Measurement device and additive manufacturing device

Abstract

To provide a measurement device and an additive manufacturing device that can improve measurement accuracy.SOLUTION: A measurement device comprises a projection unit, an image-capturing unit; and an information processing unit. The projection unit has: a light source that radiates light toward a measurement reference plane; a mask that transmits the light radiated from the light source, and generates a fringe pattern; and an actuator that moves the mask. The projection unit is configured to change a phase of the fringe pattern by moving the mask. The image-capturing unit has an imager that acquires a reflection light amount at each point of a projection plane having the fringe pattern projected of the measurement reference plane and a surface of a measured object. The information processing unit has: a reflection light amount change measurement unit that measures, at each point of the projection plane, a change in reflection light amount at each point of the projection plane accompanying a change in phase of the fringe pattern on the basis of reflection light amounts acquired a plurality of times while changing the phase of the fringe pattern; and a height measurement unit that measures a height of each point of the surface of the measured object to the measurement reference plane on the basis of the change in reflection light amount at each point of the projection plane.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a measuring device and a laminated manufacturing device.

Background Art

[0002] There is known a three-dimensional laminated manufacturing technique for manufacturing a three-dimensional shaped object by irradiating a beam such as a light beam or an electron beam onto powder laid in layers to perform laminated manufacturing. In this type of manufacturing technique, the shaped object may be deformed by the heat of the beam. In addition, sputtering generated during the manufacturing may remain, and the shape accuracy of the shaped object may be reduced. Further, void defects may be formed inside the shaped object.

[0003] Patent Document 1 discloses a laminated manufacturing device that detects these abnormalities generated during the manufacturing operation. This laminated manufacturing device has a projector that projects a fringe pattern onto the shaped object. The laminated manufacturing device detects unevenness on the shaped object based on data obtained by imaging the fringe pattern projected onto the shaped object.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a general projector, the resolution of the fringe pattern is low, and there are cases where the shape of the shaped object cannot be measured with high accuracy. In addition, for one measurement point, it is necessary to change the phase of the fringe pattern and image the fringe pattern a plurality of times, but in a projector, it takes time to switch the phase of the fringe pattern. For this reason, it has been an issue that the imaging data is insufficient and the required measurement accuracy cannot be ensured.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a measuring device and a laminated manufacturing device capable of improving measurement accuracy.

Means for Solving the Problems

[0007] In order to solve the above problems, a measuring device according to the present disclosure includes a measurement reference surface, a projection unit that projects a fringe pattern onto the surface of an object to be measured on the measurement reference surface, an imaging unit that images the fringe pattern projected onto the measurement reference surface and the surface of the object to be measured, and an information processing unit that processes information on the fringe pattern imaged by the imaging unit and measures the shape of the object to be measured. The projection unit includes a light source that irradiates light toward the measurement reference surface, a mask that transmits the light irradiated from the light source and generates the fringe pattern, and an actuator that moves the mask. The projection unit changes the phase of the fringe pattern by moving the mask. The imaging unit includes an imager that acquires the amount of reflected light at each point on the projection surface where the fringe pattern is projected among the measurement reference surface and the surface of the object to be measured. The information processing unit includes a reflected light amount change measurement unit that measures, at each point on the projection surface, the change in the amount of reflected light of the projection surface accompanying the phase change of the fringe pattern based on the amounts of reflected light acquired a plurality of times by changing the phase of the fringe pattern, and a height measurement unit that measures the height of each point on the surface of the object to be measured with respect to the measurement reference surface based on the change in the amount of reflected light at each point on the projection surface.

[0008] A laminated manufacturing device according to the present disclosure includes the above-described measuring device, a stage having a manufacturing surface on which a manufactured object is laminated and manufactured, a powder supply unit that supplies powder onto the manufacturing surface, a coater that levels the powder on the manufacturing surface to form a powder bed, and a head that irradiates the powder bed on the manufacturing surface with a beam to sinter it. The manufactured object and the powder bed are the object to be measured, the manufacturing surface is the measurement reference surface, the projection unit further includes a projection lens disposed between the mask and the measurement reference surface, and the mask and the projection lens are disposed parallel to the measurement reference surface.

Effect of the Invention

[0009] According to the measuring device and the additive manufacturing device of the present disclosure, the measurement accuracy can be improved.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] (First Embodiment) Hereinafter, the additive manufacturing apparatus 1 according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 15. Hereinafter, one direction in the horizontal direction is defined as the X direction, and the direction orthogonal to the X direction in the horizontal direction is defined as the Y direction. Also, the vertical direction is defined as the Z direction. The Z direction is orthogonal to the X direction and the Y direction.

[0012] (Additive Manufacturing Apparatus) The additive manufacturing apparatus 1 shown in FIG. 1 manufactures a shaped object 2 by additive manufacturing (AM) technology. The additive manufacturing apparatus 1 includes a chamber 3, a cylinder 4, a stage 5, a powder supply unit 6, a coater 7, a head 8, a shaping control unit 20, and a measuring device 9.

[0013] (Chamber) The chamber 3 includes a housing 3a, a beam window 3b, a projection window 3c, and an imaging window 3d. The housing 3a houses the cylinder 4, the stage 5, the powder supply unit 6, and the coater 7 inside. The beam window 3b is provided at the center of the upper part of the housing 3a. The projection window 3c and the imaging window 3d are provided at the upper part of the housing 3a. The projection window 3c and the imaging window 3d face each other horizontally with the beam window 3b in between.

[0014] (Cylinder) The cylinder 4 is formed in a cylindrical shape extending in the vertical direction. The stage 5 is housed inside the cylinder 4.

[0015] (Stage) The stage 5 is formed in a flat plate shape extending in the horizontal direction. The stage 5 has a shaping surface 5a on its upper surface. The shaping surface 5a extends in the horizontal direction. The shaped object 2 is additively manufactured on the shaping surface 5a. The stage 5 is provided so as to be movable in the vertical direction along the cylinder 4. That is, the height of the shaping surface 5a can be changed.

[0016] (Powder Supply Unit) The powder supply unit 6 supplies powder 6a onto the shaping surface 5a.

[0017] (Coater) The coater 7 moves in the horizontal direction and levels the powder 6a supplied onto the shaping surface 5a. As a result, a powder bed 6b is laid on the shaping surface 5a.

[0018] (Head) The head 8 is disposed outside the chamber 3. The head 8 is disposed directly above the center of the shaping surface 5a with the beam window 3b interposed therebetween. The head 8 irradiates the powder bed 6b on the shaping surface 5a with a beam 8a such as an optical beam or an electron beam. This beam 8a passes through the beam window 3b and irradiates the powder bed 6b. The powder bed 6b irradiated with the beam 8a is sintered. Thereby, the shaped object 2 is shaped on the shaping surface 5a.

