JPH0352804B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a device for measuring the three-dimensional shape of a target object having a relatively complex shape in a contactless and non-invasive manner, and a device for measuring the three-dimensional shape of the target object using the same. The present invention relates to a method and apparatus for forming a three-dimensional image.

[Conventional technology and its problems]

Conventionally, when producing a replica of a target object having a relatively complex shape, copy milling machines or the like or inverted molds such as molds or demasks have been used, but in such conventional techniques, For example, relatively complex and delicate objects such as human figures require extremely high skill and artistic sense, and it has been difficult to produce reproductions at an industrial level. Therefore, the inventors of the present application have developed a new duplication method that enables accurate, easy, and quick duplication of such objects. This new method attempts to reproduce a three-dimensional image of the target object by approximating the target object with a collection of cross-sectional shapes of appropriate pitches, cutting out plates with this cross-sectional shape, and superimposing the plates in the original order. It is something to do. According to this method, a replica of an object having a relatively complex three-dimensional shape can be easily produced by using a numerically controlled machine tool with a simple structure that only requires cutting out a plate. However, in order to use this replication method, a method to accurately measure the three-dimensional shape of the target object is essential, but even if this is a contact measurement method using a stylus, or a non-contact measurement method, for example, If the measurement method requires an extremely advanced information processing function, such as 3D measurement using moiré fringes,
This does not mean that the reproduction method can be easily applied to relatively complex and delicate objects. Furthermore, after obtaining a complete overall image of the target object, it is necessary to calculate the cross-sectional shape of each cross-section to be applied to the above duplication method through complex arithmetic processing. As processing functions, data storage capacity, etc. become more sophisticated, it is no longer practical in an industrial or economical sense, so it is necessary to process the information necessary for measurement easily and retain it during the measurement process. There was a need for a measuring device that could handle only a small amount of data.

[Problem of the invention and its solution]

An object of the present invention is to provide a relatively simple, non-contact, and non-invasive three-dimensional shape measuring device that can represent at least a target object as a collection of cross-sectional shapes. Furthermore, it is an object of the present invention to provide a three-dimensional shape measuring device that requires a small amount of data to obtain a cross-sectional shape and does not require complicated logic and equipment for information processing. By utilizing these measuring devices to construct a new method and device for duplicating the aforementioned target object having a relatively complex three-dimensional shape, the functions of the duplication method can be fully utilized.

The above-mentioned technical problems to which the present invention is directed are effectively solved by the following configurations as specified in claims 1 to 3. In addition, the present inventor previously filed a patent application in 1983 for the same problem as above.
The invention of No. 200987 (Japanese Unexamined Patent Publication No. 60-93424) was proposed as a basic solution, but the present invention further expands and develops the idea while maintaining the advantages of this prior invention. It is something that

That is, the device for measuring the three-dimensional shape of a target object according to the present invention is a plate-shaped light shielding body whose upper edge or lower edge forms a flat plane, and which is perpendicular to the measurement position where the target object is placed. A plate-shaped light-shielding body disposed on a plane including an edge forming a flat plane of the plate-shaped light-shielding body, on the opposite side of the measurement position with respect to the edge, at a predetermined distance from the outside of the light-shielding body. a point light source that is arranged at a position separated from the measurement position and emits light toward the measurement position; and an optical axis that intersects at a constant angle with respect to a plane that includes the edge; A two-dimensional imaging means positioned to have a predetermined relationship with the light source, a support stand to which the two-dimensional imaging means, the light shielding body, and the point light source are fixed, and the support stand is arranged vertically at a constant minute pitch Δh. a guide device that can move step by step, and a data processing device that measures the shape of a cross section of the target object from an image representing the shape of a "shade" captured by the two-dimensional imaging means and obtains data regarding the shape of the cross section. It is characterized by

In the apparatus of the present invention, the target object is placed at a measurement position, and the guide device sequentially moves the support base in one direction at a constant minute pitch Δh, and each time it moves, it irradiates light with the point light source. The "shadow" of the light shielding body is projected onto the surface of the target object, the shape of the "shadow" is imaged by the two-dimensional imaging means, and the data processing device calculates the shape of the "shadow" from the captured image. The three-dimensional shape of the target object is measured by performing a procedure of measuring the shape of one cross section of the target object and obtaining data regarding the shape of the cross section.

