Depth measurement device, depth measurement method and depth measurement program

Abstract

To provide a depth measurement device, a depth measurement method and a depth measurement program capable of improving precision of an automatic depth measurement technique and measuring a shape of an object.SOLUTION: A depth measurement device includes: a radiation source; a detector away from the radiation source by a first distance; an acquisition unit that maintains the object at a first position away from the radiation source in a depth direction heading from the radiation source toward a detection surface by a second distance, and away from the radiation source in a direction parallel to the detection surface by a third distance for an hour, moves the object from the first position to a second position away from the first position in the depth direction by a second distance, and at a fourth distance (that is different from the third distance) in the direction along the detection surface, maintains the object at the second position for two hours, and acquires a picked-up image while maintaining an exposure state; an identification unit for identifying a deviation amount of the position of an image of the object included in the picked-up image; and a calculation unit for calculating the second distance on the basis of the first distance, the difference between the third distance and the fourth distance, and the deviation amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a depth measurement device, a depth measurement method, and a depth measurement program, and in particular to a depth measurement device, a depth measurement method, and a depth measurement program capable of shape measurement. [Background technology]

[0002] In recent years, tomosynthesis technology has become widespread in imaging devices that use radiation, which acquires highly accurate internal information of a subject from a plurality of projection images acquired by irradiating the subject with radiation from a plurality of positions (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a tomographic image generating device that can obtain high-quality tomographic images of a subject by performing tomosynthesis imaging in which a radiation source is moved relative to the detection surface of a detector and radiation is irradiated onto the subject at the positions of multiple radiation sources. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Re-tabled publication No. 2020-067475 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a depth measurement device that uses tomosynthesis technology to measure the depth of an object inside a subject, the method of reconstructing multiple captured images obtained by changing the position of the radiation source using the tomographic image generating device disclosed in Patent Document 1 has the risk of causing a deterioration in the image quality of the tomographic image of the subject due to inconsistencies in the shape of the subject's image in the multiple captured images, which could lead to a decrease in the accuracy of the measured depth.

[0006] In view of the above problems, the present invention aims to provide a depth measurement device, a depth measurement method, and a depth measurement program that improve the accuracy of automatic depth measurement technology and are capable of measuring the shape of an object. [Means for solving the problem]

[0007] A first aspect of the present invention is a depth measurement device comprising: a detector of radiation emitted from the radiation source, the detector having a radiation source and a planar detection surface, the detector being at a first distance from the radiation source; an acquisition unit that maintains an object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance; moves the object to a second position where the distance in the depth direction from the first position is the second distance and the direction along the detection surface is a fourth distance different from the third distance; and maintains the object at the second position for a second time, maintaining an exposure state during this time to acquire an image; an identification unit that identifies an amount of positional deviation of an image of the object included in the image, calculated from an image of the object obtained by maintaining the object at the first position for the first time and an image obtained by maintaining the object at the second position for the second time; and a calculation unit that calculates the second distance based on the first distance, the difference between the third distance and the fourth distance, and the amount of deviation.

[0008] In a first aspect of the present invention, the amount of shift may be the distance between the position on the captured image where the brightness of the image obtained by maintaining an object contained in the captured image at a first position for the first time is at its maximum, and the position on the captured image where the brightness of the image obtained by maintaining the object at a second position for a second time is at its maximum.

[0009] The first aspect of the present invention may include a position control unit that changes the distance from the radiation source in a direction parallel to the detection surface of an object between the radiation source and the detector, while keeping the first distance constant.

[0010] In the first aspect of the present invention, the calculation unit may calculate the second distance using the following formula, where L0 is the first distance, L1 is the difference between the third distance and the fourth distance, L2 is the deviation amount, and L3 is the second distance.

[0011]

number

[0012] A second aspect of the present invention is a depth measurement method, characterized in that the computer capable of communicating with a radiation source and a detector of radiation emitted from the radiation source, which has a planar detection surface and is a first distance from the radiation source, maintains the object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance, moves the object to a second position where the distance in the depth direction from the first position is the second distance and where the distance along the detection surface is a fourth distance different from the third distance, and maintains the object at the second position for the second time, maintaining an exposure state during this time to acquire an image; identifies an amount of positional deviation of an image of the object included in the image, which is calculated from an image of the object obtained by maintaining the object at the first position for the first time and an image obtained by maintaining the object at the second position for the second time; and calculates the second distance based on the first distance, the difference between the third distance and the fourth distance, and the amount of deviation.