[0019] (Shaping control unit) As shown in FIG. 2, the shaping control unit 20 has the functions of a stage control unit 21, a powder supply control unit 22, a coater control unit 23, and a head control unit 24. The stage control unit 21 controls the stage 5 and sets the height of the shaping surface 5a. The powder supply control unit 22 controls the powder supply unit 6 and causes the powder supply unit 6 to supply the powder 6a onto the shaping surface 5a. The coater control unit 23 controls the coater 7 and levels the powder 6a on the shaping surface 5a to lay the powder bed 6b. The head control unit 24 controls the head 8 and causes the head 8 to irradiate the powder bed 6b on the shaping surface 5a with the beam 8a.

[0020] (Measurement device) The measurement device 9 is a device that measures the shapes of the surfaces of the shaped object 2 and the powder bed 6b by the fringe projection method with the shaping surface 5a as the measurement reference surface 10. Hereinafter, the measurement object of the measurement device 9 is referred to as the object to be measured 11. The object to be measured 11 is, for example, the shaped object 2 or the powder bed 6b immediately after laying. The measurement device 9 includes a projection unit 30, an imaging unit 40, and an information processing unit 50.

[0021] (Projection unit) The projection unit 30 is disposed outside the chamber 3. The projection unit 30 is disposed above the measurement reference plane 10 with the projection window 3c therebetween. Further, the projection unit 30 is disposed to be inclined with respect to the measurement reference plane 10 at a position shifted from directly above the measurement reference plane 10 where it does not interfere with the head 8. The projection unit 30 projects a fringe pattern 36 (see FIG. 4) onto the measurement reference plane 10 and the surface of the object 11 to be measured on the measurement reference plane 10. Hereinafter, the surface on which the fringe pattern 36 is projected among the measurement reference plane 10 and the surface of the object 11 to be measured may be referred to as the projection plane 12 for explanation purposes.

[0022] As shown in FIG. 3, the projection unit 30 includes a light source 32, a mask 33, an actuator 34, and a projection lens 35.

[0023] (Light source) The light source 32 irradiates radially directed light toward the measurement reference plane 10. Here, the straight line connecting the center of the light source 32 and the center of the projection lens 35 described later is the optical axis O1 of the light source 32. This optical axis O1 passes through the center 10a of the measurement reference plane 10.

[0024] (Mask) The mask 33 is disposed on the optical axis O1 of the light source 32 and between the light source 32 and the measurement reference plane 10. The mask 33 is formed by drawing a plurality of stripe patterns 33b on a transparent substrate 33a made of a transmissive material that transmits light, such as glass. These stripe patterns 33b extend in one direction (for example, the X direction). As shown in FIG. 4, when the light irradiated from the light source 32 passes through the mask 33, a striped fringe pattern 36 is generated. This fringe pattern 36 is a so-called sine wave pattern, and the amount of reflected light of the fringe pattern 36 changes sinusoidally according to the measurement position (phase).

[0025] (Actuator) The actuator 34 moves the mask 33 in one direction (for example, the Y direction). The projection unit 30 changes the phase of the fringe pattern 36 by moving the mask 33 by the actuator 34.

[0026] (Projection lens) The projection lens 35 is on the optical axis O1 of the light source 32 and is arranged between the mask 33 and the measurement reference plane 10.

[0027] (Arrangement of mask and projection lens) The mask 33 is inclined with respect to the optical axis O1 of the light source 32. That is, the mask 33 is arranged so as to intersect a plane perpendicular to the optical axis O1 of the light source 32. In the present embodiment, the mask 33 and the projection lens 35 are arranged in parallel with the measurement reference plane 10 so as to constitute a shift lens optical system.

[0028] (Imaging unit) The imaging unit 40 is arranged outside the chamber 3. The imaging unit 40 is arranged above the shaping surface 5a (measurement reference plane 10) with the imaging window 3d interposed therebetween. Further, in order to avoid interference between the imaging unit 40 and the head 8, the projection unit 30 is arranged to be inclined with respect to the measurement reference plane 10 at a position shifted from directly above the measurement reference plane 10. Furthermore, the imaging unit 40 is arranged at a position horizontally opposed to the projection unit 30 with the head 8 interposed therebetween. The imaging unit 40 images the fringe pattern 36 projected onto the measurement reference plane 10 and the surface of the object 11 to be measured through the imaging window 3d. In the present embodiment, the imaging unit 40 continuously images the fringe pattern 36 while the mask 33 is moving. As shown in FIG. 5, the imaging unit 40 includes a camera 41 and a light receiving lens 42.

[0029] (Camera) The camera 41 has an imager 44.

[0030] (Imager) The imager 44 acquires the amount of reflected light of each point on the projection surface 12 where the fringe pattern 36 is projected. As shown in FIG. 6, the imager 44 has a plurality of pixels 45. Each of the plurality of pixels 45 acquires the amount of reflected light of one point on the projection surface 12.

[0031] (Light receiving lens) The light-receiving lens 42 is on the optical axis O2 connecting the center 44b of the imager 44 and the center of the measurement reference plane 10, and is disposed between the imager 44 and the measurement reference plane 10.

[0032] (Arrangement of the imager and the light-receiving lens) In the present embodiment, the imager 44 and the light-receiving lens 42 are arranged in parallel with the measurement reference plane 10 so as to constitute a shift lens optical system.

[0033] (Information processing unit) The information processing unit 50 processes the information of the fringe pattern 36 imaged by the imaging unit 40 and measures the shape of the object to be measured 11. As shown in FIG. 7, the information processing unit 50 has functions of a projection control unit 51, an imaging control unit 52, a storage unit 53, a reflected light amount change measurement unit 54, a phase measurement unit 55, a height measurement unit 56, and a surface shape measurement unit 57.

[0034] (Projection control unit) The projection control unit 51 controls the projection unit 30 to project the fringe pattern 36 onto the measurement reference plane 10. Further, the projection control unit 51 moves the mask 33 by the actuator 34 to change the phase of the fringe pattern 36.

[0035] (Imaging control unit) The imaging control unit 52 controls the imaging unit 40 to cause the imaging unit 40 to image the fringe pattern 36 projected onto the projection plane 12.

[0036] (Storage unit) The storage unit 53 stores the image of the fringe pattern 36 imaged by the imaging unit 40, the phase of the fringe pattern 36 at each point on the projection plane 12 acquired by the phase measurement unit 55 described later, the height of the surface of the object to be measured 11 acquired by the height measurement unit 56 described later, and other information.

[0037] (Reflected light amount change measurement unit) The reflected light quantity change measurement unit 54 measures the change in the reflected light quantity at each point on the projection surface 12 accompanying the phase change of the fringe pattern 36 based on the reflected light quantities acquired a plurality of times while changing the phase of the fringe pattern 36 at each point on the projection surface 12.

