JP2017093496A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology to perform imaging while suppressing as much as possible a change in a moire fringe phase corresponding to a measurement spot when imaging a subject that moves relatively with respect to a grating.SOLUTION: An imaging device includes: an interferometer having a first grating for diffracting an electromagnetic wave that penetrates a subject and forming an interference pattern, a second grating for forming moire between itself and the interference pattern, and a detector for imaging the moire; and moving means for relatively moving the subject in a first direction with respect to the second grading. The imaging device continuously images the moire by the detector while relatively moving the subject in the first direction by the moving means. The periodic direction of the moire is perpendicular or roughly perpendicular to the first direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for imaging an interference pattern formed by an interferometer.

  Techniques for acquiring the shape and internal information of a subject by analyzing an interference pattern (interference fringes) formed by electromagnetic waves that have passed through the subject have been proposed. For example, the X-ray phase imaging method is an imaging method using a phase change caused by transmission of X-rays through a subject. As a kind of X-ray phase imaging method, there is a Talbot interferometer described in Patent Documents 1, 2, 3, and the like. The Talbot interferometer observes an interference pattern formed by the so-called Talbot effect. However, since the period of the interference pattern is small compared to the spatial resolution of a normal detector, it is common to adopt a configuration in which moire is generated between the interference pattern and the analyzer grating and the moire is imaged by the detector. is there.

  By the way, a method for obtaining a two-dimensional object image includes a case where an object is imaged at once using a detector that detects a two-dimensional intensity distribution, and a one-dimensional intensity distribution such as a line sensor. In some cases, a two-dimensional subject image is acquired using a detector that detects the above. In the latter case, since it is necessary to continuously acquire the intensity distribution while scanning the subject relative to the detector, either the subject or the detector is fixed and the other is moved. However, continuous imaging is performed. In general, such an imaging method tends to increase the imaging time relatively, but has advantages such as a relatively inexpensive detector and relatively easy imaging of a large area. In particular, since imaging with a Talbot interferometer usually requires a grid having a size corresponding to the imaging area, imaging with a large area has a significant problem in terms of cost. On the other hand, if the “scanning” imaging method as described above is used, the required grating area can be greatly reduced depending on the configuration. I can say that.

  Against this background, several methods have been proposed to effectively use the “scanning” imaging method even in imaging with a Talbot interferometer. For example, Patent Document 4 describes a method using a plurality of line sensors and the principle of the fringe scanning method. Using an analyzer grid consisting of a plurality of sub-lattices corresponding to individual line sensors, the sub-lattices are arranged so that the moire image acquired by each line sensor corresponds to the plurality of moire images obtained by the fringe scanning method To do. This makes it possible to obtain a plurality of moiré images similar to those obtained by performing a stripe scan only by scanning the subject once on a plurality of line sensors arranged in a line. A subject image can be calculated. Note that Patent Document 4 describes a method of imaging a subject to be scanned using a fixed detector, and the periodic direction of the grating used is parallel to the scanning direction (with a line-and-space pattern). It is assumed that the direction is perpendicular to the scanning direction. Patent Document 5 describes a method of imaging a fixed object based on the same principle using a scanned detector. Here, it is assumed that the periodic direction of the grating is perpendicular to the scanning direction (the direction of the line and space pattern is parallel to the scanning direction). In any of the examples, in principle, at least a part of the lattice and the detector are fixed, and the relative movement of the subject with respect to the detector also means the relative movement of the subject with respect to the lattice.

Japanese Patent No. 4445397 (International Publication No. 2004/058070) Japanese Patent No. 5162453 (International Publication No. 2006/131235) Japanese Patent No. 5174180 (International Publication No. 2010/0504843) JP 2009-543080 A (International Publication No. 2008/006470) JP-T-2014-518112 (International Publication No. 2013/004574)

  However, in the case of a scanning type imaging method, the relationship between the measurement location in the subject and the corresponding moire fringe phase changes with the relative movement of the subject, and thus subject information may not be accurately measured. .

