JP6060472B1 - 3D shape measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a center line of a line sensor and an optical path of reflected light always intersect each other by a simple method in a three-dimensional shape measuring apparatus based on a measurement principle of a triangulation method for scanning laser light. SOLUTION: The thickness of an entrance port plate member 20 is such that the outer surface of an exit port plate member 18 and the outer surface of the entrance port plate member 20 are included in the same plane, and the light incident on the entrance port plate member 20 is reflected. The optical path of the light coincides with the optical axis of the imaging lens, and the position and direction projected on the scanning plane of the laser light scanned in the direction opposite to the incident position of the incident reflected light and the incident direction are scanned laser light. Of the laser beam before entering the exit port plate member 18 and the incident port plate member 20 when the beam exits from the exit port plate member 18 and the direction and direction. The distance from the point S where the optical path of the reflected light projected onto the scanning plane intersects to the outer surface of the exit port plate member 18 is set. [Selection] Figure 4

Description

  The present invention irradiates a scanned laser beam onto a measurement object, receives a part of scattered light generated at the irradiated portion of the measurement object, and uses the measurement principle of the triangulation method to measure the three-dimensional shape of the measurement object. The present invention relates to a three-dimensional shape measuring apparatus for measuring

  Conventionally, a laser beam is irradiated onto a measurement object while scanning with a scanning device such as a galvanometer mirror or a polygon mirror, and a part of the scattered light generated at the irradiated portion of the measurement object is imaged with the scanning device. An apparatus that receives light with a line sensor via a lens and measures a three-dimensional shape of a measurement object is known. This three-dimensional shape measuring apparatus detects the irradiation direction of the scanned laser beam and the light receiving position of the line sensor at the same timing, and the distance from the light receiving position of the line sensor to the measurement object by the measurement principle of the triangulation method. Is detected, and the coordinates at the irradiation point of each laser beam are calculated to measure the three-dimensional shape of the measurement object. As such a three-dimensional shape measuring apparatus, as shown in Patent Document 1, for example, a plane that scans laser light and scans the laser light perpendicular to the optical axis of the laser light at the center of the scanning range (see FIG. There is an apparatus that changes the direction of the scanning plane by rotating a casing including a laser beam emitter, a scanning device, an imaging lens, a line sensor, and the like around a rotation axis parallel to the scanning plane. For example, as disclosed in Patent Document 2, there is an apparatus that changes the position of a scanning plane by moving the casing in a direction perpendicular to the scanning plane. For example, as shown in Patent Document 3, the casing is attached to an arm type moving device, and the position of the scanning plane is moved by moving the casing while detecting the position and direction of the casing. There is a device that changes the direction. In any method, the laser light irradiation direction, the position or direction of the scanning plane, and the light receiving position of the line sensor can be accurately detected, and the relationship between the light receiving position of the line sensor and the distance to the measurement object can be accurately determined. For example, it is possible to accurately measure the three-dimensional shape of the measurement object.

Japanese Patent Laid-Open No. 9-21820 JP 2008-180646 A JP 2004-333367 A

  In FIG. 1, a laser beam emitted from a laser light source 10 and collimated by a collimating lens 12 is irradiated to a measurement object OB while being scanned using a galvano mirror 14 and a motor 16, and the measurement object OB is irradiated. Configuration of an apparatus for measuring a three-dimensional shape of a measurement object OB by receiving a part of scattered light generated at a location (hereinafter referred to as reflected light) by a line sensor 24 via a galvanometer mirror 14 and an imaging lens 22. FIG. As shown in FIG. 1, in the three-dimensional shape measuring apparatus, the laser light exit port 18 and the reflected light entrance port 20 are windows made of a light-transmitting plate member such as a glass plate, and no opening is provided in the housing. In many cases, dust and moisture are prevented from entering the housing. In particular, a three-dimensional shape measuring apparatus that measures an object to be measured outdoors with high frequency and a three-dimensional shape measuring apparatus that is installed outdoors need to do so.

  However, when the inventor uses the laser light exit port 18 and the reflected light entrance 20 as a translucent plate-like member, the inventor has a translucent plate-like member (hereinafter referred to as an exit aperture plate-like member) of the laser light exit port 18. As the incident angle with respect to the member 18 increases, the optical path of the reflected light after entering the translucent plate member (hereinafter referred to as the incident port plate member 20) of the incident port 20 of the reflected light is projected onto the scanning plane. As a result, it was found that the laser beam deviates from the optical path. As a result, the larger the incident angle of the laser beam with respect to the exit aperture plate member 18, the more the optical path of the reflected light incident on the line sensor 24 is displaced from the optical axis of the imaging lens 22 in front of the line sensor 24. It was found that the shape of the light intensity distribution deteriorates and affects the measurement accuracy.

  The inventor has also found that the above phenomenon can be explained theoretically. FIG. 2 shows the optical path of the laser light and the optical path of the reflected light when projected onto the scanning plane, and the solid line is the optical path of the laser light and the dotted line is the optical path of the reflected light. The laser light is parallel to the paper surface of FIG. 2, whereas the reflected light has an angle based on the reflection position on the measurement object with respect to the paper surface of FIG. As shown in FIG. 1, the three-dimensional shape measuring apparatus using the measurement principle of the triangulation method is configured such that the optical axis of the laser light and the optical axis of the reflected light incident on the line sensor 24 through the imaging lens 22. This is because the angle is based on the laser light reflection position. In FIG. 2, if the reflected light incident on the entrance port plate-like member 20 is parallel to the paper surface, the reflected light path is the same as the optical path of the laser light even after incident when viewed on the scanning plane. . However, since the reflected light incident on the entrance port plate member 20 has an angle with respect to the paper surface, the incident angle of the reflected light with respect to the entrance port plate member 20 is relative to the exit port plate member 18 of the laser light. Unlike the incident angle, the optical path after the reflected light enters the entrance port plate member 20 is deviated from the optical path of the laser light as indicated by the dotted line in FIG. Then, the deviation at the time when the reflected light is emitted from the inner side surface of the entrance port plate-like member 20 is the deviation of the optical path of the reflected light with respect to the center line of the line sensor. This deviation is due to the fact that when the incident angle of the laser beam with respect to the exit aperture plate member 18 is 0 (ie, perpendicular incidence), the optical path of the reflected light is perpendicular to the entrance aperture plate member 20 when projected onto the scanning plane. Therefore, it does not occur and becomes larger as the incident angle of the laser beam with respect to the emission port plate member 18 increases. That is, no deviation occurs near the center of the scanning range of the laser beam, and the largest occurs at both ends of the scanning range of the laser beam.

  In FIG. 2, the exit aperture plate-like member 18 and the entrance aperture plate-like member 20 are overlapped when viewed on the scanning plane, but even if they are not overlapped, the optical path of the reflected light is shifted. Will occur. This is because, as shown in FIG. 3, the translucent plate-like member 1 has the same posture as the incident light Li, regardless of whether the translucent plate-like member 1 is at position A or B. If the optical paths are the same, it can be understood from the fact that the optical paths of the emitted light Lo are the same.

  In order to cope with the problem of the optical path deviation of the reflected light described above, a method of making the exit port plate member 18 and the entrance port plate member 20 as thin as possible can be considered, but there is a problem in terms of strength. In particular, a three-dimensional shape measuring apparatus installed outdoors is not possible because it needs to have a predetermined strength. In addition, there is a method of providing a system that corrects the optical path of the reflected light as much as the deviation of the optical path of the reflected light occurs. However, since the scanning speed of the laser light is high, the cost of the apparatus is increased when such a system is provided. There is a problem that is greatly improved.

  The present invention has been made to solve this problem, and an object of the present invention is to irradiate the measurement object with a scanned laser beam and receive a part of the scattered light generated at the irradiation position of the measurement object. In the three-dimensional shape measuring apparatus that measures the three-dimensional shape of the measurement object according to the measurement principle of the angle surveying method, while maintaining the strength of the exit port plate member and the incident port plate member without increasing the cost of the device, An object of the present invention is to provide a three-dimensional shape measuring apparatus in which the center line of a line sensor and the optical path of reflected light always intersect. In other words, it is an object to provide a three-dimensional shape measuring apparatus in which the optical path of reflected light projected on the scanning plane is not always shifted from the optical path of laser light.

  In order to achieve the above object, the present invention is characterized by irradiating a measurement object with a laser beam scanned using a scanning means via the first light-transmitting plate member, and causing scattering generated by the measurement object. Reflected light, which is part of the light, is received by the line sensor via the second translucent plate-like member, the scanning means, and the imaging lens, and the three-dimensional shape of the measurement object using the light receiving position in the line sensor In the three-dimensional shape measuring apparatus for measuring the second translucent plate member, the second translucent plate member is parallel to the first translucent plate member, and the thickness of the second translucent plate member is The outer surface of the first translucent plate-shaped member and the outer surface of the second translucent plate-shaped member are included in the same plane, and the optical path of the reflected light incident on the second translucent plate-shaped member is an image. It is coincident with the optical axis of the lens, and is projected onto the scanning plane of the laser beam scanned in the opposite direction of the incident position and the incident direction of the incident reflected light The incident angle of the scanned laser light with respect to the first light-transmitting plate-like member when the position and the direction coincide with the position and direction of the scanned laser light emitted from the first light-transmitting plate-like member is A line obtained by extending the optical path of the scanned laser light before entering the first light-transmitting plate-like member when the value is other than 0, and the reflected light entering the second light-transmitting plate-like member The optical path projected on the scanning plane of the laser beam that has scanned this optical path is set at the distance from the point of intersection to the outer surface of the first translucent plate-like member.

  According to this, the optical path of the reflected light projected on the scanning plane is always a laser by a very simple method of setting the thickness of the entrance plate member that is the second translucent plate member to an appropriate value. It is possible to prevent deviation from the optical path of light. When the inventor sets the thickness of the incident-light plate member that is the second light-transmissive plate member as described above, theoretically, the laser of the optical path of the reflected light projected on the scanning plane in the entire scanning range. It has been found that the deviation of the light from the optical path is reduced to a negligible level. The theory will be described in the detailed description.

  Another feature of the present invention is that a part of the scattered light generated by the measurement object is irradiated by irradiating the measurement object with the laser light scanned using the scanning means via the first light-transmissive plate member. Is reflected by the line sensor via the second translucent plate member, the scanning means, and the imaging lens, and the three-dimensional shape of the measurement object is measured using the light receiving position in the line sensor. In the three-dimensional shape measuring apparatus, the second translucent plate-like member is parallel to the first translucent plate-like member and has the same thickness, and the first and second translucent plate-like members. The relationship between the refractive indexes of the first and second translucent plate-like members is such that both sides of the first translucent plate-like member and both sides of the second translucent plate-like member are included in the same plane. The optical path of the reflected light incident on the second translucent plate-shaped member coincides with the optical axis of the imaging lens, and the incident position and incident position of the incident reflected light The scanned laser when the position and direction projected on the scanning plane of the laser beam scanned in the opposite direction coincides with the position and direction of the scanned laser beam emitted from the first translucent plate-like member When the incident angle of light with respect to the first translucent plate-shaped member is a value other than 0, the optical path of the scanned laser light and the optical path projected onto the scanning plane of the laser light scanned through the optical path of the reflected light That is, the one having the matching refractive index relationship is selected.

  This also makes the relationship between the refractive indexes of the exit port plate member, which is the first light transmissive plate member, and the incident port plate member, which is the second light transmissive plate member, appropriate. By a simple method, the optical path of the reflected light projected on the scanning plane can be prevented from always deviating from the optical path of the laser light. The inventor theoretically projected the relationship between the refractive indexes of the exit aperture plate member and the entrance aperture plate member, which are the first and second translucent plate members, on the scanning plane in the entire scanning range. It has been found that there is a relationship in which the deviation of the optical path of the reflected light from the optical path of the laser light is reduced to a negligible level. The theory will be described in the detailed description.

