JP5914850B2 - Three-dimensional measuring device and illumination device used therefor - Google Patents

Description

  The present invention provides a three-dimensional measurement of the shape of a measurement object by irradiating the measurement object with circularly polarized light and analyzing the polarization state of reflected light reflected by the measurement object or transmitted light transmitted through the measurement object. The present invention relates to a measuring device and an illumination device used therefor.

  Conventionally, in order to measure the shape of an object to be measured, a technique for irradiating the object to be measured and analyzing the polarization state of reflected light reflected by the object to be measured or transmitted light transmitted through the object to be measured is known. (See, for example, Patent Document 1). This type of technique is called ellipsometry. Hereinafter, only the reflected light will be described with respect to the light after irradiating the object to be measured, but the term of the reflected light can be read as transmitted light transmitted through the object to be measured unless otherwise specified.

  The reflected light reflected by the object to be measured is received by the optical sensor through the analyzer. The optical sensor may be configured to obtain an output corresponding to the received light intensity, but an imaging means such as a camera is used when simultaneously measuring an object to be measured over a wide range. The analyzer is rotatable around the optical axis where the optical sensor (imaging means) looks at the object to be measured.

  Since the reflected light from the object to be measured is polarized light, it can be handled in a generalized manner by elliptically polarized light. The parameter of elliptically polarized light is represented by three parameters: an angle ψ representing the inclination of the ellipse with respect to the specified reference angle, and a major axis a and a minor axis b of the ellipse. On the other hand, since the intensity I of the light passing through the analyzer is also a function of the rotation angle θ of the analyzer, the intensity I is eventually represented as a function f having four parameters a, b, θ, and ψ. That is, I = f (a, b, θ, ψ). Here, linearly polarized light is expressed under the condition b = 0, and circularly polarized light is expressed under the condition a = b. The form of the function f is known. The absolute value of the major axis “a” and the minor axis “b” varies depending on the intensity of the light irradiated to the object to be measured, but the ratio of the major axis “a” to the minor axis “b” (ellipticity) is known to know the polarization state. Therefore, the absolute values of the major axis “a” and the minor axis “b” may change, that is, the intensity of light applied to the object to be measured need not be considered.

International Publication No. 2010/021148

  In such a three-dimensional measuring apparatus, in order to realize high-precision measurement, it is necessary to irradiate completely circularly polarized light so that it is regularly reflected on the surface of the object to be measured and reflected toward the imaging means. For this purpose, it is necessary to irradiate the object to be measured with circularly polarized light from all directions.

  However, in the conventional measuring apparatus described in Patent Document 1, the light emitting surface of the illumination unit is a polyhedron combining a plurality of planes that emit circularly polarized light. For this reason, the illumination means cannot irradiate the object to be measured with circularly polarized light from all angles, which causes a measurement error.

  As a technique for solving the above-described problem, an illuminating unit in which the light emitting surface is formed in a hemispherical shape so as to cover the object to be measured can be considered.

  However, it is difficult to accurately form the light emitting surface in a hemispherical shape, and the measurement accuracy is lowered.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a three-dimensional measurement apparatus capable of accurately measuring an object to be measured and an illumination apparatus used therefor.

The three-dimensional measurement apparatus of the present invention includes an illuminating unit that irradiates an object to be measured with circularly polarized light, an imaging unit that receives reflected light from the irradiated surface of the measured object, and images the irradiated surface, and the imaging A calculation unit that detects a polarization state of the reflected light using a captured image captured by the unit and obtains an orientation of the irradiated surface; and a moving unit that moves the illuminating unit. The circularly polarized light is irradiated onto a part of the object to be measured, and the moving unit is symmetric about the optical axis of the imaging unit so that the position of the irradiated surface changes in the object to be measured. It is characterized by moving.

  In this three-dimensional measurement apparatus, it is preferable that the illuminating unit has a light emitting surface formed in a shape along an intersection line of a hemisphere including the measurement object and a plane including the optical axis.

