WO2012132811A1

WO2012132811A1 - Ranging method and laser ranging device

Info

Publication number: WO2012132811A1
Application number: PCT/JP2012/055901
Authority: WO
Inventors: 直行古山
Original assignee: Koyama Naoyuki
Priority date: 2011-03-29
Filing date: 2012-03-08
Publication date: 2012-10-04
Also published as: JP5414083B2; JPWO2012132811A1

Abstract

[Problem] To provide a ranging method and laser ranging device for measuring the distance to an object with high precision by making use of coherence that is characteristic of laser light, rather than using a mechanical means in an optical system. [Solution] In this ranging method and laser ranging device, by arranging a reflecting part (14) so as to be inclined at a predetermined angle θ, the optical path length of a reference light can be continuously varied within an optical path. An interference fringe is thereby formed in the interference light of the measurement light and the reference light received by a light-receiving part (18), and measurement contrast data can be created on the basis of light intensity data from each photodetector (22) of the light-receiving part (18). Distance is then measured on the basis of the measurement contrast data. The thickness or a distance in the thickness direction of an object can thereby be measured with high precision without the use of a mechanical means in an optical system.

Description

Ranging method and laser ranging device

The present invention relates to a distance measuring method and a laser distance measuring apparatus that measure the distance or thickness in the thickness direction of an object to be measured with high accuracy using interference of laser light.

In a conventional laser distance measuring method using laser light, for example, the laser light is divided into reference light and measurement light, and the optical path difference between the reference light and measurement light reflected by the object to be measured is obtained. Measure the distance to the object to be measured. In the conventional laser distance measuring method that performs distance measurement based on the time difference between the reference light and the measurement light, the distance measurement accuracy is far from the wavelength level of the laser light, that is, the order of nm (nanometer).

Therefore, as shown in [Patent Document 1] below, the inventor of the present application uses a plurality of laser beams having different wavelengths, and further changes the optical path difference so as to utilize the coherence characteristic of the laser beams. Inventions related to a laser distance measuring method and a laser distance measuring apparatus for performing the laser distance measuring method have been made.

International Publication No. 2008/099788 Pamphlet

The invention disclosed in [Patent Document 1] makes it possible to measure the distance to the object to be measured with high accuracy. However, in the invention of [Patent Document 1], the optical path difference is changed by mechanical means such as a motor. Therefore, high-precision ranging requires expensive mechanical means with high positional accuracy, and there is a problem that the cost increases. In addition, even mechanical means with high positional accuracy may cause errors due to backlash (reverse operation) or the like, and further improvement is desired in this respect.

The present invention has been made in view of the above circumstances, and while utilizing the coherence characteristic of laser light, the distance to the object to be measured or the distance in the thickness direction without using mechanical means in the optical system or It is an object of the present invention to provide a distance measuring method and a laser distance measuring device for measuring a thickness with high accuracy.

(1) The first laser light and the second laser light having different wavelengths are divided into reference light and measurement light by the dividing unit 12, and reflected by the reference light reflected by the reflecting unit 14 and the measurement point of the object 6 to be measured. The light receiving unit 18 receives the measured light and measures the distance L in the thickness direction of the DUT 6 based on light and dark data obtained by the interference between the reference light and the measurement light. A method,
A calculation light / dark data creating step for calculating calculated light / dark data based on the wavelengths of the first laser light and the second laser light and the light intensity of the reference light and measurement light received by the light receiving unit 18;
The reference light of each of the first laser light and the second laser light is reflected by the reflecting portion 14 whose reflecting surface is inclined, and each measurement light of the first laser light and the second laser light is reflected on the first object 6 to be measured. A first irradiating step in which the reference light reflected by the measurement point S1 and reflected by the reflection unit 14 and the measurement light reflected by the first measurement point S1 are received by the light receiving unit 18 including a plurality of light receivers 22; ,
A first brightness / darkness data creation step for creating measurement brightness / darkness data of the first measurement point S1 based on the light intensity data of each light receiver 22 of the light receiving section 18;
A first comparison step of comparing the measured light / dark data of the first measurement point S1 with the calculated light / dark data to identify the position of the measured light / dark data of the first measurement point S1 in the calculated light / dark data;
A first distance data acquisition step of acquiring first distance data from the base point of the measured light / dark data of the first measurement point S1 to the reference point of the calculated light / dark data;
The reference light of each of the first laser light and the second laser light is reflected by the reflecting portion 14, and each measurement light of the first laser light and the second laser light is reflected at the second measurement point S 2 of the object to be measured 6. A second irradiating step in which the reference light reflected by the reflection part 14 and the measurement light reflected by the second measurement point S2 are received by the light receiving part 18;
A second light / dark data creating step for creating measured light / dark data of the second measurement point S2 based on the light intensity data of each light receiver 22 of the light receiving unit 18;
A second comparison step of comparing the measured light / dark data of the second measurement point S2 with the calculated light / dark data to identify the position of the measured light / dark data of the second measurement point S2 in the calculated light / dark data;
A second distance data acquisition step of acquiring second distance data from the base point of the measured light / dark data of the second measurement point S2 to the reference point of the calculated light / dark data;
A distance measuring step for measuring the distance L in the thickness direction between the first measurement point S1 and the second measurement point S2 based on the first distance data and the second distance data;
The above-described problem is solved by providing a distance measuring method characterized by comprising:
(2) The first laser beam and the second laser beam having different wavelengths are divided into the reference beam and the measurement beam by the dividing unit 12 and reflected by the reference beam reflected by the reflecting unit 14 and the measurement point of the object 6 to be measured. The light receiving unit 18 receives the measured light and measures the distance L in the thickness direction of the DUT 6 based on light and dark data obtained by the interference between the reference light and the measurement light. A method,
A calculation light / dark data creating step for calculating calculated light / dark data based on the wavelengths of the first laser light and the second laser light and the light intensity of the reference light and measurement light received by the light receiving unit 18;
The first laser beam and the second laser beam are each divided into two reference beams and a measuring beam, and one of the first laser beam and the second laser beam (first reference beam) is inclined on the reflection surface. The light is reflected by the first reflection region 14a of the reflection unit 14, and one measurement light (first measurement light) of the first laser light and the second laser light is reflected by the first measurement point S1 of the object 6 to be measured. The reference light reflected by the one reflection region 14a and the measurement light reflected by the first measurement point S1 are received by the first light receiving region 18a of the light receiving unit 18 including a plurality of light receivers 22,
The other reference light (second reference light) of the first laser light and the second laser light is reflected by the second reflection region 14b of the reflecting portion 14 whose reflection surface is inclined, and the first laser light and the second laser light. The second measurement light (second measurement light) is reflected at the second measurement point S2 of the object 6 to be measured, and a plurality of reference lights reflected at the second reflection region 14b and measurement light reflected at the second measurement point S2 are used. An irradiating step for receiving light in the second light receiving region 18b of the light receiving unit 18 constituted by the light receiver 22;
A first light / dark data creating step for creating measured light / dark data of the first measurement point S1 based on the light intensity data of each light receiver 22 in the first light receiving region 18a;
A second light / dark data creation step for creating measurement light / dark data of the second measurement point S2 based on the light intensity data of each light receiver 22 in the second light receiving region 18b;
A first comparison step of comparing the measured light / dark data of the first measurement point S1 with the calculated light / dark data to identify the position of the measured light / dark data of the first measurement point S1 in the calculated light / dark data;
A second comparison step of comparing the measured light / dark data of the second measurement point with the calculated light / dark data to identify the position of the measured light / dark data of the second measurement point S2 in the calculated light / dark data;
A first distance data acquisition step of acquiring first distance data from the base point of the measured light / dark data of the first measurement point S1 to the reference point of the calculated light / dark data;
A second distance data acquisition step of acquiring second distance data from the base point of the measured light / dark data of the second measurement point S2 to the reference point of the calculated light / dark data;
A distance measuring step for measuring the distance L in the thickness direction between the first measurement point and the second measurement point based on the first distance data and the second distance data;
The above-described problem is solved by providing a distance measuring method characterized by comprising:
(3) The second measurement point S2 is located on the back surface of the first measurement point S1,
By reflecting the second measurement light at the second measurement point S2,
The distance measurement step measures the thickness t of the DUT 6 and provides the distance measurement method according to the above (2), thereby solving the above problem.
(4) First laser irradiation means 10a and second laser irradiation means 10b for emitting two first laser beams and second laser beams having different wavelengths, and the first laser beam and the second laser beam as reference light. A dividing unit 12 that divides each measurement light into a measurement light, a reflection unit 14 that reflects each reference light at a predetermined reflection angle, and a reference light that is composed of a plurality of light receivers 22 and reflected by the reflection unit 14 and the device under test 6 A light receiving unit 18 that receives the measurement light reflected by the light receiving unit 22 and outputs the light intensity data of each light receiver 22, and a calculation unit 20 that receives the light intensity data from the light receiving unit 18.
The calculated brightness / darkness data creation step, the first irradiation step, the first brightness / darkness data creation step, the first comparison step, the first distance data acquisition step, the second irradiation step, the second brightness / darkness data creation step and the second described in (1) above. The comparison step, the second distance data acquisition step, and the distance measurement step are performed to measure the distance L in the thickness direction between the first measurement point S1 and the second measurement point S2 of the object 6 to be measured. The above-described problem is solved by providing the laser distance measuring device 50a.
(5) First laser irradiation means 10a and second laser irradiation means 10b for emitting two first laser beams and second laser beams having different wavelengths, and two references each of the first laser beam and the second laser beam A laser beam splitting unit that splits the light into a measurement beam, and a first reference beam that reflects one reference beam (first reference beam) of the first laser beam and the second laser beam split by the laser beam splitting unit at a predetermined reflection angle. A reflection area 14a, a second reflection area 14b that reflects the other reference light (second reference light) of the first laser light and the second laser light divided by the laser light dividing means at a predetermined reflection angle, and laser light division A first emission port 16a that emits one measurement light (first measurement light) of the first laser light and the second laser light divided by the means, and the first laser light and the second laser light divided by the laser light division means The second measurement light (second measurement light) is emitted And the exit port 16b,
It is composed of a plurality of light receivers 22, receives the reference light reflected by the first reflection region 14 a and the measurement light reflected by the first measurement point S 1 of the device under test 6, and outputs the light intensity data of each light receiver 22. A first light receiving region 18a to be
It is composed of a plurality of light receivers 22, receives the reference light reflected by the second reflection region 14 b and the measurement light reflected by the second measurement point S 2 of the device under test 6, and outputs the light intensity data of each light receiver 22. A second light receiving region 18b that
A calculation unit 20 for inputting light intensity data from the first light receiving region 18a and the second light receiving region 18b,
The calculated brightness / darkness data creation step, the irradiation step, the first brightness / darkness data creation step, the second brightness / darkness data creation step, the first comparison step, the second comparison step, the first distance data acquisition step, and the second distance data described in (2) above. Laser distance measuring device 50b characterized in that the distance L in the thickness direction between first measurement point S1 and second measurement point S2 of object 6 is measured by performing an acquisition step and a distance measurement step. By providing the above, the above-described problems are solved.
(6) The first output port 16a and the second output port 16b are installed so as to face each other, and the device under test 6 is disposed between the first output port 16a and the second output port 16b. The above-mentioned problem is solved by providing the laser distance measuring device 50c according to the above (5), which measures the thickness t of 6.

