JPS6118962B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic edge line coordinate measuring device that automatically searches for and tracks the edge lines of a three-dimensional object without contact, and is capable of measuring the coordinates of the edge lines without contact. .

Generally, structures, machine parts, molds (press molds,
At the stage of manufacturing molds, etc.), models, etc., the three-dimensional coordinates of the edges where multiple planes intersect, that is, the ridge lines, are used as data representing those shapes and as standards for inspection and manufacturing. There are many. For example, when manufacturing a model or mold of an automobile body, the shape of the surface of the body is generally a free-form surface, but the three-dimensional coordinates of the ridgeline are rarely used as the manufacturing standard or inspection standard for this surface. be.
In particular, since most of the ridge lines in the appearance of the body indicate the characteristics after completion, the coordinate values of these ridge lines are particularly important, and must be precisely measured and inspected.

Measuring the general surfaces and free-form surfaces of such three-dimensional objects has already been carried out automatically using three-dimensional coordinate measuring machines, etc., but when measuring the coordinate values of the edges, it is necessary to measure the edges by visual inspection. In most cases, the measuring needle is aligned with the vertex, and while surface measurement and general machining are automated, the man-hours spent on this edge line measurement are extremely large, and the measurement accuracy varies widely. Development of an automatic measurement method was desired.

Conventionally, as a method for measuring this ridgeline position, a measurement method using laser beam deflection scanning has been proposed in order to trace the weld line with an automatic welding device. This proposed measurement method projects deflected light directly onto the measurement target, and measures by moving the device so that the projected light is evenly deflected left and right around the ridgeline. Since the projected light spreads in a fan shape, the sensitivity for detecting the deviation between the projected optical axis and the edge changes depending on the distance to the measurement target, and the detection accuracy is directly limited by the diameter of the spot beam. This has the disadvantage that high-precision measurements are difficult. Furthermore, since this conventional method does not have an automatic compensation function to measure the distance to the target, the distance at which the ridgeline position can be effectively tracked is determined by the width of the detection slit and the angle between the receiving axis and the emitting axis. The angle between the light emitting axis and the light receiving axis is made small in order to expand this range, which is limited to an extremely narrow range in the vicinity of a certain distance. As a result, the accuracy of measuring the positional deviation of the ridgeline is reduced, and this method has the disadvantage of being difficult to apply to objects with large ridge crests. Also, since it does not have a distance setting function, offline manual distance setting is required, and this conventional measurement method alone cannot
It has been impossible to automatically track the edges of an object with an arbitrarily complex three-dimensional shape and to accurately measure the three-dimensional coordinate values of the edges.

In order to eliminate the drawbacks of the conventional example, the present invention provides
A thin beam of light deflected to a certain width is projected onto the beam, and this reflected light is detected by a detection means having a light detection area that is long in the x-axis direction and has a minute width to measure the deviation in the x-direction. A ridge line that measures the distance in the y direction of the object to be measured by detecting the reflected light in the range on both sides sandwiching the width of the light detection area using two light detection means that separately detect each side. A coordinate measuring device is provided. That is, the configuration of the present invention includes a thin light beam generating device that projects a thin light beam scanned with a constant width at a constant repetition period onto the edge of the object to be measured from the normal direction of the edge so that the scanning direction crosses the edge line; The reflected light from the edge of the object to be measured is focused at a predetermined angular position in the direction perpendicular to the scanning direction of the thin beam, and "∧" or "∨" corresponds to the cross-sectional shape of the edge of the object to be measured. a light-receiving means for forming a character-shaped image, and among the imaging light of the light-receiving means, imaging light enters an area having a predetermined length in the scanning direction of the thin light beam and a minute width in the vertical direction; In other words, a first light detection means detects the intensity of light at the corner of the "∧" or "∨"-shaped image, and a first light detection means detects the intensity of the light at the corner of the "∧" or "∨"-shaped image, and a first light detection means detects the light intensity of the image formed in the upper and lower ranges sandwiching the above-mentioned area and excluding the above-mentioned area. a detection optical system head to which second and third photodetection means for detecting the intensity are fixed; such that the output signal of the first photodetection means has a constant repetition period synchronized with the scanning period; , an x-axis servo means for moving the head of the photodetection optical system in the scanning direction of the narrow beam of light, and controlling the positional deviation between the center of the scanning range and the ridge line in the scanning direction to be zero; The distance between the detection optical system head and the edge of the object to be measured is changed so that the output signals of the second and third detection means have a predetermined relationship. y-axis servo means for controlling the distance to be kept constant; z-axis servo means for moving the optical system head at a constant speed in a direction perpendicular to the scanning direction of the narrow beam, that is, in the direction of the ridge line; The apparatus is characterized by comprising means for displaying the amount of movement of the optical system head by each of the servo means for the axes, y-axis, and z-axis as coordinates of the ridge line.

Further, in the present invention (second invention), in the above configuration, the light incident on the first light detection means is further reflected at right angles to a predetermined length direction of the area of the first light detection means. , detecting the intensity of the imaged light entering a region having a predetermined length in the same direction as the region of the first light detection means and having a minute width different from the region of the first light detection means; a fourth light detection means is provided in the detection optical system head, and
The first, second, third,
The fourth light detecting means is rotated around the light receiving axis of the light receiving means while maintaining the same positional relationship, and the angle is determined to reduce an error that occurs when the normal direction of the ridge and the projection optical axis of the thin beam are tilted. It is characterized by the addition of setting servo means.