  In this three-dimensional measurement apparatus, the imaging unit images the irradiated surface for each illumination range obtained by dividing the entire circumference around which the illumination unit moves around the optical axis into a plurality of illumination ranges, and the calculation unit includes the illumination unit. The polarization state of the reflected light is detected using the captured image captured by the imaging unit for each range, and the polarization state of the illumination range and the azimuth of the illumination range are detected for each illumination range. It is preferable to obtain an inclination angle representing an angle formed by a normal direction with respect to the optical axis, and an azimuth angle representing a direction of a straight line obtained by projecting the normal line of the irradiated surface onto a plane orthogonal to the optical axis.

The three-dimensional measurement apparatus of the present invention includes an illuminating unit that irradiates an object to be measured with circularly polarized light, an imaging unit that receives reflected light from the irradiated surface of the measured object, and images the irradiated surface, and the imaging A calculation unit that detects a polarization state of the reflected light using a captured image captured by the unit and obtains an orientation of the irradiated surface; and a moving unit that moves the illuminating unit. The circularly polarized light is irradiated onto a part of the object to be measured with parallel light, the moving unit moves the illumination unit so that the position of the surface to be irradiated on the object to be measured changes, and the moving unit includes A first mechanism for moving the illuminating means axisymmetrically around the optical axis of the imaging means; and a hemisphere including the object to be measured in a direction orthogonal to the moving direction of the illuminating means by the first mechanism. Including a second mechanism for moving the illumination means. It is characterized in.

The illumination device of the present invention is a three-dimensional measurement device that irradiates the object to be measured with circularly polarized light, detects the polarization state of the reflected light reflected by the surface to be measured, and obtains the direction of the surface to be irradiated. An illumination device to be used, the illumination means for irradiating a part of the measurement object with the circularly polarized light, and the irradiation surface of the measurement object so that the position of the irradiation surface changes in the measurement object And a moving means for moving the illuminating means axisymmetrically around the optical axis of the image pickup means for picking up the surface to be irradiated by receiving the reflected light from the light source.
The illumination device of the present invention is a three-dimensional measurement device that irradiates the object to be measured with circularly polarized light, detects the polarization state of the reflected light reflected by the surface to be measured, and obtains the direction of the surface to be irradiated. An illumination device to be used, wherein the illumination unit irradiates a part of the measurement object with the circularly polarized light with parallel light, and moves the illumination unit so that the position of the irradiated surface changes in the measurement object. Moving means, and the moving means moves the illuminating means symmetrically about the optical axis of the imaging means for receiving the reflected light from the irradiated surface of the object to be measured and imaging the irradiated surface. A first mechanism; and a second mechanism for moving the illuminating means in a direction perpendicular to a moving direction of the illuminating means by the first mechanism in a hemisphere including the object to be measured. .

  According to the present invention, there is an advantage that it is possible to accurately measure an object to be measured.

1 is a schematic configuration diagram illustrating a three-dimensional measurement apparatus according to Embodiment 1. FIG. It is operation | movement explanatory drawing of the three-dimensional measuring apparatus which concerns on the same as the above. It is principle explanatory drawing of the three-dimensional measuring apparatus which concerns on the same as the above. FIG. 6 is an operation explanatory diagram of the three-dimensional measurement apparatus according to the second embodiment. It is an example of a to-be-measured object, Comprising: (a) is a perspective view, (b) is a top view, (c) is a side view. FIG. 9 is an operation explanatory diagram of the three-dimensional measurement apparatus according to the third embodiment. FIG. 10 is an operation explanatory diagram of the three-dimensional measurement apparatus according to the fourth embodiment.

(Embodiment 1)
As shown in FIG. 1, the three-dimensional measurement apparatus 1 according to the present embodiment is an apparatus that measures the surface state of the measurement object 8 using circularly polarized light. That is, the three-dimensional measuring apparatus 1 of the present embodiment irradiates the object to be measured 8 with circularly polarized light, detects the polarization state of the reflected light reflected by the surface of the object to be measured 8 (irradiated surface), and performs the above irradiation. The direction of the surface (reflection surface) is obtained. The three-dimensional measuring apparatus 1 includes an illuminating unit 2 that irradiates the object to be measured 8 with circularly polarized light, a moving unit 3 that moves the illuminating unit 2, an imaging unit 4 that images the object to be measured 8, and an imaging unit 4. Computation means 5 for obtaining the direction of the illuminated surface of the object 8 to be measured using the captured image. The light emitted from the illuminating means 2 changes from the circularly polarized state to the elliptically polarized state when reflected by the irradiated surface of the object 8 to be measured. That is, the reflected light reflected by the irradiated surface of the measurement object 8 is in an elliptically polarized state. The three-dimensional measuring apparatus 1 includes an analyzer 61 disposed between the object to be measured 8 and the imaging unit 4 and a trigger unit 7 that outputs a trigger signal according to the rotation angle of the analyzer 61. Yes. The illumination unit 2 and the moving unit 3 constitute an illumination device. The measurement object 8 is arranged on a table (not shown), and the imaging means 4 is arranged above the table. That is, the imaging means 4 is arranged so that the normal direction of the table upper surface and the optical axis 41 (see FIG. 2) are parallel. The object to be measured 8 is disposed on the optical axis 41 where the imaging means 4 looks into the object to be measured 8.

