JP3414145B2 - 3D shape measurement method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines a distance to an object by forming a light cutting line on the surface of the object, imaging the light cutting line with an image input device, and applying the principle of triangulation. The present invention relates to the three-dimensional shape measuring method described above.

[0002]

2. Description of the Related Art Conventionally, a method of measuring a three-dimensional shape of an object by a light cutting method has been proposed. In this type of light cutting method, one light cutting line is formed on an object, and this light cutting line is imaged by an image input device such as a TV camera to apply the principle of triangulation to the object. Find the distance. When measuring a three-dimensional shape, the positional relationship between the object and the light cutting line is relatively changed in the direction intersecting the light cutting line (usually the object is moved), and the measurement is performed at a plurality of points. is there.

A TV camera used as an image input device is set to have an image pickup time interval of 1/60 second or the like. If this time interval is T and the relative moving speed between the object and the light section line is V, the images obtained by the image input device are images in which the object is moved by VT. That is,
The distance to the object at the position where the object is divided by VT in the moving direction is obtained. As described above, the resolution in the moving direction of the object cannot be set to VT or less with only one light cutting line to improve the resolution. That is, when the object moves at high speed, the shape of the object cannot be measured at multiple points.

On the other hand, as in the technique disclosed in Japanese Patent Laid-Open No. 3-138507, a plurality of light cutting lines are formed on an object and the plurality of light cutting lines are formed by one image input device. Imaging at the same time is considered.

[0005]

However, the one disclosed in the above-mentioned publication is to store the image picked up by the image input device in the frame memory and then read it out to calculate the distance. It takes time to write and read images,
There is a problem that the processing time becomes relatively long.

The present invention has been made in view of the above circumstances, and an object of the present invention is not to calculate the distance based on the image stored in the frame memory but to directly obtain the distance from the image captured by the image input device. The other purpose is to reduce the processing time.The other purpose is to increase the resolution by measuring at multiple points even when the object moves at a relatively high speed, and another purpose is to remove the vibration component accompanying the transportation of the object. Therefore, the present invention is intended to provide a three-dimensional shape measuring method that can improve the measurement accuracy.

[0007]

According to a first aspect of the present invention, a light cutting line is formed on the surface of an object by light from a light source, and the light cutting line is imaged by using an image input device. In a three-dimensional shape measuring method for obtaining the distance to an object using, the pixel densities are sequentially read out in the direction intersecting the image of the light cutting line formed on the light receiving surface of the image input device, and the pixels before and after in the reading order are read. Pixels having the maximum density are obtained by comparing the densities of the two, and the distance to the object is calculated based on the position of the pixel having the maximum density on the light-receiving surface. per in stores
A plurality of optical cutting lines parallel to each other on the reference plane and
Optically cut objects on a reference plane by forming them at regular intervals
Transport in the direction that intersects the line, and
The interval is the time interval for imaging with the image input device and the object
Be a rational multiple of the product of the transmission speed and a non-integer multiple
Set this and express this multiple in fractions
The denominator when it is divided by a number and divided into a number
It is a number .

According to this method, the density of pixels is read out from the image input device and the density of the object is read from the image input device instead of obtaining the distance to the object after storing the image of the optical cutting line captured by the image input device in the frame memory. Since the distance can be calculated and the calculated distance can be stored in the memory, the frame memory is not required and the memory amount can be reduced, and the time for writing and reading to and from the frame memory is also unnecessary. The time can be shortened.

[0009]

In addition, as will be described later, the distance of each part in the transport direction of the object is measured with a resolution of 1 / the number of optical cutting lines with respect to the distance traveled by the object during the time interval of imaging by the image input device. can do. Therefore, accurate distance measurement (height measurement) can be performed even for an object that is conveyed at a relatively high speed. The invention of claim 2 is based on the invention of claim 1.
Akira smell Te, based on the light section line formed on the object to be placed on standard on standards plane, to set the inspection area within a range that does not overlap the adjacent light section line, the light section of the inspection area The distance to the object is calculated based on the line.

[0011]

The invention of claim 3 is the same as the invention of claim 1.
Te, provided with a plurality of images input device is to shift the imaging timing of the image input device for a certain time.

The invention of claim 4 resides in the invention of claim 1.
Then, each light cutting line has a plurality of light colors, and each light cutting line having a different light color is individually imaged by a plurality of image input devices provided with filters that individually pass light of each light color. Contract
Invention Motomeko 5 invention smell of claim 1 Te, the light section line is different light colors from each other, the distance is taken out optical cutting line has been captured by the image input device having the color TV camera for each color signal To ask.

According to a sixth aspect of the invention, in the first aspect of the invention, the light cutting line is formed by irradiating light from a direction obliquely intersecting with the reference plane, and the reference plane is formed. A three-dimensional shape measuring method for imaging a light cutting line by an image input device having optical axes in a direction orthogonal to each other, wherein light sources arranged on both sides of a plane including the optical axis of the image input device along the light cutting line are mutually separated. The light cutting lines are formed by irradiating light of different light colors, and the light cutting lines picked up by the image input device including the color TV camera are extracted for each color signal to obtain the distance.

According to a seventh aspect of the invention, in the first aspect of the invention, a light cutting line is formed by irradiating light from a direction obliquely intersecting the reference plane, and the reference plane is formed. A three-dimensional shape measuring method for imaging a light cutting line with an image input device having optical axes in orthogonal directions, wherein the light source is arranged alternately on both sides of a plane including the optical axis of the image input device and along the light cutting line. The light cutting line is formed by irradiating the light on the light, and the light cutting line imaged by one image input device is extracted for each light from each side with respect to the plane to obtain the distance.

The invention of claim 8 is the same as the invention of claim 1.
Then , according to the range of the distance to be measured by each light cutting line, the light cutting line is passed through a mirror arranged so that the moving width of the image of the light cutting line on the light receiving surface of the image input device can be made as large as possible. The image is captured by the image input device.

According to a ninth aspect of the present invention, in the eighth aspect of the present invention, an optical path length adjusting means is provided for making the optical path lengths from the respective optical cutting lines to the image input device substantially equal. Claim 1
0 of invention, the invention odor Te claim 1, is to image the light section line in the image input apparatus through a convex curved in a plane orthogonal to the optical cutting line.

The invention of claim 11 is based on the invention of claim 1 , wherein the object is conveyed on the reference plane in a direction intersecting the optical cutting line, and the distance to the reference plane changes with time. Then, the vibration component of the reference plane is detected, and the distance change is obtained by removing the distance change of the reference plane due to the vibration component from the measured value of the distance obtained by the optical cutting line. The invention of claim 12 is a contract
In the invention of claim 11 , the vibration component is detected by a displacement sensor separately provided so as to obtain the distance to the reference plane.