[0038] (Phase measurement unit) The phase measurement unit 55 measures the phase of the fringe pattern 36 at each point on the projection surface 12 based on the change in the reflected light quantity measured by the reflected light quantity change measurement unit 54.

[0039] (Height measurement unit) The height measurement unit 56 measures the height of each point on the surface of the object 11 to be measured with respect to the measurement reference surface 10 based on the change in the reflected light quantity at each point on the projection surface 12. In the present embodiment, the height measurement unit 56 further performs arithmetic processing on the phase measured by the phase measurement unit 55 based on the change in the reflected light quantity, and measures the height of each point on the surface of the object 11 to be measured.

[0040] (Surface shape measurement unit) The surface shape measurement unit 57 aggregates the heights of each point on the surface of the object 11 to be measured, and measures the surface shape of the shaped object 2. For example, the surface shape measurement unit 57 specifies the surface shape of the object 11 to be measured by plotting each point on the surface of the object 11 to be measured on a virtual space. Here, the surface shape of the object 11 to be measured means the shape of the surface of the object 11 to be measured that does not contact the measurement reference surface 10 and is exposed upward.

[0041] (Procedure of additive manufacturing) Hereinafter, the procedure of additive manufacturing will be described with reference to the flow of FIG. 8. First, the stage control unit 21 moves the stage 5 in the -Z direction (step S11). Thereby, the shaping surface 5a is adjusted to an appropriate height. After step S11, the powder supply control unit 22 causes the powder supply unit 6 to supply the powder 6a to the shaping surface 5a (step S12). After step 12, the coater control unit 23 controls the coater 7 to level the powder 6a on the shaping surface 5a and lay a powder bed 6b (step S13). After step S13, the head control unit 24 controls the head 8 to irradiate the powder bed 6b on the shaping surface 5a with the beam 8a from the head 8 (step S14). Thereby, the powder bed 6b is sintered and a sintered layer is formed. By repeating steps S11 to S13, a plurality of sintered layers are laminated in the Z direction on the shaping surface 5a. In this way, the shaped object 2 is laminated and shaped on the shaping surface 5a.

[0042] (Procedure of the measurement method) Hereinafter, with reference to the flow of FIG. 9, the procedure of the method for measuring the shape of the object to be measured 11 (for example, the shaped object 2) using the measuring device 9 will be described. In the present embodiment, the measuring device 9 measures the shape of the object to be measured 11 using the phase shift method. First, the measuring device 9 measures the height of each point of the object to be measured 11 (step S21). Hereinafter, with reference to the flow of FIG. 10, the procedure of step S21 will be described in detail.

[0043] As shown in FIG. 6, taking as an example the case of measuring the height of a measurement point P1 on the surface of the object to be measured 11, the procedure of step S21 will be described. In FIG. 6, the camera base point PA constituting the imaging unit 40 is shown, and the projection base point PB of the fringe pattern 36 projected by the projection unit 30 is shown. A straight line connecting the camera base point PA and the projection base point PB is defined as the reference line L1. A straight line passing through the camera base point PA and the measurement point P1 is defined as the camera line-of-sight straight line L2. The intersection of the camera line-of-sight straight line L2 and the measurement reference plane 10 is defined as the reference point PO. Further, the camera line-of-sight straight line L2 passes through the imager 44. Among the plurality of pixels 45 constituting the imager 44, the pixel 45 through which the camera line-of-sight straight line L2 passes is defined as the corresponding pixel 45a.

[0044] First, the projection control unit 51 causes the projection unit 30 to project the fringe pattern 36 onto the measurement reference plane 10 and the surface of the object to be measured 11 (projection surface 12) (step S31). This fringe pattern 36 is a sine wave pattern in which the amount of reflected light changes sinusoidally according to the phase. In step S31, the phase of the reference point PO is set to 0 in the fringe pattern 36 irradiated to the measurement point P1.

[0045] Thereafter, the imaging control unit 52 causes the imaging unit 40 to image the fringe pattern 36 projected onto the projection surface 12 (step S32). In step S32, the amount of reflected light at the measurement point P1 is acquired by the corresponding pixel 45a. In step S32, the projection control unit 51 drives the actuator 34 to move the mask 33. Then, the phase of the fringe pattern 36 changes, and the amount of reflected light at the measurement point P1 changes with the phase change of the fringe pattern 36. At this time, the imaging unit 40 continuously captures the fringe pattern 36 while the mask 33 is moving. Then, the amount of reflected light at the measurement point P1 at each time is acquired by the corresponding pixel 45a. The amount of reflected light at the measurement point P1 is acquired at least 4 times. A plurality of measurement values of the amount of reflected light at the measurement point P1 acquired by the corresponding pixel 45a are stored in the storage unit 53.

[0046] After step S32, the reflected light amount change measurement unit 54 measures the change in the reflected light amount based on the measurement values I0 to I7 acquired by the corresponding pixel 45a (step S33). As shown in FIG. 11, the reflected light amount change measurement unit 54 plots a plurality of measurement values (in the example shown in the figure, measurement values I0 to I7) of the amount of reflected light at the measurement point P1 at each time on a graph with the time axis as the horizontal axis and the amount of reflected light as the vertical axis, and fits a sine wave curve passing through these plurality of measurement values I0 to I7. This fitted sine wave curve represents the change in the amount of reflected light at the measurement point P1. Note that the maximum value of the sine wave curve is the maximum reflected light amount I H of the measurement point P1, and the minimum value of the sine wave curve represents the minimum reflected light amount I L of the measurement point P1.

[0047] After step S33, the phase measurement unit 55 measures the phase φ of the measurement point P1 with respect to the reference point PO based on the change in the reflected light amount at the measurement point P1 (step S34). The phase measurement unit 55 calculates the phase φ of the measurement point P1 from the shift amount of the horizontal axis between the sine wave curve representing the change in the reflected light amount at the reference point PO and the sine wave curve representing the change in the reflected light amount at the measurement point P1.

[0048] Note that the reflected light amount change measurement unit 54 may plot the measured values I0 to I7 of the reflected light amount at the measurement point P1 for each phase shift amount of the fringe pattern 36 on a graph with the phase shift amount on the horizontal axis and the reflected light amount on the vertical axis (the graph with the horizontal axis of FIG. 11 changed to the phase shift), and fit a sine wave curve passing through these multiple measured values I0 to I7. In this case, for example, the projection control unit 51 needs to calculate the phase shift amount from the movement amount from the actuator. The calculated phase shift amount is transmitted from the projection control unit 51 to the reflected light amount change measurement unit 54. Thereby, the reflected light amount change measurement unit 54 can plot the measured values of the reflected light amount at the measurement point P1 for each phase shift amount. And in this case, the phase measurement unit 55 sets the phase difference between the sine wave curve representing the change in the reflected light amount at the reference point PO and the sine wave curve representing the change in the reflected light amount at the measurement point P1 as the phase φ of the measurement point P1.