  Another feature of the present invention is that a part of the scattered light generated by the measurement object is irradiated by irradiating the measurement object with the laser light scanned using the scanning means via the first light-transmissive plate member. The reflected light is received by the line sensor via the second translucent plate member, the scanning means and the imaging lens, and the three-dimensional shape of the measurement object is measured using the light receiving position of the line sensor. In the three-dimensional shape measuring apparatus, the second light-transmitting plate-shaped member has a first light-transmitting plate-shaped member around the axis parallel to a line intersecting the scanning plane of the scanned laser beam. The thickness of the second light transmissive plate member has a predetermined angle with the light transmissive plate member, and the outer surface of the first light transmissive plate member and the outer surface of the second light transmissive plate member Intersects the optical axis of the imaging lens, and the optical path of the reflected light incident on the second light-transmissive plate member is the light of the imaging lens. The position and direction projected on the scanning plane of the laser beam scanned in the direction opposite to the incident position of the incident reflected light and the incident direction are from the first translucent plate-shaped member of the scanned laser light. Incident to the first translucent plate-like member when the incident angle of the scanned laser beam with respect to the first translucent plate-like member is a value other than 0 when it coincides with the emission position and direction The line where the optical path of the scanned laser light before the crossing and the optical path projected on the scanning plane of the laser light scanned on the optical path of the reflected light incident on the second light-transmissive plate-like member intersect From the intersection when the normal line of the scanning plane including and the optical path of the reflected light incident on the second translucent plate-like member are projected onto the plane perpendicular to the scan plane and the first translucent plate-like member It is to be set by the distance to the outer surface of the second translucent plate-like member

  According to this, even if the incident port plate-shaped member that is the second light-transmissive plate-shaped member has an angle with respect to the output port plate-shaped member that is the first light-transmissive plate-shaped member, The optical path of the reflected light projected on the scanning plane is always deviated from the optical path of the laser light by an extremely simple method of setting the thickness of the incident-light plate-like member, which is the second light-transmissive plate-like member, to an appropriate value. Can not be. The inventor sets the thickness of the incident aperture plate-shaped member, which is the second light-transmissive plate-shaped member, as described above even when the incident aperture plate-shaped member has an angle with respect to the output aperture plate-shaped member. Theoretically, it has been found that the deviation of the optical path of the reflected light projected onto the scanning plane from the optical path of the laser light in the entire scanning range is reduced to a negligible level. The theory will be described in the detailed description.

  Another feature of the present invention is that a part of the scattered light generated by the measurement object is irradiated by irradiating the measurement object with the laser light scanned using the scanning means via the first light-transmissive plate member. Is reflected by the line sensor via the second translucent plate member, the scanning means, and the imaging lens, and the three-dimensional shape of the measurement object is measured using the light receiving position in the line sensor. In the three-dimensional shape measuring apparatus, the second translucent plate-shaped member includes a first translucent plate around an axis parallel to a line intersecting the first translucent plate-shaped member and the scanning plane of the scanned laser beam. The first and second translucent plate-shaped members have the same angle as the first translucent plate-shaped member and have the same thickness as the first translucent plate-shaped member. The relationship of the refractive index of the light-transmitting plate member is such that the outer surface of the first light-transmitting plate member and the outer surface of the second light-transmitting plate member intersect. Is intersecting with the optical axis of the imaging lens, and the optical path of the reflected light incident on the second light-transmissive plate member is coincident with the optical axis of the imaging lens. Scanned laser when the position and direction projected on the scanning plane of the laser beam scanned in the opposite direction coincide with the position and direction of the scanned laser beam emitted from the first translucent plate-like member When the incident angle of light with respect to the first translucent plate-like member is a value other than 0, the optical path on the scanning means side from the inner surface of the first translucent plate-like member of the scanned laser beam and the reflected light The one that has a refractive index relationship that matches the optical path projected on the scanning plane of the laser beam that has scanned the optical path on the scanning means side from the inner surface of the second translucent plate-shaped member is selected. It is in.

  Even in this case, even if the incident port plate-shaped member that is the second light-transmissive plate-shaped member has an angle with respect to the output port plate-shaped member that is the first light-transmissive plate-shaped member, By a very simple method of making the relationship between the refractive indexes of the exit port plate member, which is a light transmissive plate member, and the incident port plate member, which is a second light transmissive plate member, an appropriate relationship, The optical path of the reflected light projected on the scanning plane can be prevented from always deviating from the optical path of the laser light. The inventor of the present invention provides an output port plate member and an input port plate member that are the first and second translucent plate members even when the input port plate member has an angle with respect to the output port plate member. It has been found that the relationship between the refractive indexes theoretically has a relationship in which the deviation of the optical path of the reflected light projected onto the scanning plane from the optical path of the laser light is reduced to a negligible level in the entire scanning range. The theory will be described in the detailed description.

  Another feature of the present invention is that a part of the scattered light generated by the measurement object is irradiated by irradiating the measurement object with the laser light scanned using the scanning means via the first light-transmissive plate member. Is reflected by the line sensor via the second translucent plate member, the scanning means, and the imaging lens, and the three-dimensional shape of the measurement object is measured using the light receiving position in the line sensor. In the three-dimensional shape measuring apparatus, the second translucent plate-shaped member includes a first translucent plate around an axis parallel to a line intersecting the first translucent plate-shaped member and the scanning plane of the scanned laser beam. And the first translucent plate-like member have the same thickness and refractive index as the first translucent plate-like member, and the predetermined angle γ is the outer surface of the first translucent plate-like member. The line where the outer surface of the second translucent plate member intersects the optical axis of the imaging lens, and the second translucent plate shape The optical path of the reflected light incident on the member coincides with the optical axis of the imaging lens, and the position and direction projected on the scanning plane of the laser light scanned in the opposite direction to the incident position of the incident reflected light and the incident direction, The incident angle of the scanned laser beam with respect to the first translucent plate-like member is a value other than 0 when it coincides with the position and direction of the scanned laser beam emitted from the first translucent plate-like member. Scanning laser light scans the optical path on the scanning means side from the inner surface of the first light transmitting plate-like member and the optical path on the scanning means side from the inner surface of the second light-transmissive plate member on the reflected light. This is because the angle is set so that the optical path projected onto the scanning plane of the laser beam coincides with the optical path.

  According to this, the angle γ of the incident port plate member that is the second light transmissive plate member with respect to the output port plate member that is the first light transmissive plate member is set to an appropriate angle. By a simple method, the optical path of the reflected light projected on the scanning plane can be prevented from always deviating from the optical path of the laser light. The inventor has found that the angle γ theoretically has a value at which the deviation of the optical path of the reflected light projected onto the scanning plane from the optical path of the laser light is reduced to a negligible level in the entire scanning range. . The theory will be described in the detailed description.

It is a figure which shows simply the structure of the three-dimensional shape measuring apparatus using the measurement principle of the triangulation method which scans a laser beam, irradiates a measuring object, and receives reflected light with a line sensor. It is a figure which shows the optical path of a laser beam, and the optical path of reflected light when it projects on the scanning plane of a laser beam in the three-dimensional shape measuring apparatus of FIG. It is a figure which shows that there is no change in the optical path of the light radiate | emitted from the translucent plate-shaped member even if the position of the translucent plate-shaped member changes. In 1st Embodiment, it is a figure explaining the calculation method of the thickness of the entrance-portion plate-shaped member for the shift | offset | difference not to generate | occur | produce in the optical path of a laser beam and reflected light. It is a figure which shows the relationship between the scanning angle of an emitted laser beam and the shift | offset | difference of the optical path of the reflected light with respect to the optical path of a laser beam in 1st Embodiment, (A) is a case where a scanning angle is 35 degrees, and an entrance port plate-shaped member (B) shows the case where the scanning angle is 1 ° and the thickness of the entrance plate member is optimized. It is a figure which shows the relationship between the angle with respect to the scanning plane of reflected light and the shift | offset | difference of the optical path of reflected light with respect to the optical path of laser light in 1st Embodiment. It is a figure which shows the relationship of the refractive index of the entrance port plate-shaped member and exit port plate-shaped member in order for the shift | offset | difference not to generate | occur | produce in the optical path of a laser beam and reflected light in 2nd Embodiment. It is a figure which shows the relationship between the angle with respect to the scanning plane of reflected light and the shift | offset | difference of the optical path of reflected light with respect to the optical path of laser light in 2nd Embodiment. It is a 1st figure explaining the calculation method of the thickness of the entrance-portion plate-shaped member in order to prevent deviation | shift from the optical path of a laser beam and reflected light in 3rd Embodiment. It is a 2nd figure explaining the calculation method of the thickness of the entrance-portion plate-shaped member in order to prevent the shift | offset | difference in the optical path of a laser beam and reflected light in 3rd Embodiment. It is a figure which shows the relationship between the scanning angle of an emitted laser beam and the shift | offset | difference of the optical path of the reflected light with respect to the optical path of a laser beam in 3rd Embodiment, (A) is a case where a scanning angle is 35 degrees, and an entrance port plate-shaped member (B) shows the case where the scanning angle is 1 ° and the thickness of the entrance plate member is optimized. It is a figure which shows the relationship between the angle with respect to the scanning plane of reflected light and the shift | offset | difference of the optical path of reflected light with respect to the optical path of laser light in 3rd Embodiment. It is a figure which shows the relationship of the refractive index of the entrance port plate-shaped member and exit port plate-shaped member in order for the shift | offset | difference not to generate | occur | produce in the optical path of a laser beam and reflected light in 4th Embodiment. It is a figure which shows the relationship between the scanning angle of an emitted laser beam, and the shift | offset | difference of the optical path of the reflected light with respect to the optical path of a laser beam in 4th Embodiment, (A) is a case where a scanning angle is 35 degrees and an entrance port plate-shaped member (B) shows the optimal relationship between the refractive indexes of the entrance port plate member and the exit port plate member when the scanning angle is 1 °. This is the case. It is a figure which shows the relationship between the angle with respect to the scanning plane of reflected light, and the shift | offset | difference of the optical path of reflected light with respect to the optical path of laser light in 4th Embodiment. It is a figure which shows the relationship between the scanning angle of an emitted laser beam, and the shift | offset | difference of the optical path of the reflected light with respect to the optical path of a laser beam in 5th Embodiment, (A) is a case where a scanning angle is 35 degrees, and an entrance port plate-shaped member (B) shows a case where the angle of the incident port plate member with respect to the output port plate member is optimized when the scanning angle is 1 °. It is a figure which shows the relationship between the angle with respect to the scanning plane of reflected light, and the shift | offset | difference of the optical path of reflected light with respect to the optical path of laser light in 5th Embodiment.

(First embodiment)
The first embodiment of the present invention will be described below. In the first embodiment, in the three-dimensional shape measuring apparatus in which the exit port plate member 18 and the entrance port plate member 20 are parallel, scanning is performed by appropriately setting the thickness of the entrance port plate member 20. In this mode, the optical path of the reflected light projected onto the plane is not shifted from the optical path of the laser light. Note that a three-dimensional shape measuring apparatus (scanning laser beam, irradiating the measurement object OB, receiving reflected light with a line sensor, and measuring the shape of the measurement object OB using the measurement principle of the triangulation method ( Hereinafter, the configuration of the laser scanning type three-dimensional shape measuring apparatus) is described in Patent Documents 1 to 3 which are prior art documents and is a known technique. Only how to set it properly is explained.

  FIG. 4 is a view of a laser scanning type three-dimensional shape measuring apparatus, in which the optical paths of laser light and reflected light passing through the exit port plate member 18 and the entrance port plate member 20 are projected onto the scan plane and viewed. Light is indicated by a solid line, and reflected light is indicated by a dotted line. Both surfaces of the exit port plate member 18 and the entrance port plate member 20 are perpendicular to the scanning plane, and both surfaces are in the same position when projected onto the scanning plane. The laser light enters the point L of the exit plate member 18 at an incident angle Θ, is refracted at a refraction angle α, is incident on the opposite surface at an incident angle α, and is emitted at a refraction angle Θ. Since the scanning plane is perpendicular to the exit port plate member 18, the laser light is in the scan plane even if it enters the exit port plate member 18 and is refracted. That is, it can be considered that the laser beam is in the plane of FIG.

  The reflected light is the light received by the line sensor 24 through the imaging lens 22 among the scattered light generated at the laser light irradiation point, but is received by the line sensor 24 when projected onto the scanning plane. The light is only scattered light in an optical path that substantially coincides with the optical axis of the imaging lens 22. Further, in the laser scanning type three-dimensional shape measuring apparatus, since the optical axis of the imaging lens 22 is adjusted so as to coincide with the optical axis of the laser light when projected onto the scanning plane, it is projected onto the scanning plane. Therefore, it can be considered that the reflected light returns in the same optical path as the laser light. That is, in FIG. 4, the reflected light incident on the entrance port plate member 20 overlaps with the laser light emitted from the exit port plate member 18.

  In FIG. 4 (when projected onto the scanning plane), the optical path of the reflected light incident on the entrance port plate member 20 is the same as the optical path of the laser light, but as shown in FIG. The optical path has an angle with respect to the scanning plane. If the angle of the optical path of the reflected light with respect to the scanning plane is β, the direction of the reflected light is an angle β with respect to the paper surface of FIG. Since this angle β is formed, the refraction angle of the reflected light when projected onto the scanning plane is smaller than the refraction angle α of the laser light, and the reflected light incident on the entrance port plate member 20 is shown in FIG. The light travels along the dotted optical path 4 and exits from point R. The reflected light emitted from the point R travels in parallel with the laser light when viewed on the scanning plane. As shown in FIG. 3, when light Li is incident on the parallel translucent plate-like member 1, the emitted light Lo is parallel to the light Li, and the reflected light is incident on the entrance port plate-like member 20. Can be understood from the fact that the laser beam and the optical path are the same when projected onto the scanning plane. That is, the deviation of the optical path of the reflected light from the optical path of the laser light when projected onto the scanning plane is a value obtained by multiplying the distance between the points L and R by cos Θ.