Furthermore, since the intersection angle between the plane of the "shadow" and the optical axis of the two-dimensional imaging device is kept constant, it is possible to determine the object by performing simple information processing on the image captured by the two-dimensional imaging means. The cross-sectional shape of an object can be easily measured.

According to the present invention, the two-dimensional cross-sectional shape of the target object when cut along a horizontal plane including the edge of the light shielding plate created by the "shading" of the light shielding plate projected onto the surface of the target object is sequentially measured at a constant minute pitch Δh. Even if the target object has an arbitrary and relatively complex shape, it can be measured at every minute pitch over the entire height of the target object from the top to the bottom. Its three-dimensional shape can be measured in a contact and non-invasive manner.

Further, in the method of forming a three-dimensional image having the same shape as a target object according to the second invention of the present application, the outer periphery of the target object is surrounded by a plate-like light shield, and a point light source on a horizontal plane including the edge of the light shield is irradiating the light shielding body and the target object with light to project the “shadow” of the light shielding body onto the surface of the target object, and having an optical axis that intersects at a certain angle with respect to the horizontal plane. The dimensional imaging means images the shape of the "shadow" on the surface of the target object, and the imaged "shadow"
The shape of one cross section of the target object is measured from an image representing the shape of the target object to obtain data regarding the shape of the cross section, and then the light shield and the point light source are sequentially moved at a constant minute pitch Δh to measure the shape of the target object. Repeat the same procedure as above for the cross section and the adjacent cross section, and
Thus, using the cross-sectional shape data obtained by measuring each cross-section of the target object, the thin plate material having the same thickness as the one-time micro-movement pitch Δh of the light shielding body or a thickness having a predetermined relationship therewith is used. The method is characterized in that templates of the same shape are created corresponding to each cross section of the target object, and these templates are sequentially stacked in accordance with the order of each measurement performed in the aforementioned procedure.

Furthermore, a device for forming a three-dimensional image having the same shape as a target object according to a third invention of the present application is an apparatus for implementing a method for forming a three-dimensional image having the same shape as a target object according to the second invention, which comprises: The present invention is characterized in that it is configured to include the configuration of the measuring device according to the first invention.

According to the present invention, if cross-sectional shape measurement data of a target object obtained for each height increment Δh is fed to, for example, a numerically controlled laser cutting machine, etc., and a thin plate material having a constant thickness Δh is processed, Templates having the same shape as the two-dimensional cross-sectional shape can be cut out in height increments of Δh. Therefore, by moving the light shield and the point light source from the upper end to the lower end of the target object and overlapping the templates cut out each time in the measurement order, it is possible to easily and quickly obtain the same shape as the target object. This makes it possible to reproduce 3D images.

By utilizing the measuring method and apparatus of the present invention, it becomes possible to easily form a three-dimensional image of a target object at high speed and with high precision.

〔Example〕

Next, the present invention will be explained in detail with reference to illustrated embodiments.

In FIGS. 1a and 1b showing the configuration of an embodiment embodying the idea of the present invention, illumination light irradiated from a point light source 2 to a target object 4 is
A part of the light shielding plate 11 is fixed to the support base 1 which is located between the target object 4 and the point light source, and which is slidably guided along the guide column 7. As a result, the "shadow" of the light shielding plate 11 is projected onto the surface of the target object.

This "shadow" corresponds to the unevenness of the surface of the target object, and is captured as an image as shown in FIG. 3, for example. Note that the image shown in FIG. 3 is a binarized and displayed image signal from a two-dimensional imaging device. In other words, when you take an image of the surface of a target object with a TV camera, the "shadow" parts appear completely dark, but the illuminated parts are bright, sometimes slightly dark, and have a uniform brightness. It is normal that it does not. Therefore, when performing image measurements like this, processing is applied so that all areas that are brighter than the "shadow" area (including gray areas) become white, but this is Fig. 3 shows the image after such binarization, and shows a pattern consisting of a pure white part, that is, a bright part, and a pure black part, that is, a dark part. It's getting old. In short, the present invention utilizes the shape of the boundary line between the bright area and the "shadow" shown in FIG.
From this, a three-dimensional object image of the same shape is formed.

1a and 1b again, the support base 1
is connected to a ball nut 6 which is screwed to the ball screw shaft 5, and a step motor (not shown) is connected to the ball screw shaft 5, and the step motor moves the ball nut 6 by the height of the thickness Δh of the slit light. The support stand 1 is driven up and down in stages.