According to a thirteenth aspect of the present invention, in the eleventh aspect of the present invention , a light spot is formed on the reference plane by the vibration component, and the light spot is imaged by an image input device together with a light cutting line. It is detected by the distance to the reference plane obtained by the above. According to a fourteenth aspect of the present invention, in the eleventh aspect of the present invention , the vibration component is obtained based on a light cutting line of a portion formed on the reference plane when the light cutting line is formed on the object. It is detected by the distance to the reference plane.

The operation according to the inventions of claims 3 to 14 will be clarified by the respective embodiments described later.

[0021]

DETAILED DESCRIPTION OF THE INVENTION

(Principle) The principle of the triangulation method will be described. Here, in FIG.
As shown in FIG. 1 and FIG. 22, the light receiving optical system 2 is arranged in front of the CCD element 1 by a certain distance (in FIG.
The TV camera 4 including the light receiving optical system 2 is used as an image input device), and slit light is emitted from the light source 3 from a direction intersecting the optical axis of the light receiving optical system 2. In the light receiving optical system 2, the image of the light cutting line formed on the object S by the light source 3 is CC
It is arranged at a position where an image is formed on the light receiving surface of the D element 1. In the plane that is orthogonal to the plane formed by the slit light and includes the optical axis of the light receiving optical system 2, the optical axis direction of the light receiving optical system 2 is the z direction, and the center of the light receiving optical system 2 is the origin and is separated from the CCD element 1. Receiving the light in the right direction, the light receiving optical system 2
It is assumed that the direction orthogonal to the optical axis of is the x direction and the direction from the light receiving optical system 2 to the light source 3 is positive. Considering the right-hand coordinate system, the following relational expression holds. z = D / (cotγ + κ · X) x = κ · X · z y = κ · Y · z where x, y and z are the positions of the points on the cutting line in the coordinate system, and X and Y are the CCD element 1 The position of the image of the cutting line on the light receiving surface in the x direction and the y direction, D is the distance between the center of the light receiving optical system 2 on the x axis and the plane formed by the slit light,
γ is the angle that the slit light makes with the x-axis in the xz plane, and κ is -1 / P, where P is the distance between the CCD element 1 and the center of the light receiving optical system 2 in the z direction. Here, since the distances D and P and the angle γ are known from the design values of the device, x of the image of the light cutting line on the light receiving surface of the CCD element 1 is known.
By obtaining the position coordinates in the y-direction and the y-direction, the coordinates in the above coordinate system can be obtained for each point on the light cutting line formed by the slit light. In each of the following embodiments, the coordinate position of the light cutting line in the real space is obtained from the position of the image of the light cutting line formed on the light receiving surface of the CCD element 1 based on the above-described principle.

(Embodiment 1) In the present embodiment, as shown in FIG. 2, an object S moves on a conveyor C in a certain direction (the above-mentioned x).
Negative direction: indicated by an arrow), and a plurality of (four in the figure) light sources 3 are arranged at constant intervals in the x direction (5VT: where V is the feed speed of the conveyor C, and T is An example is shown in which the CCD elements 1 are arranged at a time interval of imaging. The respective light sources 3 are arranged so as to form slit lights parallel to each other. A laser light source is preferably used as the light source 3, and a slit light is obtained by expanding the beam in one direction using a cylindrical lens or the like. Here, the light source 3 is xy
The reference plane (the upper surface of the conveyor C), which is arranged on a plane parallel to the plane and is used to measure the height of the object S, is also a plane parallel to the xy plane. Therefore, the light cutting line formed on the reference plane by the light source 3 is also equal to the distance between the light sources 3. Further, when the feeding speed of the conveyor C is V, the CCD device 1
Since the time interval of the image capturing is T, the images that are adjacent to each other in time series among the images captured by the CCD element 1 are captured when the conveyor C is advanced by VT. Therefore, the distance between the pair of adjacent light sources 3 is 5 VT.
When, it is necessary to have five images to measure the region between the adjacent light section lines. However, C
The time interval of the image pickup by the CD element 1 is T, but the CCD
The time taken to capture the image captured by the device 1 is sufficiently shorter than T, and the optical cutting line captured by the CCD device 1 is y
It has no substantial inclination to the direction.
The time for capturing an image is the electronic shutter (D
The time for taking out the electric charge of the DC element 1 is limited, and the electric charge after the limited time is discarded) or the mechanical shutter arranged in front of the CCD element 1 regulates the electric charge. CCD element 1
The light receiving optical system 2 is housed in an appropriate casing to form a TV camera 4.

A feature of the present invention is that the coordinates of the optical cutting line are obtained while reading the image without storing the image obtained by the TV camera 4 as an image pickup device in the frame memory, and the obtained coordinates are stored in the memory. Yes, as shown in FIG.
The image signal output from the TV camera 4 is sequentially input to the position calculation unit 5 to obtain the coordinate position of the light cutting line in the real space, and the obtained coordinate position is stored in the memory 6.

The position calculator 5 is a reference plane (of the conveyor C).
The object S is measured after performing the process of obtaining (upper surface).
Perform processing. Because the reference plane is a flat surface without steps
The light cutting line formed on the reference plane becomes a straight line,
On the light-receiving surface of the child 1, an image x of a light section line as shown in FIG.₁~ X_Four
Is formed. Each image x₁~ X_FourIs the light receiving surface of the CCD element 1.
Is formed in the Y direction, and the CCD element 1 rasterizes in the X direction.
The pixel value (density) is read out sequentially and the image is obtained.
Since the signal is obtained, the image x₁~ X_FourThe concentration corresponding to
Each time it is seen, there is a maximum density in the image signal.
It occurs periodically. Therefore, the position calculation unit 5
Received the signal to temporarily store the density of each pixel in the buffer,
The density of the pixel to be input next and the pixel held in the buffer
By comparing the size with that of
To obtain the pixel That is, on the light receiving surface of the CCD element 1,
By obtaining the coordinate value X of the pixel at which the degree becomes maximum,
Statue x₁~ X_FourThe coordinate value X in the x direction of
It As explained in the principle, if the coordinate value X is known,
It is possible to obtain the coordinate value z in the z direction of the reference plane in the real space.
I can do it, so the image x₁When the coordinate value X for
The coordinate value z is calculated and stored in the memory 6.
Similarly, the image x₂~ X_FourAlso for the coordinate value z
Store in memory 6. In this way, for one line in the y direction
About image x₁~ X_FourObtain the coordinate value z of the reference plane from the position
After moving, go one line in the y direction and go to the next line to see the image x ₁~ X_FourPosition of
From this, the coordinate value z of the reference plane is obtained. Then, in the same way
Determine the coordinate value z for a row.

