JP6638728B2 - Talbot-Lau interferometer - Google Patents

Description

  The present invention relates to a Talbot-Lau interferometer.

  In recent years, X-ray phase imaging has attracted attention from the viewpoint of reducing the amount of exposure, and for example, an X-ray imaging apparatus using a Talbot-Lau interferometer has been widely implemented. In an X-ray imaging apparatus using a Talbot-Lau interferometer, three metal gratings for X-rays, that is, a 0th grating, a 1st grating, and a 2nd grating, are used. The zeroth grating is a normal grating used to make a single X-ray source a multi-source, and converts the X-rays emitted from the single X-ray source into a plurality of X-rays (a plurality of X-rays). Radiation). These first and second gratings are diffraction gratings that are arranged apart from each other by a Talbot distance. As an apparatus using such a Talbot-Lau interferometer, for example, Patent Literature 1 discloses a joint imaging apparatus using a Talbot-Lau interferometer. In Patent Document 1, the 0th grating, the 1st grating, and the 2nd grating are held movably in the interferometer main body, whereby the 0th grating and the 1st grating can be adjusted to be parallel to each other and to a predetermined distance. In addition, the first grid and the second grid are parallel to each other and can be adjusted to a predetermined distance.

  However, even if the zeroth grating and the first grating are set to be parallel and at a predetermined distance from each other, and the first grating and the second grating are also set to be parallel and at a predetermined distance to each other, the Talbot-Lau interferometer does not For example, vibration is received at a place where a Talbot-Lau interferometer is installed, or vibration is received from a subject. Further, the Talbot-Lau interferometer receives a temperature change at a place where the Talbot-Lau interferometer is installed. When receiving such a vibration or a temperature change, the parallelism or the distance between the 0th lattice and the 1st lattice changes, or the parallelism or the distance between the 1st lattice and the 2nd lattice changes. I will. As a result, it may not be possible to capture a clear image of the subject.

JP 2013-085631 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a Talbot-Lau interferometer that can obtain a clearer image of a subject even when subjected to vibration or temperature change. is there.

  A Talbot-Lau interferometer according to the present invention includes 0th, 1st, and 2nd gratings and a vibration imparting member that imparts vibration to the 0th grating, wherein the 0th grating is movable in the first direction, A second axis extending in a second direction orthogonal to the first direction; and a third axis extending in a third direction orthogonal to the first and second directions. The first and second gratings are fixed to each other in a state of being parallel to each other at a predetermined distance from each other, and the vibration applying member causes the zeroth grating to vibrate in the first direction, and Vibration is caused around the axis and around the third axis. Therefore, the Talbot-Lau interferometer according to the present invention can obtain a clearer image of a subject even when subjected to vibration or temperature change.

  The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

It is a perspective view of the Talbot-Lau interferometer in an embodiment. FIG. 2 is a block diagram illustrating a configuration of a Talbot-Lau interferometer illustrated in FIG. 1. It is the schematic of the principal part of the Talbot-Lau interferometer shown in FIG. FIG. 2 is a schematic diagram illustrating an X-ray source used in the Talbot-Lau interferometer shown in FIG. 1 and a positional relationship between a zeroth grating, a first grating, and a second grating. FIG. 2 is an enlarged view of a main part of the Talbot-Lau interferometer shown in FIG. 1. It is the bottom view to which the 0th lattice held in the holding frame was expanded. It is an expansion perspective view of the 0th lattice main body which the 0th lattice has. It is a perspective view of the 0th grid | lattice held in the holding frame, and the 1st grid | lattice and the 2nd grid | lattice of the state accommodated in the storage member. FIG. 7 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating and the first grating are parallel at a first distance. FIG. 9 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating is rotated around a second axis from a state parallel to the first grating. FIG. 8 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating is rotated around a third axis from a state parallel to the first grating.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each of the drawings, configurations denoted by the same reference numerals indicate the same configurations, and the description thereof will be omitted as appropriate. In this specification, a generic name is denoted by a reference numeral with a suffix omitted, and an individual configuration is denoted by a reference numeral with a suffix.