[0049] Also, although the method of performing sine wave fitting to obtain the phase of the measurement point has been described, it is not limited to this. This method is an example of a method for obtaining the phase of the measurement point. There is also a method of calculating the initial phase by arithmetic operations as a method for obtaining the phase of the measurement point.

[0050] After step S34, the height measurement unit 56 calculates the height of the measurement point P1 with respect to the measurement reference plane 10 based on the phase φ of the measurement point P1 (step S35). In step S35, the height measurement unit 56 performs arithmetic processing using the principle of triangulation based on the length d1 of the baseline L1, the angle θA of the measurement point P1 as seen from the camera reference point PA (the angle θA formed by the straight line connecting the camera reference point PA and the measurement point P1 and the baseline L1), the angle θB of the measurement point P1 as seen from the projection reference point PB (the angle θB formed by the straight line connecting the projection reference point PB and the measurement point P1 and the baseline L1), and the phase φ of the measurement point P1, and obtains the perpendicular distance d2 between the measurement point P1 and the baseline L1. The "perpendicular distance" mentioned here means the shortest distance between a point and a straight line. Then, the height measurement unit 56 measures the height of the measurement point P1 with respect to the measurement reference plane 10 from the perpendicular distance d2 between the measurement point P1 and the baseline L1. Through the above procedure, the measurement of the height of one measurement point P1 of the object 11 to be measured is completed.

[0051] For each point on the surface of the object 11 to be measured, the procedures of steps S31 to S35 described above are executed. As a result, the height of each point on the surface of the object 11 to be measured is measured. The height of each point on the surface of the object 11 to be measured is stored in the storage unit 53. Through the above procedure, the height measurement at each point on the surface of the object 11 to be measured is completed (step S21).

[0052] After step S21, the surface shape measurement unit 57 aggregates the heights of each point on the surface of the object 11 to be measured measured in step S21, and measures the surface shape of the object 11 to be measured (step S22). For example, the surface shape measurement unit 57 specifies the surface shape of the object 11 to be measured by plotting each point on the surface of the object 11 to be measured in a virtual space. Through the above procedure, the measurement of the shape of the object 11 to be measured is completed. Note that the surface shape of the powder bed 6b before the irradiation of the beam 8a can be measured by the same procedure.

[0053] (Function and effect) According to the measurement device 9 and the additive manufacturing device 1 of the present embodiment, the following function and effect are achieved. In this embodiment, a measurement apparatus 9 includes a projection unit 30, an imaging unit 40, and an information processing unit 50. The projection unit 30 projects a fringe pattern 36 onto a measurement reference plane 10 and the surface of a measurement object 11 on the measurement reference plane 10. The imaging unit 40 images the fringe pattern 36 projected onto the measurement reference plane 10 and the surface of the measurement object 11. The information processing unit 50 processes the information of the fringe pattern 36 imaged by the imaging unit 40 and measures the shape of the measurement object 11. The projection unit 30 includes a light source 32, a mask 33, and an actuator 34. The light source 32 irradiates light toward the measurement reference plane 10. The mask 33 transmits the light irradiated from the light source 32 and generates the fringe pattern 36. The actuator 34 moves the mask 33. The projection unit 30 changes the phase of the fringe pattern 36 by moving the mask 33. The imaging unit 40 includes an imager 44 that acquires the amount of reflected light at each point on a projection plane 12 onto which the fringe pattern 36 is projected, among the measurement reference plane 10 and the surface of the measurement object 11. The information processing unit 50 includes a reflected light amount change measurement unit 54 and a height measurement unit 56. The reflected light amount change measurement unit 54 measures the change in the amount of reflected light at each point on the projection plane 12 accompanying the phase change of the fringe pattern 36, based on the amount of reflected light acquired a plurality of times while changing the phase of the fringe pattern 36 at each point on the projection plane 12. The height measurement unit 56 measures the height of each point on the surface of the measurement object 11 with respect to the measurement reference plane 10, based on the change in the amount of reflected light at each point on the projection plane 12.

[0054] With the above configuration, the projection unit 30 can change the phase of the fringe pattern 36 only by moving the mask 33. Therefore, the time required for the phase change of the fringe pattern 36 is shortened. As a result, the number of times of measuring the amount of reflected light at each point on the projection plane 12 per unit time increases. In this embodiment, since the measurement apparatus 9 measures the height of each point on the surface of the measurement object 11 based on the change in the amount of reflected light, it is possible to accurately measure the shape of the measurement object 11. Also, as described above, since the time required for the phase change of the fringe pattern 36 is shortened, the time required for the shape measurement of the measurement object 11 is shortened. In addition, in the present embodiment, the projection unit 30 has a simple configuration including a light source 32, a mask 33, and an actuator 34, and can change the phase of the fringe pattern 36, so that the projection unit 30 can be miniaturized.

[0055] In the present embodiment, the imaging unit 40 continuously images the fringe pattern 36 while the mask 33 is moving.

[0056] As a result, for example, compared with the case where a projector projects a fringe pattern while changing a projection screen as in the prior art, the time required for measuring the change in the amount of reflected light is shortened. Therefore, the time required for shape measurement of the object to be measured 11 (in the present embodiment, the shaped object 2 or the powder bed 6b) is further shortened.

[0057] In the present embodiment, the mask 33 is inclined with respect to the optical axis O1 of the light source 32 so as to intersect a plane perpendicular to the optical axis O1 of the light source 32.

[0058] For example, even if the optical axis O1 of the light source 32 is inclined with respect to the normal line of the measurement reference plane 10 in order to leave a space above the measurement reference plane 10, by adjusting the inclination angle of the mask 33 with respect to the optical axis O1 of the light source 32, the distortion of the fringe pattern 36 projected on the projection plane 12 can be reduced.

[0059] In the present embodiment, the additive manufacturing apparatus 1 includes a measurement device 9, a stage 5 having a shaping surface 5a on which the shaped object 2 is additively manufactured, a powder supply unit 6 that supplies powder 6a onto the shaping surface 5a, a coater 7 that flattens the powder 6a on the shaping surface 5a to form a powder bed 6b, and a head 8 that irradiates the powder bed 6b on the shaping surface 5a with a beam 8a to sinter it. In the present embodiment, the shaped object 2 and the powder bed 6b are the objects to be measured 11, and the shaping surface 5a is the measurement reference plane 10. The projection unit 30 further includes a projection lens 35 disposed between the mask 33 and the measurement reference plane 10. The mask 33 and the projection lens 35 are disposed parallel to the measurement reference plane 10.

