JP2008304190A - Highly precise method and device for measuring displacement of object to be measured by laser reflected light - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-accuracy method and device for measuring the displacement of an object to be measured by laser reflected light for expanding the displacement of the object to be measured as the displacement of a granular spot pattern and measuring it, using a simple means. <P>SOLUTION: This device is composed of a laser beam projector 1 for applying laser beams on a surface of the object to be measured 3, a light-receiving part 2 for imaging the granular spot pattern which is the reflected light of laser beam, an image processing device 6 for measuring displacement of the granular spot pattern in which the displacement of the object to be measured 3 is expanded and appears, and a computing device 7 for computing the displacement of the object to be measured 3 from the displacement of the granular spot pattern. The laser beam projector 1 applies a cross light 8a, having a focus 9 between the surface of the object to be measured 3 and the laser beam projector 1 on the surface of the object to be measured 3, and for the cross light 8a, the ratio of distance Ls, between the focus 9 and the surface of the object to be measured 3, to distance L<SB>0</SB>between the surface of the object to be measured 3 and the light receiving part 2 is such that 0<Ls/L<SB>0</SB>≤1/3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a measurement object displacement measuring method and apparatus for measuring the displacement of a measurement object in a non-contact manner using laser reflected light.

  When the surface of an object to be measured with a micro-uneven surface is irradiated with laser light with very high coherence, the laser light scattered at various places on the rough surface of the object to be measured interferes with an irregular phase relationship, causing the object to be measured. It is known that an inherent granular spot pattern is generated based on the rough surface of the object to be measured. This unit granular spotted pattern is used for measuring the change or identity of the object to be measured.

  The granular spot pattern has the property that when the object to be measured generates a two-dimensional movement phenomenon, the granular spot pattern also moves in two dimensions, and the measurement is performed by measuring the movement amount of this granular spot pattern. The amount of movement of the object can be measured. Conventionally, for measuring the displacement of an object to be measured using a granular spot pattern, as the shape of the laser light irradiated on the surface of the object to be measured, spot light shown in FIG. 4B, straight light shown in FIG. The light beam shown in FIG. 4D was used.

  Also, a laser including a laser projector that irradiates the object to be measured with cross light, an image pickup device that picks up a granular spot pattern that is laser reflected light as a marker, and an image processing device that performs image processing on the picked up granular spot pattern An apparatus for measuring an object to be measured using reflected light has been proposed by the present inventor (see Patent Document 1). When measurement is performed by irradiating the measurement object with cross light 8a having an emission wavelength of 670 nm, as shown in FIG. 9, the measurement error of the movement amount of the measurement object is 1.0344 μm (± 0.5172 μm). On the other hand, when the measurement object is measured by irradiating the measurement object with the straight light 8c having the emission wavelength of 670 nm, as shown in FIG. 10, the measurement error of the movement amount of the measurement object is 3.448 μm (± 1.724 μm). It is shown that when the object to be measured is irradiated with the cross light 8a and measured, the measurement error can be reduced to 1/3 or less than when the conventional straight light 8c is used.

  Further, in a device that irradiates a moving object to be measured with laser light and measures a moving distance of the object to be measured using a granular spotted pattern, the first is disposed between the laser projector and the object to be measured. The spot light obtained by converging the laser beam on the surface of the object to be measured is irradiated by the optical system, and the product of the object to be measured is obtained by the product (K × L) of the magnification K of the first optical system and the distance L from the object to be measured. A method is known in which the movement distance is expanded to the movement distance of the granular spot pattern and the movement distance of the object to be measured is obtained from the change of the granular spot pattern (for example, see Patent Document 2).