  FIG. 1 is a perspective view of a Talbot-Lau interferometer according to the embodiment. FIG. 2 is a block diagram showing the configuration of the Talbot-Lau interferometer of FIG. FIG. 3 is a schematic diagram of a main part of the Talbot-Lau interferometer of FIG. FIG. 4 is a schematic diagram showing the positional relationship between the X-ray source and the 0th, 1st, and 2nd gratings used in the Talbot-Lau interferometer of FIG. FIG. 5 is an enlarged view of a main part of the Talbot-Lau interferometer shown in FIG. FIG. 5A is a side view, and FIG. 5B is a top view. FIG. 6 is an enlarged bottom view of the 0th lattice held in the holding frame. FIG. 7 is an enlarged perspective view of the zeroth lattice main body of the zeroth lattice. FIG. 8 is a perspective view of the 0th grid held in the holding frame and the first and second grids stored in the storage member. The first direction will be described as a Z1-Z2 direction, the second direction orthogonal to the first direction will be described as an X1-X2 direction, and the third direction orthogonal to the first direction and the second direction will be described as a Y1-Y2 direction.

  The Talbot-Lau interferometer 1 in this embodiment includes an interferometer main body 10, a zero-th grating (G0 lattice) 2 held by the interferometer main body 10, and a first grating (G1 lattice) as shown in FIGS. ) 3 and a second lattice (G2 lattice) 4, a vibration imparting member 5 (shown in FIGS. 5 and 6) for imparting vibration to the 0th lattice 2, and a storage housing the first lattice 3 and the second lattice 4. And a member 6.

  The interferometer body 10 includes a support 11, an X-ray source 12, an X-ray imaging unit (imaging unit) 13, an X-ray power supply 14 for supplying power to the X-ray source 12, and an X-ray imaging unit 13. A camera control unit 15 that controls an imaging operation, a processing unit 16 that controls the overall operation of the interferometer main body 10, and an X-ray emission operation of the X-ray source 12 by controlling a power supply operation of the X-ray power supply unit 14. And an X-ray controller 17 for controlling.

  As shown in FIG. 3, the support portion 11 includes a support portion main body 110 extending in the Z1-Z2 direction (first direction), and X-ray source holders arranged in order from the Z1 side to the Z2 side of the support portion main body 110. A piece 111, a zero-th lattice holding unit 112, a zero-th lattice receiving unit 113, an imaging stage 114, and an imaging unit holding unit 115 are provided.

  The X-ray source holding piece 111 protrudes from the column main body 110 toward the X1 side, and holds the X-ray source 12 at the protruding tip.

  The 0th lattice receiving portion 113 is a plate-shaped member as shown in FIGS. 3 and 5, and can receive the 0th lattice 2 from the Z2 side. The zeroth lattice receiving portion 113 is formed so as not to hinder the progress of X-rays.

  As shown in FIG. 3, the imaging mounting table 114 is a plate-shaped member, which protrudes from the support body 110 toward the X1 side, and on which the subject S is mounted. The subject mounting portion of the imaging mounting table 114 on which the subject S is mounted is configured not to hinder the progress of X-rays.

  The imaging unit holding unit 115 is a plate-shaped member, and protrudes from the support unit main body 110 toward the X1 side, and holds the X-ray imaging unit 13. The zeroth grid holding unit 112 will be described later.

  The X-ray imaging unit 13 includes an imaging unit main body 130 that captures an image of the X-ray diffracted by the second grating 3 as illustrated in FIG. 9 and an interference between a first interference pattern 221 and a second interference pattern 613 described below. Is provided.

  The imaging unit main body 130 is, for example, a flat panel detector (FPD) including a two-dimensional image sensor in which a thin film layer including a scintillator that absorbs X-ray energy and emits fluorescent light is formed on a light receiving surface, or converts incident photons into photoelectric. The surface is converted into electrons, the electrons are doubled by a microchannel plate, and the doubled group of electrons collide with a phosphor to emit light, and the output light of the image intensifier is imaged. An image intensifier camera including a two-dimensional image sensor.

  The detection section 131 is formed substantially all around the outer circumference of the imaging section main body 130. The detection unit 131 detects an interference pattern generated by interference between the X-rays passing through the first interference pattern 211 and the X-rays passing through the second interference pattern 613, and the imaging unit main body 130 detects the interference pattern based on the interference result. An image of an X-ray diffracted by the second grating 3 is taken.

  The processing unit 16 is a device that controls the operation of the entire Talbot-Lau interferometer 1 by controlling each unit of the Talbot-Lau interferometer 1 in accordance with the function of each unit, and includes, for example, a microprocessor and its peripheral circuits. As shown in FIG. 2, the image processing section 161 and the system control section 162 are functionally provided.

  The system control unit 162 controls the X-ray emission operation of the X-ray source 12 via the X-ray power supply unit 14 by transmitting and receiving a control signal to and from the X-ray control unit 17. The imaging operation of the X-ray imaging unit 13 is controlled by transmitting and receiving a control signal between the X-ray imaging unit 13 and the imaging device. Under the control of the system control unit 162, X-rays are emitted toward the subject S, an image generated by this is captured by the X-ray imaging unit 13, and an image signal is input to the processing unit 16 via the camera control unit 15. You.

  The system control unit 162 includes a first power supply signal for operating the first piezoelectric element 51 of the vibration applying member 5 described later, a second power supply signal for operating the second piezoelectric element 52 of the vibration applying member 5 described later, and a vibration applying A third power supply signal for operating the third piezoelectric element 53 of the member 5 is output to each of the first piezoelectric element 51, the second piezoelectric element 52, and the third piezoelectric element 53.

  The image processing unit 161 processes the image signal generated by the X-ray imaging unit 13 and generates an image of the subject S.

  Next, the 0th grating 2 will be described. As shown in FIG. 6, the zeroth lattice 2 includes a zeroth lattice main body 21 and a zeroth lattice holding frame 22 that holds the zeroth lattice main body 21.

  As shown in FIG. 7, the zeroth lattice body 21 has a predetermined thickness (depth) H in the Z1-Z2 direction and extends linearly in the Y1-Y2 direction on a silicon material such as a silicon wafer. X-ray transmitting portions 212 formed as described above, and a plurality of X-ray absorbing portions having a predetermined thickness H and extending linearly in the Y1-Y2 direction and formed by embedding metal. The plurality of X-ray absorbing portions 211 and the plurality of X-ray transmitting portions 212 are alternately arranged in parallel. For this reason, the plurality of X-ray absorbers 211 are arranged at predetermined intervals in the X1-X2 direction orthogonal to the Y1-Y2 direction. This interval (pitch) P is constant in the present embodiment. That is, the plurality of X-ray absorbers 211 are arranged at equal intervals P in the X1-X2 direction. In the present embodiment, the X-ray absorbing section 211 has a plate-like or layer-like shape, and the plurality of X-ray transmitting sections 212 are plate-like or layer-like spaces sandwiched between the X-ray absorbing sections 211 adjacent to each other.

  The plurality of X-ray absorbing sections 211 function to absorb X-rays, and the X-ray transmitting sections 212 function to transmit X-rays. The X-ray absorbing section 211 has an appropriate thickness H so that X-rays can be sufficiently absorbed according to, for example, specifications. X-rays generally have high transparency, and as a result, the ratio of the thickness H to the width W in the X-ray absorbing section 211 (aspect ratio = thickness / width) is, for example, a high aspect ratio of 5 or more. Have been. The width W of the X-ray absorber 211 is the length of the X-ray absorber 211 in the third direction, and the thickness H is the length of the X-ray absorber 211 in the first direction.

  As shown in FIG. 6, the 0th lattice holding frame 22 is, in this embodiment, a rectangular tube arranged on the entire outer periphery of the 0th lattice main body 21 and has a first interference pattern 221. ing. The first interference pattern 221 has a plurality of slits arranged at equal intervals along each of the X1-X2 direction and the Y1-Y2 direction. Each slit is formed by burying a metal at a predetermined depth in a thickness direction along the Z1-Z2 direction.

  The 0th lattice 2 thus formed is movable in the Z1-Z2 direction and in the X1-X2 direction (second direction) on the 0th lattice holding portion 112 of the support portion 11 as shown in FIG. It is held rotatably around an extending X axis (second axis) 2a and about a Y axis (third axis) 2b extending in the Y1-Y2 direction (third direction).