In the above process, the CCD device 1
Each image x on the light receiving surface of₁~ X_FourFind the coordinate value X in the x direction
Therefore, on the surface of the object S based on the coordinate value X
Each image of the light section line when irradiating the slit light x₁'~ X
_FourInspection range D for obtaining the position of ′ (see FIG. 4)₁~
D_FourStipulate. That is, slit light is applied to the surface of the object S.
Image x when illuminated₁'~ X_FourThe moving direction of ′ is to the object S
It can be known by the irradiation direction of the slit light to the
Limit the height from the reference plane to the surface of the object S
If fluffy, the light formed on the surface of the object S by each slit light
Cut line image x₁'~ X_Four′ Is the light formed on the reference plane
Cut line image x₁~ X_FourHow much will you move against
Therefore, the inspection range D should be within the range including the movement range.₁
~ D_FourIs set. Inspection range D₁~ D_FourIs each
Statue x₁~ X_FourThe next image x adjacent to the pixel
₁~ X_FourIs set before the predetermined pixel of. Because of this
Therefore, the height from the reference plane to the surface of the object S can be measured.
The range is limited, but the light section line and the image x₁~ X_FourCorrespondence with
No need to attach. That is, the inspection range D₁~ D_FourThe set
What you do is each image x₁'~ X_Four′ And the optical cutting line
Clarify each image x ₁'~ X_FourCorrespondence between'and the optical cutting line
This is to reduce the amount of processing by eliminating the need for the processing for the case. Well
Inspection range D₁~ D_FourImage of a pair of light-section lines adjacent to each other
₁~ X_FourBetween each pair of adjacent light
Cut line image x₁~ X_FourThe coordinates of each point on the reference plane obtained from
Each inspection range D based on the value z₁~ D_FourStandard flat corresponding to
You can know the inclination of the surface.

The above procedure is summarized as shown in FIG. First, the TV camera 4 captures an image of the reference plane (S
1). To determine the density of each pixel from the CCD 1, the y coordinate is initialized first (S2), is set number of the image x ₁ ~x ₄ a (j) to 1 (S3). Thus CCD
The densities of the pixels of the element 1 are sequentially read in the x direction, and it is determined whether or not the density is a maximum value (S4). When the density becomes maximum, the coordinate value X of the pixel is obtained and stored in the memory 6 (S5). At the same time, the coordinate value z in the z direction in the real space is obtained and stored in the memory 6 together with the coordinate value (x, y) (S6). Next, the number of the image x ₁ ~x ₄ a (j) Increase by 1 (S7), and determines whether the number (j) is within 4 (S8), if not reach the fourth image x ₄ Repeat steps S3 to S8.

When the number (j) exceeds 4 in step S8, the y coordinate is incremented by 1 (S9) and the last line (= M).
Until (S10), steps S3 to S10 are repeated. In this way, the coordinate value X of the images x _{1 to} x ₄ of the light cutting line and the coordinate value z of the light cutting line for all the pixels of the CCD element 1 can be stored in the memory 6. That is, the coordinate value of each point of the light cutting line formed on the reference plane can be obtained. Then, the inspection ranges D _{1 to} D ₄ are determined (S
11).

After storing the information about the reference plane in the memory 6 as described above, the object S is measured. When the surface of the object S is irradiated with the slit light, a step is formed on the light cutting line. Therefore, steps x ₁ ′ to x ₄ ′ formed on the light receiving surface of the CCD element 1 also have steps as shown in FIG. Object S
The process of measuring the height of the is substantially the same as the process of obtaining the coordinate values of the light cutting line formed on the reference plane. However,
When the coordinate value of each point of the light cutting line formed on the surface of the object S is obtained, the coordinate value z having the coordinate value of (x, y) equal to the coordinate value is obtained on the reference plane. Subtracting from the coordinate value z in the z direction of the light cutting line formed on the surface of S, the subtraction result is taken as the height of the object S, and the obtained height is (x,
The difference is that it is stored in the memory 6 together with the coordinate value of y).

That is, since the light cutting line formed on the surface of the object S is displaced in the x direction from the light cutting line formed on the reference plane, a known reference corresponding to the inspection range D _{1 to} D ₄ is obtained. The coordinate value z of the reference plane corresponding to the position of the light cutting line formed on the surface of the object S is obtained based on the inclination of the plane. The coordinate value z corresponding to the coordinate value of (x, y) on the reference plane can be obtained by interpolation calculation based on the coordinate values of the pair of light cutting lines on both sides of the inspection areas D _{1 to} D ₄ . The reference plane does not change depending on the feeding of the conveyor C, and the inclination of the reference plane is mainly the light source 3 and the TV camera 4.
It is assumed that this is caused by the positional relationship between the conveyor C and the conveyor C. Since the size of the object S is approximately known, all the objects S after the surface of the object S is irradiated with the first slit light by the relationship between the feeding speed of the conveyor C and the time interval T of the image pickup of the CCD element 1. The number of images to be captured is set based on the time until the light passes through all the slit lights. Further, a sensor (not shown) detects that the leading position of the object S has reached the vicinity of the first slit light, and a predetermined number of images are captured from the time of detection.

The above procedure is summarized as shown in FIG. First, when the head position of the object S passes through the sensor, the number i of images to be captured is initialized to 1 (S1), and the image pickup by the TV camera 4 is started (S2). Further, in order to obtain the density of each pixel from the CCD element 1, first the y coordinate is initialized (S3), and the numbers (j) of the images x ₁ ′ to x ₄ ′ of the light cutting line formed on the surface of the object S are determined. ) Is set to 1 (S
4). In this way, the densities of the respective pixels of the CCD element 1 are sequentially read in the x direction, and it is judged whether or not the density is the maximum value (S).
5). However, the determination of the maximum value of the density is made in the inspection areas D _{1 to} D.
It performed only within the range of _4, and the optical cutting line obtained in each inspection area D ₁ to D ₄ is slit to form the light section line on the reference plane which defines the examination region D ₁ to D ₄ Considered to correspond to light. Therefore, the inspection area D ₁ ~
When the images x ₁ ′ to x ₄ ′ of the light-section line cannot be detected in D ₄ , it is determined that the height of the object S exceeds the measurable range, and error processing is performed. .
Note. The height of the measurable object S is about 5 VT tan γ, and the larger the distance between the light sources 3, the larger the measurable height.

When the density becomes maximum, the coordinate value X of the pixel
(S6), and at the same time, the coordinate value in the z direction in the real space
z is determined, and the base corresponding to the coordinate value of (x, y) at this time
The coordinate value z of the quasi-plane is obtained. Here, measure the height of the object S
When setting the inspection area D ₁~ D_FourNeed to ask
Therefore, the coordinate value X is not stored in the memory 6. Surface of object S
Subtract the coordinate value z of the reference plane from the coordinate value z obtained for
Then, it becomes the height of the object S. In this way
The height of the object S is stored in memory together with the coordinate values of (x, y).
6 (S7). Then the statue x₁'~ X_Four'of
The number (j) is increased by 1 (S8), and the number (j) is 4
It is determined whether it is within (S9), the fourth image x_FourReached
If not, steps S4 to S9 are repeated.

When the number (j) exceeds 4 in step S11, the y coordinate is increased by 1 (S10), and the last line (=
(S11) Steps S4 to S11 are repeated until M). In this way, the coordinate value X of the images x ₁ ′ to x ₄ ′ of the light cutting line and the coordinate value z of the light cutting line for all the pixels of the CCD element 1 can be stored in the memory 6. That is, the coordinate value of each point of the light section line formed on the object S can be obtained.