For ease of explanation, the vertical center line of the target object 4 will be referred to as the Z-axis, and two lines that are perpendicular to the Z-axis and intersect perpendicularly to each other on a plane containing the lowest point of the target object 4 will be referred to as the Z-axis. The two axes will be referred to as the X-axis and the Y-axis, respectively, and the plane will be referred to as the X-Y plane.

Also, for convenience, only the method and apparatus that use the "shadow" projected by the upper edge of the light shielding plate 1 will be illustrated and explained, but this also applies when using the "shadow" caused by the lower edge. It goes without saying that the idea of the present invention can be implemented using exactly the same method as described above. In addition to this, the present invention can also be implemented by a method that uses the upper and lower edges of one light shielding plate and simultaneously utilizes two "shades" projected by these edges.

Now, above the point light source 2, a two-dimensional imaging device 3, for example, a TV camera 3, has an optical axis at a constant angle β with respect to the X-Y plane, and the optical axis is parallel to the Z-axis. It is arranged so that it intersects with the

Note that the viewing angle of the TV camera 3 is α. In this case, as shown in the figure, the TV camera 3 is fixed to a support device 1 to which a point light source and a light shielding plate 11 are fixed, and the point light source 2, the light shielding plate 11, and the TV camera 3 are arranged in a fixed geometrical manner with respect to each other. It may also be configured to move while maintaining the same relationship.

The “shadow” of the light-shielding plate is simultaneously projected over the entire outer circumferential side of the target object 4, and the TV camera 3
In order to image the entire outer circumferential side, a plurality of point light sources 2,
2 ₁ , to 2 _o , and a plurality of TV cameras corresponding to each of these point light sources may be arranged so as to surround the target object. In this case, if the distances from the principal point S of the optical system of all TV cameras 3 to the Z axis, which is the central axis of the target object 4, are made equal, and the optical magnifications of these three groups of TV cameras are made equal, then Since the shape of the "shadow" image captured by each TV camera can be measured at the same ratio,
Although it becomes possible to simplify the calculation for determining the cross-sectional shape, it is not necessarily limited to such conditions. For example, one cross-sectional shape of the target object 4 is measured in advance using another measurement method such as a so-called contact method, and the cross-sectional shape is measured in advance.
It is also possible to calibrate the measurement data of each camera by comparing the data captured by the three groups of TV cameras with the above-mentioned actual measurement data.

In addition, when using multiple TV cameras, in order to avoid interference between lights from multiple point light sources, it is necessary to install multiple support stands 1 on which the light sources, TV cameras, and light shielding plates of each system are mounted. It is necessary to position the systems so that they are all at the same horizontal height and to precisely synchronize the operations of these systems. This can be easily met by providing a guide column that guides and slides each support base so that the amount of movement of the support bases from a preset origin position is equalized. In this case, the origin positions of each guide column must naturally be set so that they all lie on the same horizontal plane. In addition, as another example, in the case of a cylindrical light shielding plate, only one of the plurality of support stands is driven, and the other support stands follow it, so that such master and slave support is achieved. It is also possible to mechanically interlock or synchronize each system including the stand.

Next, referring to FIGS. 3 and 4, an explanation will be given of an image taken by the TV camera 3 of a "shadow" image formed on the surface of the target object 4, and the relationship between the image and the video signal. Install the TV camera 3 so that the scanning direction of the scanning line is parallel to the Y axis, and
When the TV camera 3 captures an image of the "shade" formed on the surface of the target object 4, it becomes an arc-shaped image as shown in FIG. In the figure, the points P′ _i (i.e. P′ _i1 , P′ _i2 ′, etc. – not shown) are shown in FIG. 2a,
Point P _i shown in Figure 2b (included in the slit light image)
, and the line segment '' _n is the line passing through point Z _i in Figure 2b and parallel to the Y axis, that is, the line in Figure 2a.
Matches OY _n . Also, S ₁ , S ₂ ,
... S _r is a scanning line that forms an image of the TV camera 3, and one screen consists of r lines (generally about 250 to 500 lines).