According to the distance measuring method and the laser distance measuring apparatus according to the present invention, the distance or thickness in the thickness direction of the object to be measured can be measured with high accuracy without using mechanical means in the optical system.

It is a figure which shows schematic structure of the laser ranging apparatus of the 1st form which concerns on this invention. It is a figure explaining the optical path difference of the reference light of this invention, and measurement light. It is a figure explaining preparation of the light-receiving part of this invention, and measurement brightness / darkness data. It is a figure explaining the calculation brightness data and measurement brightness data which concern on this invention. It is a figure which shows schematic structure of the laser ranging apparatus of the 2nd form which concerns on this invention. It is a figure which shows the modification of the reflection part which concerns on this invention. It is a figure which shows the example which applied the 2nd ranging method which concerns on this invention to the laser ranging apparatus of a 1st form. It is a figure which shows schematic structure of the laser ranging apparatus of the 3rd form which concerns on this invention. It is a figure which shows the modification of the laser rangefinder of the 2nd form which concerns on this invention. It is a figure which shows the modification of the laser rangefinder of the 3rd form which concerns on this invention.

Embodiments of a distance measuring method and a laser distance measuring device according to the present invention will be described with reference to the drawings. In addition, the broken line in a figure shows a laser beam.

First, the basic principle of the distance measuring method and the laser distance measuring device according to the present invention will be described with reference to the laser distance measuring device 50a of the first embodiment of FIG. 1 and FIGS. 2, 3, and 4. FIG.

The laser distance measuring device 50a according to the present invention includes a first laser irradiation unit 10a and a second laser irradiation unit 10b that respectively emit two laser beams having different wavelengths (first laser beam and second laser beam). ing. As the first laser irradiation unit 10a and the second laser irradiation unit 10b, it is preferable to use a helium neon laser, a semiconductor excitation solid laser, a semiconductor DFB laser, or the like having a relatively long coherence length. However, when the optical path length of the measurement light and the optical path length of the reference light are substantially equal, a semiconductor laser or the like having a short coherence length may be used.

Then, the first laser light emitted from the first laser irradiation means 10a is reflected by the mirror 4a provided on the optical path of the first laser light and travels toward the dividing unit 12. The second laser light emitted from the second laser irradiation means 10b is reflected by the half mirror 4b provided on the optical path of the second laser light, passes through the same optical path as the first laser light, and travels to the dividing unit 12.

A half mirror, a beam splitter, or the like is used as the splitting unit 12, and the first laser light and the second laser light that have reached the splitting unit 12 are split into two by the splitting unit 12 into reference light and measurement light. In the case where a flat beam splitter is used as the dividing unit 12, it is necessary to provide the correction plate 11 between the dividing unit 12 and the reflecting unit 14. However, when a cube-type beam splitter is used for the dividing unit 12, the correction plate 11 need not be provided.