In order to measure the entire surface of the object S, it is necessary to capture a plurality of images. Therefore, the number i is increased by 1 (S12), and it is determined whether or not the preset number N is exceeded. (S13), and if exceeded, the process ends. In the process of the present embodiment, the object S is optically cut at the interval of VT, and the interval of the slit light in the moving direction of the conveyor C is 5VT. Therefore, for example, the beginning of the object S is irradiated with the slit light first. Therefore, the next slit light is emitted to the head of the object S in the sixth image. In other words, although depending on the size of the object S, at least the entire surface of the object S is measured with five images.

(Second Embodiment) In the first embodiment, the light source 3 is set to an integral multiple of the product VT of the feed speed V of the conveyor C and the time interval T of the image pickup of the CCD element 1. However, in the present embodiment, The interval between the light sources 3 is set to a rational number multiple that is a non-integer multiple of VT. Specifically, it is set to 7VT / 4. When capturing a plurality of images, each image captures a state in which the object S is displaced by VT, whereas the position of the optical cutting line is displaced by an integer multiple (twice) of VT by VT / 4. By this, for example, an image in which the head of the object S matches any of the light cutting lines is obtained, and an image in which the head of the object S matches any of the light cutting line is obtained by the image eight sheets after. It will be. That is, if there are seven images, all the positional relationships between the light cutting line and the object S can be captured. As a result, the object S is transferred to the conveyor C.
The light is cut at the interval of VT / 4 in the moving direction of. That is, when one light source 3 is used or when the light sources 3 are arranged at intervals of an integral multiple of VT, the resolution for optically cutting the object S is VT, but in the present embodiment, VT
It becomes / 4, and the resolution is improved four times. However, at least four light sources 3 are required to obtain this resolution.

As can be easily understood from the description of this embodiment, the resolution can be increased by shifting the interval of the light sources 3 by an integer multiple of VT that is a rational multiple smaller than 1. Now, when i, j, and k are natural numbers, the interval between the light sources 3 is set as in the following equation. {I ± (j / k)} VT where j ≠ k, and j / k is reduced by the greatest common divisor of the denominator and the numerator when it is divisible. Also,
i ± (j / k) is assumed to be in the form of improper fraction. Therefore, when j / k is reduced and i ± (j / k) is expressed by an improper fraction, it is assumed to be J / K. At this time, K is the necessary and sufficient number of light sources 3. In other words, the number of light sources 3 does not improve the resolution even if more than K light sources are provided. Also,
The resolution is (1 / K) VT, and the number of times of imaging by the TV camera 4 to obtain the resolution is J times. In the above example, the number of light sources 3 is 4 because it is (7/4) VT.
Therefore, the resolution is 1/4. Also TV
The number of times of imaging by the camera 4 is 7 times for one object S.

[0036] (Embodiment 3) In Embodiment 1, had been set on the basis of the examination region D ₁ to D ₄ in the image x ₁ ~x ₄ light section line formed on the reference plane, the present embodiment Is
The setting method of the inspection areas D _{1 to} D ₄ is changed.
However, in the present embodiment, a plurality of objects S of the same type are sequentially conveyed on the conveyor C, and each object S has almost no displacement in the y direction and almost no rotational movement. Such a condition corresponds to, for example, a case where a pallet is attached to the conveyor C and the object S is attached at a fixed position on the pallet. Also,
The present embodiment can be used for the purpose of detecting whether or not the object S is significantly displaced from the height of the standard object S. For example, it can be used when inspecting the object S for foreign matter.

In this embodiment, similarly to the first embodiment, the coordinate values of the light cutting line formed on the reference plane are obtained, and the inspection areas D _{1 to} D ₄ are set. Next, by irradiating the standard object S, which is known to have no foreign matter attached thereto, with slit light, images x ₁ ′ to x ₄ ′ of light cutting lines as shown in FIG. 7 are formed. To do. Here, since the images x ₁ ′ to x ₄ ′ are deviated in the region corresponding to the object S, the inspection region D is determined for the region in which the images x ₁ ′ to x ₄ ′ are deviated.
Correction is also made so that ₁ ′ to D ₄ ′ are also shifted (in the figure, they are shifted to the left). This correction is performed in the inspection area D ₁ ~
Similar to when D ₄ is set, the image of the light section line x ₁ ′ ~
It is arranged to be displaced by a predetermined pixel with respect to x ₄ ′.
However, one inspection area D ₁ 'to D _4' form a single continuous area without being divided by the image x ₁ '~x _4' of the light section lines. When the inspection areas D ₁ ′ to D ₄ ′ are corrected in this way, when inspecting the adhesion of foreign matter on the surface of the object S, the foreign matter having the same height dimension as the height dimension of the object S is measured. It is possible to detect up to, and the dynamic range of the measurement range is improved. Other configurations and operations are similar to those of the first embodiment.

(Embodiment 4) In this embodiment, the inspection areas D ₁ ′ to D ₄ ′ are set in consideration of the shape of the object S. Now, as shown in FIG. 8A, it is assumed that the upper surface of a standard object (object with no deformation or foreign matter attached to the surface) S is inclined upward in the positive y direction. At this time, the images x ₁ ′ to x ₄ ′ of the light-section lines are straight lines obliquely inclined in the positive direction in the Y direction and in the negative direction in the X direction as shown in FIG. 8B. When thus the image x ₁ of a straight line with uniform slope '~x _4' is obtained, the image x ₁ '~x
_The direction of the light source 3 or the TV camera 4 is adjusted so that 4'is a straight line in the Y direction as shown in FIG. 8 (c). In the subsequent processing, similar to the third embodiment, the inspection areas D ₁ ′ to D ₄ ′ are set based on the images x ₁ ′ to x ₄ ′ after the orientation of the light source 3 or the TV camera 4 is adjusted, and the height of the foreign matter is increased. The size will be measured.

When the object S has the above-mentioned shape,
When the inspection areas D _{1 to} D ₄ having a constant pixel width are set from the images x _{1 to} x ₄ of the light section lines formed on the reference plane, the range in which the height dimension of the foreign matter can be measured is different at each part of the object S. become. That is, the measurable range of the height dimension is smaller in a portion of the object S having a large height dimension than in a portion of a small height dimension, but the object S is adjusted to the shape of the object S as in the present embodiment. Image x ₁ ′ of the light section line formed on the
By adjusting the directions of the light source 3 and the TV camera 4 so that .about.x ₄ ′ is parallel to the Y direction (that is, the reference axis), the range in which the height dimension of the foreign matter can be measured is the same in any part.