  If the thicknesses of the exit port plate member 18 and the entrance port plate member 20 are the same at T1, the optical path of the reflected light emitted from the entrance port plate member 20 deviates from the optical path of the laser light as described above. . However, as shown in FIG. 4, a line (a line indicated by a two-dot chain line) in which the optical path of the laser beam incident on the exit port plate member 18 is extended from the point where the reflected light exits from the entrance port plate member 20. ) And the point S, which is the point where the optical path of the reflected light incident on the entrance port plate member 20 intersects, the optical path of the emitted reflected light coincides with the optical path of the laser light. That is, as shown in FIG. 4, when the thickness of the entrance port plate member 20 is T2, the reflected light is emitted from the point S, and the optical path of the reflected light coincides with the optical path of the laser light. Hereinafter, a method for calculating the thickness T2 of the entrance port plate member 20 in which the optical path of the reflected light is not shifted from the optical path of the laser light will be described.

As shown in FIG. 4, the incident point of the reflected light to the entrance plate member 20 is the origin (0, 0, 0), the vertical direction of the outer surface of the entrance plate member 20 is the X axis, and the entrance plate member. Let us consider a coordinate axis in which the direction of the line where the outer surface of 20 intersects with the scanning plane is the Y axis, and the direction perpendicular to the scanning plane (paper surface in FIG. 4) is the Z axis. Considering the unit vector Vr parallel to the optical path before the reflected light is incident on the incident aperture plate member 20, the vector components (a, b, c) of the unit vector Vr are incident at the point L of the laser light. Using the angle Θ (the refraction angle Θ when exiting from the exit port plate member 18) and the angle β with respect to the scanning plane of the reflected light (the paper plane of FIG. 4 and the XY plane), Can be expressed as
(Equation 1)
(A, b, c) = (cosβ · cosΘ, cosβ · sinΘ, −sinβ)
The incident angle Θk at the origin (0, 0, 0) of the reflected light is an angle formed by the optical path of the reflected light before entering the entrance port plate member 20 and the normal of the outer surface of the entrance port plate member 20. Therefore, this is an angle formed by the unit vector Vr and the unit vector (1, 0, 0), and can be expressed by the following formula 2 using an equation of the inner product of the vectors.
(Equation 2)
Θk = cos ⁻¹ (cos β · cos Θ)
Further, the refraction angle αk at the origin (0, 0, 0) of the reflected light can be expressed by the following Equation 3 using the refractive index n and the incident angle Θk of the entrance port plate member 20.
(Equation 3)
αk = sin ⁻¹ (sin Θk / n)

Next, a unit vector Vi parallel to the optical path after the reflected light is incident on the incident-port plate member 20 is considered. If the vector component of the unit vector Vi is (x, y, z), the unit vector Vi is large. Therefore, the following equation 4 is established.
(Equation 4)
x ² + y ² + z ² = 1
Since the angle formed by the unit vector Vr and the unit vector Vi is an angle obtained by subtracting the refraction angle αk from the incident angle Θk, the following equation 5 is established from the vector inner product equation.
(Equation 5)
a * x + b * y + c * z = cos (Θk−αk)
Further, since the vector of the outer product of the unit vector Vr and the unit vector Vi is a vector parallel to the outer surface of the entrance port plate-like member 20, the X component of the vector is 0, and the following Expression 6 is established.
(Equation 6)
c · y−b · z = 0
In Equations 4 to 6, since the vector component (a, b, c), the incident angle Θk, and the refraction angle αk of the unit vector Vr are obtained in Equations 1 to 3, the unknown is the vector component (x, y, z) only. Therefore, the vector components (x, y, z) of the unit vector Vi can be obtained by solving the simultaneous equations of Equations 4 to 6.

In the description so far, the incident angle Θ (the refraction angle Θ when emitted from the exit port plate member 18) at the point L of the laser beam and the scanning plane of the reflected light (the paper plane of FIG. 4, the XY plane). It can be seen that the vector component (x, y, z) of the unit vector Vi can be obtained from the angle β with respect to) and the refractive index n of the entrance plate member 20. Next, considering a straight line that passes through the origin and is parallel to the unit vector Vi in the XY plane (the paper surface of FIG. 4), the formula of this straight line is:
(Equation 7)
Y = (y / x) · X
And the equation of the straight line in the XY plane of the optical path of the laser beam before entering the exit port plate member 18 is expressed as follows using the angle Θ, the angle α, and the thickness T1 of the exit port plate member 18. 8 can be represented.
(Equation 8)
Y = tan Θ · X − T1 · (tan Θ−tan α)
When X and Y are obtained by solving the simultaneous equations of Equations 7 and 8, this is the coordinates of the point S in FIG. 4, and the distance between the point S and the Y axis (the outer surface of the entrance plate member 20). Is the thickness T2 of the entrance-portion plate-like member 20 in which the optical path of the reflected light is not shifted from the optical path of the laser light. Since the distance between the point S and the Y axis is the X coordinate of the point S, if X is obtained by solving the simultaneous equations of Equations 7 and 8, the incident aperture plate does not shift the optical path of the reflected light. It is the thickness T2 of the shaped member 20. Therefore, the thickness T2 can be obtained from the following equation 9 in which X is obtained from equations 7 and 8 and X is set to T2.
(Equation 9)
T2 = T1. [(Tan Θ-tan α) / {tan Θ- (y / x)}]
The angle α is a refraction angle at the point L of the laser beam and is an incident angle when the laser beam is emitted from the exit port plate member 18, which is calculated from the angle Θ and the refractive index n of the exit port plate member 18 as follows. It can be obtained from Equation 10.
(Equation 10)
α = sin ⁻¹ (sin Θ / n)

  By the description so far, the incident angle Θ of the laser beam to the exit port plate member 18, the angle β of the reflected light with respect to the scanning plane, the thickness T 1 of the exit port plate member 18, and the exit port plate member 18 and the incident It can be seen from the refractive index n of the mouth plate-like member 20 that the thickness T2 of the incident mouth plate-like member 20 at which the optical path of the reflected light is not shifted can be obtained. As an example, when the incident angle Θ = 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, and the refractive index n = 1.5275, the incident aperture plate member 20 that does not shift the optical path of the reflected light. Thickness T2 = 1.395 mm.

  It should be noted that another expression for the calculation method of the thickness T2 of the entrance-portion plate member 20 in which the optical path of the reflected light is not shifted is as follows using FIG. First, a line obtained by extending the optical path of the scanned laser light before entering the exit port plate member 18 and the optical path of the reflected light incident on the entrance port plate member 20 are projected onto the scanning plane of the scanned laser light. A point S where the optical path intersects is obtained. Next, the distance from the intersection S to the outer surface of the exit port plate member 18 is obtained, and this distance is defined as the thickness T 2 of the entrance port plate member 20.

  In the first embodiment, the scanning angle of the laser beam is represented by an angle formed by the laser beam and the normal direction of the emission port plate member 18. The same applies to the second and subsequent embodiments to be described later. That is, in the following description, it is assumed that the scanning angle is equal to the incident angle Θ. Since the scanning angle of the scanned laser beam changes, the incident angle Θ to the exit port plate member 18 also changes. Therefore, even if the incident angle Θ is set to a certain value and the thickness T2 of the incident port plate member 20 in which the optical path of the reflected light is not shifted is obtained, the thickness T2 becomes another value at other incident angles Θ. However, if the thickness T2 is calculated using a value in the vicinity of the maximum value in the range of the scanning angle Θ (a value in the vicinity of the maximum incident angle Θ), the laser light in the optical path of the reflected light is reflected over the entire range of the scanning angle Θ. The deviation from the optical path can be made small enough to be ignored. In the following, a calculation formula for obtaining the deviation of the optical path of the reflected light from the optical path of the laser light will be described, and the case where the thickness of the entrance plate 20 is the same as that of the exit plate 18 and the optical path of the reflected light In the case where the thickness T2 does not deviate, the deviation of the optical path of the reflected light from the optical path of the laser light in the entire range of the scanning angle Θ is shown.

When the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser beam is equal to the distance between the point L and the point R in FIG. This is a value obtained by multiplying the difference between the Y values when substituting T1 into X in Equations 7 and 8, and can be expressed by Equation 11 below.
(Equation 11)
Dev = cosΘ · T1 · {tan α− (y / x)}
Further, when the thickness of the entrance plate member 20 is T2, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light is a line parallel to the Y axis whose distance from the Y axis is T2 in FIG. , A value obtained by multiplying the distance between two points, the point that intersects the line of the extension of the optical path of the laser light and the point that intersects the optical path of the reflected light, by cos Θ. This is a value obtained by multiplying the difference between the values of Y when T2 is substituted for X in Equations 7 and 8, and can be expressed by Equation 12 below.
(Equation 12)
Dev = cosΘ · {T1 · tan α− (T1−T2) · tanΘ−T2 · (y / x)}

  In FIG. 5A, for example, the range of the scanning angle Θ is 0 to 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the thickness T2 = 1.395 mm, and the refractive index n = 1.5275. And the deviation of the optical path of the reflected light with respect to the scanning angle Θ with respect to the optical path of the laser light is calculated and graphed. A dotted line is a case where the thickness of the entrance port plate-like member 20 is T1 which is the same as that of the exit port plate-like member 18, and is a deviation calculated by Equation 11. The solid line is the case where the thickness of the entrance-portion plate-like member 20 is T2 = 1.395 mm, and is a deviation calculated by Equation 12. The thickness T2 = 1.395 mm, as described above, when the angle β, the thickness T1, and the refractive index n are the above values and the scanning angle Θ (incident angle Θ) = 35 °, the optical path of the reflected light is not shifted. Is the thickness.

  As can be seen from FIG. 5A, when the thickness of the entrance plate member 20 is T2 = 1.395 mm, when the scanning angle Θ (incident angle Θ) is 35 °, the deviation is 0, The scanning angle Θ (incidence angle Θ) other than is a value other than 0, but the deviation is extremely small as compared with the case where the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18. Therefore, if the thickness of the entrance port plate member 20 is set to a thickness T2 calculated using a value near the maximum value of the scanning angle range (a value near the maximum incident angle), the entire scanning angle range is set. In FIG. 5, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  The thickness T2 is preferably a value calculated using a value in the vicinity of the maximum value in the range of the scanning angle Θ (a value in the vicinity of the maximum incident angle Θ) as the incident angle Θ of the laser beam, but it is not so. Even if the value calculated using the incident angle Θ of the laser beam is used, the deviation can be reduced as compared with the case where the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18. As an example, when the scanning angle Θ (incident angle Θ) = 1 °, the angle β = 23 °, the thickness T1 = 1.5 mm, and the refractive index n = 1.5275 are calculated, the incident light path does not deviate. The thickness T2 of the mouth plate member 20 is 1.375 mm. Then, when a similar graph is created by setting the thickness of the entrance plate member 20 to T2 = 1.375 mm, as shown in FIG. 5B, the deviation becomes large near the maximum value in the range of the scanning angle Θ. However, as compared with the case where the thickness of the entrance port plate-like member 20 is the same as that of the exit port plate-like member 18, the deviation can be considerably reduced.

  Further, since the angle β of the reflected light with respect to the scanning plane changes depending on the position of the measurement object OB with respect to the three-dimensional shape measuring apparatus, the angle β is set to a certain value, and the incident aperture plate-like member that does not shift the optical path of the reflected light. Even if the thickness T2 of 20 is obtained, the thickness T2 takes another value at other angles β. However, the angle β near the center of the measurable range of the three-dimensional shape measuring apparatus is the angle β of the optical path of the reflected light that coincides with the optical axis of the imaging lens 22, and the thickness T2 is calculated using this angle β. In this case, the deviation of the optical path of the reflected light with respect to the optical path of the laser light can be made small over the entire measurable range of the three-dimensional shape measuring apparatus. In this case, the calculation formula for obtaining the deviation of the optical path of the reflected light with respect to the optical path of the laser beam is the same as the above formulas 11 and 12, and therefore, the scanning angle Θ (incident angle Θ), the thickness T1 and the refractive index n are determined. If the value of the angle β is changed, a graph similar to the case of the scanning angle Θ can be created.