[0013] A third aspect of the present invention is a depth measurement program that is implemented in a computer capable of communicating with a radiation source and a detector of radiation emitted from the radiation source, the detector having a planar detection surface and a first distance from the radiation source. The computer implements the following functions: an acquisition function that maintains an object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance; moves the object to a second position where the distance in the depth direction is the second distance and the direction along the detection surface is a fourth distance different from the third distance; and maintains the object at the second position for the second time, maintaining an exposure state during this time to acquire an image; an identification function that identifies a positional deviation amount of an image of the object included in the image, the positional deviation amount being calculated from an image of the object obtained by maintaining the object at the first position for the first time and an image obtained by maintaining the object at the second position for the second time; and a calculation function that calculates the second distance based on the first distance, the difference between the third distance and the fourth distance, and the deviation amount.

[0014] According to the present invention, it is possible to provide a depth measurement device, a depth measurement method, and a depth measurement program that improve the accuracy of automatic depth measurement technology and are capable of measuring the shape of an object. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of an example of a depth measurement device according to a first embodiment of the present invention. [Figure 2] 2 is a schematic diagram showing the positional relationship between a radiation source, a detector, and an object shown in FIG. 1. FIG. [Figure 3] FIG. 1 is a block diagram for explaining a depth measurement device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing the positional relationship between a radiation source, a detector, and an object. [Figure 5] These are transmission images captured and acquired in the states shown in FIG. 4. [Figure 6] 1 is a transmission image captured and acquired by the depth measurement device according to the present embodiment. [Figure 7]7 is a graph showing the relationship between brightness and position for a plurality of pixels on the transmission image shown in FIG. 6. [Figure 8] 10 is an example of a transmission image captured and acquired by the depth measurement device according to the present embodiment. [Figure 9] 10 is a flowchart illustrating a depth measurement method according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings relating to the embodiment, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between planar dimensions and the like may differ from the actual ones. Therefore, specific dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios.

[0017] Furthermore, the embodiments are merely examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not limit the configuration, arrangement, layout, etc. of each component to those described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0018] (Embodiment) The depth measurement device according to this embodiment is a device that measures the depth of an object present inside a subject by irradiating the subject with radiation. The depth measurement device according to this embodiment measures the depth of the object by capturing a transmission image while exposing the subject to radiation and moving the subject parallel to the detection surface of the detector. When moving the subject parallel to the detection surface of the detector, the depth measurement device according to this embodiment maintains the position of the subject without moving for a predetermined period of time at the position where the movement starts and the position where the movement ends, thereby enabling accurate depth measurement and simultaneously measuring the shape of the object.

[0019] A schematic diagram illustrating an outline of a depth measurement device according to this embodiment is shown in Fig. 1. As shown in Fig. 1, a depth measurement device 10 according to this embodiment includes, as an example, a radiation source 101, a detector 102 for detecting radiation emitted from the radiation source 101, a measuring instrument 104 arranged between the radiation source 101 and the detector 102 for measuring the distance from the radiation source 101 to an object 103 present inside the subject 1 in a direction parallel to a detection surface 102a of the detector 102, and a processing unit 105 for measuring the depth of the object 103 from a transmission image of the object 103 generated by the detector 102 while exposing the object 103 to light.

[0020] The depth measurement device 10 may be, for example, a device that captures a transmission image of the object 103 (for example, a component and a void inside the component, etc.). The depth measurement device 10 is not limited to the example device described above, and may be configured as various devices, etc.

[0021] The depth measured by the depth measurement device 10 according to this embodiment refers to the depth of the position of the object 103 inside the object 1 relative to the object 1. In this embodiment, the depth is the distance from the radiation source 101 to the object 103 in the depth direction from the radiation source 101 toward the detection surface 102a (the Y direction in FIG. 1), and is shown as a second distance L3 in FIG. 1. The X direction in FIG. 1 is parallel to the detection surface 102a and perpendicular to the Y direction.

[0022] The specimen 1 may include components made of metal, non-metallic material, organic material, etc. Non-metallic materials include, for example, ceramics, glass, cement, stone, clay, manganese, graphite, etc. Organic materials include, for example, plastic, rubber, wood, paper, oil, and fat.

