3D shape data generation device, 3D shape data generation method, and 3D shape data generation program

Abstract

To reduce the time required to generate highly accurate 3D shape data. [Solution] The three-dimensional shape data generation device 1 includes a structured illumination unit 110, an imaging unit 120 that sequentially receives structured light of a first light-dark cycle and sequentially generates a plurality of pattern image data, and sequentially receives structured light of a second light-dark cycle that is longer than the first light-dark cycle and sequentially generates a plurality of pattern image data, a relative phase calculation unit 301a that calculates the relative phase of the object to be measured based on the plurality of pattern image data generated when the imaging unit 120 receives structured light of the first light-dark cycle, an absolute phase calculation unit that performs an averaging process on the plurality of pattern image data generated when the imaging unit 120 receives structured light of the second light-dark cycle and calculates the absolute phase of the object to be measured, and a three-dimensional shape data generation unit 301c that generates three-dimensional shape data of the object to be measured based on the relative phase and the absolute phase.

Description

Technical Field

[0001] The present disclosure relates to a three-dimensional shape data generation device, a three-dimensional shape data generation method, and a three-dimensional shape data generation program for generating three-dimensional shape data of a measurement object.

Background Art

[0002] Conventionally, a three-dimensional shape data generation device that generates three-dimensional shape data of a measurement object placed on a stage has been known. The three-dimensional shape data generation device disclosed in Patent Document 1 irradiates a structured light having a predetermined pattern onto a measurement object placed on a stage, receives the structured light reflected by the measurement object with an imaging unit, generates pattern image data of the measurement object, and is configured to generate three-dimensional shape data of the measurement object based on the generated pattern image data.

[0003] The irradiation range of the structured light of this Patent Document 1 is set to be larger than the placement surface formed by the upper surface of the stage. Thereby, the imaging range of the imaging unit is widened and the measurement range is expanded.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the measurement range is expanded as in Patent Document 1, the structured light irradiated in the measurement range becomes dim, so a longer exposure time is required for accurate measurement. As a result, the measurement time becomes longer and the convenience for the user decreases. In particular, this problem becomes prominent when irradiating a measurement object a plurality of times while phase-shifting structured light having a light-dark cycle and sequentially generating a plurality of pattern image data.

[0006] This disclosure is made in view of the above points, and its purpose is to shorten the time required to generate high-precision three-dimensional shape data. [Means for solving the problem]

[0007] To achieve the above objective, this embodiment may assume a three-dimensional shape data generation device comprising a structured illumination unit and an imaging unit. The structured illumination unit is configured to irradiate the object to be measured multiple times with structured light having a first light-dark period while phase-shifting it, and to irradiate the object to be measured multiple times with structured light having a second light-dark period longer than the first light-dark period. The imaging unit is configured to sequentially generate a plurality of pattern image data showing an image of the object to be measured by sequentially receiving the structured light having the first light-dark period reflected from the object to be measured with a first exposure time, and to sequentially generate a plurality of pattern image data showing an image of the object to be measured by sequentially receiving the structured light having the second light-dark period reflected from the object to be measured with a second exposure time shorter than the first exposure time. Based on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having the first light-dark period reflected from the object to be measured, the first calculation unit calculates the relative phase of the object to be measured. The second calculation unit generates a plurality of pattern image data by performing averaging and downsampling on the plurality of pattern image data generated by the imaging unit sequentially receiving structured light having the second light-dark period reflected from the object to be measured, and calculates the absolute phase of the object to be measured based on the plurality of pattern image data. The three-dimensional shape data generation unit generates three-dimensional shape data of the object to be measured based on the relative phase of the object to be measured calculated by the first calculation unit and the absolute phase of the object to be measured calculated by the second calculation unit.

[0008] With this configuration, pattern image data generated by irradiation with structured light having a second light-dark period that is longer than the first light-dark period can have its approximate absolute phase determined even if the resolution decreases due to averaging processing performed by the second calculation unit. To measure accurately, it is desirable to calculate the relative phase accurately, and the absolute phase only needs to be accurate enough to remove the periodic shift of the relative phase, so if the approximate absolute phase can be determined, a decrease in measurement accuracy can be avoided. By performing averaging processing on pattern image data generated by irradiation with structured light having a second light-dark period, the exposure time required to obtain the same brightness is shorter compared to when averaging processing is not performed, thus shortening the measurement time.

[0009] The structured illumination unit may include an optical element for generating the structured light, and the imaging unit may include a photodetector for receiving the structured light reflected from the object to be measured and generating the pattern image data. In this case, the resolution of the optical element can be set to be greater than the resolution of the photodetector.

[0010] With this configuration, since the resolution of the optical elements in the structured illumination unit is higher, averaging the pattern image data obtained from the photodetector in the imaging unit does not lead to a decrease in measurement accuracy, and 3D shape data can be generated.

[0011] The second calculation unit may perform an averaging process on the plurality of pattern image data based on the ratio of the resolution of the optical element to the resolution of the light-receiving element. With this configuration, by determining the averaging amount based on the relationship between the resolutions of the light-receiving element and the optical element, three-dimensional shape data can be generated without causing a decrease in measurement accuracy.

[0012] The averaging process for multiple pattern image data generated by the sequential reception of structured light having the second light-dark period reflected from the object to be measured by the imaging unit can be performed by embedded software incorporated into the measurement unit. The image data after averaging by the embedded software can be transferred to the controller for phase calculation and generation of three-dimensional shape data. This reduces the amount of data transferred from the measurement unit to the controller.

[0013] Furthermore, the first image data generation step involves irradiating the object to be measured multiple times with structured light having a first light-dark period while phase-shifting it, and sequentially receiving the structured light having the first light-dark period reflected by the object to be measured for a first exposure time to sequentially generate multiple pattern image data showing an image of the object to be measured, and the second image data generation step involves irradiating the object to be measured multiple times with structured light having a second light-dark period longer than the first light-dark period, and sequentially receiving the structured light having the second light-dark period reflected by the object to be measured for a second exposure time shorter than the first exposure time to sequentially generate multiple pattern image data showing an image of the object to be measured, and A method for generating three-dimensional shape data also falls within the scope of this disclosure, comprising: a first calculation step of calculating the relative phase of an object to be measured based on a plurality of pattern image data generated in a first image data generation step; a second calculation step of performing an averaging process on the plurality of pattern image data generated in the second image data generation step and calculating the absolute phase of an object to be measured based on the plurality of pattern image data after the averaging process; and a three-dimensional shape data generation step of generating three-dimensional shape data of an object to be measured based on the relative phase of the object to be measured calculated in the first calculation step and the absolute phase of the object to be measured calculated in the second calculation step. Furthermore, a three-dimensional shape data generation program for causing a computer to execute the three-dimensional shape data generation method also falls within the scope of this disclosure. [Effects of the Invention]