  The three-dimensional measuring apparatus 1 configured as described above irradiates complete circularly polarized light from all directions of the measurement object 8 by moving the illumination means 2 that irradiates the circular polarization to a minute region of the measurement object 8. Realize that. Hereinafter, each component of the three-dimensional measuring apparatus 1 will be described.

  The illumination unit 2 irradiates the object to be measured 8 with circularly polarized light. For example, the illuminating means 2 includes a polarizing plate (not shown) and a quarter-wave plate (not shown) arranged in an overlapping manner, and the light that has been linearly polarized through the polarizing plate is divided into quarters. Circularly polarized light is generated by passing through a single wavelength plate, and the object to be measured 8 is irradiated with the circularly polarized light. That is, the illumination unit 2 irradiates the object to be measured 8 with circularly polarized light by passing light from a light source (not shown) through the polarizing plate and the quarter-wave plate.

  As shown in FIG. 2, the illuminating means 2 of the present embodiment has a light emitting surface 21 formed in a shape along an intersection line between a hemisphere including the measurement target 8 and a plane including the optical axis 41. Yes. That is, the illumination means 2 has a light emitting surface 21 whose bottom surface is recessed like a part of a hemisphere. The illumination unit 2 is disposed so that the light emitting surface 21 surrounds the optical axis 41 of the imaging unit 4.

  Such an illuminating unit 2 irradiates a part of the measurement object 8 with circularly polarized light, and moves (scans) over the entire circumference of the optical axis 41 of the imaging unit 4 as indicated by an arrow A1 in FIG. ) While irradiating the object to be measured 8 with circularly polarized light obliquely from above and from the side. At this time, the illumination unit 2 moves so as not to block the visual field of the imaging unit 4. Therefore, the illuminating unit 2 illuminates the measurement object 8 evenly over the entire circumference like ring illumination by moving the entire circumference around the optical axis 41 of the imaging unit 4. That is, the illuminating unit 2 uniformly irradiates circularly polarized light on the object to be measured 8 obliquely from above and from the side while moving around the optical axis 41 of the imaging unit 4.

  The illumination unit 2 may have any configuration as long as the object to be measured 8 can be irradiated with circularly polarized light. The light source used for the illumination unit 2 is preferably a light source that is lit using a DC stabilized power supply so that the light output does not fluctuate while the imaging unit 4 is imaging.

  The moving means 3 uses, for example, a CPU (Central Processing Unit) as a main component, and moves the illumination means 2 as indicated by an arrow A1 in FIG. That is, the moving unit 3 moves the illuminating unit 2 so that the position of the irradiated surface in the measurement object 8 changes.

  In the present embodiment, the moving unit 3 moves the illuminating unit 2 about the optical axis 41 of the imaging unit 4 in an axisymmetric manner. That is, the moving unit 3 rotates the illumination unit 2 around the measurement object 8 one turn at every predetermined rotation angle (described later) of the analyzer 61 (see FIG. 1). In addition, the moving means 3 is good also considering the movement amount of the illumination means 2 as less than 1 rotation according to a use.