[0023] The radiation source 101 may be, for example, an X-ray source that emits X-rays. Note that the radiation emitted by the radiation source 101 is not limited to X-rays, and may be radiation of other wavelengths different from X-rays (for example, gamma rays, alpha rays, beta rays, neutron rays, etc.).

[0024] The detector 102 detects radiation emitted from the radiation source 101. As an example, the detector 102 may be an X-ray detector that detects X-rays emitted from the radiation source 101 (X-ray source). When an object 103 is present between the detector 102 and the radiation source 101, the detector 102 generates information (transmission image information (transmission X-ray image information)) related to a transmission image (transmission X-ray image) based on the radiation (X-rays) that have passed through the object 103. The detector 102 that is used is one that can be exposed continuously for a predetermined period of time, that is, a detector 102 that is capable of long-term exposure.

[0025] The measuring instrument 104 measures the distance from the radiation source 101 to the object 103 placed between the radiation source 101 and the detector 102 in a direction parallel to the detection surface of the detector 102. The measuring instrument 104 may be, for example, a device that performs measurements using a sensor such as an optical sensor or an acoustic sensor.

[0026] The processing unit 105 may be, for example, a computer (information processing device) such as a server, a desktop, a laptop, a tablet, or a smartphone. The processing unit 105 is capable of transmitting and receiving information to and from, for example, the radiation source 101, the detector 102, and the measuring instrument 104, and controls the radiation source 101, the detector 102, and the measuring instrument 104. The processing unit 105 also performs various arithmetic processing using image information generated by the detector 102, etc. One example of the arithmetic processing may be a process of measuring the depth of the object 103 from a transmission image of the object 103 generated by the detector 102 by controlling the radiation source 101 and the detector 102 to perform exposure and moving the object 103 in a direction parallel to the detection surface.

[0027] First, the object 103 is placed between the radiation source 101 and the detector 102. Fig. 2 shows the relative positions of the radiation source 101, the detector 102, and the object 103 shown in Fig. 1. In Fig. 2, as an example, the object 103 is a spherical void present inside the subject 1. The subject 1 is not shown in Fig. 2.

[0028] The distance between the radiation source and the detector 102 is defined as a first distance L0. When measuring the depth of the object 103, the object 103 is placed at a first position at the start of measurement, remains stationary at the first position for a first time, then moves in a straight line toward a second position, remains stationary at the second position for a second time, and then ends the measurement. From the start of measurement to the end of measurement, the radiation source and the detector 102 maintain an exposed state.

[0029] The first position is a position where the distance from the radiation source in the depth direction toward the detection surface is a second distance L3 and the distance from the radiation source in the direction parallel to the detection surface is a third distance L4. The second position is a position where the distance from the radiation source in the depth direction toward the detection surface is the second distance L3 and the distance from the radiation source in the direction parallel to the detection surface is a fourth distance L5.

[0030] The processing unit 105 controls the radiation source 101 to start emitting radiation when the object 103 is placed at a first position. The object 103 maintains a stationary state at the first position for a first time. Next, the object 103 (member) is moved from the first position to a second position. The object 103 maintains a stationary state at the second position for a second time. During this time, the radiation source 101 continues to emit radiation, and the detector 102 is in an exposed state.

[0031] Radiation emitted from point A of radiation source 101 passes through point B1, which is the center point of object 103 located at a first position, and is incident on point B2 on detection surface 102a of detector 102. When object 103 moves from the first position to a second position and is located at the second position, radiation emitted from point A of radiation source 101 passes through point C1, which is the center point of object 103, and is incident on point C2 on detection surface 102a of detector 102. The distance between point B2 and point C2 shown in FIG. 2 is a deviation amount L2, which will be described later.

[0032] After the object 103 remains stationary at the second position for a second time, the detector 102 ends the exposure state and generates a transmission image of the radiation transmitted through the object 103. The processing unit 105 acquires transmission image information from the detector 102 and acquires from the measuring instrument 104 a third distance L4 and a fourth distance L5, which are the distances from the radiation source 101 in a direction parallel to the detection surface of the detector 102 at the first position and the second position, respectively.