JP-A-2005-55176 JP-A-9-178425

  The measurement accuracy of the moving amount of the object to be measured is determined by the interval between the CCD pixels of the light receiving unit. However, the measuring device described in Patent Document 1 does not change the CCD element of the light receiving unit to a high-density type, By changing the shape, the measurement error could be made smaller than when straight light was used as the laser light. However, in the measurement apparatus described in Patent Document 1, the relationship between the focal position of the cross light irradiated onto the measurement object and the measurement accuracy of the movement amount of the measurement object has not been clear. An object of the present invention is to clarify the relationship between the focal position of cross light applied to a measurement object and the measurement accuracy of the amount of movement of the measurement object in a measurement apparatus for the measurement object using laser reflected light.

  In the measuring device described in Patent Document 2, the magnification of the movement amount of the granular spot pattern with respect to the movement amount of the object to be measured depends on the magnification K of the first optical system and the distance L from the object to be measured to the light receiving unit. is doing. For this reason, when the distance from the object to be measured to the light receiving unit is constant, the first optical system can be changed to an optical system having a different magnification in order to change the enlargement ratio of the amount of movement of the granular spot pattern with respect to the amount of movement of the object to be measured. There was a problem that it was necessary to change and cost was high.

  Therefore, the present invention provides a high-precision displacement measuring method and apparatus for a measured object by laser reflected light, which can expand and measure the displacement of the measured object as a granular spotted pattern displacement by simple means. It is.

In order to solve the above-mentioned problems, the present invention irradiates the surface of the object to be measured with laser light, images a granular spot pattern that is reflected light of the laser light with a light receiving unit, and increases the displacement of the object to be measured. A method for measuring the displacement of an object to be measured by laser reflected light, which measures the displacement of the appearing granular spot pattern and obtains the displacement of the object to be measured from the displacement of the granular spot pattern, wherein the laser beam is measured with the laser projector. The cross light has a focal point between the object surface and the ratio of the distance Ls from the focus of the cross light to the surface of the object to be measured and the distance L ₀ from the object surface to the light receiving part is 0 <Ls / L ₀ ≦ The object is to provide a displacement measuring method of an object to be measured by laser reflected light, which is 1/3.

  Also, in the method for measuring the displacement of the object to be measured by the laser reflected light according to the present invention, the light receiving portion is composed of a CCD element, and a granular spot pattern is directly formed by attaching a night vision tube for blocking extraneous light in front of the CCD element. An image is taken.

Further, in the displacement measuring method of the object to be measured by the laser reflected light of the present invention, the laser beam is irradiated at an angle θ _S with respect to the normal direction of the surface of the object to be measured, and the light receiving unit is arranged in the direction of the angle θ _0. Then, the displacement amount ax of the object to be measured is obtained from the measured displacement amount Ax of the granular spotted pattern based on the following equation (1).

In the method for measuring the displacement of the object to be measured by the laser reflected light according to the present invention, the ratio of the distance Ls to the distance L ₀ (Ls / L ₀ ) is changed to enlarge the displacement of the granular spotted pattern with respect to the displacement of the object to be measured. The rate is adjusted.

Further, the present invention provides a laser projector that irradiates the surface of the object to be measured with laser light, a light receiving unit that captures a granular spot pattern that is reflected light of the laser light, and the displacement of the object to be measured appears enlarged. An apparatus for measuring a displacement of an object to be measured by laser reflected light, comprising: an image processing apparatus for measuring the displacement of a granular spot pattern; and an arithmetic unit for obtaining a displacement of the object to be measured from the displacement of the granular spot pattern. The optical device irradiates the surface of the object to be measured with cross light having a focal point between the surface of the object to be measured and the laser projector, and the cross light is transmitted from the distance Ls from the focus to the surface of the object to be measured and the surface of the object to be measured. An object of the present invention is to provide a displacement measuring device for an object to be measured by laser reflected light, wherein the ratio of the distance L ₀ to the light receiving portion is 0 <Ls / L ₀ ≦ 1/3.

  Further, in the apparatus for measuring displacement of an object to be measured by laser reflected light according to the present invention, the light receiving portion is formed of a CCD element, and a night vision tube for blocking extraneous light is mounted in front of the CCD element to directly form a granular spotted pattern. An image is taken.