Embodiments will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.
is a narrow light source with good directionality such as a laser, and 2 is the light source x
Optical deflector that deflects and scans in the axial direction, 3 is optical deflector 2
4 is an object to be measured with a ridge, and 5 is an optical axis (hereinafter referred to as the projection optical axis, y-axis) of the projection lens 3, which is located at an angle from 0° to the center of deflection of the projection lens.
6 is a second light-receiving lens that has a certain angle within 90 degrees and has an optical axis (hereinafter referred to as the light-receiving axis) orthogonal to the deflection scanning direction, and focuses the reflected light from the object to be measured 4 and forms an image. It is a trapezoidal prism whose details are shown in the figure, and has a structure in which the upper base surface 6c and the lower base surface 6d transmit light, and the surfaces 6a and 6b reflect the light, and the surface 6c is the imaging surface of the light receiving lens 5. matches,
Its longitudinal direction (indicated by X in the figure) is arranged parallel to the optical deflection scanning direction (x-axis), and its width w and height l
is a trapezoidal prism having a size that sufficiently covers the image formation, 7 is a first photodetector that converts the light transmitted through the trapezoidal prism 6 into an electrical signal, and 8 is the trapezoidal prism 6
9 is a second photodetector that converts the light reflected on the 6a surface of the trapezoidal prism 6 into an electrical signal; 9 is a third photodetector that converts the light reflected on the 6b surface of the trapezoidal prism 6 into an electrical signal; 10, 13; , 14 are amplifiers that amplify the weak signals of the first, third, and second photodetectors 7, 9, and 8 to the level required for signal processing, 12 is a reference source that drives the optical deflector 2, and 11 15 is a phase detector that detects the phase of the signal that has passed through the photodetector 7 and amplifier 10 using the signal from the reference source 12 as a reference; 15 is the photodetector 7, 8,
9, an arithmetic control logic circuit that calculates the correlation between the signals of the amplifiers 10, 13, and 14; 16, a power amplifier that amplifies the signal of the phase detector 11; 17, the power amplifier 1;
6, the detection optical system head 28 on which the light source 1, light deflector 2, light projecting lens 3, light receiving lens 5, trapezoidal prism 6, and photodetectors 7, 8, and 9 are mounted is converted into a three-dimensional beam in x, y, and z. A drive motor 19 drives the arm 18 in the optical deflection scanning direction of the three-axis arms of the three-dimensional drive mechanism 29, that is, the x-axis in the example of FIG. A power amplifier for amplifying the output; 20 a drive motor for driving the arm 21 in the direction of the projection optical axis of the three-axis arms of the three-dimensional drive mechanism 29, that is, the y-axis in the example of FIG. 1; and 22 for the arm 18; A distance measuring device 23 is attached to the arm 21 and measures the amount of movement of the arm 18. A distance measuring device 23 is attached to the arm 21 and measures the amount of movement of the arm 21. A power amplifier 24 amplifies commands from the control device 30. A power amplifier 25 By the output of the amplifier 24, one axis of the three-axis arms of the three-dimensional drive mechanism, the two-axis arm 2 in the ridge direction in FIG.
6 is a drive motor that drives the arm 26; 27 is a distance measuring device that is attached to the arm 26 and measures the amount of movement of the arm 26; 30 is a main controller of the measuring device of the present invention;
1 is a display/recording device, and 32 is a locus of the deflected scanning light on the object.

Next, the operating principle of this embodiment will be explained. first,
To explain the principle of detecting the displacement of the ridge vertex in the A galvano mirror, etc. that repeatedly deflects around the projection optical axis at a sufficiently fast frequency f ₁ in one axis direction perpendicular to the projection optical axis, that is, in the positive and negative directions of the x-axis when the projection optical axis is the y-axis, by its own oscillation. The light beam is repeatedly deflected by a wide-angle deflectable light deflector 2, passes through a projection lens 3 whose focal point coincides with the center of deflection of the light deflector 2, and is directed to the ridgeline of the object to be measured 4. is cut at right angles and projected to scan the vicinity of the ridgeline. With this configuration, the projection lens 3 transforms the polarized light that is diffused fan-shaped from the deflection center into a beam array that performs band-shaped deflection scanning parallel to the projection optical axis, reducing the distance dependence of displacement detection sensitivity. However, by further converging the thin light beam, the diameter of the light spot on the object to be measured 4 can be made minute, and the detection resolution can be improved.

As an example, if the deflection angle of the light deflector 2 is 0.1 rad and the focal length of the projection lens 3 is 100 mm, the deflection scanning width will be 10 mm regardless of the distance, and the deflection scanning width will be 10 mm regardless of the distance. The diameter of the light spot on the object near the focal point O is about 0.1 mm.

This will be explained in detail with reference to FIG. 25.

As described above, the deflection center of the optical deflector 2 coincides with the focal point of the projection lens 3. As is well known, light rays passing through the focal point of a lens take a path parallel to the optical axis after passing through the lens. Similarly, a laser beam deflected by an optical deflector is the same as the beam that comes out from the focal point, no matter what angle it faces the lens.
After passing through the lens, it becomes parallel to the optical axis.

In other words, the deflection scanning width is independent of distance.
Also, its value (see Figure 25) is: W = 2 x ft x tan (θt/2) ≒ ft・θt = 100 mm x 0.1 rad = 10 mm Also, as is well known, the parallel light flux incident on the lens has a very small amount on the focal plane. It is squeezed in as a point of light. Its size (light spot diameter: w) varies depending on how close it is to ideal parallel light. In the case of a very small divergence angle (△θ) of the light beam, the light spot diameter is w≒ft×△θ Generally, the divergence angle of a light beam with good directionality, such as a gas laser, is about 1 mrad, and it is almost a parallel light beam. It can be considered as From this, w≒100mm×1mrad=0.1mm.

In such optical scanning, the trajectory 32 of the band-shaped deflected scanning light near the ridge line is created using the principle of the well-known optical cutting method.
represents the cross-sectional shape of that part. The light-receiving lens 5 is located on the yz plane in FIG. The light is focused by a light receiving lens 5 having a light receiving lens 5. In general, reflected light from ordinary objects other than well-polished metals includes specular reflected light, which causes a glossy appearance, and diffuse reflected light, which is scattered around the entire circumference. The light polarization direction is the x-axis direction, and in the arrangement shown in FIG. 1, the specularly reflected light is reflected in the direction of the reflection angle equal to the incident angle, and almost never returns to the yz plane direction.
Since the above-mentioned diffusely reflected light is scattered in the entire circumferential direction, light detection from the yz plane direction is also possible. The value of θ is typically on the order of π/4rad.
The light that has passed through the light-receiving lens 5 is near the upper base surface 6c of the trapezoidal prism 6 shown in FIG.
An image corresponding to the cross-sectional shape of the edge of the object to be measured 4 is formed, for example, an "∧"-shaped image in the case of a convex edge, and an "∨"-shaped image in the case of a concave edge. This trapezoidal prism 6
The surface 6c includes the imaging point O' of the origin O, coincides with the plane M perpendicular to the light-receiving axis, its longitudinal direction is parallel to the x-axis, and its center coincides with the imaging point O'. X and Y are shown on the plane M corresponding to the x-axis and y-axis on the side of the space to be measured. The trapezoidal prism 6 allows only the light from the bent portion of the image thus obtained, that is, the image forming point P' of the ridge apex P shown in FIG. 4 to pass through the surfaces 6c and 6d of the trapezoidal prism 6. Therefore, the width of the surface 6c is only slightly larger than the image formation P'. The light that has exited the trapezoidal prism 6 is placed immediately after the trapezoidal prism 6, and enters a photodetector 7 that effectively converts all the transmitted light into electrical signals. The output of this photodetector 7 is amplified by an amplifier 10 to a level necessary for signal processing.
This becomes a signal input to the phase detector 11. A reference signal of frequency f 1 is supplied to the reference signal input of the phase detector 11 from the reference oscillation source 12 that drives the optical deflector ₂ . Further, the phase detector 11 compares the signal from the photodetector 7 with a reference signal, and outputs a signal corresponding to the displacement of the ridge apex P with respect to the origin O in the x-axis direction.

