the device is the same as that shown in FIG. 1, so a description thereof will be omitted. The difference between the third embodiment and the first embodiment lies in the configurations of the illumination optical component 13 and the detection optical component 20. While in the first embodiment both optical components were provided with light shielding parts, in the third embodiment, slits were provided in each of them as shown in FIGS. 13 and 14 instead. This effect is similar to that of the first embodiment except that the brightness and darkness of the image is reversed. Of course, a plurality of slits may be provided as shown in FIGS. 15 and 16.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a shape recognition device that can measure the shape of an object with high precision even if the object to be measured has a large specular reflection.

[Brief explanation of the drawing]

1 to 11 are diagrams for explaining a first embodiment of a shape recognition device according to the present invention, in which FIG. 1 is a configuration diagram, and FIGS. 2 and 3 are diagrams of illumination optical components. 4 and 5 are configuration diagrams of the detection optical components, FIG. 6 is a schematic diagram showing the focusing point, FIG. 7 is a diagram showing the 8 forces of the photodetector, and FIG.
Figures to Figures 11 are diagrams for explaining the effect of shape recognition,
FIG. 12 is a configuration diagram showing a second embodiment of the present invention, and FIGS. 13 to 16 are external views of the slit. 1...XYZ table, 4. Object to be measured, 10 optical system,
11... Illumination light source, 12... Cylindrical lens, 13...
・Optical components for illumination, 15...window, 16...thin wire, 1
8...Half mirror-19...Imaging lens, 20...
Detection optical component, 21... photodetector, 22... measurement circuit.

Claims (4)

[Claims] (1) An illumination light source, a focusing lens that focuses the illumination light emitted from the illumination light source, and an illumination device that is arranged at a position where the illumination light is focused by the focusing lens, and that has a light shielding part of a predetermined shape in part. an optical component, an imaging lens that irradiates the object to be measured with the light that has passed through the illumination optical component and captures an image of the shadow of the light-blocking portion of the illumination optical component that is reflected on the object; and the imaging lens. a detection optical component disposed at the imaging position of the illumination optical component imaged by the illumination optical component, and having a light shielding portion formed at a position that is the same shape and optically conjugate as the light shielding portion of the illumination optical component; an optical system having a photodetector that detects the intensity of light that has passed through an optical component; a moving mechanism capable of moving the object to be measured in the XYZ directions; A shape recognition device comprising: a measuring means for determining the shape of the object to be measured from a position where the light intensity detected by a photodetector has a minimum value. (2) Claim (2) wherein the light shielding portions of the illumination optical component and the detection optical component are formed of at least one thin wire.
1) The shape recognition device described above. (3) An illumination light source, a focusing lens that focuses the illumination light emitted from the illumination light source, and an illumination optical system that is disposed at a position where the illumination light is focused by the focusing lens and that has a slit of a predetermined shape in a part. an imaging lens that irradiates the object to be measured with the light that has passed through the illumination optical component and captures an image of the shadow of the light-shielding portion of the illumination optical component that is reflected on the object; a detection optical component disposed at the imaging position of the imaged illumination optical component and having a slit formed in the same shape and optically conjugate position as the slit of the illumination optical component; and this detection optical component an optical system having a photodetector that detects the intensity of light passing through the object; a moving mechanism capable of moving the object to be measured in XYZ directions; and a moving mechanism that moves the optical system and the moving mechanism mutually to detect the photodetector. A shape recognition device comprising: measuring means for determining the shape of the object to be measured from a position where the light intensity detected by the method has a minimum value. (4) Claim (3) wherein the illumination optical component and the detection optical component have at least one narrow linear slit.
The shape recognition device described.