[0014] As described above, while calculating the relative phase based on the pattern image data generated by irradiating structured light with a relatively short light-dark cycle, averaging processing is performed on the pattern image data generated by irradiating structured light with a relatively long light-dark cycle, so that the absolute phase can be accurately calculated with a short exposure time, and three-dimensional shape data can be generated based on the calculated relative phase and absolute phase. Thereby, the time required for generating high-precision three-dimensional shape data can be shortened.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing the overall configuration of the three-dimensional shape data generation device according to Embodiment 1 of the present invention. [Figure 2] It is a block diagram of the three-dimensional shape data generation device. [Figure 3] It is a plan view schematically showing the optical elements included in the structured illumination unit. [Figure 4A] It is a diagram showing the gray code pattern light irradiated from the structured illumination unit. [Figure 4B] It is a diagram showing the multi-slit pattern light irradiated from the structured illumination unit. [Figure 5] It is a plan view schematically showing the light receiving elements included in the imaging unit. [Figure 6] It is a diagram for explaining the processing of the image data according to Examples 1 to 4. [Figure 7] It is a diagram corresponding to FIG. 2 according to Example 2. [Figure 8] It is a diagram corresponding to FIG. 2 according to Example 3. [Figure 9] It is a diagram corresponding to FIG. 2 according to Example 4. [Figure 10] It is a diagram for explaining the difference in processing for each operation mode. [Figure 11] It is a diagram showing an example of the operation mode setting user interface. [Figure 12] It is a diagram showing an example of the exposure time setting table. [Figure 13] It is a flowchart showing an example of the three-dimensional shape data generation procedure. [Figure 14] It is a diagram showing the overall configuration of the three-dimensional shape data generation device according to Embodiment 2 of the present invention.

Embodiments for Carrying out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0017] (Embodiment 1) FIG. 1 is a diagram showing the overall configuration of a three-dimensional shape data generation device 1 according to Embodiment 1 of the present invention. The three-dimensional shape data generation device 1 is a system that generates three-dimensional shape data of a workpiece (measurement object) W. For example, it can convert the mesh data of the workpiece W obtained by measuring the shape of the workpiece W into CAD data and output it. By using this three-dimensional shape data generation device 1, a three-dimensional shape data generation method can be executed.

[0018] Although not particularly limited, the three-dimensional shape data generation device 1 and the three-dimensional shape data generation method are used, for example, to obtain CAD data of existing products and perform next-generation model development or shape analysis on CAD / CAE, to reflect the shape of models and mock-ups in product design, to design a mating product based on the shape of the mating counterpart part, or to perform improved design based on the shape of a prototype. Therefore, examples of the workpiece W include existing products, models, mock-ups, prototypes, and the like.

[0019] In addition, the three-dimensional shape data generation device 1 can also convert the mesh data of the workpiece W into surface data and output it. By converting the mesh data of the workpiece W into surface data and outputting it, the user's reverse engineering process and reverse engineering work can be supported. Therefore, the three-dimensional shape data generation device 1 can also be called a reverse engineering support device.

[0020] In the following description, when measuring the shape of workpiece W, coordinate information of the workpiece W surface is obtained by irradiating workpiece W with structured light for measurement and obtaining coordinate information based on the structured light reflected from the surface of workpiece W. For example, a measurement method using triangulation with a fringe projection image obtained from the structured light reflected from the surface of workpiece W can be applied. However, in this invention, the principle and configuration for obtaining the coordinate information of workpiece W are not limited to this, and other methods can also be applied.

[0021] The 3D shape data generation device 1 comprises a measuring unit 100, a base unit 200, a controller 300, a display unit 400, and an operation unit 500. As shown in Figure 2, the measuring unit 100 comprises a structured illumination unit 110 and an imaging unit 120, as well as a housing 100A to which the structured illumination unit 110 and the imaging unit 120 are mounted. Furthermore, the measuring unit 100 also comprises a measurement control unit 130 that controls the structured illumination unit 110 and the imaging unit 120. The measurement control unit 130 may be provided in the housing 100A or on the controller 300 side.

[0022] The housing 100A is separate from the controller 300 and is supported by a support unit 600. The support unit 600 is portable and comprises a base unit 601, an extendable unit 602 fixed to the base unit 601, and an angle adjustment unit 603 provided on the upper part of the extendable unit 602, allowing the user to freely set the installation position. The measuring unit 100 is detachably attached to the angle adjustment unit 603. The height of the measuring unit 100 can be adjusted by extending or retracting the extendable unit 602 in the vertical direction. Furthermore, the angle adjustment unit 603 is configured to allow adjustment of, for example, rotation around the horizontal axis, rotation around the vertical axis, and rotation around the inclination axis. This allows the installation angle of the measuring unit 100 relative to the horizontal plane and the installation angle relative to the vertical plane to be adjusted arbitrarily.

[0023] The support section 600 is not limited to the configuration described above, and may be composed of, for example, a tripod, a flexible arm that can be freely bent and maintain a bent shape, a bracket, or a combination of these. The measuring section 100 can also be used by attaching it to, for example, a 6-degree-of-freedom arm of an industrial robot. Furthermore, the measuring section 100 can be used by the user holding it by hand, in which case the support section 600 is unnecessary. In other words, the support section 600 may be a component included in the 3D shape data generation device 1, or it may be a component not included in the 3D shape data generation device 1.

[0024] When a user takes the housing 100A and measures the workpiece W, the measuring unit 100 can be brought to the manufacturing site of the workpiece W for measurement. In this case, the user can measure the shape of the workpiece W by moving the measuring unit 100 to any position and taking images at any time. This can be called manual measurement.

[0025] Furthermore, by supporting the measuring unit 100 with the support unit 600 and placing the workpiece W on the automatically rotating base unit 200 (described later), the shape of a wide area of ​​the workpiece W can be measured by rotating the workpiece W on the base unit 200 and taking images at predetermined timings. This can be called semi-automatic measurement. Note that the workpiece W can also be measured by placing it on a surface plate or the like, for example, without placing it on the base unit 200.

[0026] Furthermore, by attaching the measuring unit 100 to the arm of an industrial robot and moving it, the shape of a wide range of the workpiece W can be measured without the user's intervention. This can be called fully automatic measurement. The present invention is applicable to all manual, semi-automatic, and fully automatic measurements.

[0027] As shown in Figure 2, the measurement unit 100 includes a structured illumination unit 110 that irradiates the workpiece W with structured light for measurement, and an imaging unit 120 that receives the structured light irradiated by the structured illumination unit 110 and reflected by the workpiece W, and generates pattern image data of the workpiece W. The measurement unit 100 may include a plurality of structured illumination units 110. For example, there may be a first structured illumination unit capable of irradiating the workpiece W with first structured light from a first direction, and a second structured illumination unit capable of irradiating the workpiece W with second structured light from a second direction different from the first direction. The measurement unit 100 may also include a plurality of imaging units 120.

[0028] Although not shown in the figures, it is also possible to have three or more structured illumination units 110, or to move the structured illumination unit 110 and the base unit 200 relative to each other, so that even while using a common structured illumination unit 110, the direction of illumination of the structured light can be different and projected onto the workpiece W. In addition to providing multiple structured illumination units 110 and receiving the light with a common imaging unit 120, it is also possible to provide multiple imaging units 120 for a common structured illumination unit 110 and configure them to receive the light. Furthermore, the illumination angle of the structured light projected by the structured illumination unit 110 with respect to the Z direction may be fixed or variable.

[0029] The structured illumination unit 110 includes a measurement light source 111, an optical element 112, and a plurality of lenses 113. The measurement light source 111 can be a light source that emits monochromatic light, such as a halogen lamp that emits white light, a blue LED (light-emitting diode) that emits blue light, or an organic EL. The light emitted from the measurement light source 111 is focused and then incident on the optical element 112.