[0060] In order to avoid interference between the projection unit 30 and the head 8, the projection unit 30 is arranged to be inclined with respect to the measurement reference plane 10 at a position shifted from directly above the shaping surface 5a (measurement reference plane 10). At this time, for example, if the mask 33 and the projection lens 35 intersect perpendicularly to the optical axis O1 and are inclined with respect to the measurement reference plane 10, as shown in FIG. 12, distortion occurs in the fringe pattern 36 projected onto the measurement reference plane 10. On the other hand, as in the present embodiment, since the mask 33 and the projection lens 35 are arranged parallel to the measurement reference plane 10, as shown in FIG. 13, the distortion of the fringe pattern 36 projected onto the measurement reference plane 10 is reduced. Thereby, the fringe pattern 36 becomes uniform over the entire surface of the measurement reference plane 10, and the measurement accuracy is further improved.

[0061] In the present embodiment, the imaging unit 40 further includes a light receiving lens 42 disposed between the imager 44 and the measurement reference plane 10. The imager 44 and the light receiving lens 42 are arranged parallel to the measurement reference plane 10.

[0062] In order to avoid interference between the projection unit 30 and the head 8, the projection unit 30 is arranged to be inclined with respect to the measurement reference plane 10 at a position shifted from directly above the shaping surface 5a (measurement reference plane 10). At this time, for example, if the imager 44 and the light receiving lens 42 are inclined with respect to the measurement reference plane 10, as shown in FIG. 14, distortion occurs in the image 13 of the measurement reference plane 10 acquired by the imaging unit 40. On the other hand, as in the present embodiment, since the imager 44 and the light receiving lens 42 are arranged parallel to the measurement reference plane 10, as shown in FIG. 15, the imaging unit 40 can image the measurement reference plane 10 without distortion. Thereby, the measurement accuracy is further improved.

[0063] Note that, as shown in FIG. 16, the imager 44, the light-receiving lens 42, and the measurement reference plane 10 may be arranged to form a so-called telephoto lens optical system. In this case, the imager 44, the light-receiving lens 42, and the measurement reference plane 10 are arranged along each of three arrangement reference lines L3 extending radially from a predetermined point. Further, the center 42a of the light-receiving lens 42 is arranged on a straight line (optical axis O2) connecting the center 44b of the imager 44 and the center 10a of the measurement reference plane 10.

[0064] In the shift lens optical system, when the image circle of the light-receiving lens 42 is small, it is necessary to tilt the entire imaging unit 40 and shift the image circle within an allowable range. When the imaging unit 40 is tilted, the vertical distance from the imaging center to the subject surface becomes different. In this case, if the depth of field of the imaging unit 40 is narrow, the imaging unit 40 cannot focus on the entire area of the region to be imaged. Although the depth of field can be broadened by narrowing the iris of the imaging unit 40, narrowing the iris causes the image acquired by the imaging unit 40 to become dark and the measurement accuracy to decrease. On the other hand, by arranging each component of the imaging unit 40 as in the above configuration, it is possible to focus on the entire area within the field of view of the imaging unit 40 without narrowing the iris. Therefore, the measurement accuracy can be improved.

[0065] (Second Embodiment) Hereinafter, the additive manufacturing apparatus 1 according to the second embodiment of the present disclosure will be described with reference to FIGS. 17 to 24. Among the configurations of the second embodiment, the configurations common to the above-described embodiments will be given the same names and the same reference numerals, and the description thereof will be omitted as appropriate.

[0066] (Information Processing Unit) As shown in FIG. 17, the information processing unit 50 has functions of the above-described projection control unit 51, imaging control unit 52, storage unit 53, reflected light amount change measurement unit 54, height measurement unit 56, and surface shape measurement unit 57. Further, the information processing unit 50 has a function of a reflected light amount change table creation unit 58.

[0067] (Reflected light quantity change table creation unit) The reflected light quantity change table creation unit 58 creates a reflected light quantity change table that records the change in the reflected light quantity at a plurality of height positions of the measurement reference plane 10 for each pixel 45 in a state where the object to be measured 11 is not disposed on the measurement reference plane 10.

[0068] (Height measurement unit) The height measurement unit 56 of the present embodiment specifies, for one measurement point on the surface of the object to be measured 11, the specific reflected light quantity change that is closest to the reflected light quantity change obtained by the reflected light quantity change measurement unit 54 based on the reflected light quantity obtained by one pixel 45 corresponding to the one measurement point, from among the plurality of reflected light quantity changes recorded in the reflected light quantity change table for the one pixel 45, and sets the height corresponding to the specific reflected light quantity change as the height of the one measurement point on the surface of the object to be measured 11.

[0069] (Procedure of measurement method) Hereinafter, with reference to the flow of FIG. 18, the procedure of a method for measuring the shape of the object to be measured 11 (for example, the shaped object 2) using the measuring device 9 will be described. First, a reflected light quantity change table is created (step S41). The reflected light quantity change table records the change in the reflected light quantity for each pixel 45 by changing the height of the measurement reference plane 10. Hereinafter, with reference to the flow of FIG. 19, the procedure of step S41 will be described in detail.

[0070] First, as shown in FIG. 20, with the measured object 11 not placed on the measurement reference plane 10 (the shaping surface 5a), the height of the stage 5 is moved to a predetermined position, and the height of the measurement reference plane 10 is set (step S51). After that, a fringe pattern 36 is projected onto the measurement reference plane 10 (step S52). Then, the imaging unit 40 images the fringe pattern 36 projected onto the measurement reference plane 10 (step S53). In step S53, the projection control unit 51 drives the actuator 34 to move the mask 33. After step S53, the change in the amount of reflected light is measured for each pixel 45 (step S54). In steps S52 to S54, the change in the amount of reflected light is measured for each pixel 45 in the same procedure as steps S31 to S33 of the first embodiment. The change in the amount of reflected light of each pixel 45 measured in step S54 is stored in the storage unit 53 (step S55).

[0071] After step S55, if the measurement of the change in the amount of reflected light has not been completed at all heights (step S56; NO), the process returns to step S51, the height of the measurement reference plane 10 is changed, and the procedures from step S52 to step S55 are repeated.

[0072] After step S55, if the measurement of the change in the amount of reflected light has been completed at all heights (step S56; YES), the reflected light amount change table creation unit 58 creates a reflected light amount change table (step S57). Step S41 is completed by the above procedure.

[0073] In step S41 described above, a reflected light amount change table as shown in FIG. 21 is created. FIG. 21 is a reflected light amount change table for each height at a certain pixel 45b among the plurality of pixels 45. In the example of FIG. 21, for the certain pixel 45b, the change in the amount of reflected light at each height position (z) when the measurement reference plane 10 is changed in the order of μm above and below the reference height z = 0 is recorded. Note that this reference height (z = 0) is the height position of the measurement reference plane 10 when measuring the height of the measured object 11 in step S42 that follows, and is preset before step S41.