Figure 4 corresponds to the scanning line S _i in Figure 3.
This is the output signal of the TV camera 3, and first the video signal
A video signal is output after a horizontal synchronization signal _HBL indicating the timing at which horizontal scanning is started is output prior to _Is . The video signal I _s has a large amplitude in a portion corresponding to a bright optical image, and a small amplitude in other portions. Note that immediately before scanning of one screen is started, a vertical synchronizing signal V _BL indicating the timing is output.

FIG. 5 shows how to use this TV camera 3 to
This is a block diagram of a control circuit for determining the coordinates (X _i , Y _i , Z _i ) of point P _i shown in FIGS. In FIG. 5, a video signal of a "shadow" image on the surface of the target object 4 is shown.
I _s , as well as horizontal synchronization signal H _BL and vertical synchronization signal V _BL
The _output signal of the TV camera 3 including
The H _BL , and V _BL signals are separated. 21 is a counter, count input terminal
In ₁ is the horizontal synchronization signal H _BL from the synchronization separation circuit 31.
, and the vertical synchronizing signal V _BL is connected to the reset input terminal reset ₁ . counter 21
is first reset to 0 by the vertical synchronizing signal V _BL that is output before the screen is scanned, and then S ₁
The horizontal synchronizing signal _HBL outputted prior to scanning each scanning line of ~ _Sr is counted. That is, the counter 21
The content of the count indicates the number of the scanning line that the TV camera 3 is currently scanning.

Next, the oscillation circuit 22 is a circuit that continuously outputs voltage pulses at time intervals t _a /f, which is obtained by dividing the time t _a during which one scanning line is scanned into f equal parts. The output of the oscillation circuit 22 is connected to the count input terminal in ₂ of the counter 23, and the reset input terminal
Reset ₂ is the horizontal synchronization signal from the synchronization separation circuit 31.
H _BL is connected. Therefore, the counter 2
3 is first reset to 0 by the horizontal synchronizing signal _HBL outputted prior to each horizontal scan, and then counts the voltage pulses outputted from the oscillation circuit 22. That is, the scanning point on the image plane of the TV camera 3 can be calculated based on the count of the counter 23.

On the other hand, the vertical synchronization signal V _BL ,
The video signal of the TV camera 3 from which the horizontal synchronization signal _HBL has been removed is converted into a bright part (a large part of the signal) "1" by the binarization circuit 28 based on a predetermined signal level _{K a} shown in FIG. Dark part (small signal part) “0”
is converted into a binary digital signal (binarized signal). This binary signal is connected to gate opening/closing control terminals N ₁ and N ₂ of gate circuits 24 and 26. The gate circuits 24 and 26 are connected to the opening/closing control terminals N ₁ ,
From the moment the signal applied to _N2 changes from "0" to "1" or from "1" to "0", it remains closed for a certain minute period of time, and the input and output are connected.

Therefore, when a "shadow" image on the surface of the target object 4 is captured by the TV camera 3, the scanning line number (counting content of the counter 21) where an arbitrary point P _i exists and one scanning line Position within the line (counter 2
3) is stored in the memory circuits 26 and 27 through the gate circuits 24 and 26. Here, the contents of the memory circuit 26 are assumed to be m _i , and the contents of the memory circuit 27 are assumed to be n _i . Note that the above n _i for one scanning line
In some cases, a plurality of (for example, p) are obtained, and all of them are stored in the memory circuit 27 as n _i1 to n _ip .
to be memorized.

Hereinafter, using the above m _i and n _i , Fig. 2a and Fig. 2b
A method of determining the X, Y coordinates (X _i , Y _i ) of point P _i on the surface of the target object 4 in the figure will be explained.

Now, the following relationship holds true in triangle Z _i P _i Z _L.

L tan[γ+(α/ν)×j]−Z _L Z _Q /L tan[γ
+(α/ν)×j]=X _i /L... Here, L: Length from the principal point S of the lens to the Z axis γ: Distance between the horizontal plane including the principal point S of the lens and the field of view of the TV camera Angle formed by the upper edge line α: Viewing angle of the TV camera ν: Number of scanning lines in one screen (therefore, α/ν is the angle between adjacent scanning lines) J: Number of the scanning line where point P exists Z _Q ; Point where the horizontal plane containing the principal point S of the lens intersects with the Z-axis _{L Q} ; Point where the horizontal plane containing point light source 2 intersects with the Z-axis
The equation for the length between Z _L and Z _Q above can be transformed as follows.