[0030] The optical element 112 reflects light emitted from the measurement light source 111 so that structured light is irradiated onto the workpiece W. The measurement light incident on the optical element 112 is converted to a preset pattern and preset intensity (brightness) and emitted. The structured light emitted by the optical element 112 is converted by multiple lenses 113 into light with a diameter larger than the observation and measurement field of view of the imaging unit 120, and then irradiated onto the workpiece W.

[0031] The optical element 112 is a component that can switch between an illumination state in which structured light is irradiated onto the workpiece W and a non-irradiation state in which structured light is not irradiated onto the workpiece W. For example, a DMD (Digital Micromirror Device) can be used as such an optical element 112. An optical element 112 using a DMD can be controlled by the measurement control unit 130 to switch between a reflection state in which structured light is reflected towards the optical path as the illumination state and a light-shielding state in which structured light is blocked as the non-irradiation state.

[0032] Figure 3 is a schematic plan view of the optical element 112, which consists of a DMD, and also shows the shape corresponding to the workpiece W. The optical element 112 is an element in which a large number of micromirrors (tiny mirror surfaces) 112a are arranged on a plane (in the X and Y directions). Each micromirror 112a can be individually switched ON or OFF by the measurement control unit 130, so that by combining the ON and OFF states of a large number of micromirrors 112a, it is possible to generate light with a desired projection pattern as structured light for measurement. This makes it possible to generate the pattern necessary for triangulation and measure the shape of the workpiece W. In this way, the optical element 112 functions as part of the optical system that irradiates the workpiece W with a periodic projection pattern for measurement during measurement. Furthermore, the DMD has excellent response speed and offers the advantage of being able to operate at a higher speed than shutters, etc.

[0033] By controlling the optical element 112, multiple types of structured light having a light-dark period can be generated. Specifically, the optical element 112 can generate structured light such as the Gray code pattern light shown in Figure 4A and the multi-slit pattern light shown in Figure 4B. The light-dark period of the Gray code pattern light is longer than that of the multi-slit pattern light. Therefore, the Gray code pattern light can be called low-frequency structured light, and the multi-slit pattern light can be called high-frequency structured light. The multi-slit pattern light is structured light having a first light-dark period, and the Gray code pattern light is structured light having a second light-dark period that is longer than the first light-dark period. The structured light having a second light-dark period that is longer than the first light-dark period is not limited to the Gray code pattern light, but may also be multi-slit light. In this case, the relative phase and absolute phase can be calculated from the phase difference of the multi-slits.

[0034] By controlling the optical element 112, multiple Gray code pattern lights with different light-dark periods can be generated, and multiple multi-slit pattern lights with different phases can be generated by changing the phase of the multi-slit pattern light. The method of projecting periodic patterns with different phases and estimating the phase value from multiple acquired images is called the phase shift method. Measurements using such a phase shift method can be performed using a sine wave or a binary pattern with equal width for black and white.

[0035] The structured illumination unit 110 can irradiate the workpiece W with Gray code pattern light multiple times by controlling the optical element 112 when measuring the shape of the workpiece W, and can also irradiate the workpiece W with multi-slit pattern light multiple times while phase-shifting it.

[0036] In the above example, an example using a DMD for the optical element 112 was described, but the present invention is not limited to a DMD for the optical element 112, and other materials can be used. For example, an LCOS (Liquid Crystal on Silicon: reflective liquid crystal element) may be used as the optical element 112. Alternatively, a transmissive material may be used instead of a reflective material to adjust the amount of structured light transmitted. In this case, the optical element 112 is placed on the optical path to switch between an illumination state in which light is transmitted and a light-blocking state in which light is blocked. For example, an LCD (liquid crystal display) can be used as such an optical element 112. Alternatively, the optical element 112 may be configured using a projection method using multiple line LEDs, a projection method using multiple optical paths, an optical scanner method composed of a laser and a galvanometer mirror, an AFI (Accordion fringe interferometry) method that uses interference fringes generated by superimposing beams divided by a beam splitter, or a projection method using a physical grid composed of a piezo stage and a high-resolution encoder and a moving mechanism. Furthermore, the optical element 112 can also emit uniform light without generating a pattern.

[0037] The imaging unit 120 includes a light-receiving element 121 and a plurality of lenses 122. Structured light reflected from the workpiece W is incident on the lenses 122, focused, and imaged, and then received by the light-receiving element 121 to generate pattern image data. The imaging unit 120 may include a high-magnification imaging unit equipped with a high-magnification lens 122 and a low-magnification imaging unit equipped with a low-magnification lens 122. The lenses 122 may also be zoom lenses or the like with adjustable magnification, or the imaging unit 120 may have adjustable magnification. The magnification at the time of imaging is associated with the image data, making it possible to identify the magnification at which the image data was captured.

[0038] The light-receiving element 121 is composed of an image sensor such as a CCD (charge-coupled device) or CMOS (complementary metal-oxide-semiconductor). Figure 5 is a schematic plan view of the light-receiving element 121. The light-receiving element 121 is an element in which a large number of photoelectric converters 121a are arranged on a plane (in the X and Y directions), and each photoelectric converter 121a constitutes each pixel. The optical element 112 shown in Figure 3 and the light-receiving element 121 shown in Figure 5 correspond in the X and Y directions. The number of micromirrors 112a arranged in the X direction of the optical element 112 is set to be less than the number of photoelectric converters 121a arranged in the X direction of the light-receiving element 121, and the number of micromirrors 112a arranged in the Y direction of the optical element 112 is set to be less than the number of photoelectric converters 121a arranged in the Y direction of the light-receiving element 121. In other words, the resolution of the optical element 112 is set to be greater than the resolution of the light-receiving element 121. While not particularly limited, in this example, the number of micromirrors 112a aligned in the X direction of the optical element 112 is set to 1 / 2 the number of photoelectric converters 121a aligned in the X direction of the light-receiving element 121, and the number of micromirrors 112a aligned in the Y direction of the optical element 112 is set to 1 / 2 the number of photoelectric converters 121a aligned in the Y direction of the light-receiving element 121.

[0039] Each pixel of the photodetector 121 outputs an analog electrical signal (hereinafter referred to as the "photodetector signal") corresponding to the amount of light received to the A / D converter described later. Because color photodetectors require each pixel to correspond to the reception of red, green, and blue light, their measurement resolution is lower compared to monochrome photodetectors, and sensitivity is reduced because each pixel requires a color filter. For this reason, in this embodiment, a monochrome CCD is used as the photodetector 121. However, a color photodetector may also be used as the photodetector 121.

[0040] The imaging unit 120 is equipped with an A / D converter (analog-to-digital converter), a FIFO (First In First Out) memory, a CPU, and other components (not shown). The light-receiving signal output from the light-receiving element 121 is sampled at a constant sampling period by the A / D converter and converted into a digital signal. The digital signals output from the A / D converter are sequentially stored in the FIFO memory. The digital signals stored in the FIFO memory are sequentially output to the CPU as pixel data, and the CPU generates pattern image data.

[0041] Based on the light-receiving signal output from the photodetector 121, pattern image data representing the three-dimensional shape of the workpiece W contained within the field of view of the photodetector 121 at a specific position is generated. The pattern image data is the image itself acquired by the photodetector 121. For example, when measuring the shape of the workpiece W using the phase-shift method, multiple images will constitute the pattern image data.