[0033] The processing unit 105, from the transmission image information acquired from the detector 102, identifies the amount of positional shift of the image of the object included in the captured image, calculated from an image obtained by maintaining the object at a first position for a first time and an image obtained by maintaining the object at a second position for a second time.

[0034] Furthermore, the processing unit 105 calculates the second distance L3 by the following formula, where L0 is the first distance, L1 is the difference between the third distance and the fourth distance, L2 is the deviation amount, and L3 is the second distance.

[0035]

number

[0036] Next, the depth measurement device 10 according to one embodiment will be described in detail. Here, the processing unit 105 will be particularly described. FIG. 3 is a block diagram for explaining the depth measurement device 10 (processing unit 105) according to one embodiment.

[0037] The imaging device 10 (processing unit 105) includes, for example, a communication unit 121, a storage unit 122, a display unit 123, and a control unit 110. The communication unit 121, the storage unit 122, and the display unit 123 may be an embodiment of an output unit. The control unit 110 includes, for example, a radiation source control unit 111, an acquisition unit 112, an identification unit 113, a calculation unit 114, and a position control unit 115. The control unit 110 may be configured, for example, by an arithmetic processing unit of the imaging device 10. The control unit 110 (for example, an arithmetic processing unit) may realize the functions of each unit (for example, the radiation source control unit 111, the acquisition unit 112, the identification unit 113, the calculation unit 114, and the position control unit 115) by, for example, appropriately reading and executing various programs stored in the storage unit 122. That is, the functions of each unit may be realized by computer implementation.

[0038] The communication unit 121 is, for example, a communication interface capable of transmitting and receiving various information to and from a device (external device) outside the imaging device 10. The external device may be, for example, the radiation source 101, the detector 102, a server (not shown), a user terminal (not shown), etc.

[0039] The storage unit 122 may store, for example, various information and programs. Examples of the storage unit 122 may be a memory, a solid state drive, a hard disk drive, etc. Note that the storage unit 122 may be, for example, a storage area or a server on a cloud.

[0040] The display unit 123 is a display capable of displaying, for example, various characters, symbols, images, and the like.

[0041] The radiation source control unit 111 controls the radiation source 101 via the communication unit 121 to emit radiation while the object 103 is positioned at either the first position, the second position, or a point on a line connecting the first position and the second position.

[0042] The detector 102 generates a transmission image (transmission image information) based on detecting radiation that has passed through the object 103. In this case, the object 103 is placed at a first position, the detector 102 maintains a stationary state at the first position for a first time, then moves from the first position to a second position, and maintains a stationary state at the second position for a second time, during which time the radiation source 101 continues to emit radiation and the detector 102 continues to be continuously exposed, thereby generating a transmission image. An image of the object 103 is recorded in the transmission image.

[0043] The acquisition unit 112 acquires transmission image information from the detector 102, for example, via the communication unit 121, and acquires from the measuring instrument 104 a third distance L4 and a fourth distance L5, which are the distances from the radiation source 101 in a direction parallel to the detection surface of the detector 102 at the first position and the second position, respectively.

[0044] The identification unit 113 identifies the amount of positional shift between the image of the object included in the captured image, calculated from an image obtained by maintaining the object at a first position for a first time and an image obtained by maintaining the object at a second position for a second time.

[0045] The operation of the identification unit 113 will now be described. FIG. 4 shows the positional relationship between the radiation source 101, the detector 102, and the object 401 when objects 401 and 402 are placed between the radiation source 101 and the detector 102, and transmission images are captured while the object 401 is moved relative to the radiation source 101. FIG. 5 shows transmission images 50 captured and acquired in each state shown in FIG. 4. The transmission images 50 shown in FIG. 5 express, as luminance, the intensity of the radiation 4 emitted from the radiation source 101 and incident on the detection surface of the detector 102. FIGS. 4(a) and 5(a) show the positional relationship and transmission image 50 when the object 401 is placed at a first position, FIGS. 4(b) and 5(b) show the positional relationship and transmission image 50 while the object 401 is being moved from the first position to a second position, and FIGS. 4(c) and 5(c) show the positional relationship and transmission image 50 when the object 401 has moved to the second position. In the states shown in Figures 4(a) and 4(c), the object 401 is not stationary, but is continuously moved from the state shown in Figure 4(a) to the state shown in Figure 4(c).