Next, details of the functions described above will be explained with reference to FIGS. 3 and 4. FIG. 3b is a diagram viewed from above when the origin O and the ridge apex P coincide on the projection axis consisting of the light source 1, the optical deflector 2, and the projection lens 3, that is, the y-axis. Optical axis direction of light receiving lens,
That is, on the yz plane, the trajectory of the scanning light observed from the angular direction of θ with respect to the y axis is as shown in FIG. 3b'. Also, Figure 3 a and c show the case where the ridge apex is displaced in the negative and positive directions of the x-axis with respect to the origin O, and the trajectory of the light at that time is as shown in Figure 3 a' and c'. become. Furthermore, the trajectory of the light shown in FIG.
The image is formed as shown in c. Also, Fig. 4 a′,
b′, c′ and a″, b″, c″ are the time course of the position of the imaged light point, and this imaged light point intermittently passes through the trapezoidal prism 6 and is photoelectrically converted by the photodetector 7. It shows the time course of the signal.

In Fig. 4a, when the origin O and the edge apex P coincide,
That is, it corresponds to the state shown in FIG. 3b, and FIG. corresponds to the case where the edge apex P is displaced in the negative direction of the x-axis with respect to the origin O, that is, the state shown in FIG. 3a. Fourth
As shown in figures a', b', and c', the light spot position scans the positive part of the x-axis during the positive half period of the optical deflection period, that is, from O to T/2, and during the negative half period, That is, assuming that the negative part of the x-axis is scanned between T/2 and T, the light of the image P' at the ridge apex is shown by the dotted lines in Figure 4 a, b, and c, which represent the time course of the light spot position. At the time when the solid line intersects with the solid line representing As is clear from Fig. 4, when the origin O and the ridge apex P coincide, the photodetector signal becomes a signal sequence every T/2, but
When the ridge apex P is displaced in the positive direction of the x-axis, the signal train becomes biased during the positive half period O to T/2,
When the ridge apex P is displaced in the negative direction of the x-axis, the signal train becomes biased between the negative half period T/2 and T.
Even if this signal is directly subjected to normal phase detection, a positive or negative DC signal can be obtained depending on the displacement of the object to be measured in the x-axis direction, with the zero point being the case where the ridge apex P and the origin O coincide. , as is clear from Figure 4 a″, b″, and c″, the information regarding the displacement is only included in the signal time deviation ±δt, and has no relation to the signal strength _I0 , and the signal time deviation If only the light is detected, there will be no change in sensitivity due to changes in the reflectance of the object or the output of the light source, and accuracy can be improved.

Figure 4 Signal time deviation at a″, b″, c″±
An embodiment of a phase detector that measures only δt will be described with reference to FIG. In FIG. 5, the signal of the photodetector 7 of FIG. 1 (see FIG. 6b) is transmitted to the input terminal 32.
A is input to the switch circuit 35 through buffer amplifiers 33 and 34 which are inverted and non-inverted with an amplification degree of 1.
is input. This switch circuit 35 is connected to the comparator 3
It is driven by the output of 9. A triangular wave (see FIG. 6c) whose phase matches that of the optical deflection signal is input to the reference input terminal 40 of this comparator. Now the origin O
When the ridge apex P matches and the output of the photodetector 7 is a signal train output every T/2, the output of the amplifier 36 and the low-pass wave generator 37 is zero, and the output of the integrator 38 is also zero. The output of the comparator 39 is the optical deflection signal (sixth
A rectangular wave signal with a duty cycle of 50% is output, which corresponds to Figure a). Here, when the ridge apex moves and the signal at the input terminal 32a causes a time lag of dt, an error voltage ε is generated at the output of the low-frequency converter 37, and the output of the integrator 38 also increases, thereby causing The output of the comparator 39 also changes, and as shown in FIG. 6b, the half period on the biased side of the output signal of the photodetector 7 becomes narrower, and at the point when this signal coincides with the time difference δt, The output ε of the low frequency filter 37 becomes zero again, the output of the integrator 38 stops increasing, and the output of the comparator 39
The output is a square wave whose duty cycle has changed by 2dt. That is, the circuit shown in FIG. 5 constitutes a loop that follows the time lag of the signal. After this, the signal in Figure 6d can be detected by the optical deflection signal and the mismatch detection logic (EX-OR), passed through a low-pass waveformer in an analog manner, and measured as a DC signal, or digitally measured as a DC signal. It is also possible to measure with a distance measurement counter, and the time deviation δ corresponding to the deviation δx of the ridge apex in the x-axis direction as shown in FIG.
The input/output characteristics of t can be obtained. Typically, linearity over 80% of the optical deflection range is achieved. It is clear that the above explanation holds true for both convex edges and concave edges.

Next, the principle of detecting the displacement of the ridge apex in the y-axis direction will be explained with reference to FIG. This system for detecting displacement in the y-axis direction shares an optical system with the system for detecting displacement in the x-axis direction, and is characterized in that they operate simultaneously. Figure 8 a, b, and c are the origin O of the ridge apex P.
The displacement δy in the y-axis direction with respect to the ridge apex P and the accompanying path of reflected light from the ridge apex P are shown. 8th
Figure a shows a case where there is no deviation in the y-axis direction between the edge apex P and the origin O, and the reflected light from the edge apex P passes through the trapezoidal prism 6 and faces the reflective surfaces 6a and 6b of the trapezoidal prism 6. surface 6a, surface 6
This shows a state in which all of the light reflected at point b is not incident on photodetectors 8 and 9, which effectively photoelectrically convert it. Figure 8b shows a case where the edge apex P is displaced in the negative direction of the y-axis with respect to the origin O;
The reflected light is reflected by the reflective surface 6b of the trapezoidal prism 6 and enters the photodetector 9. FIG. 8c shows the case of displacement in the positive direction of the y-axis, and the reflected light from the ridge apex P is reflected by the reflective surface 6a of the trapezoidal prism 6 and enters the photodetector 8. The signals of photodetectors 7, 8, 9 are transmitted to amplifier 1
0, 13, and 14 to a level necessary for signal processing, and input to the arithmetic control logic circuit 15 in FIG. This arithmetic control logic circuit 15 performs the operation explained in FIG. , outputs a signal corresponding to the displacement of the edge apex P in the y-axis direction.

The details of this function will be explained with reference to FIG. 9th
Figure a shows the optical trajectory 3 when there is no displacement in the y-axis direction between the origin O and the ridge apex P, and there is only displacement in the positive direction of the x-axis.
2, which corresponds to FIG. 8a. At this time, the outputs of the photodetectors 7, 8, and 9 are the first
As shown in Figures b, c, and d, the photodetector 7
The output of the photodetector 8 has two peaks during one cycle of optical deflection, the output of the photodetector 8 is zero, and the output of the photodetector 9 is an AC signal that becomes zero at the time corresponding to the peak of the photodetector 7. arise. Note that the explanation of FIG. 9 is for a convex edge, but in the case of a concave edge, the explanation of the photodetectors 8 and 9 is reversed. In this state, the arithmetic control logic circuit 1
5 detects that the edge apex P is within a specified distance near the origin, and sends out a signal indicating that it is within the specified distance or a zero signal. Figure 9b shows a state in which the apex of the convex edge is slightly displaced in the positive direction of the y-axis. Four peaks occur during one cycle, and both photodetectors 8 and 9 produce non-zero AC signals, as shown in FIGS. 10g and 10h.
In this state, the arithmetic control logic circuit 15 determines that the time between the four peaks of the photodetector 7 does not include the time 2n-1/4T (n=1, 2,...) During the time interval td, the direction of displacement of the ridge apex is determined depending on which detector the light is incident on, and a signal of a constant positive or negative value indicating "large displacement" is sent out. The case of FIG. 9 shows an example of a convex ridge, and a photodetector 8 detects light from a reflective surface 6a of the trapezoidal prism 6 corresponding to the positive direction of the y-axis at time td. Since the light is incident on y
It is detected and determined that there is a deviation in the positive direction of the axis. In the case of a concave edge, the signal waveforms of the photodetectors 8 and 9 are reversed, but the logic for determining that the edge apex exists on the side with light at time td remains unchanged.