X _i =L tan[γ+(α/ν)×j]−Z _L Z _Q /tan[γ+
(α/ν)×j]... At this time, L, γ, and _{L Q} can be measured and known at the time of installation and adjustment of each device,
Furthermore, since α and ν are constants determined by the configuration of the TV camera and optical system, the X coordinate X _i of the point P _i can be determined from the above value of j.

Furthermore, the coordinates of Y _i can be determined as follows.

From Figure 2a, Y _i /Δy _i =Y _i ′S/Z _i ′S = (Z _L S−X _i cosβ)/Z _i ′S …… Dashi _L = Ltan(γ+α/2) Δy _i =n _i × Δt ... However, Δt: Length obtained by dividing the length of one scanning line on the imaging surface 10 of the TV camera 3 into f equal parts From the formula, Y _i = (n _i × Δt) × (Z _L S− X _i cos β/Z _i ′S ... At this time, L and γ are determined by measurement as described above, and _i ′ and Δt are constants determined by the configuration of the TV camera and optical system, so Point P _i
The Y coordinate Y _i of can be determined from the values of n _i and j.

The calculations of each of the equations and can be realized by the calculation device 40 shown in FIG. 5, such as a microcomputer, according to the flowchart shown in FIG.
In this embodiment, geometrically or physically, the values of _i ,, _i , sinβ, cosβ, Δq, Δt and the value of _i ·sinβ are input in advance into the memory of the microcomputer 40 as known constants. However, if a numerical input device such as a keyboard switch (not shown) is connected to the microcomputer 40, the set values can be easily changed.

After calculating all (X _i , Y _i ) regarding one screen of the TV camera 3 and storing the calculation results in the memory 41 of the microcomputer 40, the mount 1 shown in FIG. , for example, by Δh and performs the same measurement and calculation process as above, and the microcomputer 40
The data is stored in the memory 41 of.

The above explanation was made for one measuring device including one TV camera 3. Target object 4
In order to three-dimensionally measure the entire circumference of the target object, the mount 9 on which the target object 4 is placed has a structure that can be rotated about the Z-axis as a center line, and the mount is sequentially rotated by predetermined angles. It may be measured in order. In another embodiment of the present invention, in order to increase the speed, a plurality of TV cameras 3 (four in FIG. 1a) are installed at equal distances from the Z axis, which is the center line of the target object 4, and , the measurement processing section 30 in FIG.
By providing a number equal to the number of TV cameras 3, the aforementioned m _i and n _i are respectively determined. Then, by inputting each m _i and n _i into the microcomputer 40 and calculating each (X _i , Y _i ) and storing it in the memory 41 of the microcomputer 40, the "shadow" of the entire circumference of the target object 4 is calculated. The shape of the horizontal plane including the top or bottom edge can be measured. At this time,
Multiple images are obtained by multiple TV cameras 3, and overlap occurs between adjacent images, but by setting the range to be captured by each TV camera 3 in advance, data (X _i , Y _i ) can be avoided.

Next, a means for duplicating a three-dimensional image from each section data (X _i , Y _i , Z _i ) of the target object 4 obtained by the above-described means will be explained.

Now, the data of the cross sections taken and measured by the four TV cameras shown in Figure 1a are expressed as (X _i ,
Y _i , Z _i ) ₁ to (X _i , Y _i , Z _i ) ₄ .

As shown in FIG. 5, an NC laser cutting machine control device 42 is connected to the microcomputer 40.
Furthermore, an NC laser cutting machine 43 for cutting thin plates is connected to the control device 42, forming a processing system controlled by NC commands from the microcomputer 40. First, a thin plate (made of a material that can be cut by a laser) having a thickness of Δh is set on the processing table of the laser cutting machine 43, and then cut by the microcomputer 40 to the NC laser cutting machine control device 42. Start NC cutting by giving NC command (X ₁ , Y ₁ , Z ₁ ) ₁ as the origin, and sequentially (X ₂ , Y ₂ , Z ₁ ) ₁ , ... (X _l , Y _l ,
N ₁ ) ₁ , then (X ₁ , Y ₁ , Z ₁ ) ₂ ,...(X _l ,
Y _l , Z ₁ ) ₂ , (X ₁ , Y ₁ , Z ₁ ) ₃ ,...(X _l , Y _l , Z ₁ ) ₃ ,
By cutting in the order of (X ₁ , Y ₁ , Z ₁ ) ₄ , ... (X _l , Y _l , Z _l ) ₄ , ..., the cross-sectional shape of the target object 4 at the height Z ₁ with respect to the Z axis is the same. Templates can be created.