[0046] 4 shows the subject 1 and two objects 401 and 402 inside the subject 1, and FIG. 5 shows an image 51 of the subject 1 and images 501 and 502 of the objects 401 and 402 in a transmission image 50, but here, the operation of the identifying unit 113 will be described focusing on the object 401. In addition, throughout all of the states shown in FIGS. 4(a), 4(b), and 4(c), the detector 102 maintains an exposure state, and the transmission images obtained by the radiation source 101 and the detector 102 reflect the movement of the object 401 moving from a first position to a second position.

[0047] When the object 401 is placed at a first position as shown in Fig. 4(a), the image of the object 401 shown in the transmission image shown in Fig. 5(a) shows only the object 401 placed at the first position. When the object 401 is in the process of moving from the first position to the second position as shown in Fig. 4(b), the image of the object 401 shown in the transmission image shown in Fig. 5(b) shows the object 401 moving continuously from the first position to the position shown in Fig. 4(b). When the object 401 has moved to the second position as shown in Fig. 4(c), the image of the object 401 shown in the transmission image shown in Fig. 5(c) shows the object 401 moving continuously from the first position to the second position.

[0048] The identification unit 113 identifies the amount of positional deviation of the image of the object included in the captured image, calculated from the images at the first and second positions. When the object 401 is continuously moved from the first position to the second position, the image of the object 401 shown in the transmission image uniformly shows the path of movement of the object 401, as shown in FIG. 5(c), and an accurate image of the object 401 in a stationary state cannot be obtained from FIG. 5(c). This makes it difficult to identify the amount of positional deviation of the image of the object calculated from the images at the first and second positions from FIG. 5(c). It also makes it difficult to measure the shape of the object 401, such as the hole diameter of the object 401, from FIG. 5(c).

[0049] In the depth measurement device 10 according to this embodiment, the object 401 is placed at a first position, remains stationary at the first position for a first time, then moves from the first position to a second position and remains stationary at the second position for a second time, during which the radiation source 101 continues to emit radiation and the detector 102 continues to continuously expose, thereby generating a transmission image. The transmission image thus obtained is shown in FIG. 6. Compared with the image 501 of the object 401 shown in FIG. 5(c), contours 601 and 602 of the image of the object 401 at the first position and the second position, respectively, are emphasized, making it possible to grasp the original shape of the object 401.

[0050] 7 shows the relationship between the brightness of the transmitted image in FIG. 6 and points on line D, which connects center point E at the first position and center point F at the second position of contours 601, 602 of the image of object 401 shown in FIG. 6 , and the relationship between the brightness change rate and points on line D. In this embodiment, the identification unit 113 identifies, from the relationship between brightness and points on line D shown in FIG. 7 , the distance between maximum brightness point G of the image of object 401 at the first position and maximum brightness point H of the image of object 401 at the second position as the amount of positional deviation of the image of the object.

[0051] The calculation unit 114 calculates the second distance based on the first distance measured in advance, the difference between the third distance and the fourth distance measured by the measuring instrument 104, and the amount of deviation identified by the identification unit 113.

[0052] Position control unit 115 changes the distance from the radiation source in a direction parallel to detection surface 102a of object 103 located between radiation source 101 and detector 102, while keeping the first distance constant.

[0053] FIG. 8(a) shows an example of a transmission image of an object when the object is moved from the first position to the second position without stopping at either the first or second position, i.e., under constant speed control. FIG. 8(b) shows an example of a transmission image of the object when the object is stopped at the first position for a first time and at the second position for a second time, and then moved at a slow speed from the first position to the second position, i.e., under variable speed control. The object shown in FIG. 8 is a metal plate of a constant thickness, with multiple spherical voids of different radii disposed within it. In FIG. 8, multiple spherical voids of different radii are aligned vertically on the paper. In the image of the object shown in FIG. 8(a), the object moving from the first position to the second position is represented by uniformly high-brightness areas, making it impossible to discern the object's shape from FIG. 8(a). In the image of the object shown in FIG. 8(b), the contours of the object at both the first and second positions are emphasized, allowing the original shape of the object to be discerned.

[0054] In the present embodiment, an example has been given in which the position control unit 115 moves only the object 103 by a preset distance along the X axis while keeping the distance between the radiation source 101 and the detector 102 constant. In this case, for example, the positions of the radiation source 101 and the detector 102 may be fixed. In this case, the object 103 may be placed on a jig that is movable in the X axis direction between the radiation source 101 and the detector 102. The position control unit 115 may control the jig to move by a preset distance.