(Fifth Embodiment) In each of the above-described embodiments, an example in which the slit light is emitted from the light source 3 has been shown, but in the present embodiment, the spot light is emitted to the object S and the spot light is y.
An example of using a device that can scan not only in the direction but also in the x direction will be shown. As such a light source 3, there is one that uses two vibrating mirrors having laser beams orthogonal to each other and two polygon mirrors having rotational axes orthogonal to each other.

The basic idea is the same as that of the fourth embodiment, so that the images x ₁ ′ to x ₄ ′ with respect to the light cutting line on the surface of the object S become straight lines according to the shape of the standard object S. ,
The position of the light spot is corrected. For example, in FIG.
As shown in FIG. 9B, when the light spot is scanned on the straight line in the y direction or the slit light is emitted to the object S whose thickness changes in a wave shape in the y direction as shown in FIG. At the same time, the images x ₁ ′ to x ₄ ′ of the light section line become wavy. On the other hand, in the present embodiment, the position of the light spot is corrected based on the images x ₁ ′ to x ₄ ′ of the light cutting line of the standard object S, and the light cutting line is corrected as shown in FIG. 9C. The images x ₁ ′ to x ₄ ′ of are made straight lines parallel to the Y direction (that is, the reference axis).

The technique of the fourth embodiment can be applied only when the height dimension of the object S is uniformly inclined in the y direction, but the technique of the present embodiment can be applied when the height dimension of the object S is It is possible to deal with irregular changes. (Embodiment 6) In each of the above embodiments, the TV camera 4 is set to 1
Although an example in which only two cameras are used is shown, in the present embodiment, as shown in FIG. 10, an example in which two TV cameras 4a and 4b are used is shown. It is desirable in terms of processing that both TV cameras 4a and 4b intervene a beam splitter or the like with the object S to match the field of view and the optical axis, but the images obtained by both TV cameras 4a and 4b are the same. If the correction is made based on the positions of 4a and 4b, the same processing as in the case of matching the visual field and the optical axis can be performed. Here, two light sources 3 are used, and both light sources 3 have an interval in the x direction of (7/4) VT (V is the feeding speed of the conveyor C, T is the time interval between imaging by the TV cameras 4a and 4b). Is set to. Also,
It is assumed that the TV cameras 4a and 4b are imaged at a timing shifted by T / 2. That is, the TV cameras 4a, 4
The image in which the object S advances by VT / 2 can be captured by b. That is, since the images are picked up at half the time intervals of the second embodiment, the same resolution as when using the four light sources 3 with the two light sources 3 can be obtained. Further, since the number of light cutting lines is two, the field of view of the TV cameras 4a and 4b can be narrowed. Conversely, TV camera 4
Assuming that a and 4b have the same field of view as the TV camera 4 of the second embodiment, the images x _{1 to} x ₄ and x ₁ ′ of the light-section line.
It is possible to make the moving distance of about x ₄ ′ on the light receiving surface approximately twice as large as that of the second embodiment, and it is possible to improve the measurement accuracy.

By the way, the image pickup timing of both TV cameras 4a and 4b can be changed by controlling one of the synchronizing signal and the shutter timing. Sync signal is C
This signal is generated once for each of a plurality of fields of the screen imaged by the CD element 1. That is, the relative time difference between the synchronization signals is determined by the timing at which the TV cameras 4a and 4b start imaging after the object S has passed the predetermined position.
Therefore, it is possible to keep constant which field image is to be fetched after the sync signal is generated, and to shift the sync signal generation timing by T / 2, or to make the sync signal generation timing equal. It is possible to shift the image capturing timing of the images of both TV cameras 4a and 4b by T / 2 depending on whether the image of the field shifted by / 2 is captured. Here, an electronic shutter is used as the shutter, and the shutter timing is determined by the read timing from the CCD element 1.

(Embodiment 7) In this embodiment, as shown in FIG. 11, four light sources 3a,
3b, but two TV cameras 4a and 4b are provided as in the sixth embodiment. The light sources 3a and 3b irradiate the object S with slit light beams of different colors (for example, red and blue), and the TV cameras 4a and 4b emit the light sources 3a and 3b.
Filters Fa and Fb for transmitting only one color of 3b are provided in the front. Therefore, the TV camera 4a images the light cutting line formed by the light source 3a through the filter Fa, and the TV camera 4b images the light cutting line through the filter Fb formed by the light source 3b. Here, the distance between the light sources 3a and 3b is (7/4) VT.
Is set to . Therefore, both the TV camera 4a, 4
By combining the images obtained by b, the height dimension of each part of the object S can be obtained with a resolution of VT / 4. Here, in the above configuration, each TV camera 4a, 4b has two
Image of light-cutting lines x ₁ ′, x ₃ ′ and x ₂ ′, x ₄ ′
And the images x ₁ ′, x ₃ ′ and x ₂ ′, x ₄ ′ obtained by the TV cameras 4a, 4b are obtained by arranging the light sources 3a, 3b at an interval of (14/4) VT. , T
Assuming that the V cameras 4a and 4b have the same specifications as the TV camera 4 of the second embodiment and the distance from the reference plane to the TV cameras 4a and 4b is also the same as that of the second embodiment, the inspection is performed in the present embodiment. The areas D _{1 to} D ₄ can be set approximately twice. That is, the measurement range of the height dimension is approximately doubled as compared with the second embodiment .

(Embodiment 8) In this embodiment, as shown in FIG. 12, the light sources 3a to 3d are arranged at intervals of VT / 4.
In the above-described embodiments, monochrome cameras can be used as the TV cameras 4, 4a, 4b, while different light colors (for example, red, blue, green, and purple) are used for each. In this embodiment, one color T
The V camera 4c is used as an image input device. The basic principle is similar to that of the seventh embodiment.

The light color conditions of the light sources 3a to 3d are as follows.
When the image signals of the TV camera 4c are output by color, three of the four colors can be extracted as independent image signals, and the remaining one color can be extracted as a plurality of image signals. In other words, in the above light colors, red, blue and green are T
The image signals of three colors of the V camera 4c can be independently taken out, and purple appears in the red signal and the blue signal.

The image signal of each color from the TV camera 4c is
As shown in FIG. 13, a purple light cutting line appears in the red image shown in FIG. 13A and the blue image shown in FIG. 13C, and an image xr of two light cutting lines appears. , Xp and xb,
xp will be obtained. The green image is shown in Figure 1.
As shown in 3 (b), an image xg of one green light-section line appears. Image x of the purple light section line in the red and blue images
If the light outputs of the light sources 3a to 3d are equal and the reflectances of the object S with respect to the respective colors are equal, p is a red or blue image x.
r and xb can be identified by the concentration.

Here, the four light cutting lines are formed at intervals of VT / 4, and the time interval of image pickup by the TV camera 4c is T, so that the object S can be measured with a resolution of VT / 4. Since only one image xg of the light cutting line is formed in the green image, the measurement range of the height dimension can be widened for the green image, and two images of the light cutting line can be obtained in the red and blue images. Although xr, xp or xb, xp are formed, the measurement range of the height dimension is more than the measurement range when the optical cutting lines are formed at the interval of VT / 2.