Next, the thin plate having a thickness of Δh is set on the processing table of the laser cutting machine 43 again, and the NC commands (X ₁ ,
By giving Y ₁ , Z ₂ ) ₁ , ... (X _l , Y _l , Z ₂ ) ₄ , create a template with the same cross-sectional shape as the target object 4 at the height Z ₂ with respect to the Z axis, and use this as the target object. Templates for all cross sections of the target object 4 can be created by repeating the process for the length of the target object 4 in the Z-axis direction (maximum value of the measured Z _i ). A duplicate image can be created by superimposing the templates thus created in the order of increasing or decreasing height Z _i with respect to the Z axis among the measurement data and fixing them by gluing or the like. Furthermore, the data (X _i , Y _i ) are multiplied by N or 1/N by the microcomputer 40, and the thickness Δh of the thin plate to be cut by the NC cutting machine is set to N×Δh or 1/N×Δh. For example, it can be enlarged or reduced to any size.

In the second embodiment shown in FIGS. 6a and 6b, the TV camera 3, which is a two-dimensional imaging device, is fixedly arranged at a fixed position, and its optical axis is set on a horizontal plane including the upper edge of the light shielding plate 11. are intersected at a constant angle β.

As in the case of the first embodiment, the point light source 2 is fixed to the support base 1 so as to be located on either one of the horizontal planes including the upper edge or the lower edge of the light shielding plate 11, or on both horizontal planes. , the support stand 1 is positioned vertically between the point light source 2 and the target object 4.
is fixed.

The support base 1 is also fixed to a ball nut screwed onto a ball screw shaft 5, as in the case of the first embodiment, and the ball screw shaft 5 is connected to a motor (not shown), which controls the height of the thickness Δh of the slit light. The support stand 1 is driven up and down in stages.

The point light source 2 may be, for example, a light emitting diode or a small white light bulb.

Part of the irradiated light from the point light source 2 is blocked by the light shielding plate 11, projecting a "shadow" on the surface of the target object, and this "shadow" is imaged by the TV camera 3 and displayed on the screen. Then, an image as shown in FIG. 3 appears corresponding to the unevenness of the target object.
This video is obtained by binarizing the video signal of the TV camera and converting it into a black and white image with no intermediate brightness, as in the case of the first embodiment described above.
The second embodiment of the present invention shown in FIGS. 6a and 6b utilizes the shape of the boundary line between the bright part and the "shade" in FIG. The second embodiment is the same as the first embodiment in that it is a method and apparatus for generating an object. For ease of explanation, the vertical center line of the target object 4 will be referred to as the Z-axis, and on a plane that is perpendicular to the Z-axis and includes the lowest point of the target object 4, the axes perpendicular to the Z-axis will be referred to as the X-axis. , the Y-axis, and the plane is called the "reference X-Y plane", and the reference X-Y plane and the plane parallel thereto are called the "X-Y axis system plane". In addition, here we will only describe a method that uses the boundary line of the "shading" projected by the upper edge of the light shielding plate, but it is easy to realize the "shading" by the lower edge using exactly the same method. will be understood.

When the target object is irradiated with light from the point light source 2, part of whose luminous flux is blocked by the light shielding plate 11, the "shadow" image in this cross section of the target object 4 becomes an image as shown in Fig. 3. A TV camera captures the image. As in the case of the first embodiment, this is measured as the coordinate system of the "shadow" cross-sectional plane, that is, the X-Y axis plane.

As described above, in the present invention, by using the point light source 2, the light shielding plate 11, and the two-dimensional imaging device 3 such as a TV camera, and by using the above equation, the "shadow" plane, that is, the X-Y axis The cross-sectional shape of the target object in the system plane can be determined, and this can be determined by sequentially moving the support base 1 by a constant minute pitch Δh from the top end ZT to the bottom end _Z0 of the target object 4, and calculating the shape of its "shadow". Obtain the data (x _i , y _i ), and calculate the shape data (X _i , y i ) on each “shadow” plane.
Y _i ) is input into, for example, an NC laser cutting machine, and Δh
By cutting out templates of the same shape from a plate with a thickness of , and sequentially overlapping these templates in the order of measurement, it is possible to form a three-dimensional image with exactly the same shape as the target object.