  FIG. 6 shows an example in which the scanning angle Θ (incident angle Θ) = 35 °, the thickness T1 = 1.5 mm, the thickness T2 = 1.395 mm, the refractive index n = 1.5275, and the reflected light with respect to the angle β. The deviation of the optical path relative to the optical path of the laser beam is calculated and graphed. A dotted line is a case where the thickness of the entrance port plate member 20 is the same as T1 of the exit port plate member 18, and is a deviation calculated by Equation 11, and a solid line is the thickness of the entrance port plate member 20 is T2. = 1.395 mm, which is the deviation calculated by Equation 12. As described above, when the thickness T2 = 1.395 mm, when the scanning angle Θ (incident angle Θ), the thickness T1, and the refractive index n are the above values and the angle β = 23 °, the optical path of the reflected light does not shift. Is the thickness.

  As can be seen from FIG. 6, when the thickness of the entrance plate member 20 is T2 = 1.395 mm, the deviation is 0 when the angle β is 23 °, and the deviation is so large that the angle β deviates from 23 °. Although larger, the deviation is smaller than that in the case where the thickness of the entrance port plate member 20 is the same as that of the exit port plate member T1. Therefore, if the thickness of the entrance aperture plate member 20 is set to the thickness T2 calculated using the value of the angle β of the optical path of the reflected light coincident with the optical axis of the imaging lens 22, the three-dimensional shape measuring apparatus In the entire measurable range, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  In the above description, the outer surface of the exit port plate member 18 and the outer surface of the entrance port plate member 20 are the same line when projected onto the scanning plane, that is, the outer surface of the exit port plate member 18 is incident. The outer surface of the mouth plate-like member 20 has been described as being included in the same plane. However, this condition is for convenience in calculating the thickness T2 of the entrance plate member 20 where the optical path of the reflected light does not shift and the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light. The position of the outer surface of the entrance port plate member 20 of the three-dimensional shape measuring apparatus is not limited as long as it is parallel to the outer surface of the exit port plate member 18. That is, in FIG. 4, even if the outer surface of the entrance port plate-like member 20 is at a position moved in the vertical direction, the calculation result described above does not change. This can be understood from the fact that the optical path of the emitted light does not change if the posture does not change even if the position of the translucent plate-like member 1 changes as shown in FIG.

  As can be understood from the above description, in the first embodiment, the measurement object OB is irradiated with the laser beam scanned using the scanning devices 14 and 16 via the exit port plate member 18, and the measurement object is obtained. Reflected light, which is part of the scattered light generated by OB, is received by the line sensor 24 through the entrance port plate member 20, the scanning devices 14, 16 and the imaging lens 22, and the light receiving position in the line sensor 24 is used. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the measurement object OB, the entrance port plate member 20 is parallel to the exit port plate member 18, and the thickness of the entrance port plate member 20 is determined by the exit port. The outer surface of the plate member 18 and the outer surface of the entrance port plate member 20 are included in the same plane, and the optical path of the reflected light incident on the entrance port plate member 20 coincides with the optical axis of the imaging lens 22. , Incident position and incident method of incident reflected light The exit of the scanned laser beam when the position and direction projected on the scanning plane of the laser beam scanned in the opposite direction coincides with the position and direction of the scanned laser beam exiting from the plate member 18 When the incident angle with respect to the plate-like member 18 is a value other than 0, the light is incident on the incident-plate plate-like member 20 and the line extending the optical path of the scanned laser light before entering the exit-portion plate-like member 18. The distance is set from the point S where the optical path projected on the scanning plane of the laser beam that has scanned the optical path of the reflected light to the outer surface of the exit port plate member 18.

  According to this, the level at which the deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser beam can be ignored by an extremely simple method of setting the thickness of the entrance plate member 18 to an appropriate value. Can be made as small as possible.

  In the first embodiment, the refractive indexes n of the exit port plate member 18 and the entrance port plate member 20 are equal. That is, the exit port plate member 18 and the entrance port plate member 20 are made of the same material. However, even if the material of the exit aperture plate-like member 18 and the entrance aperture plate-like member 20 is changed and the refractive index n is a different value, the entrance aperture where the optical path of the reflected light does not shift as shown in the first embodiment. The calculation method of the thickness Dev of the plate-like member 20 and the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light remains the same. In this case, assuming that the refractive index of the exit port plate member 18 is n1 and the refractive index of the entrance port plate member 20 is n2, the refractive index n2 is used for the refractive index n of Equation 3, and the refractive index of Equation 10 is used. A refractive index n1 may be used for n.

(Second Embodiment)
In the first embodiment, the thickness of the entrance port plate-like member 20 is set to an appropriate value, thereby eliminating the deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser light. However, instead of this, the first embodiment is also possible by making the exit aperture plate-like member 18 and the entrance aperture plate-like member 20 the same thickness, making the materials different, and making the relationship of the refractive indexes of both the appropriate relationships. The same effect can be obtained. In the second embodiment, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is an appropriate relationship that eliminates the deviation of the optical path of the reflected light from the optical path of the laser light. Hereinafter, a method of obtaining the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 that eliminates the deviation of the optical path of the reflected light from the optical path of the laser light will be described.

  As described in the first embodiment, when the thickness of the entrance port plate-like member 20 is the same as that of the exit port plate-like member 18, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light is a point L in FIG. Is a value obtained by multiplying the distance between the point R and the cos Θ, and can be expressed by Equation 11. In Equation 11, the thickness of the entrance plate member 20 and the thickness of the exit plate member 18 are known at T1, and the scanning angle Θ of laser light (incident angle Θ to the exit plate member 18) is set. The unknown is the ratio of the refraction angle α and the x and y components of the unit vector Vi, (y / x). As can be seen from Equation 10, the refraction angle α can be obtained from the incident angle Θ and the refractive index n (hereinafter referred to as the refractive index n1) of the exit port plate member 18. In addition, the x and y components of the unit vector Vi are based on the laser beam scanning angle Θ (incident angle Θ) and the reflected light scanning plane (the paper plane in FIG. 4, the XY plane). It can be determined from the angle β and the refractive index n (hereinafter referred to as the refractive index n2) of the entrance port plate member 20. That is, when the scanning angle Θ (incidence angle Θ) of the laser beam and the angle β of the reflected light with respect to the scanning plane are set and the refractive index n1 of the exit port plate member 18 is determined, the deviation Dev becomes 0 in Equation 11. The refractive index n2 is uniquely determined. Accordingly, if the refractive index n2 at which Dev is 0 at various values of the refractive index n1 is obtained, the exit port plate member 18 and the entrance port plate member 20 that eliminate the deviation of the optical path of the reflected light from the optical path of the laser light are obtained. The refractive index relationship can be obtained.

  FIG. 7 shows, as an example, the deviation of the optical path of the reflected light from the optical path of the laser light when the scanning angle Θ (incident angle Θ) = 35 °, the thickness T1 = 1.5 mm, and the angle β = 23 °. The relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is eliminated. As can be seen from FIG. 7, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is substantially linear.

  Also in the second embodiment, after setting the scanning angle Θ (incidence angle Θ) and the angle β of the reflected light with respect to the scanning plane, the exit aperture plate member 18 and the incident aperture plate shape that eliminate the deviation of the optical path of the reflected light. The relationship of the refractive index of the member 20 was obtained. However, in the second embodiment, if the scanning angle Θ (incident angle Θ) is another value other than 0, the refractive index relationship does not differ. As for the angle β of the reflected light with respect to the scanning plane, as in the first embodiment, if the refractive index relationship is obtained using the angle β of the optical path of the reflected light that coincides with the optical axis of the imaging lens 22, it is three-dimensional. The deviation of the optical path of the reflected light with respect to the optical path of the laser light can be made small enough to be ignored over the entire measurable range of the shape measuring apparatus.

  Table 1 below shows, as an example, the range of the scanning angle Θ (incident angle Θ) of 0 to 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, and the laser of the optical path of the reflected light with respect to the scanning angle Θ. The deviation of the light from the optical path is calculated and tabulated. “Different refractive index” is the case where the refractive index n1 = 1.6042 of the exit port plate-shaped member 18 and the refractive index n2 = 1.5275 of the incident port plate-shaped member 20, and the angle β and the thickness T1 are as described above. When the value is the scanning angle Θ (incident angle Θ) = 35 °, the refractive index relationship is such that no deviation of the optical path of the reflected light occurs. Further, “the same refractive index” is the case where the refractive index n = 1.5275 for both the exit port plate member 18 and the entrance port plate member 20. Also in this case, the deviation of the optical path of the reflected light can be calculated by Equation 11, and the value of “same refractive index” is the value on the dotted line of the graph of FIG. As can be seen from Table 1, when the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is appropriately set, the optical path of the laser light of the reflected light over the entire range of the scanning angle Θ. The deviation with respect to can be made small enough to be ignored. Further, the deviation of the optical path of the reflected light from the optical path of the laser light can be made smaller than in the case of the first embodiment.

  The relationship between the refractive index n1 of the exit aperture plate-like member 18 and the refractive index n2 of the entrance aperture plate-like member 20 in “Refractive index difference” in Table 1 is reflected when the scanning angle Θ (incident angle Θ) = 35 °. Although the refractive index relationship is determined so as not to cause a deviation of the optical path of light, the same relationship can be determined even when the scanning angle Θ (incident angle Θ) is another value other than zero. This can be understood from the fact that the deviation of the optical path of the reflected light at each scanning angle Θ in Table 1 is almost zero.

  Further, FIG. 8 shows, as an example, a graph in which the scanning angle Θ (incident angle Θ) = 35 ° and the thickness T1 = 1.5 mm, and the deviation of the optical path of the reflected light with respect to the angle β from the optical path of the laser light is calculated. It is a thing. The solid line shows the case where the refractive index n1 of the exit port plate member 18 is 1.6042, and the refractive index n2 of the entrance port plate member 20 is 1.5275, and the scanning angle Θ (incident angle Θ) and the thickness T1 are When the angle β is 23 ° with the above values, the relationship of the refractive index is such that the optical path of the reflected light does not shift. A dotted line is a case where the refractive index of the exit port plate-shaped member 18 and the entrance port plate-shaped member 20 is the same at 1.5275, and is the same as the dotted line of the graph of FIG. As can be seen from FIG. 8, the relationship is almost the same as that in FIG. 6, and the deviation increases as the angle β of the reflected light with respect to the scanning plane deviates from 23 °. The deviation is smaller than when the refractive index of the member 20 is the same. Therefore, if the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is calculated using the value of the angle β in the optical path of the reflected light coincident with the optical axis of the imaging lens 22. The shift of the optical path of the reflected light with respect to the optical path of the laser light can be made small enough to be ignored over the entire measurable range of the three-dimensional shape measuring apparatus.

  In the second embodiment, the outer surface of the exit port plate-like member 18 and the outer surface of the entrance port plate-like member 20 have been described using a calculation formula that is included in the same plane. This is for the convenience of calculating the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 and the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light. Therefore, also in the second embodiment, the position of the outer surface of the entrance port plate member 20 of the actual three-dimensional shape measuring apparatus is not limited as long as it is parallel to the outer surface of the exit port plate member 18.

  As can be understood from the above description, in the second embodiment, the measurement object OB is irradiated with the laser beam scanned using the scanning devices 14 and 16 via the emission port plate member 18, and the measurement object is obtained. Reflected light, which is part of the scattered light generated by OB, is received by the line sensor 24 through the entrance port plate member 20, the scanning devices 14, 16 and the imaging lens 22, and the light receiving position in the line sensor 24 is used. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the measuring object OB, the entrance port plate member 20 is parallel to the exit port plate member 18 and has the same thickness. The incident port plate member 20 has a refractive index relationship between the output port plate member 18 and the incident port plate member 20 such that both surfaces of the output port plate member 18 and both surfaces of the incident port plate member 20 are in the same plane. Included in the incident aperture plate-like member 20. The optical path of the incident reflected light coincides with the optical axis of the imaging lens 22, and the position and direction projected on the scanning plane of the laser beam scanned in the opposite direction of the incident position of the incident reflected light and the incident direction are scanned. The scanned laser when the incident angle of the scanned laser beam with respect to the emission port plate member 18 is a value other than 0 when it coincides with the position and direction of the emitted laser beam from the emission port plate member 18 The optical path and the optical path projected on the scanning plane of the laser beam that has scanned the optical path of the reflected light are selected so as to have a refractive index relationship.

  Even in this case, from the optical path of the laser light of the reflected light projected onto the scanning plane, the refractive index relationship between the exit aperture plate-shaped member 18 and the entrance aperture plate-shaped member 20 is made an appropriate relationship. The deviation can be reduced to a negligible level.