In addition, the apparatus for measuring displacement of an object to be measured by laser reflected light according to the present invention includes a laser projector disposed so as to irradiate the laser beam at an angle θ _S with respect to the normal direction of the surface of the object to be measured. A light receiving portion is arranged in the direction of the angle θ ₀ with respect to the normal direction of the surface of the object to be measured, and the amount of displacement ax of the object to be measured based on the following equation 2 from the amount of displacement Ax of the granular spot pattern measured by the arithmetic unit. Is to ask for.

In addition, the displacement measuring apparatus of the object to be measured by the laser reflected light according to the present invention variably controls the ratio of the distance Ls to the distance L ₀ (Ls / L ₀ ) to displace the granular spotted pattern with respect to the displacement of the object to be measured. An enlargement ratio adjusting mechanism for adjusting the enlargement ratio is provided.

The displacement measurement apparatus of the object to be measured by the laser light reflected of the present invention, the ratio of the said magnification adjusting mechanism adjusts the lens position of the laser floodlight distance Ls and the distance L ₀ (Ls / L ₀₎ Is variably controlled.

In the device for measuring the displacement of the object to be measured by the reflected laser beam according to the present invention, the magnification adjusting mechanism adjusts the position of the laser projector with respect to the object to be measured, and the ratio of the distance Ls to the distance L ₀ (Ls / L ₀ ) is variably controlled.

The method for measuring the displacement of an object to be measured by laser reflected light according to the present invention irradiates the surface of the object to be measured with laser light, images a granular spot pattern, which is reflected light of the laser light, at a light receiving unit, and displaces the object to be measured. Is a displacement measuring method of an object to be measured by laser reflected light for measuring the displacement of the granular spot pattern that appears in an enlarged manner, and obtaining the displacement of the object to be measured from the displacement of the granular spot pattern. Cross light having a focal point between the machine and the surface of the object to be measured, and the ratio of the distance Ls from the focus of the cross light to the surface of the object to be measured and the distance L ₀ from the surface of the object to be measured to the light receiving portion is 0 <Ls When the distance Ls from the focus of the cross light to the surface of the object to be measured is made closer to the distance L ₀ from the surface of the object to be measured to the light receiving unit by having the configuration of / L ₀ ≦ 1/3, the object to be measured The displacement of the granular spotted pattern is enlarged relative to the displacement of Therefore, by setting the ratio of the distance Ls to the distance L ₀ to 0 <Ls / L ₀ ≦ 1/3, the displacement of the object to be measured can be measured as a granular spotted pattern with a magnification of 3 times or more. It is possible to measure the displacement of the object to be measured with high accuracy.

  Also, in the method for measuring the displacement of the object to be measured by the laser reflected light according to the present invention, the light receiving portion is composed of a CCD element, and a granular spot pattern is directly formed by attaching a night vision tube for blocking extraneous light in front of the CCD element. By taking an image, it is possible to directly image a granular spot pattern which is reflected light of a laser beam by a CCD element, and it is possible to take an image of a granular spot pattern even in a bright place by a night vision tube. .

Further, in the displacement measuring method of the object to be measured by the laser reflected light of the present invention, the laser beam is irradiated at an angle θ _S with respect to the normal direction of the surface of the object to be measured, and the light receiving unit is arranged in the direction of the angle θ _0. The displacement amount ax of the object to be measured is obtained from the measured displacement amount Ax of the granular spotted pattern based on the above equation 1, so that the measurement is performed from the measured displacement amount Ax of the granular spotted pattern. There is an effect that the displacement amount ax of the object can be quickly obtained.