[0042] When the structured illumination unit 110 irradiates the workpiece W with multi-slit pattern light while shifting its phase, the imaging unit 120 sequentially receives the multi-slit pattern light reflected from the workpiece W for a first exposure time each time the multi-slit pattern light is irradiated onto the workpiece W. As a result, the imaging unit 120 sequentially generates a plurality of pattern image data showing the image of the workpiece W when irradiated with the multi-slit pattern light.

[0043] Furthermore, when the structural light illumination unit 110 irradiates the workpiece W with multiple Gray code pattern lights with different light-dark periods, the imaging unit 120 sequentially receives the Gray code pattern light reflected from the workpiece W each time the Gray code pattern light is irradiated onto the workpiece W, with a second exposure time shorter than the first exposure time. As a result, the imaging unit 120 sequentially generates multiple pattern image data showing the image of the workpiece W when irradiated with Gray code pattern light. The reason why the exposure time for Gray code pattern light is shorter than the exposure time for multi-slit pattern light will be explained later. The number of pattern image data for Gray code pattern light is greater than the number of pattern image data for multi-slit pattern light.

[0044] The pattern image data may also be point cloud data, which is a collection of points having three-dimensional positional information. Pattern image data of the workpiece W can be obtained using this point cloud data. Point cloud data is data represented by a collection of multiple points having three-dimensional coordinates. The generated pattern image data is transferred to the controller 300.

[0045] The operation unit 500 may include, for example, a pointing device such as a keyboard 501 or a mouse 502. A joystick may also be used as the pointing device. Furthermore, the operation unit 500 may include a touch panel or the like that senses user touch operations. The operation unit 500 is connected to the arithmetic unit 301 within the controller 300, and the arithmetic unit 301 can detect what operations are performed by the operation unit 500.

[0046] The base unit 200 comprises a base plate 201, a stage 202 that forms a mounting surface on which the workpiece W is placed, and a rotation mechanism 203. The base unit 200 may also include a clamping mechanism for clamping the workpiece W on the stage 202. The rotation mechanism 203 is provided between the base plate 201 and the stage 202 and is a mechanism that rotates the stage 202 about a vertical axis (the Z-axis shown in Figure 1) relative to the base plate 201. Therefore, the stage 202 is a rotating stage, and by rotating it with the workpiece W placed on it, it is possible to switch the relative positional relationship of the workpiece W with respect to the imaging unit 120. The direction of rotation about the Z-axis is defined as the θ direction and is indicated by the arrow θ. The base unit 200 may also include a tilt stage having a mechanism that can rotate about an axis parallel to the mounting surface.

[0047] The rotation mechanism 203 has a motor or the like controlled by the measurement control unit 130, which will be described later, and is capable of rotating the stage 202 by a desired rotation angle and then holding it in a stopped state. The base portion 200 is not an essential component of the present invention and is provided as needed. The base portion 200 may also be controlled by the controller 300.

[0048] Although not shown in the figures, the base portion 200 may be equipped with a translation mechanism that moves the stage 202 horizontally in the X and Y directions, which are mutually orthogonal. The translation mechanism also has a motor controlled by the measurement control unit 130 and the controller 300, and is capable of moving the stage 202 by a desired amount in the X and Y directions and then holding it in a stopped state. The present invention is also applicable even if the stage 202 is a fixed stage.

[0049] The controller 300 includes an arithmetic unit 301, a working memory 302, a ROM (read-only memory) 303, a storage unit 304, and a display control unit 305 that controls the display unit 400. The controller 300 can use a PC (personal computer), but it may also consist of a dedicated computer only, or a combination of a PC and a dedicated computer.

[0050] The ROM 303 of the controller 300 stores, for example, a system program. The working memory 302 of the controller 300 consists of, for example, RAM (Random Access Memory) and is used for processing various data. The storage unit 304 consists of, for example, a solid-state drive or a hard disk drive. The storage unit 304 stores a program for generating three-dimensional shape data. The storage unit 304 is also used to store various data such as pixel data (pattern image data) and measurement conditions (setting table) of the workpiece W provided by the measurement control unit 130. Measurement conditions include, for example, the settings of the structured illumination unit 110 (pattern frequency, pattern type), the magnification of the imaging unit 120, the measurement field of view (single field of view or wide field of view), the measurement position, the rotational orientation, the exposure conditions (exposure time, gain, brightness of illumination), and the resolution setting (low-resolution measurement, standard measurement, high-resolution measurement).

[0051] The arithmetic unit 301 consists of control circuits and control elements that process given signals and data, perform various calculations, and output calculation results. In this specification, the arithmetic unit 301 refers to the elements and circuits that perform calculations, and is used to mean not limited to processors such as CPUs, MPUs, GPUs, and TPUs for general-purpose PCs, regardless of their name, but also including processors such as FPGAs, ASICs, and LSIs, microcontrollers, and chipsets such as SoCs.

[0052] The arithmetic unit 301 performs various processing on the pattern image data generated by the imaging unit 120 using the working memory 302. The arithmetic unit 301 comprises a relative phase calculation unit 301a, an absolute phase calculation unit 301b, a three-dimensional shape data generation unit 301c, an exposure time setting unit 301d, and a reception unit 301e. The relative phase calculation unit 301a, absolute phase calculation unit 301b, three-dimensional shape data generation unit 301c, exposure time setting unit 301d, and reception unit 301e may consist solely of the hardware of the arithmetic unit 301, or they may consist of a combination of hardware and software. For example, by executing a three-dimensional shape data generation program, the functions of the relative phase calculation unit 301a, absolute phase calculation unit 301b, three-dimensional shape data generation unit 301c, exposure time setting unit 301d, and reception unit 301e can be realized. The 3D shape data generation program may be stored on various storage media such as CD-ROMs or DVD-ROMs, or it may be stored on a server or the like and provided in a form that can be downloaded by the user.

[0053] The relative phase calculation unit 301a is the part that calculates the relative phase of the workpiece W based on multiple pattern image data generated by the imaging unit 120 sequentially receiving multi-slit pattern light reflected from the workpiece W.

[0054] The absolute phase calculation unit 301b is the part that performs an averaging process on multiple pattern image data generated by the imaging unit 120 sequentially receiving Gray code pattern light reflected from the workpiece W, and calculates the absolute phase of the workpiece W based on the multiple pattern image data after the averaging process.

[0055] The 3D shape data generation unit 301c is the part that generates 3D shape data of the workpiece W based on the relative phase of the workpiece W calculated by the relative phase calculation unit 301a and the absolute phase of the workpiece W calculated by the absolute phase calculation unit 301b.

[0056] Figure 6 shows examples 1 to 4 of the processing of pattern image data. In Figure 6, the processing performed by the photodetector 121 of the imaging unit 120, the processing performed by the measurement control unit 130 of the measurement unit 100, and the processing performed by the controller 300 are shown separately. Since the photodetector 121 is a component built into the measurement unit 100, the processing performed by the photodetector 121 can also be called the processing performed by the measurement unit 100. The measurement unit 100 is connected to the controller 300 via a communication cable 100B. This communication cable 100B conforms to the general-purpose USB (Universal Serial Bus) communication standard. Note that the measurement unit 100 and the controller 300 may be connected wirelessly.