  Therefore, the present invention provides a technique capable of performing imaging while suppressing changes in the moire fringe phase corresponding to the measurement location as much as possible when imaging a subject that moves relative to the grating. With the goal.

  A first aspect of the present invention provides a first grating that forms an interference pattern by diffracting electromagnetic waves transmitted through a subject, a second grating that forms a moire with the interference pattern, and the moire. An interferometer having a detector for imaging, and a moving means for moving the object relative to the second grating in a first direction, and the moving means moves the object to the first position. In the imaging apparatus in which the moire is continuously imaged by the detector while relatively moving in the direction of 1, the periodic direction of the moire is perpendicular or substantially perpendicular to the first direction. An imaging device is provided.

を満たす（但し、ｍは正の整数）、ことを特徴とする撮像装置を提供する。 According to a second aspect of the present invention, there is provided a first grating that forms an interference pattern by diffracting electromagnetic waves transmitted through a subject, a second grating that forms a moire with the interference pattern, and the moire. An interferometer having a detector for imaging, and a moving means for moving the object relative to the second grating in a first direction, and the moving means moves the object to the first position. In the imaging apparatus in which the moire is continuously imaged by the detector while relatively moving in the direction of 1, the pitch of the first grating is d ₁ , the pitch of the second grating is d ₂ , The angle formed between the periodic direction of the first grating and the first direction is θ ₁ , the angle formed between the periodic direction of the second grating and the first direction is θ ₂ , the electromagnetic wave source and the first the distance between the lattice L _01, the said first grating second When L ₁₂ the distance between the _grid, the width in the first direction of the detection area of the detector and w _D,

An imaging device characterized by satisfying (where m is a positive integer) is provided.

  ADVANTAGE OF THE INVENTION According to this invention, when imaging the subject which moves relatively with respect to a grating | lattice, it becomes possible to image, suppressing the change of the moire fringe phase corresponding to a measurement location as much as possible.

1 is a schematic diagram illustrating a configuration example of an imaging apparatus according to an embodiment of the present invention. The figure which shows arrangement | positioning of an interference pattern and an analyzer grating | lattice. The schematic diagram which shows the structural example of the imaging device which has a some interferometer.

  The present invention relates to an imaging apparatus that images an interference pattern formed by an interferometer. More specifically, in the present invention, when the moire formed between the interference pattern and the grating is imaged by the detector, the moire is continuously detected by the detector while moving the subject relative to the grating in one direction. The present invention relates to an imaging apparatus that performs an image capturing operation (scanning imaging system). The principle and type of the interferometer are not limited, and the electromagnetic wave used for imaging may be in any wavelength band such as light, X-rays, and gamma rays. In this specification, X-rays indicate electromagnetic waves having energy of 2 to 200 keV. In the following, an example in which the present invention is applied to an X-ray Talbot interferometer will be described as a preferred embodiment of the present invention.

  First, the basic configuration and principle of the Talbot interferometer will be described. A Talbot interferometer is generally composed of two or three gratings (gratings) having a periodic structure. Of these, the first grating, which is normally arranged near the subject, is arranged near the beam splitter grating, the second grating, which is usually arranged near the X-ray detector, is arranged near the analyzer grating, and usually near the X-ray source. The zeroth grid may be referred to as a source grid. In many cases, a grating having a one-dimensional periodic pattern is used as these gratings. The X-ray detector used is usually a detector that can measure the two-dimensional intensity distribution of X-rays incident on the detection surface.

  The beam splitter grating is often a phase modulation type transmission diffraction grating. The X-rays incident on the beam splitter grating are diffracted by the periodic structure of the grating and form an interference pattern (also called a self-image of the grating) at a predetermined position by the so-called Talbot effect. Since the interference pattern is deformed by reflecting a phase change or the like when X-rays pass through the subject, information on the shape and internal structure of the subject can be obtained by measuring and analyzing the intensity distribution of the interference pattern. . In the present invention and the present specification, X-ray phase contrast imaging is possible even if the information is not imaged as long as it is a method for acquiring information on the subject using the phase change of the X-rays by the subject. Call the law.