[0074] After step S41, the height of each point of the object 11 to be measured is measured (step S42). Hereinafter, the procedure of step S42 will be described in detail with reference to the flowchart of FIG. 22.

[0075] As shown in FIG. 23, taking as an example the case where the height of the measurement reference plane 10 is set to the reference height z = 0, and one pixel 45b acquires the amount of reflected light of one measurement point P2 on the surface of the object 11 to measure the height of the measurement point P2, the procedure of step S42 will be described.

[0076] First, the projection control unit 51 causes the projection unit 30 to project the fringe pattern 36 onto the measurement reference plane 10 and the surface (projection plane 12) of the object 11 to be measured (step S61). Thereafter, the imaging control unit 52 causes the imaging unit 40 to image the fringe pattern 36 projected onto the projection plane 12 (step S62). In step S62, the amount of reflected light of the measurement point P2 is measured a plurality of times at one pixel 45b corresponding to the measurement point P2 by changing the phase of the fringe pattern 36. After step S62, the reflected light amount change measurement unit 54 measures the change in the amount of reflected light of each pixel 45 based on the plurality of measurement values measured in step S62 (step S63). These steps S61 to S63 are performed in the same procedure as steps S31 to S33 of the first embodiment described above, and data on the change in the amount of reflected light as shown in FIG. 24 is obtained for the pixel 45b that has acquired the amount of reflected light of the measurement point P2.

[0077] Thereafter, the change-in-reflected-light quantity table created in step S41 is compared with the data of the change in reflected light quantity measured in step S63, and the height of measurement point P2 is measured (step S64). Specifically, in step S64, the height measurement unit 56 specifies a specific change-in-reflected-light quantity A that is closest to the change in reflected light quantity (see FIG. 24) measured based on the reflected light quantity of measurement point P2 obtained by one pixel 45b, from among a plurality of changes in reflected light quantity recorded in the change-in-reflected-light quantity table shown in FIG. 21. Then, the height measurement unit 56 sets the height corresponding to the specific change-in-reflected-light quantity A as the height at measurement point P2 on the surface of the object 11 to be measured. In the illustrated example, the change-in-reflected-light quantity with z = +20 μm recorded in the change-in-reflected-light quantity table (see FIG. 21) becomes the specific change-in-reflected-light quantity A that is closest to the change in reflected light quantity at measurement point P2 (see FIG. 24). That is, the height of measurement point P2 is specified as z = +20 μm. Through the above procedure, the measurement of the height of one measurement point P2 on the object 11 to be measured is completed.

[0078] For each point on the surface of the object 11 to be measured, the procedures of steps S61 to S64 described above are executed. As a result, the height of each point on the surface of the object 11 to be measured is measured. The height of each point on the surface of the object 11 to be measured is stored in the storage unit 53. Through the above procedure, the measurement of the height at each point on the surface of the object 11 to be measured is completed (step S42).

[0079] After step S42, the surface shape measurement unit 57 aggregates the heights of each point on the surface of the object 11 to be measured measured in step S42, and measures the surface shape of the object 11 to be measured (step S43). For example, the surface shape measurement unit 57 specifies the surface shape of the object 11 to be measured by plotting each point on the surface of the object 11 to be measured in a virtual space. Through the above procedure, the measurement of the shape of the object 11 to be measured is completed. Note that, by a similar procedure, the surface shape of the powder bed 6b before the beam 8a is irradiated can be measured.

[0080] (Function and effect) According to the measurement device 9 of the present embodiment, the following function and effect are achieved. In this embodiment, the imager 44 has a plurality of pixels 45 each of which acquires the amount of reflected light of a point on the projection plane 12. The information processing unit 50 further includes a reflected light amount change table creation unit 58 that creates a reflected light amount change table in which the change in the amount of reflected light is recorded at a plurality of height positions of the measurement reference plane 10 for each pixel 45 in a state where the object 11 to be measured is not disposed on the measurement reference plane 10. The height measurement unit 56 identifies, from among a plurality of reflected light amount changes recorded in the reflected light amount change table for the one pixel 45, a specific reflected light amount change A that is closest to the reflected light amount change acquired by the reflected light amount change measurement unit 54 based on the amount of reflected light acquired by the one pixel 45 corresponding to the one measurement point on the surface of the object 11 to be measured, and sets the height corresponding to the specific reflected light amount change A as the height of the one measurement point on the surface of the object 11 to be measured.

[0081] The measuring device 9 of this embodiment can measure the height of the surface of the object 11 to be measured only by comparing the change in the amount of reflected light in the previously acquired reflected light amount change table with the change in the amount of reflected light on the surface of the object 11 to be measured. Therefore, the measuring device 9 can measure the height of each point on the surface of the object 11 to be measured without performing further arithmetic processing on the measured change in the amount of reflected light. As a result, for example, even when the fringe pattern 36 is distorted, the height of each point on the surface of the object 11 to be measured can be accurately measured without depending on the shape of the fringe pattern 36. Further, for example, when the actuator 34 is driven trapezoidally, the amount of movement of the actuator 34 becomes non-uniform during the acceleration period and the deceleration period of the actuator 34. Even if distortion occurs in the fringe pattern 36 due to such non-uniformity in the amount of movement of the actuator 34, according to this aspect, it is possible to accurately measure the height of each point on the surface of the object 11 to be measured.

[0082] (Hardware Configuration) The shape control unit 20 and the information processing unit 50 of the above-described embodiments and modified examples are implemented in the computer 1100 shown in FIG. 25. FIG. 25 is a schematic block diagram showing the configuration of the computer according to each embodiment. The computer 1100 includes a processor 1110, a main memory 1120, a storage 1130, and an interface 1140.

[0083] Then, the operations of the above-described functional units of the shape control unit 20 and the information processing unit 50 are stored in the storage 1130 in the form of a program. The processor 1110 reads the program from the storage 1130, expands it in the main memory 1120, and executes the above processing according to the program. Further, the processor 1110 secures a storage area in the main memory 1120 according to the program.

[0084] The program may be for realizing a part of the functions to be exhibited by the computer 1100. For example, the program may exhibit functions by combination with other programs already stored in the storage 1130 or by combination with other programs implemented in other devices. Further, in addition to or instead of the above configuration, the computer 1100 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device). Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, part or all of the functions realized by the processor 1110 may be realized by the integrated circuit.

[0085] Examples of the storage 1130 include a magnetic disk, a magneto-optical disk, a semiconductor memory, etc. The storage 1130 may be an internal medium directly connected to the bus of the computer 1100, or may be an external medium connected to the computer 1100 via the interface 1140 or a communication line. Also, when this program is distributed to the computer 1100 via a communication line, the computer 1100 that has received the distribution may expand the program in the main memory 1120 and execute the above processing. The storage 1130 may be a non-transitory tangible storage medium.