(Embodiment 9) This embodiment is an example in which a relatively large step St is formed on an object S as shown in FIG. When the object S having such a shape is irradiated with slit light from one side,
A blind spot is generated by the protrusion Sp, and the shape of the step St cannot be accurately measured.

Therefore, in the embodiment, four light sources 3e and 3f are provided on both sides of the surface orthogonal to the transport direction of the object S. The four light sources 3e and 3f are red and blue light sources, respectively, and one set of light sources 3e and 3f are arranged on the reference plane so as to form light cutting lines at the same position. The intervals between the four light sources 3e and 3f are set according to the first and second embodiments. Also,
The light sources 3e and 3f are arranged so as to be orthogonal to the carrying direction of the object S and symmetrical with respect to a plane including the optical axis of the TV camera 4c. A color camera is used for the TV camera 4c.

If such a structure is adopted, since the step St is formed, the red and blue light sources 3e, 3
Even if the slit light is irradiated on one of the blind spots of f and the other is irradiated, the height of the object S can be measured without forming a blind spot. The light source 3e or 3f from which the light is emitted is identified by the light color. Other configurations and operations are similar to those of the first and second embodiments.

(Embodiment 10) In this embodiment, as shown in FIG. 15, light sources 3e and 3f are arranged in the same manner as in Embodiment 9, and two TV cameras 4a and 4b are arranged as in Embodiment 6. It was done. However, the light sources 3e and 3f do not have to have different light colors, and the same color can be used. In order to distinguish which of the light sources 3e and 3f is the light source, in the present embodiment, the light sources 3e and 3f are alternately turned on, and a different TV camera 4 is provided for each of the light sources 3e and 3f.
The images captured in a and 4b are used. The present embodiment is different from the ninth embodiment in the configuration for distinguishing which light source 3e, 3f is the light to be formed, but the other configurations and operations are the same as in the ninth embodiment.

(Embodiment 11) In the present embodiment, as shown in FIG. 16, T is on the optical path between the object S and the TV camera 4.
The mirrors Ma to Md are provided so that only the images x ₁ ′ to x ₄ ′ of the light cutting lines existing in a predetermined height range are formed on the light receiving surface of the CCD element 1 provided in the V camera 4. is there.
In other words, the images x ₁ ′ to x ₄ ′ of the light cutting lines are the CCD only when the height range where the light cutting lines are formed is within a predetermined range.
The positional relationship of the mirrors Ma to Md is set so as to be formed on the light receiving surface of the element 1. The height range in which the images x ₁ ′ to x ₄ ′ of the light cutting line can be formed on the light receiving surface of the CCD element 1 is h ₁ to h ₂ (h ₁ > h ₂ ), and the height is from h ₁ to h If the number of pixels that the images x ₁ ′ to x ₄ ′ move on the light receiving surface of the CCD element 1 when changing to ₂ , the resolution with respect to height is expressed by the following equation. Without the (h ₁ -h ₂ ) / q mirrors Ma to Md, the same number of pixels would correspond to a wider height range, resulting in poor resolution. In short, when measuring in a specific height range, it is possible to perform measurement with higher accuracy by using the mirrors Ma to Md. Other configurations and operations are similar to those of the first and second embodiments.

(Embodiment 12) In this embodiment, as shown in FIG.
Phase plates 7a to 7c are inserted on the optical path between the V camera 4 and the V camera 4. Each of the phase plates 7a to 7c is a glass plate having a different refractive index, absorbs a difference in optical path length due to the use of the mirrors Ma to Md, and makes the optical path length between each light cutting line and the TV camera 4a approximately optically. They are made equal to each other, thereby suppressing the focus shift of each light cutting line. Other configurations and operations are similar to those of the eleventh embodiment.

(Embodiment 13) In this embodiment, as shown in FIG. 18, a convex mirror 8 is arranged on the optical path between the TV camera 4 and the object S in the configuration of Embodiments 1 and 2. . That is, the light cutting line is incident on the TV camera 4 through the convex mirror 8. With this configuration, the TV camera 4
The field of view can be expanded.

(Embodiment 14) In this embodiment, as shown in FIG. 19, in the configuration of Embodiment 2, the TV camera 4
In addition to the above, a displacement sensor 9 for measuring the distance to the reference plane is provided. As the displacement sensor 9, it is desirable to use a sensor using an optical triangulation method (a sensor that irradiates a light beam and uses a position sensor such as PSD to obtain a distance from a reference position by the principle of triangulation method). .

The displacement sensor 9 continuously detects the displacement of the reference plane at a specific position in the feeding direction of the conveyor C, and the displacement detected by the displacement sensor 9 corresponds to the vibration component of the reference plane. The distance to the reference plane obtained by using the line is corrected by the displacement detected by the displacement sensor 9, and the distance to the reference plane after the correction and the object S based on the image of the optical cutting line captured by the TV camera 4 The height dimension of the object S is obtained from the distance. That is, the vibration component associated with the conveyance by the conveyor C is removed from the height dimension of the object S measured by the light cutting line, and the height dimension of the object S can be detected more accurately.

(Embodiment 15) In this embodiment, as shown in FIG. 20, a light source 3g for irradiating a reference plane with spot light is added to the structure of the second embodiment. The light beam from the light source 3g is included in a plane parallel to the plane including the slit light formed by the other light source 3 and parallel to the xz plane. The light spot formed by the light beam from the light source 3g is formed at a position different from the light cutting line.

As is clear from the explanation of the principle, the light source 3g
By detecting the light spot formed by the light from the TV camera 4, the distance in the z direction of the portion where the light spot is formed can be measured by the triangulation method. Therefore, in the present embodiment, the measurement using the light spot is also performed at the same time as the measurement using the light section line. Similar to the second embodiment, first, measurement is performed on the reference plane along the light cutting line.

Next, when the light cutting line is formed on the object S and the measurement is performed, the measurement of the reference plane by the light spot is also performed at the same time. Regarding the reference plane, since the Y coordinate of the portion where the light spot is formed is known, the coordinate value in the X direction where the density has the maximum value is obtained on this Y coordinate, and the reference plane of the reference plane is calculated based on this coordinate value. The coordinate value z in the z direction is obtained. Since the time interval of imaging by the TV camera 4 is T, the resolution in the x direction of the coordinate value z in the z direction measured by the light spot is VT, which is the resolution in the x direction of the height measurement by the optical cutting line. 4 times (that is, resolution is low). Therefore, the coordinate value z obtained from the light spot is interpolated in the x direction. Accordingly, the coordinate value z of the reference plane at the position of the light cutting line formed at each position of the object S
Therefore, if the difference between the original reference plane measured using the light cutting line and the reference plane obtained using the light spot is removed from the height dimension obtained for the object S, the reference plane is obtained. More accurately by removing the fluctuation component of
The height dimension of can be obtained. Here, in the present embodiment, the light cutting line is formed in the y direction as in the second embodiment. Therefore, the coordinate value z of the reference plane at each position in the x direction obtained by the light spot is
The same value shall be used for one optical cutting line.