  Further, in many cases, the analyzer grating is a grating having a periodic transmittance distribution by periodically arranging the X-ray transmitting part and the X-ray shielding part. The analyzer grating is used for the purpose of generating moire in the intensity distribution of X-rays transmitted through the grating by being arranged at the appearance position of the interference pattern. This moire reflects the deformation of the interference pattern, and its period can be increased without limit. Therefore, even when the spatial resolution of the detector to be used is not high enough to directly detect the interference pattern, it is possible to indirectly obtain information on the interference pattern by detecting a moire having a large pattern period.

The source grating is also a grating having a structure in which an X-ray transmitting part and an X-ray shielding part are periodically arranged, like a normal analyzer grating. The source grid is usually arranged in the vicinity of the X-ray emission point in the X-ray source (X-ray generator), thereby virtually forming an array of linear light-emitting portions (micro emission points in the case of a two-dimensional grating). Used for forming purposes. A plurality of the aforementioned interference patterns formed by the X-rays emitted from the respective linear light-emitting portions formed in this way are shifted from each other by an integral multiple of the pattern period in a state where no subject is placed in the X-ray optical path. Superimposed. Thereby, even if many interference patterns overlap, a pattern does not lose | disappear, but the periodic pattern which has high X-ray intensity and fringe visibility as a whole can be formed. In order to realize such superposition, it is necessary to design the lattice period and the distance between lattices to satisfy certain conditions. A Talbot interferometer using such a source grating is sometimes called a Talbot-Lau interferometer. In the following, the term “Talbot interferometer” includes a Talbot low interferometer.

  As described above, the image acquired by the Talbot interferometer using the analyzer grating is a moire image generated between the interference pattern and the analyzer grating. In a general Talbot interferometer system, a subject image is calculated by performing a predetermined analysis based on a single moire image or a plurality of moire images acquired by shifting one of the lattice positions. The object image to be calculated is normally a distribution of local average pixel values excluding pixel value increase / decrease due to moire in the acquired moire image, and a distribution of local phase values of specific moire fringe components, Similarly, it is a distribution of local visibility values of specific moire fringe components. These are the X-ray transmittance distribution of the subject, the differential phase distribution of X-rays transmitted through the subject (component distribution along the direction of the deflection angle due to refraction), and the X-ray small angle scattering force of the subject, respectively. The distribution is roughly represented. The small-angle scattering force distribution is a distribution of components along a direction in which a small-angle scattering force is caused by fine particles, fine fibers, an edge portion of an object, or the like. The visibility value of the moire fringe component is often defined as a value obtained by dividing the amplitude of the periodic component by an average value.

  Typical examples of the moire fringe analysis method used for calculating the subject image as described above from the moire image include a fringe scanning method and a Fourier transform method. In general, imaging using the Fourier transform method is often inferior to imaging using the fringe scanning method in terms of spatial resolution and signal-to-noise ratio (signal-to-noise ratio), but has an advantage that a subject image can be calculated from a single moire image. .

  Hereinafter, a specific example in which the present invention is applied to an imaging apparatus using a Talbot interferometer will be described in detail with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted.

  FIG. 1 is a diagram schematically illustrating a configuration of an imaging apparatus according to an embodiment of the present invention. The imaging apparatus generally includes an X-ray Talbot interferometer, a transport apparatus 8 that transports the subject 7, and an information processing apparatus 9.

  The X-ray Talbot interferometer includes an X-ray source (electromagnetic wave source) 1, a source grating 2, a beam splitter grating 3, an analyzer grating 4, and an X-ray detector 5. X-rays emitted from the X-ray source 1 generate an interference pattern 6, which is a self-image of the beam splitter grating 3, on the analyzer grating 4 due to the effects of the source grating 2 and the beam splitter grating 3. The X-ray detector 5 is a line sensor, and has a structure in which pixels for detecting X-rays are arranged in a line, and can measure a one-dimensional distribution of incident X-ray intensity therebetween at regular intervals. It is.