  More specifically, the 0th lattice holding unit 112 includes a cylindrical connection shaft 112a and a substantially U-shaped holding frame 112b. One end of the connection shaft 112a is connected to the column main body 110, and the other end is extended from the column main body 110 to the X1 side.

  The holding frame 112b includes a rotating shaft 112c formed to face each other. The holding frame 112b is connected to the connecting shaft 112a so as to be movable in the Z1-Z2 direction and to be rotatable around the connecting shaft 112a.

  The 0th grid 2 is rotatably fitted to the rotating shaft 112c of the holding frame 112b, whereby the 0th grid 2 is movable in the Z1-Z2 direction and the X-axis (second axis) 2a. It is held by the zeroth grid holding portion 112 so as to be rotatable around the Y axis (third axis) 2b.

  Next, the vibration imparting member 5 will be described. In this embodiment, the vibration imparting member 5 includes a first piezoelectric element 51, a second piezoelectric element 52, and a third piezoelectric element 53.

  The first piezoelectric element 51, the second piezoelectric element 52, and the third piezoelectric element 53 are elements having substantially the same configuration. Each of the piezoelectric elements 51 to 53 converts input electric energy into mechanical energy that expands and contracts, that is, mechanical energy. For example, the element converts input electric energy into mechanical expansion / contraction movement by a piezoelectric effect. Such piezoelectric elements 51 to 53 include, for example, a laminate and a pair of external electrodes.

The stacked body is formed by alternately stacking a plurality of thin film (layered) piezoelectric layers made of a piezoelectric material and thin film (layered) internal electrode layers having conductivity. Each of the plurality of internal electrode layers is configured so that a part thereof faces the outside on a pair of outer peripheral side surfaces facing each other. The pair of external electrodes are formed along the laminating direction on the pair of outer peripheral side surfaces of the laminate, supply the electric energy to the laminate, and are sequentially and alternately connected to the plurality of internal electrodes. The piezoelectric material is, for example, lead zirconate titanate (PZT), quartz, lithium niobate (LiNbO ₃ ), potassium tantalate niobate (K (Ta, Nb) O ₃ ), barium titanate (BaTiO ₃ ) And inorganic piezoelectric materials such as lithium tantalate (LiTaO ₃ ) and strontium titanate (SrTiO ₃ ).

  The first piezoelectric element 51 is an element for vibrating the 0th grating 2 around the X axis 2a by expansion and contraction in the stacking direction (the axial direction of the first piezoelectric element 51), and the 0th grating holding frame 22 of the 0th grating 2 The X1-side and Y1-side ends of the zero-th grid holding frame 22 between the first grid holding portion 22 and the zero-th grid receiving portion 113 of the support portion 11 are respectively applied to the zero-th grid holding frame 22 and the zero-th grid receiving portion 113. It is arranged so that it may touch. In this embodiment, the first piezoelectric element 51 operates when receiving the first power supply signal.

  The second piezoelectric element 52 is an element for vibrating the 0th lattice 2 around the Y axis 2b by expansion and contraction in the stacking direction (the axial direction of the second piezoelectric element 52), and the 0th lattice holding frame 22 of the 0th lattice 2 The X1-side and Y2-side ends of the 0-th grid holding frame 22 between the 0-th grid receiving portion 113 of the support 11 and the 0-th grid holding frame 113 respectively. It is arranged so that it may touch. In this embodiment, the second piezoelectric element 52 operates when receiving the second power supply signal.

  The third piezoelectric element 53 is an element for vibrating the zeroth lattice 2 in the Z1-Z2 direction by expansion and contraction in the laminating direction (the axial direction of the third piezoelectric element 53). The third piezoelectric element 53 is provided between the 0th lattice holding frame 22 of the 0th lattice 2 and the 0th lattice receiving portion 113 of the column 11 in the Y1 side and the X1-X2 direction of the 0th lattice holding frame 22. The central part and the central part in the X1-X2 direction on the Y2 side of the zeroth lattice holding frame 22 between the above are disposed so as to be in contact with the zeroth lattice holding frame 22 and the zeroth lattice receiving part 113, respectively. Have been. In this embodiment, the third piezoelectric element 53 operates when receiving the third power supply signal. The vibration imparting member 5 is not limited to a piezoelectric actuator using a piezoelectric material, but may be changed as appropriate. For example, an electrostatic actuator may be used.