The reference light of the first laser beam and the second laser beam divided by the dividing unit 12 is reflected by the reflecting unit 14. At this time, the reflection surface of the reflection portion 14 is not perpendicular to the incident direction of the reference light but is inclined by a predetermined angle θ. Therefore, the reference light is reflected at a predetermined reflection angle (2θ as viewed from the incident direction) as shown in FIG. Then, the reference light reflected by the reflecting section 14 passes through the correction plate 11 and the beam splitter (dividing section 12) and reaches the light receiving section 18 at an angle inclined by 2θ. In consideration of dispersion of the laser light, it is desirable that the correction plate 11 and the beam splitter (dividing unit 12) be thin.

In addition, the measurement light of the first laser beam and the second laser beam divided by the dividing unit 12 is reflected at a measurement point (for example, the first measurement point S1) of the object 6 to be measured and received through the dividing unit 12. Part 18 is reached. In addition, since the inclination angle θ of the reflecting surface of the reflecting portion 14 is about 0.23 °, the reference light reflected by the reflecting portion 14 and the measuring light reflected by the object 6 are partially received by the light receiving portion 18. It interferes with this part.

The light receiving unit 18 is composed of a plurality of light receivers 22 such as a CCD and a CMOS, and one that can output light intensity data for each light receiver 22 is used.

Here, the light and dark data used in the distance measuring method of the present application will be described. As described above, the reflecting surface of the reflecting portion 14 is inclined by a predetermined angle θ. At this time, the optical path length of the reference light between the points aa ′ in FIG. 2 is Lra, the optical path length of the reference light between the points bb ′ is Lrb, and between the points a ′ and b ′ on the light receiving unit 18. Where D ′ is the optical path length Lra and the optical path length Lrb, the optical path difference (Lrb−Lra) is
(Lrb−Lra) = D′ sin2θ
That is, the optical path length of the reference light continuously changes depending on the position of the reflecting surface. On the other hand, since the optical path length of the measuring light is constant, in the example of FIG. 2, the optical path difference between the measuring light and the reference light increases from the point a ′ on the light receiving unit 18 toward the point b ′. For this reason, periodic interference fringes are generated in the interference light between the measurement light and the reference light as the optical path difference changes.

Here, suppose that, as shown in FIG. 3A, the light receiving unit 18 is installed so that the vertical rows of the plurality of light receiving units 22 constituting the light receiving unit 18 are along the interference fringes. For convenience of explanation, FIG. 3 shows a case where the number of irradiated laser beams is one. Further, the dark part of the interference fringes is indicated as B. In this case, for example, when the light intensity data of an arbitrary row n and row n−1 of the light receiver 22 are connected from the column a ′ to the column b ′, the light / dark data of the interference light is obtained as shown in FIG. can get.

If the installation angle of the light receiver 22 is optimized, as shown in FIGS. 3C and 3D, the light intensity data of a large number of rows of light receivers 22 can be used to create light and dark data. It becomes possible, and more detailed light and dark data can be created. In FIG. 3, one laser beam is irradiated. However, since two laser beams (first laser beam and second laser beam) are actually irradiated, the brightness data is the reference beam of the first laser beam. The interference light that interferes with the measurement light, the reference light of the second laser light, and the interference light that interferes with the measurement light are combined. Even in such a case, it is possible to obtain sufficient brightness / darkness data for performing the distance measuring method of the present application by optimizing the installation angle of the light receiver 22 and creating brightness / darkness data with more light intensity data. In addition, it is not necessary to use the light intensity data of all the light receivers 22 constituting the light receiving unit 18 for the light / dark data, and the light intensity data of the light receivers 22 in an area sufficient for creating the light / dark data may be used. However, it can be said that it is more preferable to use the light intensity data of all the light receivers 22 because the unevenness in the irradiation surface of the measurement light can be known. The same applies to a first light receiving region 18a and a second light receiving region 18b described later. Further, the use area in the light receiving unit 18 and the order of arrangement of the light intensity data at the time of creating the brightness / darkness data are acquired in advance before the laser ranging devices 50a to 50c are shipped, and the memories in the laser ranging devices 50a to 50c are obtained. It is preferable to memorize in the above.

Note that the length of the light / dark data obtained by the above method is basically the number of data (number of light receivers 22) used to create the light / dark data, which is different from the actual length (Lrb-Lra). Yes. The length based on the number of the light receivers 22 is hereinafter referred to as a pixel length. Where the distance L ′
Between the (pixel length) and the actual distance L, when the wavelength of the laser beam to be used is λ, and the pixel length of the interference fringe wavelength (period) of this laser beam is λ ′ In addition,
The relationship L = L′ λ / (2 × λ ′) is established.
Therefore, if the wavelength λ of the laser beam to be used (the first laser beam or the second laser beam) and the wavelength (period) λ ′ of the interference fringe at the pixel length are acquired in advance, the above conversion formula is used. The actual length can be calculated from the pixel length. The conversion from the pixel length to the actual length may be performed at the time of the light / dark data, but the intermediate calculation is performed with the pixel length, and the pixel length is changed to the actual length at the final stage of the distance measurement step. Conversion is preferable from the viewpoint of error reduction. In this example, a description will be given of an example in which an intermediate calculation is performed with the pixel length and converted to the actual length at the final stage of the distance measuring step.

Further, in the distance measuring method and laser distance measuring device according to the present invention, light and dark data (hereinafter referred to as “light intensity data”) generated based on light intensity data output from the light receiving unit 18 or first light receiving area 18a and second light receiving area 18b described later. The measured light / dark data) is compared with the light / dark data (hereinafter referred to as the calculated light / dark data) created by the calculation of the computer of the laser distance measuring device.

Here, the method for creating the calculated light / dark data will be described. The period of the interference fringes of the interference light of the laser light is determined by the wavelength (frequency) of the laser light used as described above. Since the frequencies of the first laser light and the second laser light are known, the period of the interference fringes of the interference light of the first laser light and the period of the interference fringes of the interference light of the second laser light can be calculated. In addition, the light intensity of the reference light of the first laser light, the measurement light of the first laser light, the reference light of the second laser light, and the measurement light of the second laser light received by the light receiving unit 18 may be individually acquired in advance. For example, the amplitude of each interference light of the first laser light and the second laser light can also be calculated. Thereby, the period and amplitude of the interference light by the first laser light and the period and amplitude of the interference light by the second laser light are found. The light intensity of the measurement light received by the light receiving unit 18 varies depending on the state of reflection of the object 6 to be measured. Therefore, the measurement of the light intensity of the measurement light is preferably performed every time the measurement object 6 changes greatly.

Here, the bright part is taken at the point where the optical path difference between the reference light and the measuring light is zero in any interference light of the laser light of any transmission wavelength. Therefore, the position of the arbitrary bright portion of the interference light of the first laser light created by the calculation and the position of the arbitrary bright portion of the interference light of the second laser light are overlapped and added together, thereby adding the first laser. Computed light / dark data in which the interference fringes of the interference light of the light and the interference fringes of the interference light of the second laser light are combined can be created. It should be noted that the position where the bright portions are overlapped takes the maximum light intensity on the calculated light / dark data, and the waveform of the calculated light / dark data is symmetrical before and after this. Therefore, this point is preferably used as a reference point for the calculated light / dark data. The above is the method for creating the calculated brightness / darkness data, and it is preferable that the calculation brightness / darkness data is created in advance before the distance measurement of the object 6 to be measured.