  The imaging means 4 shown in FIG. 1 receives the reflected light from the irradiated surface of the measurement object 8 and images the irradiated surface. The image pickup means 4 includes an image pickup device in which pixels are arranged on lattice points of a two-dimensional lattice, such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The reflected light from the irradiated surface of the measurement object 8 is elliptically polarized light, and the imaging means 4 receives the reflected light through the analyzer 61. Further, the image pickup means 4 includes a light receiving optical system, and reflected light (elliptical polarized light) from the irradiated surface of the measurement object 8 enters the image pickup element through the light receiving optical system. The imaging means 4 of the present embodiment continues exposure for every predetermined rotation angle (described later) of the analyzer 61 from the start of movement (start of rotation) to the end of movement (end of rotation) of the illumination means 2. The measurement object 8 is imaged.

  The imaging unit 4 captures an image of the object 8 for each predetermined rotation angle of the analyzer 61, and then generates a captured image having pixel values as gray values. For example, the imaging unit 4 generates a total of 18 captured images when imaging the measurement object 8 every time the rotation angle of the analyzer 61 changes by 10 °. The intensity of the reflected light for each location on the surface of the measurement object 8 is reflected in the pixel value of each pixel of the imaging means 4. In other words, the pixel value for each pixel of the imaging means 4 reflects the polarization state of the reflected light for each location of the measurement object 8. The pixel value for each pixel output from the imaging unit 4 is input to the calculation unit 5.

  Note that the imaging unit 4 may image the measurement object 8 for each position of the illumination unit 2 instead of continuously exposing the measurement object 8 at a predetermined rotation angle of the analyzer 61. . In this case, the imaging unit 4 generates a single captured image (composite image) obtained by integrating pixel values for each pixel, using a plurality of captured images generated by imaging at each position of the illumination unit 2. That is, the imaging unit 4 combines the captured images for each position of the illumination unit 2 to generate one captured image.

  The arithmetic means 5 has, for example, a CPU (Central Processing Unit) as a main component, and the polarization state of the reflected light is determined by using the captured images captured by the imaging means 4 at every predetermined rotation angle of the analyzer 61. To detect. That is, the arithmetic means 5 uses the relationship between the pixel value for each pixel of the captured image and the predetermined rotation angle of the analyzer 61 to correspond to the pixel with respect to the polarization state of the reflected light, that is, the surface of the object 8 to be measured. Analyze the polarization state of the site (see background art). In short, a parameter for determining the polarization state is obtained for each part of the object 8 to be measured.

  In order to obtain a parameter for determining the polarization state, as will be described later, when the analyzer 61 has three rotation angles independent from each other, it is necessary to obtain the intensity of light received at each rotation angle. Therefore, it is necessary to associate the timing of imaging by the imaging unit 4 with the rotation angle of the analyzer 61. Therefore, the trigger unit 7 generates a trigger signal that instructs the timing at which the imaging unit 4 captures the reflected light from the object 8 to be measured.

  The computing means 5 that has detected the polarization state of the reflected light determines the direction of the irradiated surface from the polarization state of the reflected light from the irradiated surface of the measurement object 8. The direction of the irradiated surface of the object to be measured 8 is the inclination angle representing the angle formed by the normal direction of the irradiated surface with respect to the optical axis 41 of the imaging means 4, and the normal line of the irradiated surface is the optical axis 41. Is an azimuth angle representing the direction of a straight line projected on a plane perpendicular to the line.

  The analyzer 61 is a linear polarizing plate, for example, and rotates between the imaging unit 4 and the measured object 8 around a rotation center parallel to the optical axis 41 (see FIG. 2) of the imaging unit 4. It is arranged and is rotationally driven by the rotating means 62. The rotating means 62 includes a motor. The angle of rotation of the analyzer 61 relative to the specified reference angle is measured by the angle sensor 63. As the angle sensor 63, a rotary encoder, a potentiometer, or the like that detects the rotation angle of the analyzer 61 is used. The angle sensor 63 may be arranged so as to directly detect the rotation from the analyzer 61 or may be arranged so as to indirectly detect the rotation of the analyzer 61 from the rotating portion of the rotating means 62.

  By the way, when circularly polarized light is irradiated from the illumination unit 2 to the object 8 to be measured, the reflected light incident on the imaging unit 4 becomes elliptically polarized light having a parameter corresponding to the direction of the surface of the object 8 to be measured. As described in the background art, the elliptical polarization parameter is the major axis a and minor axis b (or ellipticity) of the ellipse and the angle ψ representing the inclination of the ellipse with respect to the reference angle. Therefore, using the relationship between the rotation angle θ of the analyzer 61 and the gray value of each pixel of the imaging unit 4, the orientation of each part of the surface of the measurement object 8 corresponding to each pixel of the imaging unit 4 is quantitatively determined. It becomes possible to measure.