In the state shown in Fig. 9b, when the displacement of the ridge apex P in the y-axis direction becomes very small, the time interval td between the four peaks becomes small, and the photodetector on the side where light is incident at that time becomes output is decreasing. in this case,
The arithmetic control logic circuit 15 determines that the edge apex P approaches the origin O, assigns a positive or negative sign to the absolute value of the output of the photodetector on the side where it has decreased, and sends it out, finally as shown in FIG. 9a. state and stop. This transient state is shown by the broken lines in FIG. 10f, g, and h. Figure 9c shows a state in which the convex edge is displaced in the negative direction of the y-axis. In such a case, the output of the photodetector 7 becomes zero, and the output of the photodetector on the side where the edge apex P is displaced. becomes a DC signal, and the output of the photodetector on the other side also becomes zero. That is, a DC signal is generated at the output of the photodetector 9 at the convex edge, and at the output from the photodetector 8 at the concave edge. In this case, the arithmetic and control logic circuit 15 detects that the ridge apex is "largely displaced" in the y-axis direction observed by one of the photodetectors 8 and 9, which is outputting a DC signal. ” and sends out a signal with a constant positive or negative value corresponding to it.

When the displacement of the ridge apex P in the y-axis direction becomes extremely small in the state shown in FIG. Rise. In this case, the arithmetic control logic circuit 15 determines that the edge apex P has approached the origin O, assigns a positive or negative sign to the instantaneous value at the time of the output drop, and sends it out, ultimately resulting in the state shown in FIG. 9a. It reaches and stops. This transient state is shown in Figure 10j,
Indicated by dashed lines k and l.

FIG. 9d shows a state in which the ridge apex P of the convex ridge is largely displaced in the positive direction of the y-axis. In this case as well, the output of the photodetector 7 is zero, as in FIG. It becomes zero, and the judgment logic and signal sending of the arithmetic control logic circuit 15 also become zero.
Similar to figure c. However, when the edge apex P is moved closer to the origin O, the image formed is incident on the surface 6c from the image points Q' ₁ and Q' ₂ of the end points Q ₁ and Q ₂ of the deflection scan. This means that the signal change time is 2n-1/4T (n=1, 2 , . . .), what occurs is different from the case shown in FIG. 9c. Based on this condition, the arithmetic control logic circuit 15 distinguishes between cases c and d in FIG.
Even when the state shown by the broken line in Fig. 9d is reached, the transmission of a constant value with a positive or negative sign indicating "large displacement" is not stopped, and the state finally shifts to the state shown in Fig. 9b, and from then on, The control logic state of FIG. 9b is switched.

Figure 11 shows an example of the output characteristics of an arithmetic control logic circuit with such a function.
B, C, and D correspond to the respective states of displacement of the convex edge in the y-axis direction in FIG. 9. It is clear that even in the case of a concave edge, the characteristics shown in FIG. 11 can be obtained using similar judgment logic.

As described above, the present invention is capable of simultaneously detecting the displacement of a ridge apex in the x-axis direction and the y-axis direction with respect to the origin.

Next, automatic tracking operation will be explained using FIGS. 1 and 12. First, the output of the arithmetic control logic circuit 15 corresponding to the y-axis vertex displacement is sent to the power amplifier 19, where the power is amplified, and the drive motor 20 is controlled. This drive motor mechanism 20 is a three-axis drive mechanism capable of three-dimensional movement, connected to a detection system body 28 provided in a housing on which all optical systems 1 to 9 are mounted and which prevents disturbance light and electrical noise. The arm that moves in the direction of the projection optical axis among the three-axis moving arms in means such as the three-dimensional measuring machine 29 is driven. The action of this servo system keeps the distance between the detection system main body 28 and the object 4 constant. The amount of movement of the drive arm 21 is measured by the length measuring device 23 of the coordinate measuring machine 29 attached to the arm 21, and recorded as a y-axis ridge line coordinate value. Further, the output of the phase detector 11 corresponding to the displacement in the light projection deflection direction perpendicular thereto is power amplified by the power amplifier 16, controls the drive motor mechanism 17, and moves the three-axis arm in the light projection deflection direction. The arm 18 is driven. Due to the action of this servo system, the detection system main body 28 is always located in front of the object 4. To be precise, the projection optical axis and the ridge apex can always be made to coincide. The amount of movement of the drive arm 18 is measured by a length measuring device 22 attached to the arm 18, and recorded as an x-axis ridge line coordinate value. The remaining one axis of the arms 26 among the three axes is driven by a control device 30, a power amplifier 24, and a drive motor 25 at fixed pitches or programmed intervals in the direction in which the ridgeline extends, and the amount of movement of the arm 26 is as follows: It is measured by a length measuring device 27 attached thereto and recorded as a z-axis ridge line coordinate value. The control device 30 includes length measuring devices 22, 23, 27
The data is stored in a suitable display or recording device 3.
In step 1, data is transferred for each z-axis measurement point artificially designated by a program or the like, and is displayed or recorded as a three-dimensional ridgeline coordinate value. At the same time, the control device 30
In reality, if the direction in which the ridgeline extends does not match the z-axis of the coordinate measuring machine as explained above, and is expressed by the composite direction of the x-axis and y-axis of the coordinate measuring machine, for example, the appropriate direction control the drive arms of the
The detection system main body 28 may be moved in the direction in which the ridgeline extends.

In this manner, the present invention enables non-contact detection of the ridge line of an arbitrary three-dimensional object and automatic non-contact measurement of the three-dimensional coordinate value of the ridge line while automatically tracking the edge line.

In the above embodiment, when tracking the object 4 with very high accuracy, as shown in FIG.
In the example shown in the figure, the direction (represented by the y' axis, which will be referred to as the edge normal in the following explanation) and the projection optical axis (the y axis) coincide as shown in Figure 13b,
If a certain angle is generated, as in the situations shown in FIGS. 13a and 13c, if an attempt is made to measure this angle, a slight error may occur due to this angle, which may pose a problem. That is, Fig. 13 a', b'c' shows the trapezoidal prism 6.
It represents the image formation 32' of the trajectory of light on the
This image formation is distorted as shown in FIGS. 13b' to 13a' and c', and is no longer symmetrical with respect to the y-axis. Therefore, when the image is formed as shown at 32'A in FIG. 14a,
Although there is no actual displacement in the x-axis, the 14th
As shown in Figure c, the output of the photodetector 7 has a time difference shown by the broken line, so the x-axis servo system does not stop and the photodetector is detected when it reaches 32'B in Figure 14. The output of the device 7 has no time difference, and this x
The servo system will stop while the axis remains displaced. This amount of error becomes more significant as the edge angle of the object 4, indicated by φ in FIGS. 13a, b, and c, becomes larger.