  The transport device 8 is a moving means for transporting the subject 7 in the direction of the white arrow (the x direction in FIG. 1). The conveying device 8 is driven by a driving device such as a motor. At the time of imaging, the X-ray intensity distribution is continuously imaged by the X-ray detector 5 while moving the subject 7 at a constant speed by the transport device 8.

  The information processing apparatus 9 includes a general-purpose computer having hardware resources such as a CPU (Central Processing Unit), a RAM (Random Access Memory), an auxiliary storage device, and a display device. Image processing, various calculations, and control of the imaging device described later are realized by the CPU reading and executing a program stored in the auxiliary storage device. Note that some or all of the functions of the information processing apparatus 9 may be configured by a circuit such as an ASIC (Application Specific Integrated Circuit).

FIG. 2A is a schematic diagram of the interferometer viewed from the X-ray source side. Here, the scanning direction of the subject 7 being imaged is the first direction, and the direction perpendicular to the first direction in the plane perpendicular to the optical axis is the second direction. At this time, the x and y directions shown in FIG. 2A correspond to the first and second directions, respectively. As shown in the figure, the interference pattern 6 and the analyzer grating 4 overlap each other, so that moire fringes having a periodic component in the second direction are generated. In this description, as shown in the figure, the period of the interference pattern 6 is d _IP , and the period of the analyzer grating 4 is d ₂ . In addition, an angle formed by the periodic direction of the interference pattern 6 and the first direction is θ _IP , and an angle formed by the periodic direction of the analyzer grating 4 and the first direction is θ ₂ .

Furthermore, FIG. 2 (B) expresses in a frequency space how moire fringes are generated when the interference pattern 6 and the analyzer grating 4 overlap. In FIG. 2B, ξ and η represent spatial frequency axes corresponding to the x and y axes, respectively. Here, the respective harmonic components in the X-ray intensity distribution of the interference pattern 6 and the transmittance distribution of the analyzer grating 4 are ignored. The black circles in FIG. 2B represent three peaks present in the spectrum obtained by Fourier transforming the X-ray intensity distribution of the interference pattern 6. Here, multiplying the X-ray intensity distribution of the interference pattern 6 by the transmittance distribution of the analyzer grating 4 in the xy space (taking a product) corresponds to convolution of the corresponding spectra in the ξη space. Therefore, when the effect of the analyzer lattice 4 is taken into consideration, new peaks are generated at six positions indicated by white circles in the ξη space. Here, the point P _IP (ξ _IP , η _IP ) in the ξη space is a point at the position of one peak corresponding to the periodic component of the interference pattern 6 and its frequency coordinate. P ₂ (ξ ₂ , η ₂ ) is a point at one peak corresponding to the periodic component of the analyzer grating 4 and its frequency coordinate. P _M (ξ _M , η _M ) is a point at the position of one peak corresponding to the periodic component of the moire pattern and its frequency coordinate.

と表せる。 (Ξ _M , η _M ) is calculated using (ξ _IP , η _IP ) and (ξ ₂ , η ₂ ), respectively.

It can be expressed.

と書ける。ここで、ｍは正の整数であり、通常は１又は２である。また、ビームスプリッター格子３の周期方向と第１の方向とのなす角をθ_１とすると、θ_ＩＰは、

となる。 Note that the source grating (or X-ray emission point in the X-ray source if no source grating is used) -beam splitter grating distance and beam splitter grating-analyzer grating distance are L ₀₁ and L ₁₂ , respectively. If the pitch of 3 is d ₁ , d _IP is

Can be written. Here, m is a positive integer, and is usually 1 or 2. If the angle between the periodic direction of the beam splitter grating 3 and the first direction is θ ₁ , θ _IP is

It becomes.