Next, the operation of the first distance measuring method according to the present invention and the laser distance measuring apparatus 50a of the first embodiment will be described. First, calculated brightness / darkness data is created by the above-described method (calculated brightness / darkness data creation step in the first distance measuring method).

Next, as shown in FIG. 1 (a), the DUT 6 is installed so that the measurement light is irradiated to the first measurement point S1. Next, the first laser irradiation unit 10a and the second laser irradiation unit 10b are operated to irradiate the first laser beam and the second laser beam simultaneously. The irradiated first laser light and second laser light are divided into two by the dividing unit 12 into reference light and measurement light.

The reference light of the first laser beam and the second laser beam divided by the dividing unit 12 is reflected by the reflecting unit 14 whose reflecting surface is inclined at a predetermined angle θ, passes through the dividing unit 12, and receives the light receiving unit 18. To reach. Further, the measurement light of the first laser beam and the second laser beam divided by the dividing unit 12 is emitted from the emission port 16, reflected at the first measurement point S 1 of the object 6 to be measured, and then reflected by the dividing unit 12. And reaches the light receiving unit 18. The light receiving unit 18 receives the reference light of the first laser beam and the second laser beam reflected by the reflecting unit 14 and the measurement light of the first laser beam and the second laser beam reflected by the first measurement point S1 of the object 6 to be measured. Light is received (first irradiation step in the first distance measuring method). In addition, it is preferable that the optical path length of the measurement light and the optical path length of the reference light are substantially equal so that the optical path difference between the reference light and the measurement light is within the range of the coherence length during distance measurement.

Then, the light receiving unit 18 outputs the light intensity data of each light receiver 22 to the calculation unit 20. The calculation unit 20 arranges the light intensity data of the respective light receivers 22 in a predetermined order, and creates measurement brightness / darkness data of the first measurement point S1 (first measurement brightness / darkness data creation step in the first distance measuring method).

Here, since the optical path length of the reference light reflected by the reflecting portion 14 differs depending on the position of the reflection surface, the light and dark periodically change the interference light between the reference light of the first laser light and the measurement light of the first laser light. Interference fringes are formed. The interference light between the reference light of the second laser light and the measurement light of the second laser light also forms interference fringes whose brightness changes periodically. However, since the first laser beam and the second laser beam have different wavelengths, the period of interference fringes is different. Incidentally, the interference light between the first laser beam and the second laser beam becomes “beat”, and takes a constant value when time averaged. Therefore, the measurement brightness / darkness data at the first measurement point S1 is basically the interference light between the measurement light of the first laser light reflected at the first measurement point S1 and the reference light of the first laser light, and at the first measurement point S1. The reflected measurement light of the second laser light and the interference light of the reference light of the second laser light are combined.

Next, the calculation unit 20 compares the acquired measurement brightness / darkness data of the first measurement point S1 with previously calculated brightness / darkness data, and determines the position of the measurement brightness / darkness data of the first measurement point S1 in the calculation brightness / darkness data. Identify. (First comparison step in the first distance measuring method).

Note that the calculated brightness / darkness data is obtained by calculating the brightness / darkness data obtained by combining the above two interference lights, and the measured brightness / darkness data is obtained by actual measurement. Therefore, the calculated brightness data and the measured brightness data are basically the same, although the acquisition ranges are different. Here, FIG. 4 schematically shows the relationship between the calculated brightness data and the measured brightness data. In addition, the thin line in FIG. 4 shows calculation brightness data, and a thick line shows measurement brightness data. As described above, since the calculated brightness / darkness data is created by computation, the creation range (the range of the optical path difference between the reference light and the measurement light) can be arbitrarily set. Therefore, if the calculated light / dark data is created within a sufficient range that can be taken by the measured light / dark data, the measured light / dark data A at the first measurement point S1 coincides with any part of the calculated light / dark data.

Next, the calculation unit 20 calculates the first distance data La ′ from the base point (point P in FIG. 4) of the measured light / dark data at the first measurement point S1 to the reference point (point O in FIG. 4) on the calculated light / dark data. (Pixel length) is calculated (first distance data acquisition step in the first distance measuring method). The base point of the measured light / dark data can be an arbitrary position of the measured light / dark data (light intensity data of any light receiver 22).

Next, the laser distance measuring device 50a or the object to be measured 6 is translated, and the object to be measured 6 is positioned so that the measurement light is irradiated to the second measurement point S2, as shown in FIG.

Next, the first laser irradiation unit 10a and the second laser irradiation unit 10b are operated to irradiate the first laser beam and the second laser beam simultaneously. Thus, the light receiving unit 18 measures the first laser light and the second laser light reflected by the reflecting unit 14 and the first laser light and the second laser light reflected by the second measurement point S2 of the object 6 to be measured. Receiving light (second irradiation step in the first distance measuring method).

Then, the light receiving unit 18 outputs the light intensity data of each light receiver 22 to the calculation unit 20. The computing unit 20 arranges the light intensity data of the respective light receivers 22 in a predetermined order, and creates measurement brightness / darkness data of the second measurement point S2 (second measurement brightness / darkness data creation step in the first distance measuring method). Note that the measured brightness / darkness data at the second measurement point S2 is basically the interference light between the measurement light of the first laser light reflected at the second measurement point S2 and the reference light of the first laser light, and the second measurement point S2. The reflected measurement light of the second laser light and the interference light of the reference light of the second laser light are combined.

Next, the calculation unit 20 compares the acquired measurement brightness / darkness data of the second measurement point S2 with previously calculated brightness / darkness data, and determines the position of the measurement brightness / darkness data of the second measurement point S2 in the calculation brightness / darkness data. Identify. (Second comparison step in the first distance measuring method).

As described above, the calculated brightness / darkness data and the measured brightness / darkness data are basically the same although the acquisition ranges are different. Therefore, if the creation range of the calculated brightness / darkness data is optimized, the second measurement point S2 in FIG. The measured light / dark data B also matches any part of the calculated light / dark data. The difference in the positions of the measured light / dark data A at the first measurement point S1 and the measured light / dark data B at the second measurement point S2 in the calculated light / dark data is the difference between the measured light / dark data A at the first measurement point S1 and the second measurement point S2. This is due to a difference in optical path difference from the measured light / dark data B.

Next, the computing unit 20 obtains the second distance data Lb ′ (pixel length) from the base point (point P ′ in FIG. 4) of the measured brightness / darkness data at the second measurement point S2 to the reference point O on the calculated brightness / darkness data. Calculate (second distance data acquisition step in the first distance measuring method). Note that the base point at this time must be the same position in the measured light / dark data as in the first distance data acquisition step. The difference in position between the measured light / dark data A at the first measurement point S1 and the measured light / dark data B at the second measurement point S2 when the base points are the same is the optical path difference on the measured object 6 side, that is, the first measurement. This corresponds to the distance L in the thickness direction between the point S1 and the second measurement point S2.