Incidentally, the length of the light cutting line in the y direction is usually set to be wider than the width of the object S in the y direction.
It is possible to detect the vibration component of the reference plane even if the height dimension of the reference plane is obtained from the portion formed on the reference plane at the end of the light cutting line during the measurement.

[0062]

According to the first aspect of the present invention, an optical cutting line is formed on the surface of an object by the light from a light source, and the optical cutting line is imaged by using an image input device. In the three-dimensional shape measuring method for obtaining the distance to, the pixel densities are sequentially read out in the direction intersecting the image of the light cutting line formed on the light receiving surface of the image input device, and the densities of the pixels before and after in the reading order are larger or smaller. By calculating the pixel having the maximum density by comparing, the distance to the object based on the position of the pixel having the maximum density on the light-receiving surface, in storing the obtained distance in the memory , Multiple
The light cutting lines are parallel to each other on the reference plane and are at regular intervals.
Form and intersect the object on the reference plane with the light cutting line
The distance between the light cutting lines on the reference plane
The product of the time interval of imaging with the input device and the transport speed of the object
Set to be a rational multiple of and a non-integer multiple of
Express the multiple by a fraction and divide the denominator and numerator by the greatest common divisor
The denominator in the divided form is the number of light cutting lines, and instead of calculating the distance to the object after storing the image of the light cutting line captured by the image input device in the frame memory, Since it is possible to read the density of pixels from the device, find the distance to the object, and store the found distance in the memory, there is an advantage that the frame memory is unnecessary and the memory amount can be reduced. There is an advantage that the processing time can be shortened because the time for writing and reading to the memory becomes unnecessary.

Moreover, a plurality of light cutting lines are formed on the reference plane so as to be parallel to each other and at constant intervals, and the object is conveyed on the reference plane in the direction intersecting the light cutting line, and the light is cut on the reference plane. The interval of the light cutting lines is set to be a rational multiple of the product of the time interval of image capturing by the image input device and the transport speed of the object, and is set to be a non-integer multiple. When the denominator when divided by the greatest common divisor to obtain the number is the number of optical cutting lines, the number of optical cutting lines is the same as the number of optical cutting lines with respect to the distance that the object travels during the time interval of imaging by the image input device. Since it is possible to measure the distance of each part in the conveying direction of the object with the resolution of 1, there is an advantage that the distance can be accurately measured even for the object conveyed at a relatively high speed.

[0064] As the invention of claim 2, based on the light section line formed on the object to be placed on standard on standards plane, to set the inspection area within a range that does not overlap the adjacent light section line , If the distance to the object is obtained based on the light cutting line in this inspection area, the light cutting line on the reference plane and the light cutting line on the object can be easily associated by setting the inspection area. Therefore, the height of the object can be easily obtained from the difference between the two, and moreover, by setting the inspection area according to the shape of the object, the detection range of height change relative to the standard object (that is, the dynamic range) Has the advantage that it can be made large.

[0065]

[0066]

[0067] As the invention of claim 3, provided with a plurality of images input device, if an imaging timing of each image input device as shifted by a predetermined time, high with a relatively small number of the optical cutting line There is an advantage that resolution can be obtained. According to the invention of claim 4 , each light cutting line has a plurality of light colors, and each light cutting line having a different light color is individually provided by a plurality of image input devices provided with a filter for individually passing light of each light color. If the image is captured, the interval between the optical cutting lines captured by each image input device can be set relatively long, and the processing time for the image captured by each image input device can be set relatively long. That is, if the images captured by the image input devices are individually processed, the processing can be performed by a low-speed processing device. Also,
The long interval between the light cutting lines widens the range in which a change in the height of the object can be detected.

According to the fifth aspect of the present invention , each light cutting line has a plurality of light colors different from each other, and the light cutting lines picked up by the image input device including the color TV camera are extracted for each color signal to obtain the distance. By doing so, it is possible to perform processing even with a low-speed processing device by individually processing each color signal.
Further, the interval between the light-section lines of each color can be lengthened, and the range in which the change in the height of the object can be detected is widened.

According to a sixth aspect of the present invention, an image input having an optical axis in a direction orthogonal to the reference plane is formed by irradiating light from a direction obliquely intersecting the reference plane to form a light cutting line. A three-dimensional shape measuring method for capturing an image of a light cutting line by a device, wherein light of different light colors is emitted from light sources arranged on both sides of a plane including the optical axis of the image input device and along the light cutting line. Forming a light cutting line,
If the light cutting line imaged by the image input device composed of a color TV camera is taken out for each color signal and the distance is obtained, the object has a step or the like, and even if light is irradiated from one side, it becomes a blind spot and the light cutting line is obtained. Even if there is a surface on which the blind spot is not formed, the blind spot is not formed by irradiating light from both sides.

According to the invention of claim 7 , an image input having an optical axis in a direction orthogonal to the reference plane is formed by irradiating light from a direction obliquely intersecting the reference plane to form a light cutting line. A three-dimensional shape measuring method for imaging a light cutting line by a device, the light cutting line being alternately irradiated from light sources arranged on both sides of a plane including the optical axis of the image input device and along the light cutting line. If the light cutting line imaged by one image input device is taken out for each light from each side with respect to the plane and the distance is obtained, there is a step on the object and the light is radiated from one side. Even when there is a surface where the light cutting line is not formed due to the blind spot, the blind spot is not formed by irradiating the light from both sides. The difference between the invention of claim 6 and the invention of claim 7 is the difference between the use of color and the use of time in order to distinguish the optical cutting lines due to the light from each side.

According to the eighth aspect of the invention, the moving width of the image of the light cutting line on the light receiving surface of the image input device can be made as large as possible according to the range of the distance to be measured by each light cutting line. If the light input line is imaged by the image input device through the mirrors arranged in this way, the amount of movement of the light cut line with respect to changes in the distance to the object within the limited light receiving surface of the image input device can be maximized. Therefore, the resolution for detecting the change in the distance to the object is increased.

When the optical path length adjusting means for making the optical path lengths from the respective optical cutting lines to the image input device substantially equal to each other is provided as in the ninth aspect of the present invention, the light receiving surface is focused so that the images of the respective optical cutting lines are in focus. The image can be formed on the upper side, and the detection accuracy of the change in the distance to the object can be improved. As in the tenth aspect of the invention, when the image input device captures an image of the optical cutting line through the convex mirror that is curved in a plane orthogonal to the optical cutting line, the field of view of the image input device can be expanded.

According to the eleventh aspect of the present invention, the object is conveyed on the reference plane in the direction intersecting the optical cutting line, the vibration component of the reference plane is detected based on the time change of the distance to the reference plane, and By removing the distance change of the reference plane due to the above-mentioned vibration component from the measured value of the distance obtained from the cutting line to obtain the distance, it is possible to remove the height change due to the vibration of the object being conveyed, The distance to the object can be obtained with high accuracy.