(Third embodiment)
In the first embodiment, when the exit aperture plate-like member 18 and the entrance aperture plate-like member 20 are parallel, the thickness of the entrance aperture plate-like member 20 is set to an appropriate value, and projected onto the scanning plane. The deviation of the reflected light path from the laser light path is eliminated. However, even when the entrance port plate member 20 is rotated (tilted) by a predetermined angle γ around an axis parallel to the line where the exit port plate member 18 and the scanning plane intersect, the entrance port plate shape By setting the thickness of the member 20 to an appropriate value, the deviation of the optical path of the reflected light from the optical path of the laser light can be eliminated. In the third embodiment, when the entrance port plate-like member 20 is inclined by a predetermined angle γ around an axis parallel to the line intersecting the exit aperture plate-like member 18 and the scanning plane, the optical path of the reflected light This is a mode in which the thickness of the entrance port plate member 20 that eliminates the deviation from the optical path of the laser light is set.

  FIG. 9 shows a laser scanning three-dimensional shape measuring apparatus in which the entrance port plate member 20 is inclined by a predetermined angle γ around an axis parallel to a line intersecting the exit port plate member 18 and the scanning plane. FIG. 4 is a diagram in which an optical path of laser light passing through the exit port plate member 18 and reflected light passing through the entrance port plate member 20 is projected onto a scanning plane, where the laser light is indicated by a solid line and the reflected light is indicated by a dotted line. ing. Although both sides of the exit port plate member 18 are perpendicular to the scanning plane, the incident port plate member 20 forms an angle of (90 ° −γ) with the scanning plane, and is projected on the scanning plane. In the figure, only the lines on both sides of the exit port plate member 18 are displayed. As in the first embodiment, the laser light is incident on the point L of the exit aperture plate member 18 at the incident angle Θ, refracted at the refraction angle α, and incident on the opposite surface at the incident angle α and the refraction angle Θ. Exit with

  The point at which the reflected light is incident on the incident port plate member 20 is a point at which the laser beam is emitted from the incident port plate member 20 when projected onto the scanning plane. This is for convenience in calculating the thickness of the entrance port plate member 20 that eliminates the deviation of the optical path of the reflected light. Therefore, similarly to the first and second embodiments, the reflected light incident on the entrance port plate member 20 overlaps with the laser light emitted from the exit port plate member 18. As in the first and second embodiments, the optical path of the reflected light forms an angle β with respect to the scanning plane, and the direction of the reflected light forms an angle β with respect to the paper surface of FIG. However, in the third embodiment, since the entrance port plate member 20 forms an angle γ with respect to the exit port plate member 18, the refraction angle of the reflected light when viewed on the scanning plane is Depending on the size of the angle γ, the angle may be smaller or larger than the refraction angle α of the laser beam. FIG. 9 shows a case where it becomes larger, and the reflected light incident on the entrance port plate member 20 travels along the dotted optical path in FIG. The reflected light is emitted from some point on the dotted optical path, and this emission point varies depending on the magnitude of the angle γ, and thus needs to be obtained by calculation. However, if the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18, the entrance port plate member 20 always emits from the inner surface of the exit port plate member 18. As in the first and second embodiments, the reflected light emitted from the entrance plate member 20 proceeds in parallel with the laser light when projected onto the scanning plane, so that the reflected light from the optical path of the laser light passes through the optical path. The deviation is a value obtained by multiplying the distance between the point where the optical path of the emitted reflected light intersects the inner surface of the exit port plate member 18 and the point L by cos Θ.

  As can be seen from FIG. 9, when the exit point of the reflected light from the entrance port plate member 20 is in front of the inner surface of the exit port plate member 18, the reflected light path is displaced from the laser light path. However, if the thickness of the entrance port plate member 20 is made larger than the thickness T1 of the exit port plate member 18 and the exit point of the reflected light is point S, the optical path of the emitted reflected light matches the optical path of the laser beam. To do. That is, if the thickness T2 of the entrance port plate-like member 20 at which the reflected light exit point becomes the point S is obtained and the thickness of the entrance port plate-like member 20 is set to T2, the optical path of the reflected light is the laser beam. It matches the optical path. Hereinafter, a method for calculating the thickness T2 of the entrance port plate member 20 in which the optical path of the reflected light is not shifted from the optical path of the laser light will be described.

As shown in FIG. 9, the point at which the reflected light enters the entrance port plate member 20 is the origin (0, 0, 0), the vertical direction of the outer surface of the exit port plate member 18 is the X axis, and the exit port plate shape Consider a coordinate axis in which the direction of the line where the outer surface of the member 18 intersects the scanning plane is the Y axis, and the direction perpendicular to the scanning plane (paper surface in FIG. 9) is the Z axis. The vector component of the unit vector Vr parallel to the optical path before the reflected light enters the incident port plate member 20 is the number 1 shown in the first embodiment. The incident angle Θk at the origin (0, 0, 0) of the reflected light is an angle formed by the unit vector Vr and the unit vector (cos γ, 0, −sin γ) of the normal vector of the outer surface of the entrance port plate member 20. The following equation 13 can be used to express the inner product of the vectors.
(Equation 13)
Θk = cos ⁻¹ (cos γ · cos β · cos Θ + sin β · sin γ)
The refraction angle αk at the origin (0, 0, 0) of the reflected light is the number 3 shown in the first embodiment.

Next, a unit vector Vi parallel to the optical path after the reflected light is incident on the entrance port plate member 20 is considered, and the vector component of the unit vector Vi is (x, y, z). Here, the point at which the reflected light enters the entrance port plate member 20 is the origin (0, 0, 0), the vertical direction of the outer surface of the entrance port plate member 20 is the X ′ axis, and the entrance port plate member 20 Consider a coordinate axis in which the direction of the line intersecting the outer surface and the scanning plane is the Y ′ axis, and the direction perpendicular to the Y ′ axis along the outer surface of the entrance plate member 20 is the Z ′ axis. That is, consider the X′Y′Z ′ coordinate axis, which is a coordinate axis obtained by rotating the XYZ coordinate axis around the Y axis in the Y axis direction by an angle γ clockwise. Assuming that the vector component representing the vector component of the unit vector Vr by the X′Y′Z ′ coordinate axis is (a ′, b ′, c ′), (a ′, b ′, c ′) is a coordinate conversion formula. It can obtain | require by the following formula | equation 14.

If the vector component of the unit vector Vi represented by the X′Y′Z ′ coordinate axis is (x ′, y ′, z ′), in the expressions 4 to 6 shown in the first embodiment, a, b, An expression is established in which c is a ′, b ′, c ′ and x, y, z is x ′, y ′, z ′. Since the incident angle Θk, the refraction angle αk, and the vector components (a ′, b ′, c ′) of the unit vector Vr are obtained, as in the first embodiment, by solving the simultaneous equations of Equations 4 to 6, The vector component (x ′, y ′, z ′) of the unit vector Vi can be obtained. Since the obtained (x ′, y ′, z ′) is a vector component represented by the X′Y′Z ′ coordinate axis, this is used as a vector component (x, y, z) represented by the XYZ coordinate axis. This may be performed by performing the reverse coordinate transformation of Equation 14 and can be calculated by the following Equation 15 of coordinate transformation.

In the description so far, the incident angle Θ at the point L of the laser beam (the refraction angle Θ when emitted from the exit port plate member 18) and the reflected light scanning plane (the paper plane of FIG. 9, the XY plane). ), The refractive index n of the entrance port plate member 20, and the angle γ formed by the entrance port plate member 20 with respect to the exit port plate member 18, the vector component (x, y, z) of the unit vector Vi. ) Can be obtained. Next, when considering a straight line that passes through the origin and is parallel to the unit vector Vi in the XY plane (the paper surface of FIG. 9), the formula of this straight line is Equation 7 shown in the first embodiment. And the equation of the straight line in the XY plane of the optical path of the laser beam before entering the exit port plate member 18 is Formula 8 shown in the first embodiment. The equations for solving the simultaneous equations of Equations 7 and 8 to obtain X and Y are the x and y coordinates of the point S in FIG. 9, and the equation in which the x coordinate is T2 is shown in the first embodiment. It is. However, since the x-coordinate equal thickness T2 is not used in the third embodiment, T2 in Expression 9 is expressed by an expression in which Xs as the x-coordinate of the point S is expressed as Expression 16 below.
(Equation 16)
Xs = T1 · [(tan Θ−tan α) / {tan Θ− (y / x)}]
Similarly to the first embodiment, the angle α is a refraction angle at the point L of the laser beam (incident angle when emitted from the exit port plate member 18), and can be obtained by the formula 10 shown in the first embodiment. .

Next, a method of calculating the thickness T2 of the entrance port plate member 20 from Xs which is the x coordinate of the point S will be described. FIG. 10 shows the reflected light path projected onto the XZ plane. In other words, the optical path of the reflected light is projected onto a plane perpendicular to both the scanning plane and the exit port plate member 18. Assuming that the z coordinate of the reflected light exit point P is Zs, the distance from the origin to the point Q is found to be a value obtained by adding Zs · tan γ to Xs, and the thickness T2 of the entrance plate member 20 is It can be seen that this is a value obtained by multiplying the distance from the origin to the point Q by cos γ. Therefore, the thickness T2 of the entrance port plate-like member 20 is expressed by the following Expression 17.
(Equation 17)
T2 = (Xs + Zs · tanγ) · cosγ
Xs which is the x coordinate of the point S is obtained by the above-described calculation. Zs, which is the z coordinate of the point P, can be obtained as the z coordinate of the straight line passing through the origin and parallel to the unit vector Vi when the x coordinate is Xs. Therefore, the vector component (x, y, z) of the unit vector Vi ) To obtain the following equation (18).
(Equation 18)
Zs = (z / x) · Xs
The following Expression 19 is established from Expression 17 and Expression 18, and the thickness T2 of the entrance plate member 20 in which the optical path of the reflected light does not deviate from the optical path of the laser light can be calculated by this expression.
(Equation 19)
T2 = Xs · {1+ (z / x) · tan γ} · cos γ

  In the description so far, the incident angle Θ of the laser beam to the exit port plate member 18, the angle β of the reflected light with respect to the scanning plane, the thickness T 1 of the exit port plate member 18, and the exit port plate member 18 and the incident From the refractive index n of the mouth plate member 20 and the angle γ formed by the entrance port plate member 20 with respect to the exit port plate member 18, the thickness T2 of the entrance plate member 20 in which the optical path of the reflected light is not shifted is obtained. You can see that As an example, when the incident angle Θ = 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the refractive index n = 1.5275, and the angle γ = 26 °, the optical path of the reflected light is not shifted. The thickness T2 of the entrance plate member 20 is 1.725 mm.

  It should be noted that another expression for the calculation method of the thickness T2 of the entrance-portion plate-like member 20 where the optical path of the reflected light does not shift is as follows using FIGS. First, the optical path of the scanned laser light before entering the exit port plate member 18 is projected onto the scanning plane of the scanned laser light along the optical path of the reflected light incident on the entrance port plate member 20. A point S where the optical path intersects is obtained. Next, the normal line of the scanning plane including the obtained intersection S and the optical path of the reflected light incident on the entrance port plate member 20 are projected onto a plane perpendicular to the surface of the scan plane and the exit port plate member 18. Find the intersection point P. Then, the distance from the intersection P to the outer surface of the entrance port plate member 20 is determined, and this distance is defined as the thickness T2 of the entrance port plate member 20.

  Also in the third embodiment, since the scanned laser light changes in scanning angle Θ, the incident angle Θ on the exit port plate member 18 also changes. Therefore, even if the scanning angle Θ (incidence angle Θ) is set to a certain value and the thickness T2 of the entrance port plate member 20 where the optical path of the reflected light is not shifted is obtained, the thickness T2 is different at other incident angles Θ. Value. However, as in the first embodiment, if the thickness T2 is calculated using a value in the vicinity of the maximum value in the range of the scanning angle Θ (a value in the vicinity of the maximum incident angle Θ), the reflected light is reflected over the entire range of the scanning angle Θ. The deviation of the optical path with respect to the optical path of the laser light can be made small enough to be ignored. The calculation formula for obtaining the deviation of the optical path of the reflected light from the optical path of the laser light will be described below. When the thickness of the entrance port plate-like member 20 is the same as that of the exit aperture plate-like member 18, the optical path of the reflected light is In the case of the thickness T2 that does not deviate, the deviation of the optical path of the reflected light with respect to the optical path of the laser light in the entire scanning angle Θ (incident angle Θ) is shown.