Therefore, the calculation unit 20 subtracts the first distance data La ′ obtained in the first distance data acquisition step from the second distance data Lb ′ obtained in the second distance data acquisition step, and then divides by two. Thus, the distance L ′ (pixel length) in the thickness direction between the first measurement point S1 and the second measurement point S2 is calculated. When the distance L ′ is negative, it indicates that the second measurement point S2 is located closer to the laser distance measuring device 50a than the first measurement point S1. Then, the distance L ′ in the thickness direction between the first measurement point S1 and the second measurement point S2 is calculated by converting the pixel length of the distance L ′ into an actual length (first distance measurement method). Ranging step). The above is the operation of the first distance measuring method and the laser distance measuring device 50a of the first embodiment according to the present invention.

Next, the operation of the second distance measuring method according to the present invention and the laser distance measuring device 50b of the second embodiment will be described with reference to FIG. The laser distance measuring device 50 b has a laser beam splitting unit 28 that splits the first laser beam and the second laser beam into two before the splitting unit 12. The laser beam splitting unit 28 and the splitting unit 12 constitute a laser beam splitting unit that splits the first laser beam and the second laser beam into two reference beams and measurement beams, respectively. In addition to the half mirror and beam splitter, the laser beam splitting unit 28 may be configured to divide the first laser beam and the second laser beam into two orthogonally polarized beams using a Savart plate. As described above, the laser beam splitting unit 28 splits the first laser beam and the second laser beam into two. One of the first laser light and the second laser light divided by the laser light dividing unit 28 is further divided into two by the dividing unit 12 into reference light and measurement light. Then, one reference light (hereinafter referred to as first reference light) of the first laser beam and the second laser beam divided by the dividing unit 12 is reflected by the first reflection region 14 a of the reflecting unit 14 and is divided by the dividing unit 12. , And reaches the first light receiving region 18a of the light receiving unit 18 constituted by a plurality of light receivers 22. One measurement light of the first laser light and the second laser light (hereinafter referred to as first measurement light) divided by the dividing unit 12 is a first measurement point of the DUT 6 from the first emission port 16a. The light is emitted toward S1, reflected by the first measurement point S1 and the dividing unit 12, and reaches the first light receiving region 18a of the light receiving unit 18.

Further, the other first laser light and second laser light divided by the laser light dividing unit 28 are reflected by the mirror 4c, and further divided into two by the dividing unit 12 into reference light and measurement light. Then, the other reference light (hereinafter referred to as second reference light) of the first laser light and the second laser light divided by the dividing unit 12 is reflected by the second reflection region 14b of the reflecting unit 14 and is divided. , And reaches the second light receiving region 18b of the light receiving unit 18 composed of a plurality of light receivers 22. The other measurement light of the first laser beam and the second laser beam (hereinafter referred to as second measurement beam) divided by the dividing unit 12 is sent from the second emission port 16b to the second measurement point of the object 6 to be measured. The light is emitted toward S2, reflected by the second measurement point S2 and the dividing unit 12, and reaches the second light receiving region 18b of the light receiving unit 18.

It should be noted that a step may be provided between the first reflection region 14a and the second reflection region 14b in the reflection portion 14, or the step may be eliminated to be a straight line. Further, the step between the first reflection region 14a and the second reflection region 14b may be large as shown in FIG. 6A or small as shown in FIG. 6B. Furthermore, the positions of the first reflection region 14a and the second reflection region 14b may be positioned on the near side when the first reflection region 14a is viewed from the light receiving unit 18, as shown in FIG. 6C. Furthermore, the inclination of the reflection surfaces of the first reflection region 14a and the second reflection region 14b may be opposite to each other as shown in FIG. Further, as in a reflection portion 14 in FIGS. 9 and 10 to be described later, the direction in which the first reflection area 14a and the second reflection area 14b are arranged differs from the inclination direction of the reflection surfaces (in FIGS. 9 and 10). 90 °).

Next, the operation of the second distance measuring method according to the present invention and the laser distance measuring apparatus 50b of the second embodiment will be described. In the second distance measuring method, in addition to the calculated light / dark data, the first reference distance data Las ′ (pixel length) of the first measurement light system and the second reference distance data Lbs ′ (pixel length) of the second measurement light system. ) And need to get. An example of a method for obtaining the first reference distance data Las 'and the second reference distance data Lbs' will be described later.

First, calculation light / dark data is created by the same method as the first distance measuring method (calculated light / dark data creation step in the second distance measuring method). Next, the first reference distance data Las 'and the second reference distance data Lbs' are obtained by a predetermined method.

Next, as shown in FIG. 5A, the first measurement light of the first laser light and the second laser light is placed at the first measurement point S 1 at the first laser light and the second laser light. The second measurement light is installed so as to irradiate the second measurement point S2 vertically. Next, the first laser irradiation unit 10a and the second laser irradiation unit 10b are operated to irradiate the first laser beam and the second laser beam simultaneously.

Thereby, the first measurement light of the first laser light and the second laser light is reflected at the first measurement point S1 of the object 6 to be measured and reaches the first light receiving region 18a as described above. The second measurement light of the first laser light and the second laser light is reflected at the second measurement point S2 of the object 6 to be measured and reaches the second light receiving region 18b. Further, the first reference light of the first laser light and the second laser light is reflected by the first reflection region 14a of the reflecting portion 14 and reaches the first light receiving region 18a. Further, the second reference light of the first laser light and the second laser light is reflected by the second reflection region 14b of the reflecting portion 14 and reaches the second light receiving region 18b (irradiation step in the second distance measuring method).

The reflection surfaces of the first reflection region 14a and the second reflection region 14b are inclined at a predetermined angle θ, and the reference light reflected by the first reflection region 14a and the second reflection region 14b has an optical path length depending on the positions of the reflection surfaces. Is different. Therefore, the interference light between the first measurement light of the first laser light received by the first light receiving region 18a and the first reference light of the first laser light, the first measurement light of the second laser light, and the second laser light Together with the interference light with the first reference light, an interference fringe is formed. Further, interference light between the second measurement light of the first laser light received by the second light receiving region 18b and the second reference light of the first laser light, the second measurement light of the second laser light, and the second laser light Together with the interference light with the second reference light, an interference fringe is formed. Then, the light receiving unit 18 outputs the light intensity data of each light receiver 22 in the first light receiving region 18a and the second light receiving region 18b to the arithmetic unit 20. The first light receiving region 18a and the second light receiving region 18b may be provided in one light receiving unit 18, or the first light receiving region 18a and the second light receiving region 18b may be configured by individual light receiving units 18. Also good.

The calculation unit 20 arranges the light intensity data of the respective light receivers 22 in the first light receiving region 18a in a predetermined order, and creates measurement light / dark data of the first measurement point S1 (the first measurement light / dark in the second distance measuring method). Data creation step). Note that the measurement light / dark data at the first measurement point S1 basically includes the interference light between the first measurement light of the first laser light reflected at the first measurement point S1 and the first reference light of the first laser light, Interference light of the first measurement light of the second laser light reflected at the measurement point S1 and the first reference light of the second laser light is combined.

In addition, the calculation unit 20 arranges the light intensity data of the respective light receivers 22 in the second light receiving region 18b in a predetermined order, and creates the measurement light / dark data of the second measurement point S2 (second in the second distance measuring method). Measurement light / dark data creation step). Note that the measured brightness / darkness data at the second measurement point S2 basically includes interference light between the second measurement light of the first laser light reflected at the second measurement point S2 and the second reference light of the first laser light, Interference light of the second measurement light reflected by the measurement point S2 and the second reference light of the second laser light is combined.