  The three parameters ψ, a, and b are uniquely determined by obtaining the intensity I received by each pixel of the image sensor while the analyzer 61 is set to at least three rotation angles θ independent of each other. That the rotation angle θ is independent means that the difference between the two rotation angles θ is not a multiple of 180 °. If the analyzer 61 is set to at least three rotation angles θ and the intensity I at each rotation angle θ is applied to the above equation, three equations including three parameters ψ, a, and b are obtained. The parameters ψ, a, and b can be determined. That is, the polarization state of the reflected light is obtained, and the shape of the measurement object 8 can be measured from the polarization state of the reflected light.

  The trigger means 7 has a function of generating a trigger signal based on the rotation angle of the analyzer 61 detected by the angle sensor 63, and a function of generating a trigger signal at an appropriate time regardless of the output of the angle sensor 63. doing.

  The trigger means 7 using the output of the angle sensor 63 uses the rotation angle of the analyzer 61 output from the angle sensor 63, and generates a trigger signal at three rotation angles independent from each other. The rotation angle at which the trigger signal is generated can be appropriately set unless the difference between the two rotation angles of the three rotation angles is a multiple of 180 °. On the other hand, the trigger means 7 that does not use the output of the angle sensor 63 generates a trigger signal at an appropriate timing. The trigger signal described above is given to the imaging means 4.

  Now, as shown in FIG. 3, a small area 91 is defined as a range corresponding to each pixel of the imaging means 4 on the surface of the measurement object 8, and the surface of the measurement object 8 is a plane in the range of the small area 91. I reckon. Hereinafter, the angle formed by the normal vector 92 of the small area 91 with respect to the optical axis 41 of the image pickup means 4 is represented by an inclination angle φ1, and the normal vector 92 of the small area 91 is parallel to the surface of a table (not shown). An angle formed by a straight line 921 projected onto the reference plane 93 with respect to a reference angle in the reference plane 93 is represented by an azimuth angle ω1. The reference plane 93 is parallel to the imaging surface of the imaging unit 4. The inclination angle φ1 is set to 0 ° in the direction toward the image pickup means 4 and 180 ° in the direction toward the object 8 to be measured. The azimuth angle ω1 is set such that when the horizontal direction in the pixel array of the image pickup means 4 is the x direction and the vertical direction is the y direction, the positive direction of the x axis is 0 ° and the negative direction of the x axis is 180 °. To do. The coordinate system shown in FIG. 3 is a right-handed system, and the intersection point between the optical axis 41 of the imaging unit 4 and the reference plane 93 is the origin.

  As described above, when the tilt angle φ1 and the azimuth angle ω1 are defined, the measurable range for the object 8 is 0 to 90 ° at the maximum for the tilt angle φ1 and the maximum for the azimuth angle ω1. 0 to 180 °. Here, the restriction of the inclination angle φ1 occurs when a part having the inclination angle φ1 of 90 ° or more is a blind spot from the imaging unit 4 and is out of the field of view. Further, the restriction of the azimuth angle ω1 is caused by the fact that the analyzer 61 is rotationally symmetric twice. That is, the analyzer 61 can distinguish the angle of the ellipse in elliptically polarized light only in the range of 0 to 180 °.

  Thereby, the direction of the small region 91 forming each part of the surface of the measurement object 8 is measured. By measuring the orientation of the small area 91, the surface roughness of the object 8 to be measured is measured. Further, if attention is paid to the continuity of the small area 91, the three-dimensional shape of the surface of the measurement object 8 can be estimated.

  Next, the operation of the three-dimensional measurement apparatus 1 according to this embodiment will be described with reference to FIG. First, the illumination means 2 irradiates a part of the measurement object 8 with circularly polarized light. Subsequently, the moving means 3 moves the illuminating means 2 symmetrically around the optical axis 41 of the imaging means 4 at every predetermined rotation angle of the analyzer 61. The imaging unit 4 captures an image of the measurement object 8 by continuing exposure from the start of movement of the illumination unit 2 to the end of movement. Thereafter, the calculation means 5 detects the polarization state of the reflected light from the measurement object 8 using a plurality of captured images captured by the imaging means 4 at every predetermined rotation angle of the analyzer 61, and the measurement object The inclination angle and azimuth angle of the surface 8 (irradiated surface) are obtained.