Also, just to be sure, the above calculation can be applied to the TV camera 3 shown in the lower part of FIG. By arranging a point light source, data on the upper and lower shadows can be collected simultaneously, making it possible to reduce measurement time by approximately half. Also, depending on the shape of the image, it may be advantageous to change the intersection angle between the optical axis of the lower TV camera 3 and the plane of the "shadow".

These operations can also be easily computed by similar general-purpose microcomputers.

I would venture to add that within the technical scope of the present invention, "shading" caused by a point light source and the edge of a light shielding plate is not covered.
Of course, this also includes the use of an appropriate number of two-dimensional imaging devices in order to image the entire circumference of the image.

In addition, the sensitivity of the two-dimensional imaging device only needs to be able to recognize shadows and distinguish them from bright areas.On the other hand, point light sources do not have such a luminous intensity. Good to have. Furthermore, regarding the values on the X-Y axis plane mentioned above, when forming similar objects, it is possible to form objects of arbitrary size by processing the magnification of the two-dimensional imaging device or the measurement data with a predetermined constant. It is also obvious in light of the principles of the present invention that it can be formed.

〔Effect of the invention〕

As has become clear through the above description, according to the method and apparatus of the present invention, all of the technical problems are solved very effectively and the following unique and remarkable effects are brought about.

(b) Not only in the case of a target object with a simple external shape, but also in the case of a target object with a relatively complex shape, and even in the case of a target object itself made of various materials. By applying the method and apparatus of the present invention, a reproduced three-dimensional image can be obtained easily, quickly, and with high precision.

(b) In the present invention, since a normal point light source can be used as the light source, a special optical system required to obtain slit light with a predetermined minute thickness can be omitted, and the configuration of related parts including the light source can be omitted. becomes simple.

(c) In the present invention, the "shading" of the edge of the light shielding body is sequentially projected onto the surface of the target object at a constant pitch, and the "shading" is photographed to obtain cross-sectional shape data.
The boundary between the “shadow” and the bright area is clear, so
Since it is easy to identify it using a two-dimensional imaging means, extremely high accuracy can be expected from the reproduced three-dimensional image based on the cross-sectional shape data of the target object obtained in this way.

(d) In the present invention, the angle formed by the optical axis of the two-dimensional imaging means with respect to the reference X-Y plane of the target object is
that is constant throughout the measurement process;
Moreover, this two-dimensional imaging means is integrally coupled with the point light source and the light shielding body so as to have a predetermined geometric (that is, spatial) relationship with each other, and is supported by a single support base. Since it is only necessary to move these components integrally in a predetermined minute pitch throughout the measurement process, it is not only easy to position the main components and configure their installation or support. The moving mechanism itself and the control circuit for its movement can also be simple.

[Brief explanation of drawings]

1a and 1b are drawings showing the configuration of a first embodiment of an apparatus embodying the idea of the present invention regarding a three-dimensional image forming method and apparatus, FIG. 1a is a plan view of the apparatus, and FIG. 1b is a FIG. Figures 2a and 2b are drawings for explaining the basic principle of the present invention, and correspond to the above-mentioned figures 1a and 1b, respectively. This clarifies the measurement of the "shadow" of FIG. 3 is a drawing conceptually illustrating bright areas and "shadow" images appearing on the display screen of a TV camera used as a two-dimensional imaging device in the above embodiment of the present invention, together with scanning lines. . FIG. 4 also shows the device of the above embodiment,
3 is a drawing showing an example of a waveform diagram of an output signal from a TV camera. FIG. FIG. 5 is a block diagram showing a control circuit for processing an output signal from a TV camera in the above-mentioned embodiment. FIGS. 6a and 6b are drawings showing the configuration of a second embodiment of the apparatus embodying the idea of the method and apparatus of the present invention, and are a plan view and a side view of the embodiment, respectively. Further, FIG. 7 is a flowchart showing the arithmetic processing process within the microcomputer in FIG. 5 above. Explanation of reference numbers in the figures: 1...Support stand, 2...
point light source, 3... two-dimensional imaging device (for example, TV camera), 4... target object, 5... ball screw shaft,
6...ball nut, 7...guide pillar, 11...shading plate.