Next, the calculation unit 20 compares the acquired measurement brightness / darkness data of the first measurement point S1 with previously calculated brightness / darkness data, and determines the position of the measurement brightness / darkness data of the first measurement point S1 in the calculation brightness / darkness data. Identify. (First comparison step in the second distance measuring method).

In addition, the calculation unit 20 compares the acquired measurement brightness / darkness data of the second measurement point S2 with previously calculated brightness / darkness data, and specifies the position of the measurement brightness / darkness data of the second measurement point S2 in the calculation brightness / darkness data. To do. (Second comparison step in the second distance measuring method).

Next, the calculation unit 20 calculates first distance data La ′ (pixel length) from the base point of the measured light / dark data at the first measurement point S1 to the reference point on the calculated light / dark data (in the second distance measuring method). First distance data acquisition step).

In addition, the calculation unit 20 calculates second distance data Lb ′ (pixel length) from the base point of the measured brightness / darkness data at the second measurement point S2 to the reference point on the calculated brightness / darkness data (the second distance measurement method uses the second distance measurement method). 2 distance data acquisition step). Note that the measurement light / dark data of the first measurement point S1 and the base points of the measurement light / dark data of the second measurement point S2 are the measurement light / dark data set when the first reference distance data Las ′ and the second reference distance data Lbs ′ described later are acquired. It is the same as the position inside.

Here, an example of a method for obtaining the first reference distance data Las 'and the second reference distance data Lbs' will be described. The following acquisition method is suitable for the laser distance measuring device 50b according to the present invention, but this method is not necessarily used. The acquisition of the first reference distance data Las 'and the second reference distance data Lbs' is not necessarily performed for each measurement, and may be performed at the time of shipment of the laser distance measuring device and recorded in a memory or the like.

First, as shown in FIG. 5B, the first exit port 16a and the second exit port 16b are closed with a flat plate 5 having a smooth surface. At this time, the distance from the first exit 16a to the flat plate 5 is equal to the distance from the second exit 16b to the flat plate 5. Next, the first laser irradiation unit 10a and the second laser irradiation unit 10b are operated to irradiate the first laser beam and the second laser beam simultaneously. Thereby, the first measurement light of the first laser light and the second laser light is reflected at the first measurement point S 1 ′ of the flat plate 5. Further, the second measurement light of the first laser light and the second laser light is reflected at the second measurement point S2 'of the flat plate 5 (irradiation step). Then, in this state, the first light / dark data creation step to the second distance data acquisition step in the second distance measuring method are performed. The base point of the measured light / dark data in the first distance data acquisition step and the second distance data acquisition step can be basically set at an arbitrary position. However, the base point set here cannot be changed when the object 6 is measured.

Then, the first distance data La ′ obtained in the first distance data acquisition step becomes the first reference distance data Las ′, and the second distance data Lb ′ obtained in the second distance data acquisition step becomes the second reference distance data Lbs ′. It becomes. The first reference distance data Las 'corresponds to the optical path difference between the first measurement light and the first reference light reflected at the first measurement point S1' of the flat plate 5. The second reference distance data Lbs ′ corresponds to the optical path difference between the second measurement light and the second reference light reflected at the second measurement point S 2 ′ of the flat plate 5. Therefore, the difference between the first reference distance data Las 'and the second reference distance data Lbs' substantially corresponds to the position difference between the first reflection area 14a and the second reflection area 14b. The above is the method for obtaining the first reference distance data Las 'and the second reference distance data Lbs' suitable for the distance measuring device 50b.

Next, the calculation unit 20 obtains the first distance data La ′ obtained in the first distance data obtaining step, the second distance data Lb ′ obtained in the second distance data obtaining step, the first reference distance data Las ′, and the first distance data La ′. Based on the two reference distance data Lbs ′, a distance L ′ (pixel length) in the thickness direction between the first measurement point S1 and the second measurement point S2 is calculated by, for example, the following formula (second measurement). Ranging step in the distance method).
L ′ = ((La′−Las ′) − (Lb′−Lbs ′)) / 2
When the distance L ′ is negative, it indicates that the second measurement point S2 is located closer to the laser distance measuring device 50a than the first measurement point S1. Then, the distance L is calculated by converting the pixel length of the distance L ′ into an actual length. The above is the operation of the second distance measuring method and the laser distance measuring apparatus 50b of the second embodiment according to the present invention.

It should be noted that the second distance measuring method can be performed by the laser distance measuring device 50a of the first embodiment. In this case, as shown in FIG. 7, the device under test 6 is arranged so that the measurement light is simultaneously irradiated onto the first measurement point S1 and the second measurement point S2 of the device under test 6. And a part of measurement light irradiated to 1st measurement point S1 turns into one 1st measurement light. The first measurement light is reflected at the first measurement point S 1 and reaches the first light receiving region 18 a which is a part of the light receiving unit 18 via the dividing unit 12. Further, a part of the measurement light irradiated to the second measurement point S2 becomes the other second measurement light. The second measurement light is reflected at the second measurement point S2, and reaches the second light receiving region 18b which is a part of the light receiving unit 18 via the dividing unit 12. Further, a part of the reference light corresponding to the first measurement light becomes one first reference light. The first reference light is reflected by the first reflection region 14 a that is a part of the reflection unit 14, and reaches the first light reception region 18 a that is a part of the light reception unit 18 via the dividing unit 12. Further, a part of the reference light corresponding to the second measurement light becomes the other second reference light. The second reference light is reflected by the second reflection region 14 b that is a part of the reflection unit 14, and reaches the second light reception region 18 b that is a part of the light reception unit 18 via the dividing unit 12. Thereafter, the distance L in the thickness direction between the first measurement point S1 and the second measurement point S2 is calculated in the same manner as in the second distance measurement method described above. The discrimination between the first light receiving area 18a and the second light receiving area 18b may be made from the discontinuity of the acquired measurement light / dark data, or a blank area between the first light receiving area 18a and the second light receiving area 18b. And the DUT 6 may be arranged so that the boundary portion (step) between the first measurement point S1 and the second measurement point S2 is in a range corresponding to the blank area.

Next, the third distance measuring method according to the present invention and the operation of the laser distance measuring device 50c according to the third embodiment will be described with reference to FIG. Note that the laser range finder 50c of the third embodiment is between the first measurement point S1 located on the one surface side of the object 6 to be measured and the second measurement point S2 located on the back surface of the first measurement point S1. The distance t in the thickness direction is measured by measuring the distance in the thickness direction. Therefore, the configuration is basically the same as that of the laser distance measuring device 50b of the second embodiment except that the optical paths of the first measurement light and the second measurement light are different.