  In the three-dimensional measurement apparatus 1 of the present embodiment described above, the illumination unit 2 that irradiates a part of the measurement object 8 with circularly polarized light is moved so that the irradiated surface of the measurement object 8 changes, thereby illuminating unit. 2 to irradiate the object to be measured 8 with circularly polarized light from all directions. As a result, the measurement object 8 can be accurately measured.

(Embodiment 2)
The three-dimensional measurement apparatus 1 according to the second embodiment uses the captured image captured for each of the illumination ranges 221 and 222 as illustrated in FIG. 4 to indicate the direction (tilt angle and azimuth angle) of the irradiated surface of the measurement object 8. Is different from the three-dimensional measurement apparatus 1 according to the first embodiment. In addition, about the component similar to the three-dimensional measuring device 1 of Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The three-dimensional measuring apparatus 1 according to this embodiment divides the entire circumference in which the illumination unit 2 moves around the optical axis 41 of the imaging unit 4 into a plurality (two in the illustrated example) of illumination ranges 221 and 222.

  The illuminating means 2 of the present embodiment is a device that can be turned on / off according to the illumination position (orientation), and is individually lit for each of the illumination ranges 221 and 222.

  The imaging means 4 of the present embodiment images the illuminated surface of the measurement object 8 in the illumination ranges 221 and 222. That is, the imaging unit 4 is only exposed when the object to be measured 8 is irradiated with circularly polarized light only while the illumination unit 2 is moving in the illumination range 221 and only when the illumination unit 2 is moving in the illumination range 222. The measured object 8 is imaged in each case where the measured object 8 is irradiated with circularly polarized light, and a captured image is generated. Note that description of functions similar to those of the imaging unit 4 of Embodiment 1 is omitted.

  The calculation means 5 of this embodiment detects the polarization state of reflected light using a captured image for each of the illumination ranges 221 and 222. The computing means 5 that detects the polarization state of the reflected light in each of the illumination ranges 221 and 222 uses the polarization state of the reflected light for each of the illumination ranges 221 and 222 and the azimuth of the illumination ranges 221 and 222 to measure the object 8. The inclination angle and azimuth angle of the irradiated surface are obtained. Note that a description of the same functions as those of the computing unit 5 of the first embodiment will be omitted.

  Next, the operation of the three-dimensional measurement apparatus 1 of the present embodiment will be described with reference to FIG. First, the illumination unit 2 starts moving under the control of the moving unit 3. As shown in FIG. 4A, the illumination unit 2 is turned on while moving in the illumination range 221 and irradiates the object to be measured 8 with circularly polarized light. Thereafter, when the illumination unit 2 moves from the illumination range 221 to the illumination range 222, the illumination unit 2 is turned off while the illumination range 222 is moving, and stops the irradiation of the circularly polarized light on the object 8 to be measured. The imaging unit 4 captures an image of the measurement object 8 by continuing exposure while the illumination unit 2 rotates once.

  Subsequently, the illumination means 2 changes the lighting timing. As shown in FIG. 4B, the illumination unit 2 is turned off while moving in the illumination range 221 and stops the irradiation of the circularly polarized light on the object 8 to be measured. Thereafter, when the illumination unit 221 moves from the illumination range 221 to the illumination range 222, the illumination unit 2 turns on while moving the illumination range 222, and irradiates the object to be measured 8 with circularly polarized light. The imaging unit 4 captures an image of the measurement object 8 by continuing exposure while the illumination unit 2 rotates once.