Claims (1)

[Scope of Claims] 1. A plate-shaped light-shielding body having at least one of its upper edge and lower edge forming a flat plane, the plate-shaped light-shielding body being disposed vertically opposite to a measurement position where a target object is placed. and disposed on a plane including an edge forming a flat plane of the plate-shaped light shield, on the opposite side of the edge to the measurement position, at a position spaced apart from the outside of the light shield by a predetermined distance, a point light source that emits light toward the measurement position; and an optical axis that intersects at a constant angle with respect to a plane including the edge, and has a predetermined relationship with the light shield and the point light source. a positioned two-dimensional imaging means; a support stand to which the two-dimensional imaging means, the light shielding body, and the point light source are fixed; a guide device that can move the support stand by a constant minute pitch Δh in the vertical direction; A device for measuring the three-dimensional shape of a target object, comprising: a data processing device that measures the shape of a cross section of the target object from an image representing the shape of a "shadow" captured by a dimensional imaging means and obtains data regarding the shape of the cross section. The target object is placed at a measurement position, and the guide device sequentially moves the support stand in one direction at a certain minute pitch Δh, and each time it moves, the point light source irradiates the support stand to measure the target object. Projecting the "shadow" of the light shield onto the surface of the target object, capturing an image of the shape of the "shadow" by the two-dimensional imaging means, and determining the target object from the captured image by the data processing device. A device for measuring the three-dimensional shape of a target object, which measures the shape of one cross section of a target object and obtains data regarding the shape of the cross section. 2. Surrounding the outer periphery of the target object with a plate-shaped light shielding body, and irradiating the light shielding body and the target object with light from a point light source on a horizontal plane including the edge of the light shielding body, so as to illuminate the surface of the target object. Projecting the "shadow" of the light shielding body, and imaging the shape of the "shadow" on the surface of the target object using a two-dimensional imaging means having an optical axis intersecting at a certain angle with respect to the horizontal plane; The shape of one cross section of the target object is measured from the image showing the shape of the "shade" created, data regarding the shape of the cross section is obtained, and then the light shield and the point light source are sequentially moved at a constant minute pitch Δh. The same procedure as described above is sequentially repeated for the cross-sections of the target object adjacent to the above-mentioned one cross-section while Then, templates of the same shape corresponding to each cross section of the target object are created from a thin plate material having the same thickness as the one-time micro-movement pitch Δh of the light shielding body, or a thickness having a predetermined relationship therewith. A method for forming a three-dimensional image having the same shape as the target object, comprising sequentially stacking templates according to the order of each measurement performed in the above-described procedure. 3. Projecting the "shadow" of the light shield onto the surface of the target object by irradiating light from a point light source on a horizontal plane including the edge of the plate-shaped light shield surrounding the outer periphery of the target object, and With a two-dimensional imaging device that has optical axes that intersect at a certain angle,
imaging the shape of a “shadow” on the surface of the target object;
The shape of one cross section of the target object is measured from the captured image representing the shape of the "shade" to obtain data regarding the shape of the cross section, and then the light shield and the point light source are sequentially moved at a constant minute pitch Δh. While moving the target object, the same procedure as described above is repeated for the cross section adjacent to the one cross section of the target object, and the cross-sectional shape data obtained by the measurement for each cross section of the target object is thus obtained. Using the above, templates of the same shape corresponding to each cross section of the target object are created from a thin plate material having the same thickness as the minute movement pitch Δh or a thickness having a predetermined relationship therewith, and these templates are of,
By sequentially stacking the layers according to the order of each measurement performed in the same procedure as described above,
The device forms a three-dimensional image having the same shape as the target object, wherein the plate-like light shield surrounds the outer periphery of the target object such that at least a part of it is interposed between the target object and the point light source. arranged vertically, and
At least one of its upper or lower edges forms a flat plane; The two-dimensional imaging device is mounted on a support stand integrally with the object at a distance, and the two-dimensional imaging device detects the shadow of the light shielding body generated on the surface of the target object by light irradiation from the point light source. In order to image the shape, it is positioned and mounted on the support base so as to have a predetermined relationship with the light shield and the point light source, and the "shadow" imaged by the two-dimensional imaging device
and a processing device that measures the shape of the cross-sectional shape and processes the cross-sectional shape data obtained by the measurement; A device for forming a three-dimensional image having the same shape as a target object, characterized in that the device is equipped with a guide device for moving the object by a constant minute pitch Δh.