In the laser range finder 50c of the third embodiment, the first measurement light of the first laser light and the second laser light is reflected by the mirror 8a, the mirror 8b, and the mirror 8c provided on the optical path and is transmitted from the first emission port 16a. The light is emitted toward the second emission port 16b. The first exit port 16a and the second exit port 16b are provided at positions facing each other. As shown in FIG. 8A, the DUT 6 includes the first exit port 16a and the second exit port 16b. It is arranged between. Therefore, the first measurement light of the first laser beam and the second laser beam emitted from the first emission port 16a is reflected at the first measurement point S1 of the object 6 to be measured, and the mirror 8c, the mirror 8b, the mirror 8a, and the dividing unit. 12 to reach the first light receiving region 18 a of the light receiving unit 18. The first measurement light S1 and the second measurement light of the second laser light are reflected by the mirror 8d, the mirror 8e, and the mirror 8f provided on the optical path, and the first measurement point S1 of the DUT 6 from the second emission port 16b. The light is emitted toward the second measurement point S2 located on the back surface of. Then, the light is reflected at the second measurement point S2 of the DUT 6 and reaches the second light receiving region 18b of the light receiving unit 18 via the mirror 8f, the mirror 8e, the mirror 8d, and the dividing unit 12. It is preferable that the optical path length of the first measurement light and the optical path length of the second measurement light be as equal as possible. Moreover, it is preferable to optimize the optical path length of each reference light and the optical path length of each measurement light so that the optical path difference between each reference light and each measurement light is within the range of the coherence length during distance measurement.

The acquisition of the first reference distance data Las 'and the second reference distance data Lbs' in the third distance measuring method and the third laser distance measuring apparatus 50c according to the present invention is performed as follows, for example.

First, as shown in FIG. 8B, a block gauge 7 having a known thickness ta is installed at an intermediate position between the first emission port 16a and the second emission port 16b. At this time, the distance from the first exit port 16a to the block gauge 7 and the distance from the second exit port 16b to the block gauge 7 are arranged substantially equal. The thickness ta of the block gauge 7 is preferably thinner than the thickness t of the object 6 to be measured.

Next, the first laser irradiation unit 10a and the second laser irradiation unit 10b are operated to irradiate the first laser beam and the second laser beam simultaneously. As a result, the first measurement light of the first laser light and the second laser light is reflected at the first measurement point S 1 ′ of the block gauge 7. The second measurement light of the first laser light and the second laser light is reflected at the second measurement point S2 'located on the back surface of the first measurement point S1' (irradiation step). Then, in this state, steps equivalent to the first light / dark data creation step to the second distance data acquisition step in the second distance measuring method are performed. The base point of the measured light / dark data in the first distance data acquisition step and the second distance data acquisition step can be basically set at an arbitrary position. However, the base point set here cannot be changed when the object 6 is measured. Then, the first distance data La ′ obtained in the first distance data acquisition step becomes the first reference distance data Las ′, and the second distance data Lb ′ obtained in the second distance data acquisition step becomes the second reference distance data Lbs ′. It becomes. The first reference distance data Las 'corresponds to the optical path difference between the first measurement light and the first reference light reflected at the first measurement point S1' of the block gauge 7. The second reference distance data Lbs ′ corresponds to the optical path difference between the second measurement light and the second reference light reflected at the second measurement point S 2 ′ of the block gauge 7. The above is the method for obtaining the first reference distance data Las 'and the second reference distance data Lbs' suitable for the distance measuring device 50c.

Next, the calculated brightness data is created by performing the same steps as the calculated brightness data creation step in the second distance measuring method. Next, the DUT 6 is disposed between the first exit port 16a and the second exit port 16b. In this state, the irradiation step to the second distance data acquisition step in the second distance measuring method are performed. The first distance data La ′ acquired in the first distance data acquisition step here corresponds to the optical path difference between the first measurement light and the first reference light reflected at the first measurement point S1 of the object 6 to be measured. The second distance data Lb ′ acquired in the second distance data acquisition step corresponds to the optical path difference between the second measurement light and the second reference light reflected at the second measurement point S2 of the object 6 to be measured.

Next, the computing unit 20 includes the first distance data La ′ obtained in the first distance data obtaining step, the second distance data Lb ′ obtained in the second distance data obtaining step, and the first reference distance data Las ′. Based on the second reference distance data Lbs ′ and the thickness ta of the block gauge 7, for example, the distance L in the thickness direction between the first measurement point S1 and the second measurement point S2, that is, the thickness t of the object 6 to be measured is as follows: (A ranging step in the third ranging method) is calculated as follows.

First, the distance L ′ is calculated from the first distance data La ′, the second distance data Lb ′, the first reference distance data Las ′, and the second reference distance data Lbs ′ by the following formula. The distance L ′ corresponds to the pixel length obtained by subtracting the thickness ta of the block gauge 7 from the thickness t of the object 6 to be measured.
L ′ = ((La′−Las ′) + (Lb′−Lbs ′)) / 2
Next, the distance L ′ is calculated by converting the pixel length of the distance L ′ into an actual length. Then, the thickness t of the object to be measured 6 is calculated by adding the thickness ta of the block gauge 7 to the obtained distance L. The above is the operation of the third distance measuring method according to the present invention and the laser distance measuring apparatus 50c of the third embodiment.

As described above, according to the distance measuring method and the laser distance measuring device according to the present invention, the optical path length of the reference light is continuously changed in the optical path by installing the reflecting portion 14 at a predetermined angle θ. Can be made. Thereby, interference fringes are formed in the measurement light received by the light receiving unit 18 and the interference light by the reference light, and measurement light / dark data can be created based on the light intensity data of each light receiver 22 of the light receiving unit 18. . Then, distance measurement is performed by comparing the measured brightness / darkness data with the calculated brightness / darkness data calculated in advance. Thus, the distance or thickness in the thickness direction of the object to be measured can be measured with high accuracy without using mechanical means in the optical system.

The configuration of the laser distance measuring devices 50a to 50c is an example, and is not limited to FIGS. 1 and 5 to 8. Further, in the laser

distance measuring devices

50b and 50c of FIGS. 5 and 8, the optical paths of the laser light (reference light and measurement light) divided by the laser light dividing unit 28 and the dividing unit 12 are all parallel to the paper surface. However, the present invention is not particularly limited to this. For example, as in a modification of the laser distance measuring device 50b of the second embodiment shown in FIG. May be divided, or the dividing unit 12 may divide the laser beam in a direction perpendicular to the paper surface as in a modification of the laser distance measuring device 50c of the third embodiment shown in FIG. . Further, the laser beam division direction may be an arbitrary angle between the direction parallel to the paper surface and the direction perpendicular to the paper surface, and the optical path of each laser beam may take any three-dimensional optical path. Furthermore, the configuration of each part of the other laser distance measuring devices 50a to 50c can be changed and implemented without departing from the gist of the present invention.