FIG. 15 shows another embodiment of the present invention in which the optical system is rotated so that the image of the light trajectory matches that shown in FIG. 13b in order to eliminate the above-mentioned error. 1 is a narrow light source with good directivity such as a laser, 2 is an optical deflector that deflects and scans the light in the x-axis direction, and 3 is a light projector whose focus is aligned with the center of deflection of the optical deflector 2. A lens 4 is an object to be measured having an edge, 5 has a constant angle within 0° to 90° with the optical axis of the projection lens 3 (hereinafter referred to as the projection optical axis, i.e., y axis),
The light receiving lens has an optical axis (hereinafter referred to as the light receiving axis) perpendicular to the deflection scanning direction and focuses the reflected light from the object to be measured 4 and forms an image. 6 is a trapezoidal prism whose details are shown in FIG. The structure is such that the base surface 6c and the lower base surface 6d transmit light, and the surfaces 6a and 6d reflect the light. ) is a trapezoidal prism arranged parallel to the light deflection scanning direction (x-axis) and whose width w and height l are large enough to cover the image formation. A first photodetector 8 converts the light reflected on the 6a surface of the trapezoidal prism 6 into an electrical signal, 9 a second photodetector that converts the light reflected on the 6b surface of the trapezoidal prism 6. Third photodetectors 10, 13, and 14 that convert light into electrical signals amplify the weak signals of the first, second, and third photodetectors 7, 8, and 9 to the level required for signal processing, respectively. 12 is a reference oscillation source that drives the optical deflector 2;
Reference numeral 1 refers to a photodetector 7 using the signal from the reference source 12 as a reference, and a phase detector that detects the phase of the signal that has passed through the amplifier 10. Reference numeral 15 refers to photodetectors 7, 8, 9 using the signal from the reference source 12 as a reference. Amplifier 10, 13, 1
an arithmetic control logic circuit that calculates the correlation between the signals of No. 4; 1;
6 is a power amplifier for amplifying the signal of the phase detector 11; 17 is a power amplifier 16; the light source 1; the optical deflector 2; the light projecting lens 3; the light receiving lens 5; the trapezoidal prism 6; and the photodetectors 7, 8, 9. The optical deflection scanning direction of the three-axis arm of the three-dimensional drive mechanism 29, which has the function of moving the detection optical system head 28 carrying the detection optical system head 28 in three dimensions of x, y, and z, that is, the x-axis in the example of FIG. 19 is a power amplifier that amplifies the output of the arithmetic control logic circuit; 20 is a drive motor that drives the arm 18;
A drive motor 22 that drives the arm 21 in the projection optical axis direction of the three-axis arms of the dimensional drive mechanism 29, that is, the y-axis in the example of FIG. 1, is attached to the arm 18, and measures the amount of movement of the arm 18. distance measuring device,
23 is a distance measuring device that is attached to the arm 21 and measures the amount of movement of the arm 21; 24 is a power amplifier that amplifies commands from the control device 30; 25 is a power amplifier 2;
A drive motor 27 is attached to the arm 26 and drives the remaining one axis of the three-axis arms of the three-dimensional drive mechanism, the two-axis arm 26 in the ridgeline direction in FIG. 30 is the main controller of the measuring device of the present invention; 31 is the display/recording device; 32 is the locus of the deflected scanning light on the object; 44 is the main controller for the measuring device of the present invention;
The semi-transparent mirror 45 that branches in directions is arranged on the imaging plane of the origin O, is perpendicular to the branched light receiving axis, has an opening whose longitudinal direction is arranged parallel to the x-axis, and whose opening width is trapezoidal. An optical slit with a width different from the width of the surface 6c of the prism 6, 46 a photodetector that converts the light transmitted through the slit 45 into an electrical signal, 47 a photodetector 45, a photodetector 46, or only the slit 45 mounted thereon, with the light receiving axis Rotating drum rotating at the center, 48
49 is a rotary drum on which only the trapezoidal prism 6 and the photodetectors 7, 8, 9 or the trapezoidal prism 6 and the photodetectors 8, 9 are mounted and rotates around the light receiving axis; An internal rotating mechanism that rotates in opposite directions, the amount and direction of which are controlled by electrical signals; 50 is an amplifier that amplifies the signal from the photodetector 46 to a level necessary for signal processing; 51; 52 is a phase detector that detects the phase of the signal from the photodetector 46 and the amplifier 50 based on the signal from the reference source 12; 52 is a phase detector 51;
an arithmetic unit that subtracts the difference between the output of the phase detector 11 and the output of the phase detector 11;
53 is a power amplifier that amplifies the input signal and rotates the rotation mechanism 49; 54 is a power amplifier that outputs the output of the arithmetic unit 52;
A comparator that converts into zero and negative three values; 55 is an arithmetic unit that performs subtraction with a coefficient using the output of the phase detector 51 and the output of the phase detector 11; 56 is a control unit that controls the input of the power amplifier 53; A switch mechanism that switches between the output of the control device and the output of the arithmetic unit 52 according to a command from the device; 57 a mechanism that rotates the entire detection optical system around the z-axis; 58 a power amplifier; and 59 an external rotation mechanism 57. Measuring device for measuring the rotation angle of 60
is a rotation angle detector that detects the rotation angle of the internal rotation mechanism 49.