  For example, when the object 8 to be measured has a shape as shown in FIG. 5, the normal vector of the first surface 81 is 811 and the normal vector of the second surface 82 is 821, as shown in FIG. Become. The normal vector of the third surface 83 is 831, the normal vector of the fourth surface 84 is 841, and the normal vector of the fifth surface 85 is 851. In such an object 8 to be measured, as shown in FIGS. 5B and 5C, the normal vector 811 of the first surface 81 and the normal vector 821 of the second surface 82 have an inclination angle φ1. The direction of the straight line projected on the xy plane is exactly the opposite. The three-dimensional measuring apparatus 1 according to the present embodiment can distinguish the first surface 81 and the second surface 82 even in the measurement object 8 having a shape as shown in FIG. φ1 and azimuth angle ω1 can be uniquely determined.

  In the three-dimensional measurement apparatus 1 according to the present embodiment described above, the entire circumference in which the illumination unit 2 moves is divided into a plurality of illumination ranges 221 and 222, and the imaging unit 4 determines the object 8 to be measured for each of the illumination ranges 221 and 222. The irradiated surface is imaged. Thereby, the azimuth angle of the irradiated surface of the measurement object 8 can be uniquely determined, and the indefiniteness of the azimuth angle can be eliminated.

  As a modification of the present embodiment, the imaging unit 4 performs exposure for each position of the illumination unit 2 (illumination ranges 221 and 222) while the illumination unit 2 always irradiates the object 8 with circularly polarized light all around. You may divide and image. Thereby, the imaging unit 4 can generate a captured image for each of the illumination ranges 221 and 222. The timing at which the imaging unit 4 images the measurement object 8 is determined by the trigger signal output from the trigger unit 7 as in the first embodiment. The exposure period is determined by a clock signal that drives the imaging means 4.

(Embodiment 3)
As shown in FIG. 6, the three-dimensional measurement apparatus 1 according to the third embodiment is different from the three-dimensional measurement apparatus 1 according to the first embodiment in that the illumination unit 2 irradiates the measurement object 8 with circularly polarized light with parallel light. Is different. In addition, about the component similar to the three-dimensional measuring device 1 of Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The illumination means 2 of this embodiment irradiates the to-be-measured object 8 with circularly polarized light with parallel light, as shown in FIG. In addition, description is abbreviate | omitted about the function similar to the illumination means 2 of Embodiment 1. FIG.

  The moving means 3 of the present embodiment has a first mechanism for moving the illuminating means 2 about the optical axis 41 of the imaging means 4 and a hemisphere including the measurement target 8 with the optical axis 41 as the diameter. And a second mechanism for moving the illumination means 2 in the circumferential direction. Note that description of functions similar to those of the moving unit 3 of the first embodiment is omitted.

  The illuminating unit 2 moves (scans) the circularly polarized light around the optical axis 41 of the imaging unit 4 as indicated by an arrow A21 in FIG. Irradiate. The illuminating means 2 performs the above operation by the second mechanism of the moving means 3 while changing the position on the circumference whose diameter is the optical axis 41 in the hemisphere including the measurement object 8 (arrow A22 in FIG. 6). , A23).

  Also in the three-dimensional measuring apparatus 1 of the present embodiment described above, since the circularly polarized light can be irradiated from the illuminating unit 2 to the object 8 to be measured from all directions, the shape of the object 8 to be measured can be accurately measured. it can.

  Note that the function of irradiating the object 8 to be measured with the circularly polarized light in the present embodiment may be applied to the three-dimensional measurement apparatus 1 of the second embodiment.

(Embodiment 4)
As shown in FIG. 7, the three-dimensional measurement apparatus 1 according to the fourth embodiment is different from the three-dimensional measurement apparatus 1 according to the first embodiment in that the illumination unit 2 moves so as to face the surface of the measurement object 8. Is different. In addition, about the component similar to the three-dimensional measuring device 1 of Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The illumination means 2 of this embodiment is installed so as to face the surface of the measurement object 8 as shown in FIG. In addition, description is abbreviate | omitted about the function similar to the illumination means 2 of Embodiment 1. FIG.

  The moving means 3 of this embodiment moves the illuminating means 2 as indicated by an arrow A3 in FIG. 7 so that the irradiated surface of the measured object 8 changes in a state where the illuminating means 2 faces the surface of the measured object 8. Let Note that description of functions similar to those of the moving unit 3 of the first embodiment is omitted.

  In the three-dimensional measurement apparatus 1 of the present embodiment described above, the illumination unit 2 can irradiate the object to be measured 8 with the circularly polarized light only from the direction necessary for the measurement, so that the movement time of the illumination unit 2 is shortened. As a result, the measurement time can be shortened.