Assuming that the thickness of the entrance port plate member 20 is T, the X coordinate of the point where the reflected light shown in FIG. 10 is emitted from the entrance port plate member 20 is a plane expression representing the inner surface of the entrance port plate member 20. , By obtaining the intersection coordinates of a straight line equation passing through the origin and parallel to the unit vector Vi (vector component (x, y, z)). The plane equation is the following equation 20, and the straight line equation is the following equation 21.
(Equation 20)
cos γ · X −sin γ · Z−T = 0
(Equation 21)
X / x = Y / y = Z / z
When the X coordinate of the exit point of the reflected light is Xp and X is obtained by solving the simultaneous equations of Equations 20 and 21 to obtain X, the following Equation 22 is obtained.
(Equation 22)
Xp = T / {cosγ−sinγ · (z / x)}

When the optical path of the reflected light is projected onto the scanning plane, the optical path after exiting from the entrance port plate member 20 is parallel to the optical path of the laser light. Therefore, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light is the Y-coordinate of the exit point of the reflected light and the optical path before entering the laser beam exit aperture plate member 18 when the X-coordinate is Xp or This is a value obtained by multiplying the difference from the Y coordinate of the line extending the optical path by cos Θ. Since this is a value obtained by multiplying the difference between the values of Y when Xp is substituted for X in Equations 7 and 8 shown in the first embodiment by cos Θ, the deviation Dev can be expressed by Equation 23 below. .
(Equation 23)
Dev = cosΘ · {T1 · tan α− (T1−Xp) · tan θ−Xp · (y / x)}

  That is, by substituting the X-coordinate Xp of the exit point of the reflected light obtained by substituting the thickness of the entrance port plate-like member 20 into T of Equation 22 into Equation 23, the optical path of the reflected light with respect to the optical path of the laser light The deviation Dev can be obtained. If T1 is substituted for the thickness of the entrance plate member 20, the deviation Dev when the thickness of the entrance plate member 20 is the same as that of the exit plate member 18 can be obtained. By substituting T2 obtained by Equation 19 into the thickness of the plate-like member 20, the deviation Dev when the thickness of the entrance-portion plate-like member 20 is set to the thickness T2 at which the optical path of the reflected light is not displaced can be obtained. .

  FIG. 11A shows, as an example, a range of the scanning angle Θ (incident angle Θ) of 0 to 35 °, an angle β = 23 °, a thickness T1 = 1.5 mm, a thickness T2 = 1.725 mm, and a refractive index. In this graph, the deviation of the optical path of the reflected light with respect to the scanning angle Θ with respect to the optical path of the laser light is calculated with n = 1.5275 and the angle γ = 26 °. The dotted line is the case where the thickness of the entrance port plate member 20 is the same T1 as that of the exit port plate member 18, and the solid line is the case where the thickness of the entrance port plate member 20 is T2 = 1.725 mm. It is. As described above, the thickness T2 = 1.725 mm is the optical path of the reflected light when the angle β, the thickness T1, the refractive index n, and the angle γ are the above values and the scanning angle Θ (incident angle Θ) = 35 °. The thickness T2 is not deviated.

  As can be seen from FIG. 11A, the same relationship as in FIG. 5A of the first embodiment is shown. That is, when the thickness of the entrance port plate member 20 is T2 = 1.725 mm, the shift is 0 when the scanning angle Θ (incident angle Θ) is 35 °, and the other scanning angle Θ (incident angle Θ). In this case, a value other than 0 is obtained, but the deviation is extremely small as compared with the case where the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18. Therefore, if the thickness of the entrance port plate member 20 is set to a thickness T2 calculated using a value near the maximum value of the scanning angle range (a value near the maximum incident angle), the entire scanning angle range is set. In FIG. 5, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  Also in the third embodiment, the thickness T2 is calculated using a value near the maximum value in the range of the scan angle (value near the maximum angle of incidence) as the laser beam scan angle Θ (incident angle Θ). However, even if a value calculated using the scanning angle Θ (incident angle Θ) of the laser beam that is not so is used, the thickness of the entrance port plate member 20 is equal to that of the exit port plate member 18. The deviation can be reduced as compared with the case of the same T1. As an example, when the scanning angle Θ (incident angle Θ) = 1 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the refractive index n = 1.5275, and the angle γ = 26 °, the reflected light is calculated. The thickness T2 of the entrance-portion plate-like member 20 where the optical path is not shifted is equal to 1.666 mm. Then, when a similar graph is created by setting the thickness of the entrance plate member 20 to T2 = 1.666 mm, it becomes as shown in FIG. 11B, and the deviation becomes large near the maximum value in the range of the scanning angle Θ. However, as compared with the case where the thickness of the entrance port plate-like member 20 is the same as that of the exit port plate-like member 18, the deviation can be considerably reduced.

  Also in the third embodiment, since the angle β of the reflected light with respect to the scanning plane changes depending on the position of the measurement object OB with respect to the three-dimensional shape measuring apparatus, the angle β is set to a certain value and the optical path of the reflected light is set. Even if the thickness T2 of the incident aperture plate member 20 that is not deviated is obtained, the thickness T2 takes another value at other angles β. However, the angle β near the center of the measurable range of the three-dimensional shape measuring apparatus is the angle β of the optical path of the reflected light that coincides with the optical axis of the imaging lens 22, and the thickness T2 is calculated using this angle β. In this case, the deviation of the optical path of the reflected light with respect to the optical path of the laser light can be made small over the entire measurable range of the three-dimensional shape measuring apparatus. In this case, the calculation formula for obtaining the deviation of the optical path of the reflected light with respect to the optical path of the laser beam is the same as the above formulas 22 and 23, and therefore, the scanning angle Θ (incident angle Θ), the thickness T1, the refractive index n and the angle. If γ is determined and the value of the angle β is varied, a graph similar to that of FIG. 6 of the first embodiment can be created.

  FIG. 12 shows, as an example, a scanning angle Θ (incident angle Θ) = 35 °, a thickness T1 = 1.5 mm, a thickness T2 = 1.725 mm, a refractive index n = 1.5275, and an angle γ = 26 °. FIG. 6 is a graph showing the deviation of the optical path of the reflected light with respect to the angle β relative to the optical path of the laser light. The dotted line is the case where the thickness of the entrance port plate member 20 is the same as T1 of the exit port plate member 18, and the solid line is the case where the thickness of the entrance port plate member 20 is T2 = 1.725 mm. is there. The thickness T2 = 1.725 mm is a thickness at which the optical path of the reflected light is not shifted when the scanning angle Θ (incident angle Θ), the thickness T1, the refractive index n, and the angle γ are the above values and the angle β = 23 °. It is.

  As can be seen from FIG. 12, when the thickness of the entrance plate member 20 is T2 = 1.725 mm, the deviation is 0 when the angle β is 23 °, and the deviation is so large that the angle β deviates from 23 °. However, the deviation is extremely small as compared with the case where the thickness of the entrance port plate member 20 is the same as that of the exit port plate member 18. Therefore, if the thickness of the entrance aperture plate member 20 is set to the thickness T2 calculated using the value of the angle β of the optical path of the reflected light coincident with the optical axis of the imaging lens 22, the three-dimensional shape measuring apparatus In the entire measurable range, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  In the above description, the point where the reflected light is incident on the entrance port plate member 20 is the same as the point where the laser light is emitted from the entrance port plate member 20 when projected onto the scanning plane. It was. However, this condition is for convenience in calculating the thickness T2 of the entrance plate member 20 where the optical path of the reflected light does not shift and the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light. The position of the outer surface of the entrance port plate member 20 of the three-dimensional shape measuring apparatus is not limited as long as it is inclined around a line where the exit port plate member 18 and the scanning plane intersect. That is, in FIG. 9, the point where the reflected light is incident on the incident port plate member 20 is any point on the optical path of the laser light emitted from the output port plate member 18 or on the line extending the optical path. Even so, the calculation results described above do not change. This can be understood from the fact that the optical path of the emitted light does not change if the posture does not change even if the position of the translucent plate-like member 1 changes as shown in FIG.

  As can be understood from the above description, in the third embodiment, the measurement object OB is irradiated with the laser beam scanned using the scanning devices 14 and 16 via the emission port plate member 18, and the measurement object is obtained. Reflected light, which is part of the scattered light generated by OB, is received by the line sensor 24 through the entrance port plate member 20, the scanning devices 14, 16 and the imaging lens 22, and the light receiving position in the line sensor 24 is used. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the measuring object OB, the entrance port plate member 20 has an axis parallel to a line intersecting the exit port plate member 18 and the scanning plane of the scanned laser beam. There is a predetermined angle γ with the exit port plate member 18 around, and the thickness of the entrance port plate member 20 is a line where the outer surface of the exit port plate member 18 and the outer surface of the entrance port plate member 20 intersect. Intersects the optical axis of the imaging lens 22 The optical path of the reflected light incident on the entrance port plate member 20 is coincident with the optical axis of the imaging lens 22, and the scanning plane of the laser light scanned in the direction opposite to the incident position of the incident reflected light and the incident direction. The incident angle of the scanned laser light with respect to the emission port plate member 18 is other than 0 when the position and direction projected onto the beam coincide with the position and direction of the scanned laser beam emitted from the emission port plate member 18. When the value is a value, the scanning path of the laser beam that has scanned the optical path of the laser beam scanned before entering the exit port plate member 18 and the optical path of the reflected light incident on the entrance port plate member 20 is scanned. The normal line of the scanning plane including the point where the optical path projected on the plane intersects and the optical path of the reflected light incident on the entrance port plate member 20 are set to a plane perpendicular to the plane of the scan plane and the exit port plate member 18. From the intersection when projected, the entrance plate member 20 It is set as the distance to the outer surface.

  According to this, even if the entrance port plate member 20 has an angle γ with respect to the exit port plate member 18, it is extremely easy to set the thickness of the entrance port plate member 18 to an appropriate value. By this method, the deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser light can be reduced to a negligible level.

  In the third embodiment, the refractive indexes n of the exit port plate member 18 and the entrance port plate member 20 are equal. That is, the exit port plate member 18 and the entrance port plate member 20 are made of the same material. However, as in the first embodiment, even if the material of the exit port plate member 18 and the entrance port plate member 20 is changed and the refractive index n is a different value, the reflection shown in the third embodiment is shown. The calculation method of the thickness T2 of the entrance plate member 20 where the optical path of the light does not shift and the deviation Dev of the reflected light path with respect to the optical path of the laser light remains the same. In this case, as in the first embodiment, the refractive index of the entrance port plate member 20 is used for the refractive index n of Formula 3, and the refractive index of the exit port plate member 18 is used for the refractive index n of Formula 10. do it.

(Fourth embodiment)
In the second embodiment, when the exit port plate member 18 and the entrance port plate member 20 are parallel and have the same thickness, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is described. By setting appropriately, the deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser light was eliminated. However, the exit port plate member 18 and the entrance port plate member 20 have the same thickness, and the entrance port plate member 20 has a predetermined axis around an axis parallel to the line where the exit port plate member 18 and the scanning plane intersect. Even when the angle γ is rotated (tilted), the optical path of the laser light in the optical path of the reflected light can be set by appropriately setting the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20. Deviations from can be eliminated. In the fourth embodiment, the exit port plate member 18 and the entrance port plate member 20 have the same thickness, and the entrance port plate member 20 is parallel to the line intersecting the exit port plate member 18 and the scanning plane. When the optical axis of the reflected light is tilted by a predetermined angle γ around the axis, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is set so as to eliminate the deviation of the optical path of the reflected light from the optical path of the laser beam. It is a form. Hereinafter, a method of obtaining the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 that eliminates the deviation of the optical path of the reflected light from the optical path of the laser light will be described.

  As described in the third embodiment, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light can be obtained by Expression 22 and Expression 23. In Equations 22 and 23, the thickness T of the entrance port plate member 20 and the thickness T1 of the exit port plate member 18 are the same and known. Further, the inclination angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is also known, and when the scanning angle Θ of laser light (incident angle Θ to the entrance port plate member 20) is set, the unknown is refracted. The angle α is the ratio of the x and y components of the unit vector Vi (y / x), and the ratio of the x and z components of the unit vector Vi is (z / x). The refraction angle α can be obtained from the incident angle Θ and the refractive index n of the exit port plate member 18 (hereinafter referred to as the refractive index n1) using Equation 10. Further, as described above, the x, y, and z components of the unit vector Vi are obtained from the equation (1), equations (3) to (6), equations (14), and (15), and the laser beam scanning angle Θ (incident angle Θ) and reflected light. , The angle β with respect to the scanning plane (the plane of FIG. 9, the XY plane), the refractive index n of the entrance plate member 20 (hereinafter referred to as the refractive index n2), and the exit plate of the entrance plate member 20 It can be obtained from the inclination angle γ with respect to the shaped member 18. That is, when the scanning angle Θ (incident angle Θ) of the laser beam and the angle β of the reflected light with respect to the scanning plane are set and the refractive index n1 of the exit port plate member 18 is determined, the deviation Dev becomes 0 in Equation 23. The rate n2 is uniquely determined. Accordingly, if the refractive index n2 at which Dev is 0 at various values of the refractive index n1 is obtained, the exit port plate member 18 and the entrance port plate member 20 that eliminate the deviation of the optical path of the reflected light from the optical path of the laser light are obtained. The refractive index relationship can be obtained.