In the method for measuring the displacement of the object to be measured by the laser reflected light according to the present invention, the ratio of the distance Ls to the distance L ₀ (Ls / L ₀ ) is changed to enlarge the displacement of the granular spotted pattern with respect to the displacement of the object to be measured. By adjusting the rate, the magnification rate of the granular spotted pattern relative to the displacement of the object to be measured can be increased by moving the focus of the cross light closer to the surface of the object to be measured or by moving the light receiving part away from the surface of the object to be measured. Since it can be easily adjusted, there is an effect that an appropriate measurement accuracy can be selected according to the displacement amount and the displacement speed of the object to be measured.

The apparatus for measuring displacement of an object to be measured by laser reflected light according to the present invention includes a laser projector that irradiates the surface of the object with laser light and a light receiving unit that captures a granular spot pattern that is reflected light of the laser light. And an image processing device that measures the displacement of the granular spot pattern that appears as the displacement of the measured object expands, and an arithmetic unit that obtains the displacement of the measured object from the displacement of the granular spot pattern. An apparatus for measuring displacement of an object, wherein the laser projector irradiates the surface of the object to be measured with cross light having a focal point between the surface of the object to be measured and the laser projector, and the cross light is measured from the focus. by having the configuration ratio of the distance L ₀ from the distance Ls and the measured object surface to the object surface to the light receiving portion is _{0 <Ls / L 0 ≦ 1} /3, the distance from the object to be measured the surface to the light receiving portion measured object table from the focal point of the cross beam with respect to L ₀ When close the distance Ls to the surface, because the displacement of the granular speck pattern with respect to displacement of the object to be measured is gradually enlarged, the ratio of the distance Ls and the distance L ₀ to _{0 <Ls / L 0 ≦ 1} /3 As a result, the displacement of the object to be measured can be measured by enlarging it three times or more as the displacement of the granular spotted pattern, and the displacement of the object to be measured can be measured with high accuracy.

  In the apparatus for measuring the displacement of an object to be measured by laser reflected light according to the present invention, the light receiving portion is composed of a CCD element, and a night vision tube for blocking extraneous light is mounted in front of the CCD element to directly form a granular spot pattern. By taking an image, it is possible to directly image a granular spot pattern, which is reflected light of a laser beam, by the CCD element, and it is possible to pick up a granular spot pattern even in a bright place by a night vision tube. .

In addition, the apparatus for measuring displacement of an object to be measured by laser reflected light according to the present invention includes a laser projector disposed so as to irradiate the laser beam at an angle θ _S with respect to the normal direction of the surface of the object to be measured. A light receiving portion is arranged in the direction of angle θ ₀ with respect to the normal direction of the surface of the object to be measured, and the amount of displacement ax of the object to be measured based on the above equation 2 from the amount of displacement Ax of the granular spot pattern measured by the arithmetic unit. Thus, there is an effect that the displacement amount ax of the object to be measured can be quickly obtained by calculation from the measured displacement amount Ax of the granular spotted pattern.

In addition, the displacement measuring apparatus of the object to be measured by the laser reflected light according to the present invention variably controls the ratio of the distance Ls to the distance L ₀ (Ls / L ₀ ) to displace the granular spotted pattern with respect to the displacement of the object to be measured. By providing an enlargement ratio adjustment mechanism that adjusts the enlargement ratio of the object, the focal spot of the cross light is brought closer to the surface of the object to be measured, or the light receiving part is moved away from the surface of the object to be measured, thereby causing a granular spot pattern with respect to the displacement of the object to be measured Therefore, it is possible to easily adjust the magnification rate of the displacement, so that it is possible to select an appropriate measurement accuracy according to the displacement amount and the displacement speed of the object to be measured.

The displacement measurement apparatus of the object to be measured by the laser light reflected of the present invention, the ratio of the said magnification adjusting mechanism adjusts the lens position of the laser floodlight distance Ls and the distance L ₀ (Ls / L ₀₎ As a result, the focal position of the cross light can be changed easily and quickly, and the magnification rate of the granular spotted pattern relative to the displacement of the object to be measured can be adjusted quickly.