6 DUT 10a First laser irradiation means 10b Second laser irradiation means 12 Dividing part 14 Reflecting part 14a First reflecting area 14b Second reflecting area 16a First emitting port 16b Second emitting port 18 Light receiving unit 18a First light receiving region 18b Second light receiving area 20 Calculation unit 22 Light receiver 50a to 50c Laser ranging device S1 First measurement point S2 Second measurement point L Distance (in the thickness direction of the measurement object) Thickness (of the measurement object)

Claims

The first laser beam and the second laser beam having different wavelengths are divided into reference light and measurement light by the dividing unit, respectively, and the reference light reflected by the reflecting unit and the measurement light reflected by the measurement point of the object to be measured are received. A distance measuring method for measuring the distance in the thickness direction of the object to be measured based on light and dark data obtained by the light received by the unit and the reference light and measurement light interfering with each other,
A calculation light / dark data creating step for calculating calculated light / dark data based on the wavelengths of the first laser light and the second laser light and the light intensity of the reference light and measurement light received by the light receiving unit;
The reference light of each of the first laser light and the second laser light is reflected by the reflecting portion whose reflection surface is inclined, and each measurement light of the first laser light and the second laser light is reflected at the first measurement point of the object to be measured. A first irradiating step in which the reference light reflected by the reflective portion and the measurement light reflected by the first measurement point are received by the light receiving portion configured by a plurality of light receivers;
A first light / dark data creating step for creating measurement light / dark data of the first measurement point based on the light intensity data of each light receiver of the light receiving unit;
A first comparison step of comparing the measured light / dark data of the first measurement point with the calculated light / dark data to identify the position of the measured light / dark data of the first measurement point in the calculated light / dark data;
A first distance data acquisition step of acquiring first distance data from a base point of the measured light / dark data of the first measurement point to a reference point of the calculated light / dark data;
Reflecting each reference beam of the first laser beam and the second laser beam by the reflection unit, reflecting each measurement beam of the first laser beam and the second laser beam at the second measurement point of the object to be measured, A second irradiation step of causing the light receiving unit to receive the reference light reflected by the reflection unit and the measurement light reflected by the second measurement point;
A second light / dark data creating step for creating measurement light / dark data of the second measurement point based on the light intensity data of each light receiver of the light receiving unit;
A second comparison step of comparing the measured light / dark data of the second measurement point with the calculated light / dark data and specifying the position of the measured light / dark data of the second measurement point in the calculated light / dark data;
A second distance data acquisition step of acquiring second distance data from the base point of the measured light / dark data of the second measurement point to the reference point of the calculated light / dark data;
A distance measuring step for measuring the distance in the thickness direction between the first measurement point and the second measurement point based on the first distance data and the second distance data;
A ranging method characterized by comprising:
The first laser beam and the second laser beam having different wavelengths are divided into reference light and measurement light by the dividing unit, respectively, and the reference light reflected by the reflecting unit and the measurement light reflected by the measurement point of the object to be measured are received. A distance measuring method for measuring the distance in the thickness direction of the object to be measured based on light and dark data obtained by the light received by the unit and the reference light and measurement light interfering with each other,
A calculation light / dark data creating step for calculating calculated light / dark data based on the wavelengths of the first laser light and the second laser light and the light intensity of the reference light and measurement light received by the light receiving unit;
The first laser beam and the second laser beam are each divided into two reference beams and a measurement beam, and one of the first laser beam and the second laser beam is reflected by a first reflecting surface of the reflecting portion. The reflected light is reflected by the region, and one measurement light of the first laser light and the second laser light is reflected by the first measurement point of the object to be measured, and is reflected by the reference light reflected by the first reflection region and the first measurement point. The measurement light is received by the first light receiving region of the light receiving unit configured by a plurality of light receivers,
The other reference light of the first laser light and the second laser light is reflected by the second reflection region of the reflection portion whose reflection surface is inclined, and the other measurement light of the first laser light and the second laser light is measured. The reference light reflected by the second measurement point of the object and the measurement light reflected by the second measurement point and the measurement light reflected by the second measurement point are received by the second light receiving region of the light receiving unit including a plurality of light receivers. An irradiation step;
A first light / dark data creating step for creating measurement light / dark data of the first measurement point based on the light intensity data of each light receiver in the first light receiving region;
A second light / dark data creation step for creating measurement light / dark data of the second measurement point based on the light intensity data of each light receiver in the second light receiving region;
A first comparison step of comparing the measured light / dark data of the first measurement point with the calculated light / dark data to identify the position of the measured light / dark data of the first measurement point in the calculated light / dark data;
A second comparison step of comparing the measured light / dark data of the second measurement point with the calculated light / dark data and specifying the position of the measured light / dark data of the second measurement point in the calculated light / dark data;
A first distance data acquisition step of acquiring first distance data from a base point of the measured light / dark data of the first measurement point to a reference point of the calculated light / dark data;
A second distance data acquisition step of acquiring second distance data from the base point of the measured light / dark data of the second measurement point to the reference point of the calculated light / dark data;
A distance measuring step for measuring the distance in the thickness direction between the first measurement point and the second measurement point based on the first distance data and the second distance data;
A ranging method characterized by comprising:
The second measurement point is located on the back surface of the first measurement point,
By reflecting the second measurement light at the second measurement point,
The distance measuring method according to claim 2, wherein the distance measuring step measures the thickness of the object to be measured.
A first laser irradiating means and a second laser irradiating means for emitting two first and second laser beams having different wavelengths;
A dividing unit for dividing the first laser beam and the second laser beam into reference light and measurement light, respectively;
A reflection part for reflecting each reference light at a predetermined reflection angle;
A light receiving unit configured to receive a reference light reflected by the reflection unit and a measurement light reflected by the object to be measured, and output light intensity data of each light receiver;
A calculation unit for inputting light intensity data from the light receiving unit, and
The calculated light / dark data creation step, the first irradiation step, the first light / dark data creation step, the first comparison step, the first distance data acquisition step, the second irradiation step, the second light / dark data creation step and the second comparison according to claim 1. Laser ranging, wherein a distance in the thickness direction between the first measurement point and the second measurement point of the object to be measured is measured by performing a step, a second distance data acquisition step, and a distance measurement step apparatus.
A first laser irradiating means and a second laser irradiating means for emitting two first and second laser beams having different wavelengths;
Laser beam splitting means for splitting the first laser beam and the second laser beam into two reference beams and measurement beams, respectively;
A first reflection region that reflects one reference light of the first laser light and the second laser light divided by the laser light dividing means at a predetermined reflection angle;
A second reflection region that reflects the other reference light of the first laser light and the second laser light divided by the laser light dividing means at a predetermined reflection angle;
A first emission port for emitting one measurement light of the first laser light and the second laser light divided by the laser light dividing means;
A second emission port for emitting the other measurement light of the first laser light and the second laser light divided by the laser light dividing means;
A first light receiving region that is composed of a plurality of light receivers and receives the reference light reflected by the first reflection region and the measurement light reflected by the first measurement point of the object to be measured and outputs light intensity data of each light receiver. When,
A second light receiving region that is composed of a plurality of light receivers and receives the reference light reflected by the second reflection region and the measurement light reflected by the second measurement point of the object to be measured and outputs light intensity data of each light receiver When,
An arithmetic unit for inputting light intensity data from the first light receiving region and the second light receiving region;
The calculated brightness / darkness data creation step, the irradiation step, the first brightness / darkness data creation step, the second brightness / darkness data creation step, the first comparison step, the second comparison step, the first distance data acquisition step, and the second distance data acquisition according to claim 2. A laser distance measuring device characterized by performing a step and a distance measuring step to measure a distance in a thickness direction between a first measurement point and a second measurement point of an object to be measured.
The first outlet and the second outlet are installed so as to face each other, and the object to be measured is disposed between the first outlet and the second outlet to measure the thickness of the object to be measured. 6. The laser range finder according to claim 5, wherein: