阅读说明：本技术 观察方法和观察装置 (Observation method and observation device ) 是由 丰仓祥太 于 2019-09-05 设计创作，主要内容包括：在本观察方法中,从光学相干断层成像仪获取测量对象在与深度方向相交的平面中的多个不同位置处的测量值(S100)。在本观察方法中,对多个位置中的每个位置处的同一深度位置的测量值求平均(S104)。在本观察方法中,在深度方向上对多个深度位置中的每个深度位置处的平均值计算积分值(S105)。在本观察方法中,基于积分值来计算测量对象的收缩参数(S106)。(In the present observation method, measurement values of a measurement object at a plurality of different positions in a plane intersecting with a depth direction are acquired from an optical coherence tomography (S100). In the present observation method, the measurement values of the same depth position at each of the plurality of positions are averaged (S104). In the present observation method, an integrated value is calculated in the depth direction for the average value at each of a plurality of depth positions (S105). In the present observation method, a contraction parameter of a measurement object is calculated based on an integrated value (S106).)

1. A method of viewing, comprising:

acquiring measurement values of a measurement object at different plural positions in a plane intersecting with a depth direction from an optical coherence tomography;

calculating an average value by averaging measurements at the same depth position at each of the plurality of positions;

calculating an integrated value by integrating the average value at each of the depth positions in the depth direction; and

calculating a contraction parameter of the measurement object based on the integrated value.

2. The observation method of claim 1, further comprising:

detecting, at each of the plurality of positions, a peak position of the measurement value in the depth direction, wherein,

calculating the average includes: averaging measurements at each of the plurality of locations at the same depth position that references the peak position.

3. The observation method according to claim 1 or 2, wherein,

calculating the integration value includes: the measurements are integrated over a range of predetermined depth positions.

4. The observation method according to any one of claims 1 to 3, wherein,

a calibration curve is used to convert the integration value into the contraction parameter.

5. A method of viewing, comprising:

acquiring measurement values of a measurement object at different plural positions in a plane intersecting with a depth direction from an optical coherence tomography;

calculating an integrated value by integrating the measurement value at each of the plurality of positions in the depth direction;

calculating an average value by averaging the integrated values calculated for each of the plurality of positions; and

calculating a contraction parameter of the measurement object based on the average value.

6. A viewing device, comprising:

a controller that acquires measurement values of a measurement object at different plural positions in a plane intersecting a depth direction from an optical coherence tomography, calculates an average value by averaging the measurement values at the same depth position at each of the plural positions, calculates an integrated value by integrating the average value at each of the depth positions, and calculates a contraction parameter of the measurement object based on the integrated value.

Technical Field

The present disclosure relates to an observation method and an observation apparatus.

Background

Ceramics are excellent in various physical properties such as hardness, heat resistance, corrosion resistance, and electrical insulation. Accordingly, ceramic structures manufactured to achieve the functions required in a particular application are being used for a variety of purposes.

The ceramic structure is produced by performing steps such as a mixing step, a molding step, a drying step, and a firing step on raw materials (see patent document 1). The ceramic structure being fabricated shrinks during steps such as the drying step and the firing step. The shrunk structure is ground to conform to the desired dimensions. The structure after shrinkage is hard and takes time to grind. Therefore, the size of the structure before shrinkage (hereinafter, referred to as a "molded body") in the molding step is determined such that the structure is as close as possible to the size required after shrinkage.

The shrinkage during the manufacturing process varies depending on factors such as the properties of the shaped body. Therefore, even with the same mixing, the size of the molded body to be determined varies with each batch of the mixed raw materials. In the molding step of the related art, an intermediate molded body is molded by a rubber press or the like, a shrinkage rate is estimated by inspecting the intermediate molded body, the size of the molded body is determined based on the shrinkage rate, and the intermediate molded body is cut into a size matching the size of the molded body. The inspection of the intermediate molded body takes a relatively long time. Therefore, a part of the intermediate molded body made of raw materials mixed in the same lot is extracted to inspect the intermediate molded body of the part, and the shrinkage rate estimated based on the inspection is taken as the shrinkage rate of the molded body of the same lot to adjust cutting conditions such as the cutting amount.

CITATION LIST

Patent document

Patent document 1: japanese patent laid-open No.2017-170869

Disclosure of Invention

The observation method according to the first aspect includes:

acquiring measurement values of a measurement object at different plural positions in a plane intersecting with a depth direction from an optical coherence tomography;

calculating an average value by averaging measurements at the same depth position at each of the plurality of positions;

calculating an integrated value by integrating the average value at each of the depth positions in the depth direction; and

calculating a contraction parameter of the measurement object based on the integrated value.

In addition, the observation method according to the second aspect includes:

acquiring measurement values of a measurement object at different plural positions in a plane intersecting with a depth direction from an optical coherence tomography;

calculating an integrated value by integrating the measurement value at each of the plurality of positions in the depth direction;

calculating an average value by averaging the integrated values calculated for each of the plurality of positions; and

calculating a contraction parameter of the measurement object based on the average value.

Further, an observation apparatus according to a third aspect includes:

a controller that acquires measurement values of a measurement object at different plural positions in a plane intersecting a depth direction from an optical coherence tomography, calculates an average value by averaging the measurement values at the same depth position at each of the plural positions, calculates an integrated value by integrating the average value at each of the depth positions, and calculates a contraction parameter of the measurement object based on the integrated value.

Drawings

In the drawings:

fig. 1 is a functional block diagram showing a schematic configuration of a viewing system including a viewing apparatus of a first embodiment;

fig. 2 is a diagram showing a relationship between a measured value calculated by a controller of the optical coherence tomography in fig. 1 and a depth direction;

fig. 3 is a diagram for explaining measured values calculated at a plurality of positions by the optical coherence tomography in fig. 1;

fig. 4 is a diagram for explaining how the controller of the observation apparatus in fig. 1 aligns the depth position of the peak as the measurement value with the reference position;

fig. 5 is a diagram for explaining how the controller of the observation apparatus in fig. 1 averages measured values respectively detected at a plurality of positions for the same depth position;

fig. 6 is a diagram for explaining how the controller of the observation apparatus in fig. 1 calculates the integrated value from the average value of the measurement values at the same depth position;

FIG. 7 is a graph for explaining a calibration curve showing a correspondence between an integrated value of measured values and a density of a green embryo;

fig. 8 is a flowchart for explaining a contraction parameter output process performed by the controller of the observation apparatus in fig. 1 in the first embodiment; and

fig. 9 is a flowchart for explaining the contraction parameter output process performed by the controller of the observation apparatus in the second embodiment.

Detailed Description

Hereinafter, an embodiment of a viewing device to which the present disclosure is applied will be described with reference to the drawings.

As shown in fig. 1, a viewing system 11 including a viewing apparatus 10 according to a first embodiment of the present disclosure is configured to include an optical coherence tomography imager 12 and the viewing apparatus 10. The observation system 11 observes, for example, a molded body which is an intermediate of the ceramic structure as the object obj to be measured. Note that, in fig. 1, a solid line with arrows connecting the functional blocks shows the travel of the light beam. In fig. 1, the flow of control signals or communication information is shown by a dotted line connecting the functional blocks. The communication indicated by the dotted line may be wired communication or wireless communication.

The optical coherence tomography 12 captures an image from the surface of the measurement object obj to a maximum depth of about 10mm by Optical Coherence Tomography (OCT). In the first embodiment, the optical coherence tomography 12 is a wavelength-swept type OCT apparatus, but may be another type of OCT apparatus. Optical coherence tomography 12 includes light source 13, beam splitter 14, reference mirror 15, scanner 16, detector 17, and controller 18.

For example, the light source 13 emits light in a frequency band that can be detected by the detector 17, such as light in a near infrared band. The light source 13 may be a wavelength sweep type light source, and may repeatedly emit light of a wavelength varying within a predetermined range along a time axis. Note that, in a configuration in which the optical coherence tomographic imager 12 is an OCT apparatus of a type other than the wavelength-scanning type, the light source 13 may be a light source corresponding to the type. The light source 13 includes a collimator lens, for example, and emits collimated light having a narrow diameter.

A beam splitter 14 is arranged in the emission direction of the light source 13. For example, the beam splitter 14 is a half mirror. The beam splitter 14 splits the light emitted from the light source 13 and makes the light travel in two directions. In addition, the beam splitter 14 causes coherent light obtained by mixing the reference light incident from the reference mirror 15 and the signal light incident from the measurement object obj to travel toward the detector 17.

A reference mirror 15 is provided in one of the traveling directions of the light split by the beam splitter 14. The reference mirror 15 is arranged such that the mirror plane is perpendicular to the traveling direction, and reflects incident light as reference light toward the beam splitter 14.

The scanner 16 scans the measurement object obj by using, as irradiation light, light traveling in a direction different from the reference mirror 15 among the light split by the beam splitter 14. The scanner 16 may scan by any of a variety of methods. For example, the scanner 16 may perform scanning by reflecting the irradiation light while changing the reflection direction using a reflection member such as a galvanometer mirror. In addition, the scanner 16 can also perform scanning by changing the irradiation position of the irradiation light on the surface of the measurement object obj using a movable stage.

Note that, in the optical coherence tomography 12, the measurement object obj is set such that the irradiation light irradiates the measurement object obj at an incident angle equal to or larger than 0 °. The irradiation light that irradiates the respective positions of the measurement object obj by the scanner 16 advances in the depth direction from the surface while being attenuated by absorption, and is reflected and scattered at each depth position. The reflected and scattered signal light is incident on the beam splitter 14.

The detector 17 receives the coherent light traveling from the beam splitter 14. The detector 17 outputs a measurement signal having an intensity corresponding to the amount of received light.

The controller 18 includes one or more processors and memory. The processor may include a general-purpose processor for performing a specific function by loading a specific program, and a special-purpose processor dedicated to a specific process. The special purpose processor may comprise an Application Specific Integrated Circuit (ASIC). The processor may also include a Programmable Logic Device (PLD). The PLD may include a Field Programmable Gate Array (FPGA). The controller 18 may also be a system on chip (SoC) or a System In Package (SiP) in which one or more processors cooperate.

The controller 18 calculates the intensity of reflected light in the depth direction at any irradiation position EP of the irradiation light EL as shown in fig. 2 as a measurement value by performing inverse fourier transform on the measurement signal acquired from the detector 17. The controller 18 identifies the irradiation position EP in a plane intersecting with the depth direction, which overlaps with the irradiation direction of the irradiation light EL, by acquiring the position information from the scanner 16. The controller 18 outputs the irradiation position EP and the reflected light intensity in the depth direction to the observation device 10 in association with each other.

The viewing device 10 comprises a controller 19 and a storage device 20.

The controller 19 includes one or more processors and memory. The processor may include a general-purpose processor for performing a specific function by loading a specific program, and a special-purpose processor dedicated to a specific process. The special purpose processor may comprise an Application Specific Integrated Circuit (ASIC). The processor may also include a Programmable Logic Device (PLD). The PLD may comprise an FPGA. The controller 19 may also be a SoC or SiP in which one or more processors are protected from action.

As shown in fig. 3, the controller 19 acquires measurement values of the measurement object obj at a plurality of different positions in a plane intersecting the depth direction, or in other words, a plurality of irradiation positions EP, from the optical coherence tomography 12. Note that, in the first embodiment, as described above, the measurement value of the measurement object obj is the reflected light intensity in the depth direction. The controller 19 may cause the storage device 20 to store the acquired measurement values in the depth direction at each of the plurality of locations.

The controller 19 may detect, as a peak position, a position in the depth direction at which a peak occurs in the measurement values of the measurement object obj at each of the plurality of positions. As shown in fig. 4, the controller 19 may align a reference position in the depth direction of the measurement value of the measurement object obj at each of the plurality of positions (for example, from the first irradiation position to the fifth irradiation position) with the detected peak position.

As shown in fig. 5, the controller 19 calculates an average value by averaging the measurement values at the same depth position at each of the plurality of positions. In the configuration of aligning the reference position in the depth direction with the detected peak position as described above, the controller 19 may average the measurement values at the same depth position, which refers to the peak position, at each of the plurality of positions.

As shown in fig. 6, the controller 19 integrates the average measurement value in the depth direction to calculate an integrated value. Note that, in calculating the integration value, the controller 19 may integrate the measurement values included in the range of the predetermined depth position. The predetermined depth position may be a depth position in a coordinate system with a reference point in the optical coherence tomography 12 as an origin, or a depth position based on a peak position in the depth direction.

Based on the integrated value, the controller 19 calculates a contraction parameter of the measurement object obj. Note that the shrinkage parameter is an arbitrary variable indicating the internal state of the molded article as the measurement object obj, and the shrinkage parameter affects the degree of shrinkage when the measurement object obj is dried and fired. The shrinkage parameter is a parameter such as green density or porosity of the shaped part. The integral value is related to a shrinkage parameter, such as green density, and may vary depending on the density of the formed part. Thus, controller 19 may calculate the contraction parameter by converting from the integrated value using a calibration curve of the contraction parameter against the integrated value (such as the calibration curve shown in FIG. 7).

The controller 19 reports the calculated shrinkage parameters to the ceramic structure manufacturing apparatus. Based on the reported shrinkage parameter, the manufacturing apparatus determines a cutting condition for the measurement object obj for which the shrinkage parameter has been calculated. The manufacturing apparatus cuts the measurement object obj under the determined cutting conditions, and manufactures a ceramic structure by being subjected to a drying step and a firing step. Note that the controller 19 may also calculate the cutting condition based on the shrinkage parameter. In the configuration in which the controller 19 calculates the cutting conditions, the controller 19 controls the manufacturing apparatus to cut the measurement object obj according to the calculated cutting conditions.

For example, the storage 20 includes any type of storage device, such as Random Access Memory (RAM) and Read Only Memory (ROM). The storage device 20 stores various programs that make the controller 19 function, and various information used by the controller 19.

For example, the storage device 20 stores the reflected light intensity in the depth direction at each of a plurality of positions for each measurement object obj. In addition, for example, the storage device 20 stores a calibration curve of the contraction parameter with respect to the integration value. In addition, for example, the storage device 20 stores the contraction parameter calculated for each measurement object obj.

Next, the contraction parameter output process performed by the controller 19 in the first embodiment will be described using the flowchart in fig. 8. When the optical coherence tomography 12 starts measuring the measurement value of any of the measurement objects obj, the contraction parameter output processing starts together. Note that, for example, the controller 19 may recognize the start of measurement by the optical coherence tomography 12 by a synchronization signal acquired from the optical coherence tomography 12.

In step S100, the controller 19 acquires a measurement value of the measurement object obj at any irradiation position EP, or in other words, the reflected light intensity in the depth direction. After the acquisition, the process advances to step S101.

In step S101, the controller 19 detects a position in the depth direction at which a peak occurs in the measurement values acquired in step S101 as a peak position. After the peak position is detected, the process proceeds to step S102.

In step S102, the controller 19 determines whether measurement values have been acquired at all positions at which the measurement object obj is to be measured. Note that the controller 19 may determine whether or not the measurement values have been acquired at all the positions based on a synchronization signal acquired from the optical coherence tomography 12, notification information indicating completion, or the like. In the case where the measurement values have not been acquired at all the positions, the process returns to step S100. In the case where the measurement values have been acquired at all the positions, the process proceeds to step S103.

In step S103, the controller 19 aligns the reference position in the depth direction of the measurement value at each of the plurality of positions with the peak position detected in step S101. After the positioning is referred to, the process advances to step S104.

In step S104, the controller 19 averages the measured value at each of the plurality of positions aligned with the reference position in step S103 for the same depth position, respectively, to calculate an average value. After the average value is calculated, the process proceeds to step S105.

In step S105, the controller 19 integrates the measurement values averaged in step S104 within the range of the predetermined depth position to calculate an integrated value. After the integrated value is calculated, the process proceeds to step S106.

In step S106, the controller 19 calculates a contraction parameter based on the integrated value calculated in step S105. After the contraction parameter is calculated, the process proceeds to step S107.

In step S107, the controller 19 outputs the shrinkage parameter calculated in step S106 to the manufacturing apparatus. After the contraction parameter is output, the contraction parameter output process ends.

In the observation apparatus 10 according to the first embodiment having the above-described configuration, the measurement values of the measurement object obj measured at a plurality of positions by the optical coherence tomography 12 are used. Therefore, since the observation apparatus 10 uses the measurement result from the optical coherence tomography 12 capable of rapid and non-invasive imaging, the observation apparatus 10 can rapidly observe each measurement object obj that is finally processed into a finished product.

Also, the observation device 10 according to the first embodiment averages the measurement values at each of the plurality of positions. Therefore, the observation device 10 can calculate the contraction parameter for estimating the contraction of the entire measurement object obj while reducing the variation in the measurement value due to the plurality of positions.

Further, the observation device 10 according to the first embodiment averages the measurement values at the same depth position. As the light travels farther in the depth direction of the measurement object obj, the irradiation light from the optical coherence tomography 12 attenuates greatly. Therefore, even if the internal state of the measurement object obj is uniform in the depth direction, the measurement values at different depths are usually different values. With respect to this phenomenon, the observation device 10 having the above-described configuration averages the measured values in the same depth direction approximately having the same degree of attenuation, and therefore the influence of the variation caused by the attenuation can be eliminated from the average value.

Further, the observation device 10 according to the first embodiment integrates the respective average values of the plurality of depth positions in the depth direction, and calculates the contraction parameter of the entire measurement object obj based on the integrated values. Therefore, the observation device 10 can detect a parameter that affects shrinkage in steps such as the drying step and the firing step.

Further, the observation device 10 according to the first embodiment performs averaging of measurement values at the same depth position with reference to the peak position. In the optical coherence tomography 12, the surface of the measurement object is inclined with respect to the traveling direction (or in other words, the depth direction) of the irradiation light to reduce strong back reflection detected from the surface of the measurement object. As described above, as the irradiation light EL irradiating the measurement object obj travels in the depth direction from the surface, the irradiation light EL is greatly attenuated, and therefore, as the depth position from the surface becomes longer, the intensity of the measurement value also decreases. With respect to such a phenomenon, the observation device 10 having the above-described configuration averages the measurement values at the same depth position with reference to the peak position estimated as the surface position, and therefore, even with the configuration in which the measurement object obj is inclined with respect to the depth direction, the influence of the variation due to the attenuation can be removed from the average value.

Further, the observation device 10 according to the first embodiment integrates the measurement values over a range of predetermined depth positions. With the resolving power of the optical coherence tomography, the surface of the measurement object obj can be detected with one or two pixels (or in other words at one or two depth positions, respectively). The measurement value obtained by detecting the surface of the measurement object obj with one pixel is greatly different in intensity from the measurement value detected with two pixels. Therefore, the average of the measured values at the depth position corresponding to the surface where the intensity is particularly strong has relatively low reliability as the measured value. On the other hand, the observation device 10 having the above-described configuration can integrate the average value of the measurement values in a range other than the depth position corresponding to the surface, and therefore, the estimation accuracy of estimating the shrinkage of the measurement object obj based on the shrinkage parameter can be improved.

Moreover, in the observation device 10 according to the first embodiment, the integrated value is converted into the contraction parameter by using the calibration curve. Therefore, the observation device 10 can reduce the processing load on the controller 19.

Next, an observation device according to a second embodiment of the present disclosure will be described. In the second embodiment, the order of processing performed by the controller of the observation apparatus is different from that of the first embodiment. Hereinafter, the second embodiment will be described focusing on the different points from the first embodiment. Note that members having the same configuration as that of the first embodiment are denoted by the same reference numerals.

As shown in fig. 1, the observation device 10 according to the second embodiment includes a controller 19 and a storage device 20 as in the first embodiment. Note that in the second embodiment, the rigidity and function of the optical coherence tomographic imager 12 are the same as those of the optical coherence tomographic imager 12 according to the first embodiment.

In the second embodiment, as in the first embodiment, the controller 19 of the observation apparatus 10 acquires the measurement values of the measurement object obj at the plurality of irradiation positions EP. In the second embodiment, as in the first embodiment, the observation device 19 can detect, as a peak position, a position in the depth direction at which a peak appears in the measurement values of the measurement object obj at each of the plurality of positions. Also in the second embodiment, as in the first embodiment, the observation device 19 may also align the reference position in the depth direction of the measurement value of the measurement object obj at each of the plurality of positions with the detected peak position.