[0057] In Example 1, the photodetector 121 generates multiple pattern image data 800 when irradiated with Gray code pattern light and multiple pattern image data 800 when irradiated with multi-slit pattern light. The measurement control unit 130 of the measurement unit 100 transfers the pattern image data 800 generated by the photodetector 121 to the controller 300 without performing any processing on each of the pattern image data 800. The relative phase calculation unit 301a of the controller 300 calculates the relative phase of the workpiece W based on the multiple pattern image data 801 when irradiated with multi-slit pattern light, and the absolute phase calculation unit 301b calculates the absolute phase of the workpiece W based on the multiple pattern image data 801 when irradiated with Gray code pattern light. The 3D shape data generation unit 301c of the controller 300 generates 3D shape data of the workpiece W by performing 3D image processing and drawing processing, such as generating a phase image 802, point cloud data 803, mesh data 804, etc., based on the relative phase of the workpiece W calculated by the relative phase calculation unit 301a and the absolute phase of the workpiece W calculated by the absolute phase calculation unit 301b.

[0058] The mesh data generated here as three-dimensional shape data contains multiple polygons and can also be called polygon data. A polygon is data composed of information that identifies multiple points and information that shows the polygonal surface formed by connecting those points. For example, it can consist of information that identifies three points and information that shows the triangular surface formed by connecting those three points. Mesh data and polygon data can also be defined as data represented by a collection of multiple polygons. The generated mesh data of the workpiece W is converted into surface data and output.

[0059] In Example 2, the photodetector 121 generates multiple pattern image data 810 when irradiated with Gray code pattern light and multiple pattern image data 810 when irradiated with multi-slit pattern light. The measurement control unit 130 of the measurement unit 100 performs an averaging process on the multiple pattern image data 810 when irradiated with Gray code pattern light. As shown in Figure 7, the averaging process is performed by an averaging processing unit 130a, which is composed of embedded software or the like incorporated into the measurement control unit 130. The embedded software is, for example, an FPGA or a microcomputer.

[0060] One example of averaging is binning. Binning is a process that reduces the number of pixels and increases the brightness value by performing averaging and downsampling and adding the brightness values ​​of multiple pixels.

[0061] Averaging can be performed using either an unweighted kernel or a Gaussian kernel. When averaging with a Gaussian kernel and then downsampling, the resulting pixel values ​​after downsampling can be higher compared to averaging with an unweighted kernel and then downsampling.

[0062] Downsampling after applying a Gaussian filter is an example of binning, and this process can reduce the effects of noise. Furthermore, performing averaging on the pattern image data immediately after output from the imaging unit 120 means that the size of the image can be reduced in the preceding stage, which speeds up the subsequent processing described later, namely phase calculation and generation of 3D shape data. In addition, even if the resolution of the pattern image data generated by irradiation with Gray code pattern light, which has a relatively long light-dark period compared to multi-slit pattern light, is reduced by averaging, a rough absolute phase can be grasped, so a decrease in measurement accuracy can be avoided.

[0063] Comparing the resolution of the optical element 112 shown in Figure 3 and the photodetector 121 shown in Figure 5, there is a twofold difference. Therefore, even if the pattern image data of the Gray code pattern light is downsampled to half in both the X and Y directions, resulting in a resolution of 1 / 4, the spatial resolution of the optical element 112 is not compromised. That is, if the resolution of the optical element 112 is Ra and the resolution of the photodetector 121 is Rb, the phase can be calculated without compromising the spatial resolution of the optical element 112 by setting the downsampling ratio to Rb / Ra or less. In this way, averaging processing is performed on the pattern image data of the Gray code pattern light based on the ratio of the resolution of the optical element 112 to the resolution of the photodetector 121. The above resolution ratio is just an example, and other ratios may also be used.

[0064] On the other hand, averaging is not performed on the multiple pattern image data when irradiated with multi-slit pattern light. This makes it possible to calculate the relative phase with high accuracy without reducing the resolution of the pattern image data generated by irradiation with multi-slit pattern light, which has a relatively shorter light-dark period compared to Gray code pattern light.

[0065] The measurement control unit 130 transfers the pattern image data 811 of the Gray code pattern light, which has undergone averaging processing, to the controller 300. At this time, the transfer time is shortened because the size of the image has been reduced by the averaging processing. The measurement control unit 130 also transfers the pattern image data of the multi-slit pattern light, which has not undergone averaging processing, to the controller 300.

[0066] The relative phase calculation unit 301a of the controller 300 calculates the relative phase of the workpiece W based on the pattern image data of the multi-slit pattern light transferred from the measurement control unit 130. The absolute phase calculation unit 301b of the controller 300 also calculates the absolute phase of the workpiece W based on the pattern image data of the Gray code pattern light after averaging processing, transferred from the measurement control unit 130. In Example 2, the first calculation unit of the present invention is composed of the relative phase calculation unit 301a, and the second calculation unit of the present invention is composed of the averaging processing unit 130a and the absolute phase calculation unit 301b of the measurement control unit 130.

[0067] The 3D shape data generation unit 301c of the controller 300 calculates the relative phase and absolute phase of the workpiece W based on the pattern image data 812 transferred from the measurement control unit 130, and generates a phase image 813, point cloud data 814, mesh data 815, etc., i.e., performs 3D image processing and drawing processing based on the calculated relative phase and absolute phase of the workpiece W.

[0068] In addition, in Example 2, the averaging processing unit 130a of the measurement control unit 130 may perform averaging processing on the pattern image data of the multi-slit pattern light. In this case, the time required to transfer the pattern image data of the multi-slit pattern light to the controller 300 can be shortened, and the subsequent processing can be sped up.

[0069] Example 3, shown in Figure 6, is an example in which the above averaging process is performed on the light-receiving element 121. In this example, as shown in Figure 8, the averaging processing unit 121b provided on the light-receiving element 121 performs the above averaging process on the pattern image data 820 of the Gray code pattern light, and then transfers the pattern image data 821 on which the averaging process has been performed to the controller 300. In the controller 300, similar to Example 2, the relative phase and absolute phase of the workpiece W are calculated based on the pattern image data 822, and based on the calculated relative phase and absolute phase of the workpiece W, the phase image 823, point cloud data 824, mesh data 825, etc., i.e., 3D image processing and drawing processing are performed. In Example 3, the pattern image data of the multi-slit pattern light may also be averaged by the averaging processing unit 121b.

[0070] Example 4 shown in Figure 6 is an example in which the measurement control unit 130 of the measurement unit 100 calculates relative phase and absolute phase and generates three-dimensional shape data. As shown in Figure 9, the measurement control unit 130 is provided with a relative phase calculation unit 130b, an absolute phase calculation unit 130c, and a three-dimensional shape data generation unit 130d. The light-receiving element 121 acquires pattern image data 830 of multi-slit pattern light, and the relative phase calculation unit 130b calculates the relative phase of the workpiece W based on the pattern image data 831 of multi-slit pattern light output from the light-receiving element 121. The absolute phase calculation unit 130c calculates the absolute phase of the workpiece W based on the pattern image data 831 of Gray code pattern light transferred from the light-receiving element 121. The three-dimensional shape data generation unit 130d performs the generation of phase images 832, point cloud data 833, mesh data 834, etc., i.e., 3D image processing and drawing processing, similar to the three-dimensional shape data generation unit 301c in Example 2. In addition, in Example 4, the measurement control unit 130 may perform an averaging process on the pattern image data of the Gray code pattern light or the pattern image data of the multi-slit pattern light.