[0086] Also, the program may be for realizing a part of the functions described above. Further, the program may be what realizes the functions described above in combination with other programs already stored in the storage 1130, so-called a differential file (differential program).

[0087] (Other Embodiments) As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0088] In the above embodiment, the case where the measuring device 9 measures the shape of the shaped object 2 and the powder bed 6b shaped by the additive manufacturing apparatus 1 has been described, but it is not limited thereto. For example, the measuring device 9 may be used to measure the shape of a shaped object shaped by an external device.

[0089] In the above embodiment, the case where the projection unit 30 and the imaging unit 40 are provided outside the chamber 3 has been described, but it is not limited thereto. The projection unit 30 and the imaging unit 40 may be provided inside the chamber 3.

[0090] In the above embodiment, the case where one projection lens 35 is provided in the projection unit 30 has been described, but it is not limited thereto. A plurality of projection lenses 35 may be provided in the projection unit 30.

[0091] In the above-described embodiment, the case where one light-receiving lens 42 is provided in the imaging unit 40 has been described. However, the present invention is not limited to this. A plurality of light-receiving lenses 42 may be provided in the imaging unit 40.

[0092] In the above-described embodiment, the case where the projection unit 30 projects a sine wave pattern has been described. However, the present invention is not limited to this. The pattern projected by the projection unit 30 may be any pattern capable of calculating a phase. For example, the projection unit 30 may project a rectangular wave pattern.

[0093] <Supplementary Note> The measuring device 9 and the additive manufacturing device 1 described in each embodiment are understood as follows, for example.

[0094] (1) The measuring device 9 according to the first aspect includes a measurement reference plane 10, a projection unit 30 that projects a fringe pattern 36 onto the surface of the object 11 to be measured on the measurement reference plane 10, an imaging unit 40 that images the fringe pattern 36 projected onto the measurement reference plane 10 and the surface of the object 11 to be measured, and an information processing unit 50 that processes information on the fringe pattern 36 imaged by the imaging unit 40 and measures the shape of the object 11 to be measured. The projection unit 30 includes a light source 32 that irradiates light toward the measurement reference plane 10, a mask 33 that transmits the light irradiated from the light source 32 and generates the fringe pattern 36, and an actuator 34 that moves the mask 33. The projection unit 30 changes the phase of the fringe pattern 36 by moving the mask 33. The imaging unit 40 includes an imager 44 that acquires the amount of reflected light at each point on the projection surface 12 where the fringe pattern 36 is projected, among the measurement reference plane 10 and the surface of the object 11 to be measured. The information processing unit 50 includes a reflected light amount change measurement unit 54 that measures the change in the amount of reflected light at each point on the projection surface 12 accompanying the phase change of the fringe pattern 36 based on the amounts of reflected light acquired a plurality of times by changing the phase of the fringe pattern 36 at each point on the projection surface 12, and a height measurement unit 56 that measures the height of each point on the surface of the object 11 to be measured with respect to the measurement reference plane 10 based on the change in the amount of reflected light at each point on the projection surface 12.

[0095] According to this aspect, the projection unit 30 can change the phase of the fringe pattern 36 only by moving the mask 33. Therefore, the time required for the phase change of the fringe pattern 36 is shortened. As a result, the number of times of measuring the amount of reflected light at each point on the projection surface 12 per unit time increases. In this aspect, since the measuring device 9 measures the height of each point on the surface of the object 11 to be measured based on the change in the amount of reflected light, it is possible to accurately measure the shape of the object 11 to be measured.

[0096] (2) The measuring device 9 according to the second aspect is the measuring device 9 according to (1), and the imaging unit 40 may continuously image the fringe pattern 36 while the mask 33 moves.

[0097] According to this aspect, for example, compared with the case where a projector controls a fringe pattern while changing a projection screen as in the prior art, the time required for measuring the change in the amount of reflected light is shortened.

[0098] (3) The measuring device 9 according to the third aspect is the measuring device 9 according to (1) or (2), and the mask 33 may be inclined with respect to the optical axis O1 of the light source 32 so as to intersect a plane perpendicular to the optical axis O1 of the light source 32.

[0099] For example, even if the optical axis O1 of the light source 32 is inclined with respect to the normal line of the measurement reference plane 10 in order to create a space above the measurement reference plane 10, by adjusting the inclination angle of the mask 33 with respect to the optical axis O1 of the light source 32, the distortion of the fringe pattern 36 projected onto the projection surface 12 can be reduced.

[0100] (4) The measuring device 9 of the fourth aspect is any one of the measuring devices 9 of (1) to (3). The imager 44 has a plurality of pixels 45 each of which acquires the amount of reflected light of a point on the projection plane 12. The information processing unit 50 further includes a reflected light amount change table creation unit 58 that creates a reflected light amount change table in which the change in the amount of reflected light is recorded at a plurality of height positions of the measurement reference plane 10 for each of the pixels 45 in a state where the object to be measured 11 is not disposed on the measurement reference plane 10. The height measurement unit 56 specifies, for one measurement point on the surface of the object to be measured 11, the specific reflected light amount change that is closest to the reflected light amount change acquired by the reflected light amount change measurement unit 54 based on the amount of reflected light acquired by one of the pixels 45 corresponding to the one measurement point, from among the plurality of reflected light amount changes recorded in the reflected light amount change table for the one pixel 45, and may set the height corresponding to the specific reflected light amount change as the height of the one measurement point on the surface of the object to be measured 11.

[0101] The measuring device 9 of this aspect can measure the height of the surface of the object to be measured 11 simply by comparing the change in the amount of reflected light in the pre-acquired reflected light amount change table with the change in the amount of reflected light on the surface of the object to be measured 11. Thereby, for example, even when there is distortion in the fringe pattern 36, the height of each point on the surface of the object to be measured 11 can be accurately measured without depending on the shape of the fringe pattern 36. Also, even if distortion occurs in the fringe pattern 36 due to non-uniformity in the movement amount of the actuator 34, according to this aspect, it is possible to accurately measure the height of each point on the surface of the object to be measured 11.

[0102] (5) The additive manufacturing apparatus 1 according to the fifth aspect includes any one of the measuring devices 9 from (1) to (4), a stage 5 having a shaping surface 5a on which the shaped object 2 is additively manufactured, a powder supply unit 6 that supplies powder 6a onto the shaping surface 5a, a coater 7 that levels the powder 6a on the shaping surface 5a to form a powder bed 6b, and a head 8 that irradiates the powder bed 6b on the shaping surface 5a with a beam 8a to sinter it. The shaped object 2 and the powder bed 6b are the object to be measured 11, the shaping surface 5a is the measurement reference surface 10, the projection unit 30 further includes a projection lens 35 disposed between the mask 33 and the measurement reference surface 10, and the mask 33 and the projection lens 35 are disposed parallel to the measurement reference surface 10.