  FIG. 13 shows, as an example, the laser of the optical path of the reflected light when the scanning angle Θ (incident angle Θ) = 35 °, the thickness T1 = 1.5 mm, the angle β = 23 °, and the angle γ = 26 °. This is the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 that eliminate the deviation from the optical path of light. As can be seen from FIG. 13, as in the second embodiment, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is substantially linear.

  Also in the fourth embodiment, after setting the scanning angle Θ (incident angle Θ) and the angle β of the reflected light with respect to the scanning plane, the exit port plate member 18 and the entrance port plate member that eliminate the deviation of the optical path of the reflected light. Since the relationship of the refractive index of 20 is obtained, the deviation of the optical path of the reflected light with respect to the scanning angle Θ (incident angle Θ) and the angle β of the reflected light with respect to the scanning plane is shown as in the first to third embodiments. Also in this case, the deviation of the optical path of the reflected light can be obtained by Equations 22 and 23.

  In FIG. 14A, as an example, the range of the scanning angle Θ (incident angle Θ) is 0 to 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the angle γ = 26 °, and the scanning angle Θ. Is a graph showing the deviation of the optical path of the reflected light with respect to the optical path of the laser beam. The solid line shows the case where the refractive index n1 of the exit port plate member 18 is 1.5275 and the refractive index n2 of the entrance port plate member 20 is 1.6835, and the angle β, the thickness T1, and the angle γ are the above values. Thus, when the scanning angle Θ (incident angle Θ) = 35 °, there is a refractive index relationship in which the deviation of the optical path of the reflected light does not occur. The dotted line is the case where the refractive index n = 1.5275 for both the exit port plate member 18 and the entrance port plate member 20. Unlike the second embodiment, in the fourth embodiment, when the scanning angle Θ (incident angle Θ) is other than 35 °, the deviation of the optical path of the reflected light is a value other than 0, but the exit port plate-like member 18 is used. Is smaller than the case where the refractive index of the entrance plate member 20 is the same. Therefore, when the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is set appropriately, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  Also in the fourth embodiment, the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is a value near the maximum value of the scan angle range (maximum) as the scan angle Θ (incident angle Θ). It is preferable to use a value calculated using a value near the incident angle of the incident angle), but even if the refractive index relationship calculated using the other scanning angle Θ (incident angle Θ) is used, the exit port plate member 18 is used. And the deviation can be reduced as compared with the case where the refractive indexes of the entrance plate member 20 are the same. As an example, the reflection when the incident angle Θ = 1 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the angle γ = 26 °, and the refractive index n1 of the exit port plate member 18 = 1.5275. When the refractive index n2 of the entrance-portion plate member 20 in which the optical path of light is not shifted is calculated, n2 = 1.6226. Then, when a similar graph is created with the refractive index n2 of the entrance-portion plate member 20 being 1.6226, as shown in FIG. 14B, the deviation increases near the maximum value of the scanning angle range. Compared with the case where the refractive index of the exit port plate member 18 and the entrance port plate member 20 is the same, the deviation can be reduced.

  FIG. 15 shows an example in which the scanning angle Θ (incident angle Θ) = 35 °, the thickness T1 = 1.5 mm, the angle γ = 26 °, and the deviation of the optical path of the reflected light with respect to the angle β relative to the optical path of the laser light. The solid line represents the case where the refractive index n1 of the exit port plate member 18 is 1.5275 and the refractive index n2 of the entrance port plate member 20 is 1.6835, and the scanning angle When Θ (incident angle Θ), thickness T1, and angle γ are the above values and the angle β = 23 °, the refractive index relationship is such that no deviation of the optical path of the reflected light occurs. A dotted line is a case where the refractive index of the exit port plate-shaped member 18 and the entrance port plate-shaped member 20 is the same at 1.5275, and is the same as the dotted line of the graph of FIG. As can be seen from FIG. 15, the deviation increases as the angle β of the reflected light with respect to the scanning plane deviates from 23 °. However, when the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 are the same. The deviation is extremely small. Therefore, if the relationship between the refractive indexes of the exit port plate member 18 and the entrance port plate member 20 is calculated using the value of the angle β in the optical path of the reflected light coincident with the optical axis of the imaging lens 22. The shift of the optical path of the reflected light with respect to the optical path of the laser light can be made small enough to be ignored over the entire measurable range of the three-dimensional shape measuring apparatus.

  In the fourth embodiment, the point where the reflected light is incident on the incident aperture plate-like member 20 is the same as the point where the laser beam is emitted from the incident aperture plate-like member 20 when projected onto the scanning plane. The calculation formula is used, but this condition is that the optical path of the laser light in the optical path of the reflected light and the relationship between the refractive indexes of the exit aperture plate-like member 18 and the incident aperture plate-like member 20 where the optical path of the reflected light does not deviate. This is a convenience for calculating the deviation Dev with respect to. Also in the fourth embodiment, the position of the outer surface of the entrance port plate member 20 of the actual three-dimensional shape measuring apparatus is not limited as long as it is inclined around the line where the exit port plate member 18 and the scanning plane intersect.

  As can be understood from the above description, in the fourth embodiment, the measurement object OB is irradiated with the laser beam scanned using the scanning devices 14 and 16 via the emission port plate member 18, and the measurement object is obtained. Reflected light, which is part of the scattered light generated by OB, is received by the line sensor 24 through the entrance port plate member 20, the scanning devices 14, 16 and the imaging lens 22, and the light receiving position in the line sensor 24 is used. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the measuring object OB, the entrance port plate member 20 has an axis parallel to a line intersecting the exit port plate member 18 and the scanning plane of the scanned laser beam. The exit port plate member 18 has a predetermined angle with the exit port plate member 18 and has the same thickness as the exit port plate member 18. The exit port plate member 18 and the entrance port plate member 20 are formed of the exit port plate member. 18 and an entrance plate member The line where the outer surface of the entrance aperture plate member 20 of the exit aperture plate member 18 intersects with the refractive index of 0 intersects with the optical axis of the imaging lens 22 and is incident on the entrance aperture plate member 20. The optical path of the light coincides with the optical axis of the imaging lens 22, and the position and direction projected on the scanning plane of the laser light scanned in the direction opposite to the incident position of the incident reflected light and the incident direction are scanned laser light. When the incident angle of the scanned laser beam with respect to the emission port plate member 18 is a value other than 0 when the position and direction of the emission port plate member 18 coincide with each other, the emission of the scanned laser beam The optical path projected on the scanning plane of the laser beam scanned from the inner surface of the mouth plate member 18 to the scanning devices 14 and 16 side and the optical path on the scanning device 14 and 16 side from the inner surface of the incident port plate member 20 of the reflected light. Selects those with a refractive index relationship that matches So that has been.

  Even in this case, even when the incident port plate member 20 has an angle γ with respect to the output port plate member 18, the relationship between the refractive indexes of the output port plate member 18 and the incident port plate member 20 is appropriately set. By the extremely simple method of establishing the above relationship, the deviation of the optical path of the reflected light projected onto the scanning plane from the optical path of the laser light can be reduced to a negligible level.

(Fifth embodiment)
In the first to fourth embodiments, the thickness of the entrance port plate member 20 is set to an appropriate value, or the exit port plate member 18 and the entrance port plate member 20 have the same thickness. The deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser light was eliminated by either making the relationship between the refractive indexes of the plate member 18 and the entrance aperture plate member 20 appropriate. However, even if the thickness and refractive index of the exit port plate member 18 and the entrance port plate member 20 are the same, the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is set to an appropriate value. As a result, the deviation of the optical path of the reflected light from the optical path of the laser light can be eliminated. In the fifth embodiment, the angle γs of the entrance port plate member 20 with respect to the exit port plate member 18 is set to eliminate the deviation of the optical path of the reflected light from the optical path of the laser beam.

  As described in the third embodiment, the refraction angle of the reflected light when projected onto the scanning plane is determined by the size of the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18. There are cases where the refractive angle is smaller than or larger than the light refraction angle α. More specifically, when the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is 0, the refraction angle of the reflected light when projected onto the scanning plane is the refraction angle α of the laser beam. As shown in FIG. 4, the optical path of the reflected light after entering the entrance port plate member 20 is on the right side of the optical path of the laser light in the traveling direction of the reflected light. If the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is increased from this state, the refraction angle of the reflected light when projected on the scanning plane is increased, and the entrance port is increased. The optical path of the reflected light after entering the plate-like member 20 moves to the left in the traveling direction of the reflected light. As shown in FIG. 9, the optical path of the reflected light is on the left side of the optical path of the laser light in the traveling direction of the reflected light.

  Further, when the angle γ of the incident port plate member 20 with respect to the output port plate member 18 is 0, the reflected light is emitted from the inner surface of the output port plate member 18 when projected onto the scanning plane. As the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is increased, the incident port plate member 20 moves toward the front side in the traveling direction of the reflected light. That is, if the angle γ is increased from 0, the optical path of the reflected light moves to the left in the traveling direction, and the emission point of the reflected light moves to the near side in the traveling direction, the reflected light In some cases, the emission point is included in a line obtained by extending the optical path of the laser beam before entering the emission port plate member 18. The angle γ at this time is the angle γs of the incident port plate member 20 with respect to the output port plate member 18 that eliminates the deviation of the optical path of the reflected light from the optical path of the laser beam. Hereinafter, a method of obtaining the angle γs of the incident port plate member 20 with respect to the output port plate member 18 that eliminates the deviation of the optical path of the reflected light from the optical path of the laser light will be described.

  As described in the third embodiment, when the entrance port plate member 20 has an angle γ with respect to the exit port plate member 18, the deviation Dev of the optical path of the reflected light with respect to the optical path of the laser light is expressed by Equation 22. It can be obtained by Equation 23. In Equations 22 and 23, the thickness T of the entrance port plate member 20 and the thickness T1 of the exit port plate member 18 are the same and known. When the scanning angle Θ (incident angle Θ) of the laser beam is set, the refraction angle α can be obtained from the refractive index n of the exit port plate member 18, and the x, y, and z components of the unit vector Vi are As described above, the laser beam scanning angle Θ (incident angle Θ) and the reflected light scanning plane (from the paper surface of FIGS. , XY plane), the refractive index n of the entrance port plate member 20, and the inclination angle γ of the entrance port plate member 20 with respect to the exit port plate member 18. That is, the scanning angle Θ (incident angle Θ) of the laser light and the angle β with respect to the scanning plane of the reflected light are set, and the thickness T1 of the entrance port plate member 20 and the exit port plate member 18 and the entrance port plate member 20 are set. If the refractive index n of the emission port plate member 18 is known, the angle γs at which the deviation Dev becomes 0 can be obtained in Equation 23. As an example, when the scanning angle Θ (incident angle Θ) = 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, and the refractive index n = 1.5275 are calculated, the incident light path does not deviate. The angle γs of the mouth plate-like member 20 with respect to the emission mouth plate-like member 18 is 9.3 °.

  Also in the fifth embodiment, after setting the scanning angle Θ (incident angle Θ) and the angle β of the reflected light with respect to the scanning plane, the exit port plate member of the entrance port plate member 20 eliminates the deviation of the optical path of the reflected light. Since the angle γs with respect to 18 is obtained, similarly to the first to fourth embodiments, the deviation of the optical path of the reflected light with respect to the scanning angle Θ (incident angle Θ) and the angle β with respect to the scanning plane of the reflected light is shown. Also in this case, the deviation of the optical path of the reflected light can be obtained by Equations 22 and 23.

  In FIG. 16A, as an example, the scanning angle Θ (incident angle Θ) ranges from 0 to 35 °, the angle β = 23 °, the thickness T1 = 1.5 mm, and the refractive index n = 1.5275. 5 is a graph showing the deviation of the optical path of reflected light with respect to the angle Θ relative to the optical path of laser light. The solid line shows the case where the angle γ = 9.3 ° of the entrance port plate member 20 with respect to the exit port plate member 18, and the angle β, the thickness T1, and the refractive index n are the above values, and the scan angle Θ (incident angle). When Θ) = 35 °, the angle γs at which the optical path of the reflected light does not shift. The dotted line is the case where the angle γ = 0, and is the same as the dotted line in FIG. As can be seen from FIG. 16A, when the scanning angle Θ (incidence angle Θ) is other than 35 °, the deviation of the optical path of the reflected light becomes a value other than 0, but the exit of the exit port plate member 20 Compared with the case where the angle γ = 0 with respect to the mouth plate-like member 18 (that is, parallel), the deviation is extremely small. Accordingly, when the angle γ of the exit port plate member 20 with respect to the exit port plate member 18 is appropriately set, the deviation of the optical path of the reflected light from the optical path of the laser light can be made small enough to be ignored.