[0055] Alternatively, the position control unit 115 may move each of the radiation source 101 and the detector 102 by a preset distance while keeping the object 103 fixed. In this case, for example, the position control unit 115 may fix the radiation source 101 and the detector 102 to the tip of a robot arm, keep the object 103 fixed, and control the robot arm to move each of the radiation source 101 and the detector 102 by a preset distance.

[0056] Next, a depth measurement method according to an embodiment will be described. FIG. 9 is a flowchart illustrating a depth measurement method according to an embodiment.

[0057] In step ST101, the object is maintained at a first position for a first time, then moved to a second position and maintained at the second position for a second time, during which time the exposed state is maintained and a captured image is acquired (acquisition step).

[0058] In step ST102, the amount of image positional deviation calculated from an image of an object included in a captured image obtained by maintaining the object at a first position for a first time and an image obtained by maintaining the object at a second position for a second time is identified (identification step).

[0059] In step ST103, the second distance is calculated based on the first distance, the difference between the third distance and the fourth distance, and the amount of deviation (calculation step).

[0060] [Variations] In the above-described embodiment, the depth measurement device 10 is configured to emit radiation such as X-rays from the radiation source 101 and detect the radiation that has passed through a member such as metal or resin (for example, penetrating radiation such as penetrating X-rays) with the detector 102. This enables the imaging device 10 to measure the depth of the member and the depth of a void (object 103) inside the member.

[0061] As a modification, the depth measurement device 10 may include a light source capable of emitting light such as ultraviolet light, visible light, and infrared light, and a light receiver that detects the light emitted from the light source. In this case, the depth measurement device 10 may emit light from the light source and detect the transmitted light that has passed through a member (object) such as a semiconductor or glass with the light receiver. Similarly, as a modification, the depth measurement device 10 may include an electromagnetic wave source capable of emitting electromagnetic waves of various wavelengths and a detector that detects the electromagnetic waves emitted from the electromagnetic wave source. In this case, the depth measurement device 10 may emit electromagnetic waves from the electromagnetic wave source and detect the transmitted electromagnetic waves that have passed through a member (target object) with a photoreceiver. This allows the imaging device 10 to measure the depth of the component and the depth of the void (object) inside the component.

[0062] [Functions and circuits] Next, the functions and circuits of the depth measurement device 10 described above will be explained. Each unit of the depth measurement device 10 may be realized as a function of a computer's arithmetic processing unit, etc. That is, the radiation source control unit 111, acquisition unit 112, identification unit 113, calculation unit 114, and position control unit 115 of the depth measurement device 10 may be realized as a radiation source control function, an acquisition function, an identification function, a calculation function, and a position control function, respectively, by a computer's arithmetic processing unit, etc. The depth measurement program can cause a computer to realize each of the above-described functions. The imaging program may be recorded on a computer-readable non-transitory storage medium, such as a memory, a solid-state drive, a hard disk drive, or an optical disk. The storage medium may also be referred to as a non-transitory computer-readable medium that stores the depth measurement program. The imaging program may also be transmitted online. As described above, each unit of the depth measurement device 10 may be realized by a computer processing unit or the like. The processing unit or the like is configured, for example, by an integrated circuit or the like. Therefore, each unit of the depth measurement device 10 may be realized as a circuit that constitutes the processing unit or the like. That is, the radiation source control unit 111, acquisition unit 112, identification unit 113, calculation unit 114, and position control unit 115 of the depth measurement device 10 may be realized as a radiation source control circuit, acquisition circuit, identification circuit, calculation circuit, and position control circuit that constitute the processing unit or the like of a computer. The communication unit 121, storage unit 122, and display unit 123 (output unit) of the depth measurement device 10 may be realized as a communication function, storage function, and display function (output function) including the functions of an arithmetic processing device, etc. The communication unit 121, storage unit 122, and display unit 123 (output unit) of the depth measurement device 10 may be realized as a communication circuit, storage circuit, and display circuit (output circuit) by being configured, for example, by an integrated circuit, etc. The communication unit 121, storage unit 122, and display unit 123 (output unit) of the depth measurement device 10 may be realized as a communication device, storage device, and display device (output device) by being configured, for example, by being configured by a plurality of devices.