  In each embodiment, the case where the reflected light of the light emitted from the illumination unit 2 to the object to be measured 8 is incident on the imaging unit 4 is described. However, the light emitted from the illumination unit 2 to the object to be measured 8 is described. The transmitted light may be incident on the imaging unit 4. Therefore, the reflected light in the description of each embodiment can be read as transmitted light unless otherwise specified.

DESCRIPTION OF SYMBOLS 1 Three-dimensional measuring apparatus 2 Illuminating means 21 Light emission surface 221,222 Illumination range 3 Moving means 4 Imaging means 41 Optical axis 5 Calculation means 8 Object to be measured

Claims (6)

Illumination means for irradiating the object to be measured with circularly polarized light;
Imaging means for receiving the reflected light from the illuminated surface of the measurement object and imaging the illuminated surface;
A calculation means for detecting a polarization state of the reflected light using a picked-up image picked up by the image pickup means and obtaining an orientation of the irradiated surface;
Moving means for moving the illumination means,
The illumination means irradiates a part of the object to be measured with the circularly polarized light,
The three-dimensional measuring apparatus characterized in that the moving means moves the illuminating means axisymmetrically around the optical axis of the imaging means so that the position of the irradiated surface in the measurement object changes. 2. The three-dimensional measuring apparatus according to claim 1, wherein the illuminating means has a light emitting surface formed in a shape along an intersection line of a hemisphere including the object to be measured and a plane including the optical axis. . The imaging means images the irradiated surface for each illumination range obtained by dividing the entire circumference in which the illumination means moves around the optical axis into a plurality of illumination ranges,
The computing means detects the polarization state of the reflected light using the captured image captured by the imaging means for each illumination range, and uses the polarization state for each illumination range and the direction of the illumination range. An inclination angle representing an angle formed by a normal direction of the irradiated surface with respect to the optical axis, and an azimuth angle representing a direction of a straight line obtained by projecting the normal of the irradiated surface onto a plane orthogonal to the optical axis. And ask
The three-dimensional measuring apparatus according to claim 1 or 2, wherein Illumination means for irradiating the object to be measured with circularly polarized light;
Imaging means for receiving the reflected light from the illuminated surface of the measurement object and imaging the illuminated surface;
A calculation means for detecting a polarization state of the reflected light using a picked-up image picked up by the image pickup means and obtaining an orientation of the irradiated surface;
Moving means for moving the illumination means,
The illuminating means irradiates a part of the measurement object with the circularly polarized light with parallel light,
The moving means moves the illuminating means so that the position of the irradiated surface changes in the object to be measured,
The moving means includes a first mechanism for moving the illuminating means about the optical axis of the imaging means, and a moving direction of the illuminating means by the first mechanism in a hemisphere including the object to be measured. And a second mechanism for moving the illumination means in a direction orthogonal to
A three-dimensional measuring apparatus characterized by that. An illumination device used in a three-dimensional measurement device that irradiates a measurement object with circularly polarized light, detects a polarization state of reflected light reflected by the irradiation surface of the measurement object, and obtains the direction of the irradiation surface. ,
Illumination means for irradiating a part of the object to be measured with the circularly polarized light;
In order to change the position of the irradiated surface in the object to be measured, the light beam reflected from the irradiated surface of the object to be measured is received in an axially symmetrical manner around an optical axis of an imaging unit that images the irradiated surface. Moving means for moving the illumination means;
A lighting device comprising: An illumination device used in a three-dimensional measurement device that irradiates a measurement object with circularly polarized light, detects a polarization state of reflected light reflected by the irradiation surface of the measurement object, and obtains the direction of the irradiation surface. ,
Illuminating means for irradiating a part of the measurement object with the circularly polarized light with parallel light;
A moving means for moving the illuminating means so that the position of the irradiated surface in the measurement object changes,
The moving means receives a reflected light from the irradiated surface of the object to be measured and moves the illuminating means about the optical axis of the imaging means for imaging the irradiated surface; A second mechanism for moving the illumination means in a direction orthogonal to the movement direction of the illumination means by the first mechanism in a hemisphere including the object to be measured.
A lighting device characterized by that.

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