  Also in the fifth embodiment, the angle γs of the incident aperture plate-like member 20 with respect to the exit aperture plate-like member 18 where the optical path of the reflected light does not shift is a scanning angle range as the laser beam scan angle Θ (incident angle Θ). It is preferable to use a value calculated using a value in the vicinity of the maximum value (a value in the vicinity of the maximum incident angle), but an angle γs calculated using the scanning angle Θ (incident angle Θ) of the laser beam that is not so is used. However, the deviation can be reduced as compared with the case where the angle γ = 0 (that is, parallel) of the entrance port plate member 20 with respect to the exit port plate member 18. For example, when the scanning angle Θ (incident angle Θ) = 1 °, the angle β = 23 °, the thickness T1 = 1.5 mm, the refractive index n = 1.5275, and the angle γs is calculated, the angle γs = 11.7. °. When a similar graph is created with the angle γ = 11.7 °, as shown in FIG. 16B, the deviation increases near the maximum value in the range of the scanning angle Θ, but the angle γ = 0. Compared with, the deviation can be considerably reduced.

  FIG. 17 shows an example where the scanning angle Θ (incident angle Θ) = 35 °, the thickness T1 = 1.5 mm, the refractive index n = 1.5275, and the optical path of the laser beam of the reflected light with respect to the angle β. The solid line represents the case where the angle γ of the entrance port plate member 20 with respect to the exit port plate member 18 is 9.3 °, and the scanning angle Θ (incident angle Θ). When the thickness T1 and the refractive index n are the above values and the angle β = 23 °, the angle γs at which the optical path of the reflected light does not shift. The dotted line is the case where the angle γ = 0, and is the same as the dotted line in the graph of FIG. As can be seen from FIG. 17, the deviation becomes larger as the angle β of the reflected light with respect to the scanning plane deviates from 23 °, but the deviation is smaller than that in the case where the angle γ = 0. Therefore, the angle γs of the incident aperture plate-like member 20 with respect to the exit aperture plate-like member 18 where the optical path of the reflected light is not shifted is calculated using the value of the angle β in the optical path of the reflected light that coincides with the optical axis of the imaging lens 22. In this case, the deviation of the optical path of the reflected light with respect to the optical path of the laser light can be made small over the entire measurable range of the three-dimensional shape measuring apparatus.

  In addition, also in 5th Embodiment, the point in which reflected light injects into the entrance-portion plate-shaped member 20 is the same as the point in which a laser beam radiate | emits from the entrance-portion plate-shaped member 20 when projected on a scanning plane. The calculation formula is used, but this condition is that the angle γs of the incident port plate member 20 with respect to the exit port plate member 18 where the optical path of the reflected light does not shift and the shift of the optical path of the reflected light with respect to the optical path of the laser beam. This is a convenience for calculating Dev. Also in the fifth embodiment, the position of the outer surface of the entrance port plate member 20 of the actual three-dimensional shape measuring apparatus is not limited as long as it is inclined around a line where the exit port plate member 18 and the scanning plane intersect.

  As can be understood from the above description, in the fifth embodiment, the measurement object OB is irradiated with the laser beam scanned using the scanning devices 14 and 16 via the emission port plate member 18, and the measurement object is obtained. Reflected light, which is part of the scattered light generated by OB, is received by the line sensor 24 through the entrance port plate member 20, the scanning devices 14, 16 and the imaging lens 22, and the light receiving position in the line sensor 24 is used. In the three-dimensional shape measuring apparatus for measuring the three-dimensional shape of the measuring object OB, the entrance port plate member 20 has an axis parallel to a line intersecting the exit port plate member 18 and the scanning plane of the scanned laser beam. It has a predetermined angle γ around the exit port plate member 18 and has the same thickness and refractive index as the exit port plate member 18, and the predetermined angle γ is incident on the outer surface of the exit port plate member 18. The outer surface of the mouth plate-like member 20 The line intersecting the optical axis of the imaging lens 22 intersects the optical path of the reflected light incident on the entrance port plate member 20, and the incident optical axis of the reflected light is incident. Scanned laser when the position and direction projected on the scanning plane of the laser beam scanned in the opposite direction to the position and the incident direction coincide with the position and direction of the scanned laser beam emitted from the exit port plate member 18 When the incident angle of the light with respect to the exit plate 18 is a value other than 0, the optical path from the inner surface of the scanned exit plate 18 of the laser beam to the scanning devices 14 and 16 side, and the reflected light entrance The angle is set so that the optical path projected on the scanning plane of the laser light scanned from the inner surface of the plate-like member 20 on the scanning devices 14 and 16 side coincides.

  Even in this case, the deviation of the optical path of the reflected light projected on the scanning plane from the optical path of the laser beam can be made by an extremely simple method of setting the angle γ of the incident aperture plate-shaped member 20 to the output aperture plate-shaped member 18 to an appropriate angle. Can be reduced to a negligible level.

DESCRIPTION OF SYMBOLS 1 ... Translucent plate-shaped member, 10 ... Laser light source, 12 ... Collimating lens, 14 ... Galvano mirror, 16 ... Motor, 18 ... Emission port translucent member, 20 ... Incident port translucent member, 22 ... Imaging Lens, 24 ... Line sensor, OB ... Measurement object

Claims (5)

The laser beam scanned using the scanning unit is irradiated onto the measurement object via the first light-transmitting plate member, and the reflected light, which is a part of the scattered light generated at the measurement object, is reflected on the second transmission light. In a three-dimensional shape measuring apparatus that receives light with a line sensor via an optical plate-like member, the scanning unit, and an imaging lens, and measures a three-dimensional shape of the measurement object using a light receiving position in the line sensor,
The second translucent plate-like member is parallel to the first translucent plate-like member,
The thickness of the second translucent plate-shaped member is
The outer surface of the first translucent plate-like member and the outer surface of the second translucent plate-like member are included in the same plane, and the optical path of the reflected light incident on the second translucent plate-like member Is coincident with the optical axis of the imaging lens, and the position and direction of the incident position of the incident reflected light and the direction opposite to the incident direction projected on the scanning plane of the scanned laser light are the scanned laser. When it is coincident with the position and direction of light emitted from the first translucent plate-like member,
When the incident angle of the scanned laser light with respect to the first translucent plate-shaped member is a value other than 0, the scanned laser light before entering the first translucent plate-shaped member From the point where the line in which the optical path is extended and the optical path projected on the scanning plane of the scanned laser light the optical path of the reflected light incident on the second light transmissive plate member intersects the first transparent light. A three-dimensional shape measuring apparatus, which is set by a distance to the outer surface of the optical plate-like member. The laser beam scanned using the scanning unit is irradiated onto the measurement object via the first light-transmitting plate member, and the reflected light, which is a part of the scattered light generated at the measurement object, is reflected on the second transmission light. In a three-dimensional shape measuring apparatus that receives light with a line sensor via an optical plate-like member, the scanning unit, and an imaging lens, and measures a three-dimensional shape of the measurement object using a light receiving position in the line sensor,
The second translucent plate member is parallel to the first translucent plate member and has the same thickness,
The first and second translucent plate-like members have a refractive index relationship between the first and second translucent plate-like members.
The both sides of the first translucent plate-like member and the both sides of the second translucent plate-like member are included in the same plane, and the optical path of the reflected light incident on the second translucent plate-like member Is coincident with the optical axis of the imaging lens, and the position and direction in which the incident position of the incident reflected light and the direction opposite to the incident direction are projected onto the scanning plane of the scanned laser light are the scanned laser light. When it is coincident with the position and direction of emission from the first translucent plate-shaped member,
When the incident angle of the scanned laser light with respect to the first translucent plate-like member is a value other than 0, the scanned laser light and the reflected light path of the scanned laser light are scanned. 3. A three-dimensional shape measuring apparatus, wherein a refractive index that matches the optical path projected on the scanning plane is selected. The laser beam scanned using the scanning unit is irradiated onto the measurement object via the first light-transmitting plate member, and the reflected light, which is a part of the scattered light generated at the measurement object, is reflected on the second transmission light. In a three-dimensional shape measuring apparatus that receives light with a line sensor via an optical plate-like member, the scanning unit, and an imaging lens, and measures a three-dimensional shape of the measurement object using a light receiving position in the line sensor,
The second light-transmitting plate-like member is formed around the axis parallel to a line intersecting the first light-transmitting plate-like member and the scanning plane of the scanned laser light. Having a predetermined angle with the shaped member,
The thickness of the second translucent plate-shaped member is
A line where the outer surface of the first light transmissive plate member and the outer surface of the second light transmissive plate member intersect each other intersects with the optical axis of the imaging lens, and the second light transmissive plate. The optical path of the reflected light incident on the member is coincident with the optical axis of the imaging lens, and the position where the incident position of the incident reflected light is opposite to the incident direction is projected onto the scanning plane of the scanned laser light And the direction coincides with the position and direction of the scanned laser beam emitted from the first translucent plate-like member,
When the incident angle of the scanned laser light with respect to the first translucent plate-shaped member is a value other than 0, the scanned laser light before entering the first translucent plate-shaped member A method of the scanning plane including a point where a line in which an optical path is extended intersects with an optical path projected on the scanning plane of the scanned laser light with the optical path of reflected light incident on the second light-transmissive plate member Line and the optical path of the reflected light incident on the second translucent plate-like member from the intersection when the scanning plane and a plane perpendicular to the first translucent plate-like member are projected to the second The three-dimensional shape measuring apparatus is set by the distance to the outer surface of the translucent plate-shaped member. The laser beam scanned using the scanning unit is irradiated onto the measurement object via the first light-transmitting plate member, and the reflected light, which is a part of the scattered light generated at the measurement object, is reflected on the second transmission light. In a three-dimensional shape measuring apparatus that receives light with a line sensor via an optical plate-like member, the scanning unit, and an imaging lens, and measures a three-dimensional shape of the measurement object using a light receiving position in the line sensor,
The second light-transmitting plate-like member is formed around the axis parallel to a line intersecting the first light-transmitting plate-like member and the scanning plane of the scanned laser light. And having a predetermined angle with the shaped member, and having the same thickness as the first translucent plate-like member,
The first and second translucent plate-like members have a refractive index relationship between the first and second translucent plate-like members.
A line where the outer surface of the first light transmissive plate member and the outer surface of the second light transmissive plate member intersect each other intersects with the optical axis of the imaging lens, and the second light transmissive plate. The optical path of the reflected light incident on the member is coincident with the optical axis of the imaging lens, and the position where the incident position of the incident reflected light is opposite to the incident direction is projected onto the scanning plane of the scanned laser light And the direction coincides with the position and direction of the scanned laser beam emitted from the first translucent plate-like member,
The scanning from the inner surface of the first light transmissive plate member of the scanned laser light when the incident angle of the scanned laser light to the first light transmissive plate member is a value other than zero. Refractive index relationship between the optical path on the means side and the optical path projected on the scanning plane of the scanned laser light from the inner surface of the second light-transmissive plate member of the reflected light to the scanning means side What is selected is a three-dimensional shape measuring apparatus. The laser beam scanned using the scanning unit is irradiated onto the measurement object via the first light-transmitting plate member, and the reflected light, which is a part of the scattered light generated at the measurement object, is reflected on the second transmission light. In a three-dimensional shape measuring apparatus that receives light with a line sensor via an optical plate-like member, the scanning unit, and an imaging lens, and measures a three-dimensional shape of the measurement object using a light receiving position in the line sensor,
The second light-transmitting plate-like member is formed around the axis parallel to a line intersecting the first light-transmitting plate-like member and the scanning plane of the scanned laser light. And having a predetermined angle γ and the same thickness and refractive index as the first translucent plate-shaped member, and the predetermined angle γ is:
A line where the outer surface of the first light transmissive plate member and the outer surface of the second light transmissive plate member intersect each other intersects with the optical axis of the imaging lens, and the second light transmissive plate. The optical path of the reflected light incident on the member is coincident with the optical axis of the imaging lens, and the position where the incident position of the incident reflected light is opposite to the incident direction is projected onto the scanning plane of the scanned laser light And the direction coincides with the position and direction of the scanned laser beam emitted from the first translucent plate-like member,
The scanning from the inner surface of the first light transmissive plate member of the scanned laser light when the incident angle of the scanned laser light to the first light transmissive plate member is a value other than zero. The optical path on the means side and the optical path projected on the scanning plane of the scanned laser light from the inner surface of the second translucent plate-like member of the reflected light to the scanning plane of the laser light are set to coincide with each other. A three-dimensional shape measuring apparatus.