[0071] (Operating Mode) The 3D shape data generation device 1 has multiple operating modes, and is configured to allow the user to switch between operating modes. As shown in Figure 10, the operating modes include a high-speed mode that enables high-speed processing, a standard mode that is slower than the high-speed mode, and a high-resolution mode that is slower than the standard mode but can obtain high-resolution 3D shape data. Figure 10 explains the case of Example 2 shown in Figure 6, but similarly, the operating modes can be switched in Examples 1, 3, and 4. Note that the number of operating modes is not limited to three; for example, there may be two modes, such as a high-speed mode and a standard mode, or there may be four or more operating modes.

[0072] In high-speed mode, the measurement control unit 130 performs binning on the pattern image data (3000 x 3000 pixels) of the Gray code pattern light generated by the photodetector 121. The image after binning becomes 1500 x 1500 pixels. At this point, binning is not performed on the pattern image data of the multi-slit pattern light. The measurement control unit 130 transfers the pattern image data of the Gray code pattern light that has undergone binning and the pattern image data of the multi-slit pattern light that has not undergone binning to the controller 300.

[0073] The arithmetic unit 301 of the controller 300 performs averaging on the pattern image data of the multi-slit pattern light. The averaging process for the pattern image data of the multi-slit pattern light is performed by image processing software installed on the controller 300. The image after averaging becomes 1500 × 1500 pixels. The relative phase calculation unit 301a calculates the relative phase of the workpiece W based on the pattern image data of the multi-slit pattern light after averaging, and the absolute phase calculation unit 301b calculates the absolute phase of the workpiece W based on the pattern image data of the Gray code pattern light after averaging. The three-dimensional shape data generation unit 301c of the controller 300 performs three-dimensional image processing and drawing processing based on the relative phase and absolute phase of the workpiece W. Thus, in the high-speed mode, averaging is performed on both the pattern image data of the multi-slit pattern light and the pattern image data of the Gray code pattern light, which increases the processing speed of the subsequent stages and enables high-speed processing. However, because the resolution of both pattern image data is reduced, the mesh data becomes lower resolution compared to other operating modes. This high-speed mode corresponds to the first operating mode of the present invention.

[0074] Next, the standard mode will be described. The standard mode differs from the high-speed mode in that it does not perform averaging on the pattern image data of the multi-slit pattern light. In other words, since mesh data can be generated based on the pattern image data of the 1500 x 1500 pixel Gray code pattern light and the pattern image data of the 3000 x 3000 pixel multi-slit pattern light, high-resolution mesh data can be obtained compared to the high-speed mode. However, since the data capacity of the pattern image data of the multi-slit pattern light is larger than that of the high-speed mode, the processing speed is reduced. The standard mode corresponds to the second operating mode of the present invention.

[0075] Next, the high-resolution mode will be described. In high-resolution mode, the 3D shape data generation unit 301c generates a phase image based on relative phase and absolute phase, and performs upsampling on the phase image, which is different from the standard mode. By performing upsampling, a phase image of 6000 x 6000 pixels is generated. Therefore, the 3D shape data generation unit 301c acquires 6000 x 6000 point cloud data, resulting in higher resolution mesh data compared to the standard mode. Performing upsampling results in a slower processing speed compared to the standard mode. Upsampling may be performed in the preceding stage, but faster processing can be achieved by performing it in the succeeding stage. The high-speed mode corresponds to the second operating mode of the present invention.

[0076] The reception unit 301e shown in Figure 2 is the part that accepts the selection of which operating mode—high-speed mode, standard mode, or high-definition mode—to use for generating 3D shape data. For example, as shown in Figure 11, the display control unit 305 generates an operating mode setting user interface 700 and displays it on the display unit 400. The operating mode setting user interface 700 is equipped with a high-speed button 701 to be operated when selecting high-speed mode, a standard button 702 to be operated when selecting standard mode, and a high-definition button 703 to be operated when selecting high-definition mode. When a user presses one of the buttons 701 to 703 using the operation unit 500, the reception unit 301e identifies which button was pressed. When the high-speed button 701 is pressed, the reception unit 301e receives the request as "generate 3D shape data in high-speed mode." When the standard button 702 is pressed, the reception unit 301e receives the request as "generate 3D shape data in standard mode." When the high-definition button 703 is pressed, the reception unit 301e receives the request as "generate 3D shape data in high-definition mode." The calculation unit 301 and the measurement control unit 130, etc., are controlled to operate in the mode received by the reception unit 301e.

[0077] (Setting the exposure time) The exposure time setting unit 301d shown in Figure 2 is responsible for setting the exposure time of the imaging unit 120. When the exposure time setting unit 301d sets the exposure time, it uses the exposure time setting table shown in Figure 12. The setting table is stored in the storage unit 304.

[0078] The setting table holds target brightness values ​​for determining the exposure time of the imaging unit 120. The target brightness values ​​include a target brightness value for high-speed mode (corresponding to the first target brightness value of the present invention) for determining the exposure time of the imaging unit 120 when high-speed mode is selected, a target brightness value for standard mode (corresponding to the second target brightness value of the present invention) for determining the exposure time of the imaging unit 120 when standard mode is selected, and a target brightness value for high-definition mode (corresponding to the third target brightness value of the present invention) for determining the exposure time of the imaging unit 120 when high-definition mode is selected. The target brightness value for high-speed mode is set to the lowest, the target brightness value for high-definition mode is set to the highest, and the target brightness value for standard mode is set to a brightness value between the target brightness value for high-speed mode and the target brightness value for high-definition mode. Each target brightness value is an example.

[0079] A higher target brightness value allows for a longer exposure time by the imaging unit 120, resulting in a brighter image and reduced shape noise. However, in faster modes, the number of point clouds is ultimately reduced after subsequent processing, so even if noise increases due to a lower target brightness value, it will be thinned out and become less noticeable. Therefore, the target brightness value is set lower in faster modes.

[0080] Furthermore, the setting table stores the ratio of the exposure time of the imaging unit 120 when illuminated with multi-slit pattern light to the exposure time of the imaging unit 120 when illuminated with Gray code pattern light. Each ratio is an example and is shown as "Gray code / multi-slit exposure time ratio" in Figure 12. The exposure time of the imaging unit 120 when illuminated with multi-slit pattern light is the first exposure time, and the exposure time of the imaging unit 120 when illuminated with Gray code pattern light is the second exposure time.

[0081] The exposure time setting unit 301d sets the exposure time of the imaging unit 120 when the multi-slit pattern light is irradiated, based on the brightness values ​​of multiple pattern image data generated by the imaging unit 120 at multiple different exposure times and the target brightness value stored in the setting table. Specifically, the imaging unit 120 takes images while changing the exposure time, acquiring multiple exposure images with different exposure times. From the acquired multiple exposure images, the relationship between exposure time and average brightness is determined, and the exposure time is automatically set such that the average brightness becomes the target brightness value. It is also possible for the user to adjust and change the automatically set exposure time.

[0082] The exposure time setting unit 301d sets the exposure time of the imaging unit 120 when the multi-slit pattern light is irradiated, based on the exposure time of the imaging unit 120 when the multi-slit pattern light is irradiated, as set as described above, and the ratio of the exposure time held in the setting table (Gray code / multi-slit exposure time ratio).