であることが望ましい。 Here, consider the width of the X-ray detector 5 in the first direction. Since the X-ray detector 5 is a line sensor, its detection area has a width corresponding to one pixel in the first direction. When measuring the X-ray intensity distribution, all the information in this range is averaged and acquired. Therefore, when the phase change of the moire fringes in this range is large, the visibility of the detected moire fringes is reduced and accurate measurement is possible. It may not be possible. In order to avoid this problem, the period of the moire fringes should be made sufficiently large, or the period direction of the moire fringes should be set to be perpendicular or substantially perpendicular to the first direction (however, X related to the second direction). It is assumed that the spatial resolution of the line detector 5 is sufficiently high with respect to the period of moire fringes). In other words, it is sufficient that ξ _M is sufficiently close to zero. So ideally

It is desirable that

と表せる。但しここではＸ線検出器５は第２の方向に対して理想的な空間分解能を有していると仮定している。ここで、右辺の係数部はビジビリティの変換率を表している。ビジビリティの低下を抑制し、高精度な被検体情報を得るためには、好ましくは右辺の係数部が０．５以上であるとよく、より好ましくは右辺の係数部が０．８以上であるとよい。 Further, the allowable value of ξ _M from the viewpoint of the visibility of the detected moire fringes depends on the width of the X-ray detector 5. When the width of the detection area of the X-ray detector 5 and w _D, visibility V _M of moiré fringes detected _'by using the real visibility V _M of the moire fringes,

It can be expressed. However, here, it is assumed that the X-ray detector 5 has an ideal spatial resolution in the second direction. Here, the coefficient part on the right side represents the conversion rate of visibility. In order to suppress deterioration of visibility and obtain highly accurate subject information, the coefficient part on the right side is preferably 0.5 or more, and more preferably the coefficient part on the right side is 0.8 or more. Good.

であればよい。また、右辺の係数部が０．５以上であるためにはｗ_Ｄ｜ξ_Ｍ｜＜０．６０であれば良いので、

であればよい。 In order for the coefficient part on the right side to be 0.8 or more, w _D | ξ _M | <0.36 is sufficient.

If it is. Further, in order for the coefficient part on the right side to be 0.5 or more, it is sufficient if w _D | ξ _M | <0.60.

If it is.

と書ける。 In addition, when the scanning imaging method is applied to the Talbot interferometer in this way, it is preferable to use an analysis method that uses the spatial X-ray intensity distribution of the moire fringe as the carrier wave, such as the Fourier transform method described above. Thereby, even if the X-ray detector 5 is one line sensor, it is possible to acquire a subject image that is normally acquired by a Talbot interferometer. However, when such an analysis method is used, since the spatial resolution of the interferometer is limited by the moire fringe period, the moire fringe period is relatively short and the period direction is sufficiently perpendicular to the first direction. There is a need. Accordingly, assuming that the width of one pixel in the second direction of the X-ray detector 5 is a _y and moire fringes having a period of 20 pixels or less need to be generated, the design of the interferometer can be expressed by Equation (7) or It is necessary to satisfy | η _M |> 1 / (20a _y ) simultaneously with satisfying (8). The latter equation is

Can be written.

Incidentally, in general, in a scanning X-ray imaging apparatus, a TDI (Time Delay Integration) sensor may be used as a detector instead of a line sensor. In general, the use of a TDI sensor enables high-speed imaging at the same time as obtaining a high spatial resolution. However, on the other hand the detection region across the width (corresponding to the above-described w _D) is widened. Therefore, a TDI sensor may be used instead of the line sensor as the X-ray detector 5 in the present embodiment, but in this case, the design conditions of the optical system for satisfying the equations (7) and (8) are generally severe. .