Next, the operating principle of this embodiment will be explained. first,
The operating principles of the configurations numbered 1 to 32 are the same as those described in FIGS. 1 to 8, and will therefore be omitted. Next, the operating principle of this embodiment for detecting the inclination of the edge normal and the projection optical axis will be explained. FIG. 16a shows an image 32' on the front surface of the trapezoidal prism 6, _FIG . transmission width,
d ₂ is the opening width of the slit 45. FIG. 16c shows the light spot position over time, and FIGS. 16d and 16e show the outputs of the photodetector 7 and the photodetector 46. The images 32' and 32'' have exactly the same form and are shown superimposed on FIGS. 17a, b, and c for explanation, and FIGS. 17a, b, and c are respectively shown in FIG.
It corresponds to the states c′, b′, and a′. As shown in FIG. 14, the time difference information included in the output of the photodetector 7 or 46 is simply the sum of a term related to the displacement in the x-axis direction and an error term due to the inclination of the ridge normal and the projection optical axis. There is. Furthermore, the term related to the tilt error has a dependence on the width of the light transmission region, that is, d ₁ and d ₂ in FIG. 17, and is approximately the product of the width of the light transmission region and the error component. . This is shown in FIG. It is shown that the output appears enlarged by the ratio of the widths of the light transmission areas of the trapezoidal prism 6 and the slit 45 (or, contrary to the figure, it is reduced if d ₁ > d ₂ ).Time difference related to x-axis displacement appears in the same amount in the outputs of the photodetector 7 and the photodetector 46. Therefore, by simply adding and subtracting the two pieces of information obtained from the photodetector 7 and the photodetector 46, a term related to the x-axis displacement and an error term due to the tilt can be obtained. This will be explained with reference to Fig. 15.The light branched by the semi-transparent mirror 44 forms an image on the slit 45 in the same way as the front surface of the trapezoidal prism 6, and Only the light from the curved portion passes through the slit 45 and is photoelectrically converted by the photodetector 46. This signal is amplified by the amplifier 50 and input to the phase detector 51 which measures only the time difference described above.
Phase detection is performed using the reference source 12 as a reference, which is exactly the same as in the system from the photodetector 7 to the phase detector 11. Next, the output of the phase detector 11 and the output of the phase detector 51 are subtracted by the arithmetic unit 52, and the error term due to the slope is separated. Further, the calculation unit 55 performs subtraction by multiplying the ratio of the widths of the light transmission areas of the trapezoidal prism 6 and the slit 35 by a coefficient.
The term related to x-axis displacement is separated.

Next, the operation of compensating for errors due to tilt will be explained. First, using the term related to the displacement of the x-axis and the term related to the error due to the inclination, which are separated by the computing units 52 and 55, the term related to the displacement is sent to the x-axis servo system, and the term related to the inclination is left unchanged, and the term is detected via the power amplifier 58. Even if the head external rotation mechanism 57 is driven,
Although compensation for errors due to inclination is carried out, it would unnecessarily increase the size and weight of the detection head attached to the tip of the three-axis drive mechanism 29, which is not a good idea.

A major feature of the present invention is that it incorporates a compensation mechanism for errors caused by this inclination, thereby reducing the burden on the accuracy of the external rotation mechanism. This compensation mechanism will be explained with reference to FIGS. 15 to 18. FIG. 18a shows an image of the front surface of the trapezoidal prism 6 and the slit 45 in a state where the y-axis servo system and the x-axis servo system are activated and stopped by the automatic tracking operation described above. At this time, the output of the photodetector 7 shown in FIG. 18a' appears to have a time difference of zero, but the first
The output of the photodetector 46 shown in FIG. drive,
The rotating drums 48 and 47 are rotated synchronously to reach the state shown in FIG. 18b. Due to this rotation, the time difference between the outputs of the photodetector 46 shown in FIG. 18b'' becomes zero, but a time difference occurs again in the output of the photodetector 7 shown in FIG. 18b'. The calculation is performed by the calculator 55, the x-axis servo system is driven, and this process is repeated until the state shown in FIG. As shown in Fig. 18 c' and c'', both become zero.
This operation compensates for the error due to the tilt, and allows the x-axis displacement to be determined with high precision. Note that compensation for errors due to this inclination can be performed within a range of ±20° when the ridge angle is 90°, and can be compensated within a range of ± a few degrees even when the crest angle is as large as 150°. can.

The built-in compensation rotation mechanisms 47, 48 described above,
49 and 53, the external rotation mechanisms 58 and 57 do not need to have high precision, and may be driven at a rough rotation angle of several degrees. That is, when the control device 30 detects by the rotation angle detector 60 that the internal rotation angles of the internal rotation mechanisms 47 to 49 exceed ± several degrees, the control device 30 causes the switch 56 to stop the internal rotation mechanisms.
At the same time, the rotation direction is determined based on the output of the comparator 54, the external rotation mechanism 57 is driven via the power amplifier 58, the detection optical system head is rotated by a fixed pitch of several degrees, the switch 56 is switched again, and the next rotation is performed. control to enter measurement. In addition, the control device 41 reads the rotation angle of the detection optical system head using the goniometer 59, detects that the projection axis, which is the y-axis, is different from the y-axis direction of the three-dimensional drive mechanism, and determines the subsequent direction of the projection optical axis. The operation of the servo system that corrects the displacement and the displacement in the direction perpendicular to it is controlled so as to be realized by combining the movements of the x' and y' axis arms. That is,
In the embodiment shown in FIG. 15, in order to make it easier to understand, the outputs of the phase detector and arithmetic unit are shown as being directly connected to the x-axis servo system and the y-axis servo system, but in reality, Both servo systems are under the control of a controller 30.

As explained above, x with respect to the origin of the edge vertex
Displacement in the axial direction and the y-axis direction can be detected simultaneously.

Next, the automatic tracking operation will be explained with reference to FIGS. 15 and 19. First, the output of the arithmetic control logic circuit 15 corresponding to the y-axis vertex displacement is sent to the power amplifier 19, where the power is amplified, and the drive motor 20 is controlled. This drive motor mechanism 20 is a three-axis drive mechanism capable of three-dimensional movement, which is connected to a detection system main body 28 mounted on all the optical systems 1 to 9 and provided in a housing that prevents disturbance light and electrical noise. The arm 21 that moves in the direction of the projection optical axis among the three-axis moving arms in a means such as a three-dimensional measuring machine 29 is driven. The action of this servo system keeps the distance between the detection system main body 28 and the object 4 constant. The amount of movement of this drive arm 21 is determined by the amount of movement of the three-dimensional measuring machine 2 attached to this arm 21.
9, and recorded as a y-axis ridgeline coordinate plot. Further, the output of the arithmetic unit 55 corresponding to the displacement in the direction of deflection of light emitted perpendicular thereto is power amplified by a power amplifier 16, and controls the drive motor mechanism 17, which controls the arm of the three-axis arm that moves in the direction of deflection of light emitted. 18. Due to the action of this servo system, the x-axis servo system and the built-in rotation mechanism operate simultaneously or repeatedly, and stop when the time difference between the outputs of both the photodetector 7 and the photodetector 46 becomes zero. The amount of movement of the drive arm 18 is measured by a length measuring device 22 attached to the arm 18, and is recorded as an x-axis ridge line coordinate value. The remaining one axis of the arms 26 among the three axes is driven by a control device 30, a power amplifier 24, and a drive motor 25 at fixed pitches or programmed intervals in the direction in which the ridgeline extends, and the amount of movement of the arm 26 is as follows: Measured by a length measuring device 27 attached to it,
It is recorded as a z-axis ridge line coordinate value. Control device 30
stores the data of the length measuring devices 22, 23, and 27, transfers the data to an appropriate display or recording device 31 for each Z-axis measurement point artificially instructed by a program, etc., and displays it as a three-dimensional coordinate value of the ridge line. or recorded. At the same time, if the direction in which the ridge line actually extends, the direction of the projection optical axis, etc. do not match the respective axes of the three-dimensional measuring machine, the control device 30 may express the direction by, for example, the composite direction of the x-axis and y-axis of the three-dimensional measuring machine. In this case, appropriate arms may be controlled simultaneously using information from the goniometer 59, etc., and the detection system main body 28 may be moved.