In the device for measuring the displacement of the object to be measured by the reflected laser beam according to the present invention, the magnification adjusting mechanism adjusts the position of the laser projector with respect to the object to be measured, and the ratio of the distance Ls to the distance L ₀ (Ls / By variably controlling L ₀ ), the distance Ls from the focal point to the surface of the object to be measured can be easily grasped from the amount of movement of the laser projector, and the granular spotted pattern with respect to the displacement of the object to be measured can be obtained. There is an effect that the magnification rate of the displacement can be adjusted with certainty.

Embodiments of the present invention will be described based on examples shown in the drawings.
An apparatus for measuring displacement of an object to be measured by laser reflected light according to the present invention images a laser projector 1 that irradiates the surface of the object 3 with laser light and a granular spot pattern that is reflected light of the laser light. From the light receiving unit 2, the image processing device 6 that measures the displacement of the granular spot pattern that appears as the displacement of the measurement object 3 expands, and the arithmetic device 7 that calculates the displacement of the measurement object 3 from the displacement of the granular spot pattern The laser projector 1 is configured to irradiate the surface of the object 3 with cross light 8a having a focal point 9 between the surface of the object 3 to be measured and the laser projector 1, and the cross light 8a. Is characterized in that the ratio of the distance Ls from the focal point 9 to the surface of the object to be measured 3 and the distance L ₀ from the surface of the object to be measured 3 to the light receiving unit 2 is 0 <Ls / L ₀ ≦ 1/3. .

In the embodiment shown in FIGS. 1 to 3, the laser projector 1 uses visible light having high luminance and directivity to draw a stable granular spotted pattern on the object 3 to be measured. A circuit, a drive circuit, and a lens are included. As shown in FIG. 4A, the laser projector 1 emits a cross light 8 a having a focal point 9 between the laser projector 1 and the surface of the measurement object 3, and a laser irradiation position 4 of the measurement object 3. Can be irradiated. As shown in FIG. 2, the laser projector 1 is arranged so that the laser beam can be irradiated at an angle θ _S with respect to the normal direction z of the laser irradiation position 4 of the measurement object 3.

In the illustrated embodiment, the light receiving unit 2 is composed of a CCD element, and is used to take a granular spot pattern drawn on the measurement object 3 and has a function of outputting an NTSC signal (analog signal). As shown in FIG. 2, the light receiving unit 2 is disposed at a distance L ₀ from the laser irradiation position 4 in the direction of the angle θ ₀ with respect to the normal direction z of the laser irradiation position 4 of the measurement object 3. A granular spot pattern based on the laser irradiation position 4 can be taken by scattering of the laser beam. As shown in FIG. 3, the irradiation angle θ _S of the laser beam is adjusted to the direction obtained by adding the offset angle 5 to the angle θ ₀ with respect to the normal direction z of the laser irradiation position 4 of the object 3 to be measured. Is preferred.

  In addition, the light receiving unit 2 is equipped with a night vision tube 13 that blocks external light in front of the CCD element, and is configured to directly capture a granular spotted pattern even in a bright place.

In the embodiment shown in FIGS. 1 to 3, the laser projector 1 includes a distance Ls from the focal point 9 of the cross light 8a to the laser irradiation position 4 of the measured object 3, and from the laser irradiation position 4 to the light receiving unit 2. the ratio of the distance L ₀ (Ls / L ₀₎ is variably controlled, it is provided with magnification adjusting mechanism for adjusting the magnification of the displacement of the granular speck pattern with respect to the displacement of the object to be measured 3.

As shown in FIG. 2, when the cross light 8 a is irradiated at an angle θ _S with respect to the normal direction z of the laser irradiation position 4, and a granular spot pattern that is reflected light is imaged at an angle θ ₀ , The displacement Ax of the granular spot pattern in a certain light receiving unit 2 is expressed by the following equation (3).

  In the present invention, only the two-dimensional displacement ax of the measured object 3 is handled, so that the displacement amount Ax on the observation surface can be expressed by Equation 4 when variables other than ax are ignored.