The differential phase information and the scattering information obtained by the Talbot interferometer shown in FIG. 2A are information corresponding to the periodic direction (direction of the angle θ _IP ) of the interference pattern 6. Although it is possible to generate a subject image from such information on one direction, in order to obtain a more accurate structure inside the subject, measurement in a plurality of directions is performed on the same subject, and a plurality of directions are obtained. It is desirable to generate an image on the basis of information regarding. Therefore, a configuration may be adopted in which a plurality of interferometers are arranged along the scanning direction (first direction) of the subject, and measurement in a plurality of directions is continuously performed while moving the subject (or interferometer). Good. In this case, the periodic direction of the interference pattern of each interferometer (the periodic direction of the beam splitter grating) is different from each other, and the periodic direction of the moire in each interferometer satisfies any one of the expressions (7) to (9). What is necessary is just to design the optical system of each interferometer so that it may be satisfied. When N (N is an integer greater than 2) interferometers are used, it is preferable to design the interferometer so that the periodic direction of the interference pattern is shifted by (180 / N) degrees.

FIG. 3A shows an example in which two interferometers are arranged in series. The period pattern of the interference pattern 6a of the first interferometer and the interference pattern 6b of the second interferometer are shifted by 90 degrees (θ _IPb = θ _IPa +90 degrees). According to this configuration, differential phase information and the like in two directions can be obtained with a single scan. FIG. 3B shows an example in which three interferometers are arranged in series. The interference patterns 6a, 6b, and 6c of the interferometers are shifted by 60 degrees in the periodic direction (θ _IPb = θ _IPa +60 degrees, θ _IPc = θ _IPa +120 degrees). According to this configuration, it is possible to obtain differential phase information and the like in three directions with a single scan.

(Example)
A specific example of the imaging apparatus according to the above embodiment will be described. The imaging apparatus of the present embodiment uses a TDI sensor as an X-ray detector, and performs imaging while moving the subject in the first direction at a constant speed during imaging. The interferometer includes an X-ray tube having a tungsten anode as an X-ray source. The X-ray tube emits X-rays having a constant energy band centered on photon energy around 25 keV by adjusting the tube voltage and filter. The interferometer is designed to function particularly effectively for X-rays having a wavelength of around 0.05 nm (photon energy of about 25 keV). The source grating, beam splitter grating, and analyzer grating all have a one-dimensional grating pattern. The source grating and the analyzer grating have a pattern in which linear X-ray shielding portions and linear X-ray transmission portions are alternately arranged, and this is realized by a multi-slit structure made of gold. In addition, the beam splitter grating has a pattern in which linear phase advancement portions and linear phase delay portions are alternately arranged, and this is realized by a silicon structure with a number of grooves formed on the surface. Yes. Note that the widths of the phase advancing portion and the phase delay portion are equal, and the depth of the groove is adjusted so as to give a phase difference of π rad to the 25 keV X-rays that have passed through each.

The grating pitches d ₀ and d ₁ of the source grating and the beam splitter grating are 20.0 μm and 8.0 μm, respectively. Further, the distance L ₀₁ between the source grating and the beam splitter grating and the distance L ₁₂ between the beam splitter grating and the analyzer grating are 800 mm and 200 mm, respectively. At this time, the pitch d _{IP of the} interference pattern is m = 2, and d _IP = (L ₀₁ + L ₁₂ ) / (mL ₀₁ ) d ₁ = 5.0 μm. Note that the angle between the interference pattern and the first direction of the periodic direction of the beam splitter grating is θ _IP = θ ₁ = 0 degrees.

The TDI sensor has a structure in which each pixel has a size of 50 μm × 50 μm, and 120 pixels are arranged along the scanning direction of the subject. That is, the width w _D of the entire detection region is 6 mm.

At this time, in order for the design of the optical system to satisfy Expression (5), the pitch d ₂ of the analyzer grating and the angle θ ₂ formed by the periodic direction of the analyzer grating and the first direction are d ₂ / cos ( It is only necessary to satisfy θ ₂ ) = 5.0 μm. Furthermore, in order to make the moiré fringe visibility detected by satisfying the expression (7) 80% or more of the ideal value, 4.9985 μm <d ₂ / cos (θ ₂ ) <5.00015 μm may be satisfied. Alternatively, in order to make the moiré fringe visibility detected by satisfying the equation (8) 50% or more of the ideal value, it is sufficient to satisfy 4.9975 μm <d ₂ / cos (θ ₂ ) <5.00025 μm.