[0103] According to this aspect, in order to avoid the projection unit 30 interfering with the head 8, even if the projection unit 30 is disposed at a position shifted from directly above the shaping surface 5a (measurement reference surface 10) and inclined with respect to the measurement reference surface 10, the distortion of the fringe pattern 36 projected onto the measurement reference surface 10 is reduced.

[0104] (6) The additive manufacturing apparatus 1 according to the sixth aspect is the additive manufacturing apparatus 1 according to (5), wherein the imaging unit 40 further includes a light receiving lens 42 disposed between the imager 44 and the measurement reference surface 10, and the imager 44 and the light receiving lens 42 may be disposed parallel to the measurement reference surface 10.

[0105] According to this aspect, in order to avoid the imaging unit 40 interfering with the head 8, even if the imaging unit 40 is disposed at a position shifted from directly above the shaping surface 5a (measurement reference surface 10) and inclined with respect to the measurement reference surface 10, the imaging unit 40 can image the measurement reference surface 10 without distortion.

[0106] (7) The additive manufacturing apparatus 1 according to the seventh aspect is the additive manufacturing apparatus 1 according to (5), wherein the imaging unit 40 further includes a light receiving lens 42 disposed between the imager 44 and the measurement reference plane 10, and the imager 44, the light receiving lens 42, and the measurement reference plane 10 are arranged along each of three arrangement reference lines L3 radially extending from a predetermined point, and the center 42a of the light receiving lens 42 may be arranged on a straight line (optical axis O2) connecting the center 44b of the imager 44 and the center 10a of the measurement reference plane 10.

[0107] According to this aspect, it is possible to focus on the entire area within the field of view of the imaging unit 40 without narrowing the iris of the imaging unit 40. Therefore, the measurement accuracy can be improved.

Explanation of Reference Numerals

[0108] 1... Additive manufacturing apparatus, 2... Object to be manufactured, 3... Chamber, 3a... Housing, 3b... Beam window, 3c... Projection window, 3d... Imaging window, 4... Cylinder, 5... Stage, 5a... Forming surface, 6... Powder supply unit, 6a... Powder, 6b... Powder bed, 7... Coater, 8... Head, 8a... Beam, 9... Measuring device, 10... Measurement reference plane, 11... Object to be measured, 12... Projection plane, 13... Image, 20... Forming control unit, 21... Stage control unit, 22... Powder supply control unit, 23... Coater control unit, 24... Head control unit, 30... Projection unit, 32... Light source, 33... Mask, 33a... Substrate, 33b... Strip pattern, 34... Actuator, 35... Projection lens, 36... Fringe pattern, 40... Imaging unit, 41... Camera, 42... Light receiving lens, 44... Imager, 44b... Center, 45... Pixel, 45a... Corresponding pixel, 50... Information processing unit, 51... Projection control unit, 52... Imaging control unit, 53... Storage unit, 54... Reflected light quantity change measurement unit, 55... Phase measurement unit, 56... Height measurement unit, 57... Surface shape measurement unit, 58... Reflected light quantity change table creation unit, O1... Optical axis, O2... Optical axis (straight line), P1... Measurement point, P2... Measurement point, PA... Camera reference point, PB... Projection reference point, L1... Baseline, L2... Camera line of sight straight line, L3... Arrangement reference line

Claims

1. A measurement reference plane, a projection unit that projects a fringe pattern onto the surface of the object to be measured on the measurement reference plane, an imaging unit that images the fringe pattern projected onto the measurement reference plane and the surface of the object to be measured, an information processing unit that processes the information of the fringe pattern imaged by the imaging unit and measures the shape of the object to be measured, comprising: The projection unit a light source that irradiates light toward the measurement reference plane, a mask that transmits the light irradiated from the light source and generates the fringe pattern, an actuator that moves the mask, having: The projection unit changes the phase of the fringe pattern by moving the mask, The imaging unit has an imager that acquires the amount of reflected light at each point on the projection plane where the fringe pattern is projected, among the measurement reference plane and the surface of the object to be measured, The information processing unit a reflected light amount change measurement unit that measures the change in the amount of reflected light at each point on the projection plane accompanying the phase change of the fringe pattern, based on the amount of reflected light acquired a plurality of times with the phase of the fringe pattern changed at each point on the projection plane; a height measurement unit that measures the height of each point on the surface of the object to be measured with respect to the measurement reference plane, based on the change in the amount of reflected light at each point on the projection plane; having: a measuring device.

2. The imaging unit continuously images the fringe pattern while the mask is moving, according to the measuring device of Claim 1.

3. The mask is inclined with respect to the optical axis of the light source so as to intersect a plane perpendicular to the optical axis of the light source, according to the measuring device of Claim 1 or 2.

4. The imager has a plurality of pixels each of which acquires the amount of reflected light at one point on the projection plane, The information processing unit further has a reflected light amount change table creation unit that creates a reflected light amount change table in which the change in the amount of reflected light is recorded at a plurality of height positions of the measurement reference plane for each pixel, in a state where the object to be measured is not disposed on the measurement reference plane, For one measurement point on the surface of the object to be measured, the height measurement unit identifies, from among the plurality of reflected light amount changes recorded in the reflected light amount change table at the one pixel, the specific reflected light amount change that is closest to the reflected light amount change acquired by the reflected light amount change measurement unit, based on the amount of reflected light acquired at the one pixel corresponding to the one measurement point, and sets the height corresponding to the specific reflected light amount change as the height of the one measurement point on the surface of the object to be measured. The measuring device according to claim 1 or 2.

5. The measuring device according to claim 1 or 2, a stage having a modeling surface on which a modeled object is laminated and modeled, a powder supply unit that supplies powder onto the modeling surface, a coater that flattens the powder on the modeling surface to form a powder bed, a head that irradiates a beam onto the powder bed on the modeling surface to sinter it, comprising: wherein the modeled object and the powder bed are the object to be measured, the modeling surface is the measurement reference surface, the projection unit further includes a projection lens disposed between the mask and the measurement reference surface, the mask and the projection lens are disposed parallel to the measurement reference surface, a laminated manufacturing apparatus.

6. the imaging unit further includes a light receiving lens disposed between the imager and the measurement reference surface, the imager and the light receiving lens are disposed parallel to the measurement reference surface, the laminated manufacturing apparatus according to claim 5.

7. the imaging unit further includes a light receiving lens disposed between the imager and the measurement reference surface, the imager, the light receiving lens, and the measurement reference surface are disposed along each of three arrangement reference lines extending radially from a predetermined point, the center of the light receiving lens is disposed on a straight line connecting the center of the imager and the center of the measurement reference surface, the laminated manufacturing apparatus according to claim 5.

Images