  That is, the enlargement ratio Ax / ax of the amount Ax of the granular spotted pattern with respect to the two-dimensional displacement amount ax of the object 3 to be measured is expressed by Equation 5.

Here, if the irradiation angle θ _S of the cross light 8a and the angle θ ₀ at which the granular spot pattern is imaged are made constant, they can be replaced with constants, so the enlargement ratio Ax / ax is expressed by Equation 6.

Therefore, the enlargement ratio Ax / ax of the displacement Ax of the granular spot pattern with respect to the displacement ax of the measurement object 3 is the distance Ls from the focal point 9 to the laser irradiation position 4 and the distance from the laser irradiation position 4 to the light receiving unit 2. It can be adjusted by changing the ratio of L ₀ (Ls / L ₀ ). The enlargement ratio Ax / ax can be increased by moving the focal point 9 closer to the laser irradiation position 4 or moving the light receiving unit 2 away from the laser irradiation position 4. Change magnification Ax / ax is better to change the distance Ls by adjusting the position of the focal point 9, because larger than changing the distance L _0, magnification adjustment mechanism so as to adjust the position of the focal point 9 Preferably there is.

  Further, when the laser light is parallel light, Ls = ∞, so that the amount of displacement Ax of the granular spotted pattern on the observation surface is expressed by Equation 7.

FIG. 7 shows the result of measuring the amount of displacement Ax of the granular spotted pattern on the observation surface by changing the position of the focal point 9 using the displacement measuring apparatus for the object to be measured by the laser reflected light according to the present invention. A straight line a in the figure is parallel light, and straight lines b to g are cross lights having different focal positions. In this measurement, the distance L ₀ from the laser irradiation position 4 to the light receiving unit 2 is constant at 300 mm, and the distance Ls from the focal point 9 to the laser irradiation position 4 is measured on the laser projector 1 from the position of Ls = 150 mm. Done by approaching object 3. Further, the irradiation angle θ _S of the laser beam is 20 °, and the angle θ _{0 of the} light receiving surface is 10 °.

FIG. 8 shows changes in the enlargement ratio Ax / ax depending on the position of the focal point 9 of the cross light 8a. For example, it can be seen that the magnification Ax / ax is about 6.4 times when the distance Ls = 50 mm, and the magnification Ax / ax is about 10 times when the distance Ls = 30 mm. The ratio between the distance Ls and the distance L ₀ is preferably 0 <Ls / L ₀ ≦ 1/3 because the enlargement ratio Ax / ax can be three times or more. Further, when the focal point 9 is brought close to the surface of the object 3 to be measured, the enlargement ratio Ax / ax increases. However, when the focal point 9 is brought too close to the surface of the object 3 to be measured, the enlargement ratio is caused by a minute change in the distance Ls during measurement. Since Ax / ax changes, the ratio of the distance Ls to the distance L ₀ is more preferably 1/20 ≦ Ls / L ₀ ≦ 1/5, which stabilizes when the enlargement ratio Ax / ax is five times or more.

  As shown in FIG. 1, the magnification adjustment mechanism includes a focus adjustment device 12 provided in the laser projector 1, and adjusts the position of the focus position adjustment lens with respect to the laser element of the laser projector 1. Thus, the distance Ls from the focal point 9 of the cross light 8a to the surface of the object to be measured 3 can be adjusted. The enlargement ratio adjusting mechanism includes a driving device 11 that can drive the laser projector 1 along the laser irradiation direction, and adjusts the position of the laser projector 1 with respect to the laser irradiation position 4 of the object 3 to be measured. Thus, the distance Ls can be adjusted.

  In the illustrated embodiment, the image processing device 6 is configured to perform image processing on a granular spot pattern imaged by the light receiving unit 2 by a phase-only correlation method. In order to calculate the correlation (similarity) of the input image of the granular spot pattern to be collated with the registered image of the original granular spot pattern, the input image of the granular spot pattern captured by the light receiving unit 2 is digitized and subjected to Fourier transform. It is mathematically processed and decomposed into amplitude (grayscale data) and phase (image contour data). The correlation between the registered image and the input image is obtained using only the phase data without using the grayscale data of the two data.