Here, a case where the period of moire fringes is set to 200 μm and analysis by the Fourier transform method is performed is considered. Since the width _ay of one pixel in the second direction of the TDI sensor is 50 μm, this moire fringe period corresponds to 4 pixels. The design of the optical system at this time must satisfy d ₂ / | sin (θ ₂ ) | = 200 μm. Therefore, in order to satisfy this condition and d ₂ / cos (θ ₂ ) = 5.0 μm at the same time, d ₂ and θ ₂ may be set to 4.9984 μm and 1.432 degrees (or −1.432 degrees), respectively.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, the method of the present invention can be applied to an interferometer other than a Talbot interferometer, and can also be applied to an interferometer using electromagnetic waves other than X-rays. The interferometer may not include an X-ray source (electromagnetic wave source) and may be combined with the X-ray source at the time of imaging. In the above specific example, the subject is moved by the transfer device. However, the subject may be fixed and the interferometer may be moved, or both the subject and the interferometer may be moved.

  3: beam splitter grating (first grating), 4: analyzer grating (second grating), 5: X-ray detector, 6: interference pattern, 7: subject, 8: transport device (moving means)

Claims (12)

An interferometer having a first grating that forms an interference pattern by diffracting an electromagnetic wave transmitted through a subject, a second grating that forms a moire with the interference pattern, and a detector that images the moire. When,
Moving means for moving the subject in a first direction relative to the second grating,
In the imaging apparatus, the moire is continuously imaged by the detector while the subject is relatively moved in the first direction by the moving unit.
An image pickup apparatus, wherein a period direction of the moire is perpendicular or substantially perpendicular to the first direction. An interferometer having a first grating that forms an interference pattern by diffracting an electromagnetic wave transmitted through a subject, a second grating that forms a moire with the interference pattern, and a detector that images the moire. When,
Moving means for moving the subject in a first direction relative to the second grating,
In the imaging apparatus, the moire is continuously imaged by the detector while the subject is relatively moved in the first direction by the moving unit.
The pitch of the first grating is d ₁ ,
The pitch of the second grating is d ₂ ,
An angle formed between the periodic direction of the first grating and the first direction is θ ₁ ,
An angle formed between the periodic direction of the second grating and the first direction is θ ₂ ,
L ₀₁ , the distance between the electromagnetic wave source and the first grating,
L ₁₂ , the distance between the first grating and the second grating,
When the width of the detection area of the detector in the first direction is w _D ,

(Where m is a positive integer),
An imaging apparatus characterized by that.

The imaging device according to claim 2, wherein:

The imaging device according to claim 2, wherein: The imaging apparatus according to claim 2, wherein the m is 1 or 2. 6. The imaging apparatus according to claim 1, further comprising an information processing apparatus that acquires information related to the subject by analyzing the moire imaged by the detector. The pitch of the first grating is d ₁ ,
The pitch of the second grating is d ₂ ,
An angle formed between the periodic direction of the first grating and the first direction is θ ₁ ,
An angle formed between the periodic direction of the second grating and the first direction is θ ₂ ,
L ₀₁ , the distance between the electromagnetic wave source and the first grating,
L ₁₂ , the distance between the first grating and the second grating,
When the width of one pixel in the direction perpendicular to the first direction of the detector is a _y ,

The imaging device according to any one of claims 1 to 6, wherein: The imaging apparatus according to claim 1, wherein the detector is a line sensor. The imaging device according to claim 1, wherein the detector is a TDI sensor. A plurality of the interferometers are arranged along the first direction;
10. The imaging apparatus according to claim 1, wherein periodic directions of interference patterns formed by the first grating of each interferometer are different from each other. The imaging apparatus according to claim 1, wherein the interferometer is a Talbot interferometer. The imaging apparatus according to claim 1, wherein the electromagnetic wave is an X-ray.

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