Here, the vibration component is detected by a displacement sensor separately provided so as to obtain the distance to the reference plane as in the invention of claim 12 , or as in the invention of claim 13 , and detect the distance of the light spot to form a light spot to a reference plane determined by imaging by the image input device with the light section line above, claim 1
As in the invention of 4 , it is possible to detect by the distance to the reference plane obtained based on the light cutting line of the portion formed on the reference plane when the light cutting line is formed on the object.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

2 is a perspective view showing an optical system of Embodiment 1. FIG.

FIG. 3 is a diagram showing an image with respect to a reference plane according to the first embodiment.

FIG. 4 is a diagram showing an image of an object according to the first embodiment.

FIG. 5 is an operation explanatory diagram of the first embodiment.

FIG. 6 is an operation explanatory diagram of the first embodiment.

FIG. 7 is a diagram showing an image of an object according to the third embodiment.

FIG. 8 is an operation explanatory diagram of the fourth embodiment.

FIG. 9 is an operation explanatory diagram of the fifth embodiment.

FIG. 10 is a perspective view showing an optical system according to a sixth embodiment.

FIG. 11 is a perspective view showing an optical system according to a seventh embodiment.

FIG. 12 is a perspective view showing an optical system according to an eighth embodiment.

FIG. 13 is a diagram showing an image of the above.

FIG. 14 is a perspective view showing an optical system according to a ninth embodiment.

FIG. 15 is a perspective view showing an optical system according to a tenth embodiment.

FIG. 16 is a schematic diagram showing an optical system according to an eleventh embodiment.

FIG. 17 is a schematic diagram showing an optical system according to a twelfth embodiment.

FIG. 18 is a schematic diagram showing an optical system according to a thirteenth embodiment.

FIG. 19 is a perspective view showing an optical system according to a fourteenth embodiment.

FIG. 20 is a perspective view showing an optical system according to a fifteenth embodiment.

FIG. 21 is a diagram illustrating the principle of the present invention.

FIG. 22 is a diagram illustrating the principle of the present invention.

[Explanation of symbols]

1 CCD element 2 Light receiving optical system 3 light sources 3a-3g light source 4 TV camera 4a-4c TV camera 5 Position calculator 6 memory 7a to 7c Phase plate 8 convex mirror 9 Displacement sensor Fa and Fb filters Ma-Md mirror

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-50730 (JP, A) JP-A-4-98106 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/00-11/30

Claims (14)

(57) [Claims] 1. A three-dimensional method for determining a distance to an object by using a triangulation method by forming a light cutting line on the surface of an object by light from a light source and imaging the light cutting line using an image input device. In the shape measuring method, the densities of the pixels are sequentially read out in the direction intersecting the image of the light cutting line formed on the light receiving surface of the image input device, and the density is compared by comparing the densities of the pixels before and after in the reading order. After finding the maximum pixel and finding the distance to the object based on the position of the pixel where the density is maximum on the light receiving surface, when storing the found distance in the memory , multiple light cutting lines are used. On the reference plane
Are formed so that they are parallel to each other and at regular intervals.
Transport the object on the surface in the direction that intersects the optical cutting line, and
The interval of the light cutting line on the plane is the
It is a rational multiple of the product of the time interval and the transport speed of the object
Set it to be an integer multiple and express this multiple as a fraction.
And numerator divided by the greatest common divisor
A three-dimensional shape measuring method, characterized in that the denominator is the number of light cutting lines . 2. A standard object placed on a reference plane.
Based on the light cutting line formed on the
Set the inspection area within the range that does not overlap, and
Characterized by finding the distance to the object based on the light section line
The three-dimensional shape measuring method according to claim 1 . 3. A plurality of image input devices are provided, and
The image capturing timing of each image input device is staggered for a certain period of time.
The three-dimensional shape measuring method according to claim 1, further comprising : 4. Each light cutting line has a plurality of light colors,
Multiple image inputs with filters that individually pass light
Each device can individually image each light section line with different light color.
The three-dimensional shape measuring method according to claim 1, wherein: 5. Each light cutting line has a plurality of light colors different from each other.
Imaged by an image input device consisting of a color TV camera
Find the distance by extracting the cut light line for each color signal
The three-dimensional shape measuring method according to claim 1 . 6. A direction intersecting obliquely with the reference plane
When a light cutting line is formed by irradiating light from the
, The images input instrumentation having an optical axis in the direction orthogonal to the reference plane
Is a three-dimensional shape measurement method that captures an optical cutting line by
The plane of the plane including the optical axis of the image input device and along the optical cutting line.
Irradiate different colors of light from the light sources placed on both sides.
By forming a light cutting line, the color TV camera
The optical cutting line imaged by the image input device
The three-dimensional shape measuring method according to claim 1, wherein the distance is taken out and the distance is obtained . 7. Is the direction diagonally intersecting with the reference plane?
When a light cutting line is formed by irradiating light from the
Image input device having an optical axis in a direction orthogonal to the reference plane.
Is a three-dimensional shape measurement method that captures an optical cutting line by
The plane of the plane including the optical axis of the image input device and along the optical cutting line.
By alternately radiating light from the light sources arranged on both sides
A light cutting line is formed and imaged by one image input device
Take out the light cutting line separately for each light from the above plane
The three-dimensional shape measuring method according to claim 1, wherein the distance is obtained by using the method. 8. A range of distance to be measured by each light section line
Image of the light cutting line on the light receiving surface of the image input device
Through a mirror arranged so that the movement width can be as large as possible.
And the light cutting line is imaged by the image input device.
The three-dimensional shape measuring method according to claim 1 . 9. An optical path from each light cutting line to the image input device.
Characterized by the provision of optical path length adjusting means for making the lengths almost equal
The three-dimensional shape measuring method according to claim 8 . 10. A convex curved in a plane orthogonal to the light cutting line.
Taking an image of the optical cutting line with an image input device through a face mirror
The three-dimensional shape measuring method according to claim 1, which is characterized in that . 11. An object intersects a light cutting line on a reference plane.
Direction, and based on the time change of the distance to the reference plane.
Then, the vibration component of the reference plane is detected, and it is determined by the optical cutting line.
Distance of the reference plane due to the above vibration component
The distance is obtained by removing the change amount.
The three-dimensional shape measuring method described in 1 . 12. The vibration component is a distance to a reference plane.
It can be detected by a separately provided displacement sensor as required.
The three-dimensional shape measuring method according to claim 11, wherein: 13. The vibration component is an optical spot on the reference plane.
Forming a preparative image input with light cutting line the light spot
The distance to the reference plane obtained by imaging with the device
The three-dimensional shape measuring method according to claim 11, further comprising detecting . 14. The vibration component forms a light cutting line on an object.
Light cut line of the part formed on the reference plane when
It can be detected by the distance to the reference plane calculated based on
3-dimensional shape measuring how according to claim 11, wherein the door.