[0063] The depth measurement device 10 can be configured by combining one or any combination of the above-described multiple units. In this disclosure, the term "information" is used, but the term "information" can be replaced with "data" and the term "data" can be replaced with "information."

[0064] The present invention makes it possible to obtain a clearer view of the internal structure than ever before, and to detect small defects that could not be detected in the past.

[0065] As mentioned above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention-specifying matters according to the scope of the claims that are appropriate from the above description. [Explanation of symbols]

[0066] 1. Subject 4. Radiation 10 Depth measuring device 101 Radiation source 102 detector 102a Detection surface 103, 401, 402 Objects 104 Measuring Instruments 105 Processing section 110 control section 111 Radiation Source Control Unit 112 Acquisition Department 113 Specific section 114 Calculation Unit 115 Position control section 121 Communications Department 122 Storage section 123 Display section 50 Transparent Images 51, 501, 501 statue 601, 602 Contour

Claims

1. A radiation source; a detector for detecting radiation emitted from the radiation source, the detector having a planar detection surface and being located at a first distance from the radiation source; an acquisition unit that maintains the object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance, moves the object from the first position to a second position where the distance in the depth direction is the second distance and a fourth distance along the detection surface that is different from the third distance, and maintains the object at the second position for a second time, while maintaining an exposed state during this period and acquiring a captured image; an identification unit that identifies a positional deviation amount of an image of the object included in the captured image, the positional deviation amount being calculated from an image of the object obtained by maintaining the object at the first position for the first time period and an image of the object obtained by maintaining the object at the second position for the second time period; a calculation unit that calculates the second distance based on the first distance, a difference between the third distance and the fourth distance, and the deviation amount; A depth measurement device comprising:

2. The depth measurement device of claim 1, wherein the amount of deviation is the distance between the position on the captured image where the brightness of the image obtained by maintaining the object in the first position for the first time is at its maximum value, and the position on the captured image where the brightness of the image obtained by maintaining the object in the second position for the second time is at its maximum value.

3. The depth measurement device according to claim 1 , further comprising a position control unit that changes the distance from the radiation source in a direction parallel to the detection surface of the object between the radiation source and the detector while keeping the first distance constant.

4. The calculation unit calculates the first distance as L ０ , the difference between the third distance and the fourth distance is L １ , the deviation amount L ２ , the second distance is L ３ Then, the second distance L is calculated by the following formula: ３ Calculate [Equation 1] The depth measurement device according to claim 1 .

5. a computer capable of communicating with a radiation source and a detector of radiation emitted from the radiation source, the detector having a planar detection surface and being located at a first distance from the radiation source; an acquisition step of maintaining the object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance, moving the object from the first position to a second position where the distance in the depth direction is the second distance and a fourth distance along the detection surface that is different from the third distance, and maintaining the object at the second position for a second time, while maintaining an exposed state during this period and acquiring a captured image; an identifying step of identifying a positional deviation amount of an image of the object included in the captured image, the positional deviation amount being calculated from an image of the object obtained by maintaining the object at the first position for the first time period and an image of the object obtained by maintaining the object at the second position for the second time period; a calculation step of calculating the second distance based on the first distance, a difference between the third distance and the fourth distance, and the deviation amount; A depth measurement method comprising:

6. a computer that can communicate with a radiation source and a detector of radiation emitted from the radiation source, the detector having a planar detection surface and being at a first distance from the radiation source; an acquisition function of maintaining the object at a first position for a first time, where the distance from the radiation source in a depth direction from the radiation source toward the detection surface is a second distance and the distance from the radiation source in a direction parallel to the detection surface is a third distance, moving the object from the first position to a second position where the distance in the depth direction is the second distance and a fourth distance along the detection surface that is different from the third distance, and maintaining the object at the second position for a second time, while maintaining an exposed state during this period and acquiring a captured image; an identifying function for identifying a positional deviation amount of an image of the object included in the captured image, the positional deviation amount being calculated from an image of the object obtained by maintaining the object at the first position for the first time and an image of the object obtained by maintaining the object at the second position for the second time; a calculation function for calculating the second distance based on the first distance, a difference between the third distance and the fourth distance, and the deviation amount; A depth measurement program that makes this possible.

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