In this manner, the present invention enables non-contact detection of the ridge line of an arbitrary three-dimensional object and automatic non-contact measurement of the three-dimensional coordinate value of the ridge line while automatically tracking the edge line.

FIG. 20 shows another embodiment of the embodiment shown in FIG. 1, and the same reference numerals as in FIG. 1 indicate the same components. In other words, 1 is a thin light beam source with good directivity such as a laser, 2 is an optical deflector that deflects and scans the light in the x-axis direction, and 3 is a light projection lens whose focus is aligned with the center of deflection of the optical deflector 2. , 4 is an object to be measured with an edge, and 5 is a light beam that has a constant angle from 0° to 90° with the optical axis of the projection lens 3 (projection optical axis, i.e., y-axis) and is orthogonal to the deflection scanning direction. 7, 8, 9 are first, second, and
The third photodetectors, 10, 13 and 14 are respectively the first and
An amplifier that amplifies the weak signals from the second and third photodetectors 7, 8, and 9 to a level required for signal processing; 12 is a reference source that drives the optical deflector 2; 11 is a signal from the reference source 12; a phase detector that detects the phase of the signal that has passed through the photodetector 7 and the amplifier 10 with reference to
15 is an arithmetic control logic circuit that calculates the correlation between the signals of the photodetectors 7, 8, 9 and amplifiers 10, 13, and 14 using the signal of the reference source 12 as a reference; 16 is the power that amplifies the signal of the phase detector 11; An amplifier 17 uses the output of the power amplifier 16 to control the detection optical system head 28 on which the light source 1, optical deflector 2, light projecting lens 3, light receiving lens 5, trapezoidal prism 6, and photodetectors 7, 8, and 9 are mounted. A drive motor 19 that drives the light deflection scanning direction of the three-axis arms of the three-dimensional drive mechanism 29, which has the function of moving in the three dimensions of , y, and z, that is, the x-axis arm 18 in the example of FIG. 20 is a power amplifier that amplifies the output of the arithmetic control logic circuit, and 20 is a drive motor that drives the arm 21 in the projection optical axis direction of the three-axis arms of the three-dimensional drive mechanism 29, that is, in the example of FIG. 1, the y-axis arm 21. , 22 is a distance measuring device that is attached to the arm 18 and measures the amount of movement of the arm 18;
23 is a distance measuring device attached to the arm 21 and measures the amount of movement of the arm 21; 24 is a control device 30;
A power amplifier 25 amplifies the command of the power amplifier 24, and a drive motor 25 that drives the remaining one of the three axes of the three-axis arm of the three-dimensional drive mechanism, the two-axis arm 26 in the ridge direction in FIG. 27 is a distance measuring device attached to the arm and measures the amount of movement of the arm 26; 30 is the main controller of the measuring device of the present invention; 31 is a display/recording device; and 32 is the locus of the deflected scanning light on the object. , this embodiment differs from the embodiment shown in FIG.
A half mirror 62 is provided between the slit 61 and the light-receiving lens 5, and a part of the light incident on the first photodetector 7 is divided into a width approximately equal to the width of the first slit. The light is made incident on second and third photodetectors 8 and 9 which are arranged side by side with a gap between them. The operation of this embodiment is completely the same as that of the embodiment shown in FIG. 1, so a description thereof will be omitted.

Furthermore, FIG. 21 shows another embodiment of the embodiment shown in FIG. The arrangement of and the numbers 1 to 5 and 10 to 31 are the same as those shown in Fig. 20, and the operation of this embodiment is completely the same as that of the embodiment shown in Fig. 15, so the explanation will be omitted. .

In the above embodiment, the first, second, and third photodetectors 7, 8, and 9 were each composed of separate photodetectors, but as shown in FIG. Integrated photodetector 63 provided with photodetectors 7, 8, and 9
Edges can be measured in the same way using .
That is, as shown in FIG. 23, the first,
This integrated photodetector 63 may be provided in place of the second and third photodetectors 7, 8, 9 and the trapezoidal prism 6. In this embodiment, the other configurations are exactly the same as the configuration in FIG. 1, and the operation is also the same, so the explanation will be omitted.

Furthermore, as shown in FIG. 24, by providing this integrated photodetector 63 on the rotating drum 48 of the embodiment shown in FIG. 15, the same operation as in the embodiment shown in FIG. 15 can be performed. be able to. This 24th
The operation of the embodiment shown in the figure is otherwise the same as that of the embodiment shown in FIG. 15, so a description thereof will be omitted.

As described above, according to the present invention, the ridgeline of an arbitrary three-dimensional object can be detected in a non-contact manner, automatically tracked, and the three-dimensional coordinate values of the ridgeline can be measured in a non-contact manner.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of an automatic edge coordinate measuring device according to the present invention, Fig. 2 is a detailed diagram of a trapezoidal prism, and Figs. FIG. 5 is a circuit diagram of an embodiment of the signal processing circuit, and FIG.
Signal waveform diagrams for each part in the figure, Figure 7 is a diagram showing an example of the characteristics of the detection output with respect to displacement in the direction perpendicular to the optical axis of the ridgeline, and Figures 8 to 10 are diagrams showing the characteristics of the detection output for displacement in the direction perpendicular to the optical axis of the ridgeline. FIG. 11 is a diagram showing an example of the output characteristics of the arithmetic control logic circuit, and FIG. 12 is an illustration of an embodiment of the automatic measuring device for three-dimensional coordinates of an edge line according to the present invention. The configuration diagram, Figures 13 and 14 are as follows:
A diagram for explaining an example in which the bisector of the projection optical axis and the ridge apex angle has an inclination, FIG. 15 is a configuration diagram of another embodiment of the present invention, and FIGS. 16 to 18 are FIG. 5 is an explanatory diagram of the operation, FIG.
FIG. 21 is a block diagram of still another embodiment of the present invention.
22 is a diagram showing a configuration example of an integrated photodetector, and FIG. 23 is a diagram showing a configuration example of another embodiment of the present invention.
24 is a block diagram of still another embodiment of the present invention, and FIG. 25 is an explanatory diagram of the principle of operation of the apparatus of the present invention. 1... Thin light source, 2... Light deflector, 3... Light projecting lens, 4... Target to be measured, 5... Light receiving lens,
6... Trapezoidal prism, 7, 8, 9... Photodetector,
12... Reference source, 15... Arithmetic control logic circuit, 16... Power amplifier, 17, 20... Drive motor, 22, 27... Distance measuring device, 30... Main controller, 31... Display record Device.