[0083] As shown in Figure 10, in high-speed mode, the photodetector 121 generates image data 900, and the measurement control unit 130 performs an averaging process on multiple pattern image data from the image data 900 generated by the photodetector 121 when Gray code pattern light is irradiated to generate image 901, while the multiple pattern image data from when multi-slit pattern light is irradiated remains as image data 902. The controller 300 generates a phase image 903, point cloud data 904, and mesh data 905 based on the image data 901 from when Gray code pattern light is irradiated and the image data 902' obtained by performing an averaging process on multiple pattern image data from when multi-slit pattern light is irradiated, which are transferred from the measurement control unit 130.

[0084] In standard mode, the photodetector 121 generates image data 910, and the measurement control unit 130 performs an averaging process on multiple pattern image data from the image data 910 generated by the photodetector 121 when Gray code pattern light is irradiated to generate image 911, while the multiple pattern image data from when multi-slit pattern light is irradiated remains as image data 912. Based on the image data 911 from when Gray code pattern light is irradiated and the multiple pattern image data 912 from when multi-slit pattern light is irradiated, which are transferred from the measurement control unit 130, the controller 300 generates a phase image 913, point cloud data 914, and mesh data 915.

[0085] In high-resolution mode, the light-receiving element 121 generates image data 920, and the measurement control unit 130 performs an averaging process on multiple pattern image data from the image data 920 generated by the light-receiving element 121 when Gray code pattern light is irradiated to generate image 921, while the multiple pattern image data from when multi-slit pattern light is irradiated remains as image data 922. The controller 300 generates an upsampled phase image 923 based on the image data 921 from when Gray code pattern light is irradiated and the multiple pattern image data 922 from when multi-slit pattern light is irradiated, which are transferred from the measurement control unit 130, and generates point cloud data 924 and mesh data 925 based on this phase image 923.

[0086] In other words, in standard mode and high-resolution mode, the pattern image data of the Gray code pattern light is binned, so 4 pixels are added together and treated as 1 pixel, resulting in a 1 / 4 reduction in the number of pixels. As a result, the signal-to-noise ratio (S / N) per pixel is higher compared to the pattern image data of the multi-slit pattern light that is not binned. Therefore, when matching the S / N of the pattern image data of the multi-slit pattern light and the Gray code pattern light, the exposure time when the multi-slit pattern light is irradiated can be reduced to 1 / 4 (=0.25), as shown in Figure 12. Since the binning mode is the same in standard mode and high-resolution mode, the ratio is also the same.

[0087] Gray code pattern light is more resistant to disturbances than multi-slit pattern light. Therefore, even if the signal-to-noise ratio (S / N) of the Gray code pattern image data is slightly lower than that of the multi-slit pattern image data, there is no problem in terms of resolution. For this reason, in high-speed mode, the exposure time is reduced to 1 / 8.

[0088] Furthermore, the pattern image data of the multi-slit pattern light can be downsampled after applying a kernel Gaussian filter. Due to the pixel averaging effect of the kernel Gaussian filter, the signal-to-noise ratio per pixel is improved compared to when the filter is not applied. Therefore, the exposure time can be reduced.

[0089] (Method for generating 3D shape data) Next, the method for generating 3D shape data will be explained in detail with reference to the flowchart shown in Figure 13. In step SA1 after the start, the reception unit 301e accepts the user's input to select an operating mode (one of high-speed mode, standard mode, or high-definition mode). In step SA2, multiple exposure images are acquired to set the exposure time. In step SA3, the exposure time setting unit 301d obtains a target brightness value corresponding to the operating mode accepted in step SA1 from the setting table stored in the storage unit 304.

[0090] In step SA4, the exposure time setting unit 301d determines the relationship between exposure time and average brightness from the multiple exposure images acquired in step SA2, and sets the exposure time such that the average brightness of the pattern image data captured when the multi-slit pattern light is irradiated becomes the target brightness value acquired in step SA3.

[0091] In step SA5, the exposure time setting unit 301d obtains the Gray code / multi-slit exposure time ratio corresponding to the operating mode received in step SA1 from the setting table stored in the memory unit 304. The exposure time when the Gray code pattern light is irradiated is set so that the obtained time ratio is achieved.

[0092] In step SA6, the structured illumination unit 110 irradiates the workpiece W multiple times with multi-slit pattern light while shifting its phase, and the imaging unit 120 sequentially receives the multi-slit pattern light reflected from the workpiece W at the exposure time set in step SA4, thereby sequentially generating multiple pattern image data. This is the first image data generation step.

[0093] In step SA7, the structured illumination unit 110 irradiates the workpiece W multiple times with Gray code pattern light while shifting its phase, and the imaging unit 120 sequentially receives the Gray code pattern light reflected from the workpiece W at the exposure time set in step SA5, thereby sequentially generating multiple pattern image data. This is the second image data generation step.

[0094] In step SA8, the averaging processing unit 130a performs averaging on the pattern image data of the Gray code pattern light. In step SA9, the relative phase calculation unit 301a calculates the relative phase of the workpiece W based on the pattern image data of the multi-slit pattern light. In high-speed mode, the averaging processing is performed on the pattern image data of the multi-slit pattern light before calculating the relative phase.

[0095] In step SA10, the absolute phase calculation unit 301b calculates the absolute phase of the workpiece W based on the pattern image data of the Gray code pattern light after averaging. Step SA9 constitutes the first calculation step of the present invention. Steps SA8 and SA10 constitute the second calculation step of the present invention.

[0096] Step SA11 generates a phase image based on the relative phase calculated in step SA9 and the absolute phase calculated in step SA10. At this time, if high-resolution mode is enabled, upsampling is performed on the phase image. In step SA12, point cloud data is generated using the phase image generated in step SA11. In step SA13, mesh data is generated using the point cloud data. Steps SA11 to SA13 are the three-dimensional shape data generation steps of the present invention.

[0097] The first image data generation step, the second image data generation step, the first calculation step, the second calculation step, and the three-dimensional shape data generation step described above are steps performed by a computer (including the controller 300 and the measuring unit 100) on which the three-dimensional shape data generation program is installed.

[0098] (Embodiment 2) Figure 14 shows the overall configuration of the three-dimensional shape data generation device 1 according to Embodiment 2 of the present invention. The three-dimensional shape data generation device 1 according to Embodiment 2 differs from that of Embodiment 1 in that the measuring unit 100 and the base unit 200 are integrated. Hereinafter, the same reference numerals are used for parts that are the same as in Embodiment 1 and their descriptions are omitted, while the different parts will be described in detail.

[0099] Specifically, a support section 250 for supporting the measuring section 100 is provided on the rear side of the base section 200, extending upward. The measuring section 100 is fixed to the upper part of this support section 250. The measuring section 100 is equipped with a structured illumination section 110 and an imaging section 120 such that the optical axis is directed toward the stage 202.

[0100] Even with a three-dimensional shape data generation device 1 like that in Embodiment 2, three-dimensional shape data can be generated in the same way as in Embodiment 1.