  The arithmetic unit 7 displays and outputs a granular spot pattern imaged by the light receiving unit 2 and a correlation value (amount of movement of the object 3 to be measured) of the phase data of the registered image and the input image processed by the image processing unit 6. Equipment.

In the illustrated embodiment, when the measurement object 3 is moved upward, as shown in FIGS. 5 (a) to 5 (d), the granular spotted pattern mark 10 is moved upward accordingly.
When the measurement object 3 is moved in the right direction, as shown in FIGS. 6A to 6D, the granular spotted pattern marker 10 is moved in the right direction.
The amount of displacement of the X direction, the Y direction, and the XY composite curve length is obtained by performing addition / subtraction based on the dot pitch or the CCD pixel pitch of the video screen in the horizontal and vertical directions from the movement of the indicator 10 on the screen of the display device. Thus, the displacement Ax of the granular spotted pattern can be derived.

  Further, the calculation device 7 is configured so that the displacement amount ax of the measurement object 3 can be obtained based on the following formula 10 from the displacement amount Ax of the granular spot pattern derived by the display device.

In addition, as described above, the relationship between the laser projector 1 and the light receiving unit 2 is fixed, not limited to the case of measuring the movement amount of the measurement object 3 by moving the measurement object 3 vertically and horizontally. It is possible to measure the relative displacement amount of the measurement object 3, the laser projector 1, and the light receiving unit 2.
Therefore, by moving the laser projector 1 and the light receiving unit 2 while fixing the measurement object 3 and calculating the movement of the granular spot pattern drawn on the measurement object 3, the relative movement with respect to the measurement object 3 is performed. The amount can be measured. Furthermore, although the granular spot pattern also moves with the movement of the object 3 to be measured, by moving the laser projector 1 and the light receiving unit 2 so as to always display and output the same granular spot pattern, It is also possible to obtain the movement amount of the measurement object 3 by measuring the movement amounts of the laser projector 1 and the light receiving unit 2.

Further, the measurement method and apparatus for the object to be measured by the laser reflected light according to the present invention are not limited to the measurement of the movement amount of the object to be measured 3 as in the illustrated embodiment, and by providing a plurality of the measurement apparatuses, A deformation amount and a deformation speed such as expansion, contraction, and growth of the measurement object can be measured.
In addition, by memorizing the granular spot pattern, it can be used for measuring the alignment of the object to be measured, identity, etc., and by measuring the change in the granular spot pattern, the object to be measured is solidified, It is also possible to measure changes such as softening and the rate of change.

The block diagram which shows one Example of the highly accurate displacement measuring apparatus of the to-be-measured object by this invention laser reflected light. The perspective view which shows the principal part of the one Example. The block diagram which shows the principal part of the one Example. The figure which shows the shape of a laser beam. The figure which shows transition of the granular spot pattern at the time of the upward movement of to-be-measured object. The figure which shows transition of the granular spot pattern at the time of the right direction movement of to-be-measured object. The figure which shows the movement amount of the granular spot pattern by the focus position of cross light. The figure which shows the change of the expansion ratio by the focus position of cross light. The figure which shows the measured value of the moving amount of the to-be-measured object by cross light irradiation. The figure which shows the measured value of the moving amount of the to-be-measured object by straight light irradiation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser projector 2 Light-receiving part 3 Object to be measured 4 Laser irradiation position 5 Offset angle 6 Image processing device 7 Arithmetic device 8a Cross light 8b Spot light 8c Straight light 8d Beam light 9 Focus 10 Marking 11 Driving device 12 Focus adjustment device 13 Night vision tube

Claims (10)