Claims (1)

[Scope of Claims] 1. A thin light beam generating device that projects a thin light beam scanned with a constant width at a constant repetition period onto the edge of the object to be measured from the normal direction of the edge so that the scanning direction crosses the edge line; The reflected light from the edge of the object to be measured is focused at a predetermined angular position in the direction perpendicular to the scanning direction of the thin beam, and "∧" or "∨" corresponds to the cross-sectional shape of the edge of the object to be measured. a light-receiving means for forming a letter-shaped image, and a first region of the imaging light of the light-receiving means having a predetermined length in the scanning direction of the thin beam and a minute width in the vertical direction; a first light detection means for detecting the intensity of the image light, that is, the light of the corner part of the "∧" or "∨"-shaped image;
Detection in which second and third light detection means are fixed, each detecting the intensity of the imaged light in the second and third areas in the upper and lower ranges sandwiching the first area and excluding the area. moving the photodetecting optical system head in the scanning direction of the narrow beam so that the output signal of the first photodetecting means has a constant repetition period synchronized with the scanning period; x-axis servo means for controlling the positional deviation between the center of the scanning range and the ridge line in the scanning direction to zero, and the output signals of the first, second, and third detection means to have a predetermined relationship. y-axis servo means for changing the distance between the detection optical system head and the edge of the object to be measured so as to maintain a constant distance interval between the detection optical system head and the edge of the object to be measured; z-axis servo means for moving the optical system head at a constant speed in a direction perpendicular to the scanning direction of the narrow beam, that is, in the direction of the ridge line; and movement of the optical system head by each of the x-axis, y-axis, and z-axis servo means. 1. An automatic edge line coordinate measuring device comprising means for displaying the amount as coordinates of the edge line. 2. The light receiving means includes a light receiving lens that is arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and that focuses the reflected light from the edge of the object to be measured, and a light receiving lens whose upper base surface is from the light receiving lens. The first light detecting means detects the light transmitted through the trapezoidal prism, and the second light detecting means detects the light transmitted through the trapezoidal prism. The means and the third light detection means are arranged relative to the trapezoidal prism so as to respectively detect the light reflected by the two side surfaces of the trapezoidal prism. The automatic ridgeline coordinate measuring device according to scope 1. 3. The light receiving means includes a light receiving lens that is arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and that focuses the reflected light from the edge of the object to be measured, and a light receiving lens that collects the light from the light receiving lens. a half mirror that partially transmits the light and partially reflects it to the side; and a first mirror that has a predetermined length in the scanning direction of the thin beam and a minute width in the vertical direction, out of the light that has passed through the half mirror; a mask having a slit for passing only a portion corresponding to the area, the first light detection means detects the light passing through the mask, the second light detection means and the third light detection means are arranged relative to the half mirror so as to respectively detect the imaging light of the second and third regions out of the light reflected laterally of the half mirror. An automatic edge coordinate measuring device according to claim 1. 4. The light receiving means includes a light receiving lens arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and converging the reflected light from the edge of the object to be measured; , having dimensions corresponding to the predetermined length and the minute width so as to receive the imaging light of the first area, and disposed at the imaging position of the light from the light receiving lens; The detection means of
Claim 1, characterized in that the first light detection means is arranged close to both sides in the width direction of the first light detection means so as to receive the imaging light of the second and third regions. The automatic ridge coordinate measuring device described above. 5. A thin light beam generating device that projects a thin light beam scanned in a constant width at a constant repetition period onto the edge of the object to be measured from the normal direction of the edge so that the scanning direction crosses the edge line, and a scanning direction of the thin light beam. The reflected light from the edge of the object to be measured is focused at a predetermined angular position in the direction perpendicular to the edge of the object to be measured, and an "∧" or "∨"-shaped image corresponding to the cross-sectional shape of the edge of the object to be measured is formed. and, among the imaged light of the light receiving means, the imaged light that enters a first region having a predetermined length in the scanning direction of the narrow beam and a minute width in the vertical direction, that is, "∧ ” or “∨”-shaped image;
second and third light detection means for respectively detecting the intensity of the imaged light in the second and third regions in the upper and lower ranges sandwiching the first region and excluding the region; the light incident on the light detection means is reflected at right angles to a predetermined length direction of the region of the first detection means;
A first detector for detecting the intensity of the imaged light entering a region having a predetermined length in the same direction as the region of the first light detecting means and having a minute width different from the region of the first light detecting means. a detection optical system head to which a fourth photodetection means is fixed; and a detection optical system head that is fixed to the first photodetection means such that the output signal of the first photodetection means has a constant repetition period synchronized with the scanning period. x-axis servo means that moves in the scanning direction of the light beam and controls the positional deviation between the center of the scanning range and the ridge line in the scanning direction to zero; and outputs of the first, second, and third detection means. The distance between the head of the detection optical system and the edge of the object to be measured is changed so that the signals have a predetermined relationship, and the distance between the head of the detection optical system and the edge of the object to be measured is controlled to be kept constant. The axis servo means and the first, second, third, and fourth light detection means are kept in the same positional relationship so that the output signal of the fourth light detection means has a predetermined repetition period,
angle setting servo means for rotating the light receiving means around the light receiving axis to reduce errors that occur when the normal direction of the ridge and the projection optical axis of the thin beam are tilted; z-axis servo means for moving the optical system head at a constant speed in a direction perpendicular to the scanning direction of the optical system, that is, in the direction of the ridgeline; 1. An automatic edge coordinate measuring device comprising: means for displaying coordinates. 6. The light receiving means includes a light receiving lens arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and converging the reflected light from the edge of the object to be measured, and an upper base side surface of the light receiving lens. The first light detecting means detects the light transmitted through the trapezoidal prism, and the second light detecting means detects the light transmitted through the trapezoidal prism. The means and the third light detection means are arranged relative to the trapezoidal prism so as to respectively detect the light reflected by the two side surfaces of the trapezoidal prism. The automatic ridgeline coordinate measuring device according to scope 5. 7. The light receiving means includes a light receiving lens that is arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and that focuses the reflected light from the edge of the object to be measured, and a light receiving lens that collects the light from the light receiving lens. a half mirror that partially transmits the light and partially reflects it to the side; and a first mirror that has a predetermined length in the scanning direction of the thin beam and a minute width in the vertical direction, out of the light that has passed through the half mirror; a mask having a slit for passing only a portion corresponding to the area, the first light detection means detects the light passing through the mask, the second light detection means and the third light detection means are arranged relative to the half mirror so as to respectively detect the imaging light of the second and third regions out of the light reflected laterally of the half mirror. An automatic edge coordinate measuring device according to claim 5. 8. The light receiving means includes a light receiving lens arranged at a predetermined angular position in a direction perpendicular to the scanning direction of the thin light beam and converging the reflected light from the edge of the object to be measured; , having dimensions corresponding to the predetermined length and the minute width so as to receive the imaging light of the first area, and disposed at the imaging position of the light from the light receiving lens; The detection means of
Claim 5, characterized in that the first light detection means is arranged close to both sides of the first light detection means in the width direction so as to receive the imaging light of the second and third regions. The automatic ridge coordinate measuring device described above. 9. A patent characterized in that the fourth light detection means has a half mirror inserted into the optical path of the light emitted from the light receiving lens, and is arranged at a position to receive the light reflected by the half mirror. An automatic edge coordinate measuring device according to any one of claims 6 to 8.