[0101] The embodiments described above are merely illustrative in all respects and should not be interpreted restrictively. Furthermore, any modifications or changes that fall within the equivalent scope of the claims are all within the scope of the present invention. [Industrial applicability]

[0102] As described above, the 3D shape data generation device relating to this disclosure can be used to generate 3D shape data of a workpiece. [Explanation of symbols]

[0103] 1. 3D Shape Data Generation Device 110 Structured lighting section 112 Optical elements 120 Imaging Unit 121 Photodetector 301a Relative phase calculation unit 301b Absolute Phase Calculation Unit 301c 3D Shape Data Generation Unit 301e Reception Desk 304 Storage section

Claims

1. A structured illumination unit that irradiates the object to be measured multiple times with structured light having a first light-dark period while phase-shifting it, and also irradiates the object to be measured multiple times with structured light having a second light-dark period that is longer than the first light-dark period, An imaging unit sequentially generates a plurality of pattern image data representing an image of an object by sequentially receiving the structured light having the first light-dark period reflected from the object to be measured for a first exposure time, and sequentially generates a plurality of pattern image data representing an image of an object by sequentially receiving the structured light having the second light-dark period reflected from the object to be measured for a second exposure time shorter than the first exposure time, A first calculation unit calculates the relative phase of an object based on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having the first light-dark period reflected from the object to be measured, A second calculation unit generates a plurality of pattern image data by performing averaging and downsampling on a plurality of pattern image data generated when the imaging unit sequentially receives the structured light having the second light-dark period reflected from the object to be measured, and calculates the absolute phase of the object to be measured based on the plurality of pattern image data. A three-dimensional shape data generation device comprising: a three-dimensional shape data generation unit that generates three-dimensional shape data of an object to be measured based on the relative phase of the object to be measured calculated by the first calculation unit and the absolute phase of the object to be measured calculated by the second calculation unit.

2. A three-dimensional shape data generation apparatus according to claim 1, A storage unit that stores a setting table in which a target brightness value for determining the exposure time of the imaging unit and the ratio of the first exposure time to the second exposure time are stored, The system further comprises an exposure time setting unit for setting the exposure time of the imaging unit, The exposure time setting unit is, The first exposure time is set based on the brightness values ​​of the pattern image data generated by the imaging unit at multiple different exposure times and the target brightness value stored in the setting table. A three-dimensional shape data generation device that sets the second exposure time based on the set first exposure time and the ratio of the first exposure time to the second exposure time held in the setting table.

3. A three-dimensional shape data generation apparatus according to claim 1, The structured illumination unit includes an optical element for generating the structured light. The imaging unit includes a light-receiving element for receiving structured light reflected from the object to be measured and generating the pattern image data. A three-dimensional shape data generation device in which the resolution of the optical element is set to be greater than the resolution of the light-receiving element.

4. A three-dimensional shape data generation apparatus according to claim 3, The second calculation unit is a three-dimensional shape data generation device that performs an averaging process on the plurality of pattern image data based on the ratio of the resolution of the optical element to the resolution of the light-receiving element.

5. A three-dimensional shape data generation apparatus according to claim 1, further, The first calculation unit performs an averaging process on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having the first light-dark period reflected from the object to be measured, and calculates the relative phase of the object to be measured based on the plurality of pattern image data after the averaging process. The second calculation unit performs an averaging process on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having the second light-dark period reflected from the object to be measured, and calculates the absolute phase of the object to be measured based on the plurality of pattern image data after the averaging process. A three-dimensional shape data generation apparatus comprising a reception unit that accepts a selection of which of the following two operating modes the generation of three-dimensional shape data is to be performed: a first calculation unit calculates the relative phase of an object to be measured without performing an averaging process on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having a first light-dark period reflected from the object to be measured; and a second calculation unit performs an averaging process on a plurality of pattern image data generated by the imaging unit sequentially receiving structured light having a second light-dark period reflected from the object to be measured, and calculates the absolute phase of the object to be measured based on the plurality of pattern image data after the averaging process; and

6. A three-dimensional shape data generation apparatus according to claim 5, A measuring unit having the aforementioned ROM unit, The controller, which is separate from the measurement unit, further comprises the first calculation unit, the second calculation unit, and the three-dimensional shape data generation unit. The averaging process for a plurality of pattern image data generated by the imaging unit sequentially receiving the structured light having the second light-dark period reflected from the object to be measured is performed by embedded software incorporated into the measurement unit. A three-dimensional shape data generation device in which image data, after averaging processing has been performed by the aforementioned embedded software, is transferred to the controller.

7. A three-dimensional shape data generation apparatus according to claim 6, A three-dimensional shape data generation device in which averaging processing of multiple pattern image data generated by sequentially receiving structured light having the first light-dark period reflected from the object to be measured by the imaging unit is performed by the image processing software of the controller.

8. A three-dimensional shape data generation apparatus according to claim 5, The three-dimensional shape data generation unit generates a phase image based on the relative phase of the object to be measured calculated by the first calculation unit and the absolute phase of the object to be measured calculated by the second calculation unit, and upsamples the generated phase image, when the second operating mode is selected.

9. A three-dimensional shape data generation apparatus according to claim 5, The system further includes a storage unit that stores a first target brightness value for determining the exposure time of the imaging unit when the first operating mode is selected, and a second target brightness value for determining the exposure time of the imaging unit when the second operating mode is selected. A three-dimensional shape data generation device in which the second target brightness value is set higher than the first target brightness value.

10. A first image data generation step involves irradiating the object to be measured multiple times with structured light having a first light-dark period while phase-shifting it, and sequentially receiving the structured light having the first light-dark period reflected by the object to be measured for a first exposure time to sequentially generate a plurality of pattern image data showing an image of the object to be measured. A second image data generation step involves irradiating the object to be measured multiple times with structured light having a second light-dark period longer than the first light-dark period, and sequentially receiving the structured light having the second light-dark period reflected by the object to be measured for a second exposure time shorter than the first exposure time, thereby sequentially generating a plurality of pattern image data representing an image of the object to be measured. A first calculation step which calculates the relative phase of the object to be measured based on a plurality of pattern image data generated in the first image data generation step, A second calculation step involves performing an averaging process on the multiple pattern image data generated in the second image data generation step, and calculating the absolute phase of the object to be measured based on the multiple pattern image data after the averaging process. A method for generating three-dimensional shape data, comprising: a three-dimensional shape data generation step that generates three-dimensional shape data of an object to be measured based on the relative phase of the object to be measured calculated by the first calculation step and the absolute phase of the object to be measured calculated by the second calculation step.

11. A first image data generation step involves irradiating the object to be measured multiple times with structured light having a first light-dark period while phase-shifting it, and sequentially receiving the structured light having the first light-dark period reflected by the object to be measured for a first exposure time to sequentially generate a plurality of pattern image data showing an image of the object to be measured. A second image data generation step involves irradiating the object to be measured multiple times with structured light having a second light-dark period longer than the first light-dark period, and sequentially receiving the structured light having the second light-dark period reflected by the object to be measured for a second exposure time shorter than the first exposure time, thereby sequentially generating a plurality of pattern image data representing an image of the object to be measured. A first calculation step which calculates the relative phase of the object to be measured based on a plurality of pattern image data generated in the first image data generation step, A second calculation step involves performing an averaging process on the multiple pattern image data generated in the second image data generation step, and calculating the absolute phase of the object to be measured based on the multiple pattern image data after the averaging process. A three-dimensional shape data generation program that causes a computer to perform a three-dimensional shape data generation step, which generates three-dimensional shape data of an object to be measured based on the relative phase of the object to be measured calculated in the first calculation step and the absolute phase of the object to be measured calculated in the second calculation step.

Images