The surface of the object to be measured is irradiated with a laser beam, the granular spot pattern that is the reflected light of the laser beam is imaged by the light receiving unit, and the displacement of the granular spot pattern that appears as the displacement of the object to be measured expands is measured. A method for measuring a displacement of an object to be measured by laser reflected light for obtaining a displacement of the object to be measured from a spot pattern displacement, wherein the laser light is a cross light having a focal point between a laser projector and the surface of the object to be measured. The ratio of the distance Ls from the focus of the cross light to the surface of the object to be measured and the distance L ₀ from the surface of the object to be measured to the light receiving portion is 0 <Ls / L ₀ ≦ 1/3. A method for measuring the displacement of an object to be measured by light.   2. An object to be measured by reflected laser light according to claim 1, wherein the light receiving portion is composed of a CCD element, and a night vision tube for blocking extraneous light is mounted in front of the CCD element so as to directly image a granular spotted pattern. Displacement measurement method. When the laser beam is irradiated at an angle θ _S with respect to the normal direction of the surface of the object to be measured and the light receiving portion is arranged in the direction of the angle θ ₀ , the following equation 1 is obtained from the measured displacement Ax of the granular spot pattern. The displacement measuring method of the object to be measured by the laser reflected light according to claim 1 or 2, wherein the displacement amount ax of the object to be measured is obtained based on the above.

By changing the ratio of the distance Ls and the distance _{L 0 (Ls / L 0)} , according to any one of claims 1 to 3 to adjust the magnification of the displacement of the granular speck pattern with respect to the displacement of the object to be measured A method for measuring the displacement of an object to be measured by reflected laser light. A laser projector that irradiates the surface of the object to be measured with a laser beam, a light receiving unit that captures a granular spot pattern that is reflected light of the laser beam, and a displacement of the granular spot pattern that appears as the displacement of the object to be measured expands. An apparatus for measuring displacement of an object to be measured by laser reflected light, comprising: an image processing apparatus for measuring; and an arithmetic unit for obtaining a displacement of the object to be measured from the displacement of the granular spotted pattern, wherein the laser projector is the object to be measured The surface of the object to be measured is irradiated with cross light having a focal point between the surface and the laser projector, and the cross light is a distance Ls from the focus to the surface of the object to be measured and a distance L from the surface of the object to be measured to the light receiving unit. _A device for measuring the displacement of an object to be measured by laser reflected light, wherein the ratio of 0 is 0 <Ls / L ₀ ≦ 1/3.   6. The object to be measured by reflected laser light according to claim 5, wherein the light receiving portion is composed of a CCD element, and a night vision tube for blocking extraneous light is mounted in front of the CCD element to directly image a granular spotted pattern. Displacement measuring device. A laser projector is disposed so as to irradiate the laser beam at an angle θ _S with respect to the normal direction of the surface of the object to be measured, and a light receiving unit in the direction of an angle θ ₀ with respect to the normal direction of the surface of the object to be measured The displacement amount ax of the measurement object is obtained from the displacement amount Ax of the granular spotted pattern measured by the arithmetic unit based on the following equation (2). Displacement measuring device for measuring objects.

The distance ratio between Ls and the distance L ₀ of (Ls / L ₀₎ is variably controlled, claims 5 to 7 including a magnification adjusting mechanism for adjusting the magnification of the displacement of the granular speck pattern with respect to the displacement of the object to be measured An apparatus for measuring the displacement of an object to be measured by the laser reflected light according to any one of the above. It is due to the reflected laser beam according to claim 8, wherein the magnification adjusting mechanism has a ratio of the by adjusting the lens position of the laser floodlight distance Ls and the distance L ₀ of (Ls / L ₀₎ is variably controlled Displacement measuring device for measuring objects. The laser reflection according to claim 8, wherein the enlargement ratio adjusting mechanism adjusts a position of a laser projector with respect to an object to be measured to variably control the ratio (Ls / L ₀ ) between the distance Ls and the distance L _0. Device for measuring the displacement of an object to be measured by light.

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