In the second embodiment, unlike the first embodiment, the controller 19 integrates the measurement value at each of the plurality of positions in the depth direction to calculate the integrated value for each of the plurality of positions before averaging. Note that in the second embodiment, the controller 19 may integrate the measurement values included in the range of the predetermined depth position when calculating the integration value, as in the first embodiment. The predetermined depth position in the second embodiment may be the same as that in the first embodiment.

In the second embodiment, unlike the first embodiment, the controller 19 averages the integrated values calculated for each of the plurality of positions to calculate an average value. In the second embodiment, the controller 19 calculates the contraction parameter of the measurement object obj based on the calculated average value, unlike the first embodiment. In the second embodiment, the controller 19 may report the calculated shrinkage parameter to the manufacturing apparatus or calculate a cutting condition based on the calculated shrinkage parameter to control the manufacturing apparatus, as in the first embodiment.

Next, the contraction parameter output process performed by the controller 19 in the second embodiment will be described using the flowchart in fig. 9. In the second embodiment, as in the first embodiment, when the optical coherence tomography 12 starts measuring the measurement value of any one of the measurement objects obj, the contraction parameter output process starts together.

In steps S200 to S203, the controller 19 performs the same operations as those in steps S100 to S103 of the contraction parameter output process of the first embodiment. In step S204, the controller 19 integrates the measurement value at each of the plurality of positions aligned with the reference position in step S203 within the range of the predetermined depth position to calculate an integrated value. After the integrated value is calculated, the process proceeds to step S205.

In step S205, the controller 19 averages the integrated values calculated in step S204 for each of the plurality of positions to calculate an average value. After the average value is calculated, the process proceeds to step S206.

In step S206, the controller 19 calculates a contraction parameter based on the average value calculated in step S205. After the contraction parameter is calculated, the process proceeds to step S207.

In step S207, the controller 19 outputs the shrinkage parameter calculated in step S206 to the manufacturing apparatus. After the contraction parameter is output, the contraction parameter output process ends.

In the observation apparatus 10 according to the second embodiment having the above-described configuration, as in the first embodiment, the measurement values of the measurement object obj measured at a plurality of positions by the optical coherence tomography 12 are used. Therefore, the observation device 10 can quickly observe each measurement object obj that is finally processed into a finished product.

Further, the observation device 10 according to the second embodiment integrates the measurement value at each of the plurality of positions in the depth direction, and finally calculates the contraction parameter of the entire measurement object obj based on the integrated value. Therefore, the observation device 10 according to the second embodiment can detect the parameters that affect the shrinkage in the steps such as the drying step and the firing step.

Also, the observation device 10 according to the second embodiment averages the integrated values at each of the plurality of positions. Therefore, the observation apparatus 10 according to the second embodiment can calculate the contraction parameter for estimating the contraction of the entire measurement object obj while reducing the variation in the integral value caused by the plurality of positions.

The present disclosure has been described based on the drawings and examples, but it should be noted that various modifications and changes can be easily made by those skilled in the art based on the present disclosure. Therefore, it should be noted that these modifications and changes are included in the scope of the present disclosure.

Although the foregoing discloses a system described as including various modules and/or units performing specific functions, it should be noted that these modules and units are schematically illustrated to briefly describe their functions, and do not necessarily indicate specific hardware and/or software. In this sense, it is sufficient that the modules, units and other structural elements are hardware and/or software implemented to substantially perform the specific functions described herein. The various functions of the different structural elements may be combined or separated into hardware and/or software in any manner, and each of the various functions of the different structural elements may be used alone or in some combination with each other. In addition, devices such as keyboards, displays, touch screens, and pointing devices are included, but input/output, I/O devices, or user interfaces not limited to the above devices may be connected to the system either directly or through intervening I/O controllers. In this manner, the various aspects of the disclosure may be implemented in a number of different modes, and all such modes are included within the scope of the disclosure.

List of reference numerals

10 Observation device

11 viewing system

12 optical coherence tomography

13 light source

14 beam splitter

15 reference mirror

16 scanner

17 Detector

18 controller

19 controller

20 storage device

EL irradiation light

EP irradiation position

Obj measures the object.