  The vibration imparting member 5 arranged as described above is covered by the upper cover 17a together with the 0th lattice 2 as shown in FIG.

  Next, the first grating 3 will be described. The first grating 3 is a diffraction grating that generates a Talbot effect by X-rays emitted from the X-ray source 12. Although not shown, the first grating 3 has a predetermined thickness (depth) in the Z1-Z2 direction, extends linearly in the Y1-Y2 direction, and is alternately arranged in parallel, similarly to the zeroth grating body 21. A plurality of X-ray absorbing sections and a plurality of X-ray transmitting sections are provided. The first grating 3 is configured to satisfy a condition for generating the Talbot effect, and is a grating sufficiently coarser than the wavelength of the X-ray radiated from the X-ray source 12, for example, a grating constant (period of the diffraction grating). Is a phase type diffraction grating having a wavelength of about 20 or more of the X-ray. Note that the first grating 3 may be an amplitude diffraction grating.

  The first grating 3 is arranged in parallel with a zeroth grating 2 and a distance (first distance) L4 that is an integral multiple of the wavelength of the X-ray as shown in FIG. Is done.

  Next, the second grating 4 will be described. The second grating 4 is a transmission-type amplitude diffraction grating that is arranged at a position substantially apart from the first grating 3 by a Talbot distance L2 and that diffracts X-rays diffracted by the first grating 3. Like the first grating 3, the second grating 4 also has a predetermined thickness (depth) in the Z1-Z2 direction, extends linearly in the X1-X2 direction, and is alternately arranged in parallel, though not shown. A plurality of X-ray absorbing sections and a plurality of X-ray transmitting sections are provided.

The second grating 4 is arranged so as to satisfy the following equations 1 and 2 with the first grating 3 which is a phase type diffraction grating.
1 = λ / (a / (L1 + L2 + L3)) (1)
Z1 = (m + ／) × (d2 / λ) (formula 2)
Here, l is the coherence length, λ is the wavelength of the X-ray (usually the center wavelength), and a is the aperture diameter of the X-ray source 12 in a direction substantially orthogonal to the diffraction member of the diffraction grating. L1 is the distance from the X-ray source 12 to the first diffraction grating 3, L2 is the distance from the first diffraction grating 3 to the second diffraction grating 4 (second distance), and L3 is the distance 2 is the distance from the diffraction grating 103 to the X-ray imaging unit 13, m is an integer, and d is the period of the diffraction member (period of the diffraction grating, lattice constant, distance between centers of adjacent diffraction members, the pitch P).

  Next, the storage member 6 will be described. The storage member 6 includes a frame portion 61, a temperature sensor 62, and a temperature adjustment member 63, as shown in FIG.

  The frame portion 61 includes a side portion 611 and a peripheral edge portion 612, and the inside thereof is sealed. The side portion 611 is made of a material that can transmit X-rays, for example, glass.

  The peripheral portion 612 includes a second interference pattern 613 for causing interference with the first interference pattern 221 of the 0th grating 2 as shown in FIG. The second interference pattern 613 includes a plurality of slits arranged at regular intervals along the X1-X2 direction and the Y1-Y2 direction so as to correspond to the first interference pattern 221. Each slit is formed by burying a metal at a predetermined depth in a thickness direction along the Z1-Z2 direction.

  The first grating 3 and the second grating 4 are fixedly arranged in parallel and spaced apart from each other by a predetermined distance and sealed inside the frame portion 61. The first grating 3 and the second grating 4 sealed in the frame portion 61 are arranged on the Z2 side of the imaging mounting table 114 as shown in FIG. 3 so as to satisfy the above (Formula 1) and Formula (2). Are located. The first grid 3 and the second grid arranged as described above are covered with the lower cover 17b as shown in FIG.

  The temperature sensor 62 detects the temperature inside the storage member 6, and in this embodiment, is attached to the inner surface of the frame 61 as shown in FIG.

  The temperature adjustment member 63 is an element that adjusts the temperature inside the storage member 6, and includes, for example, a Peltier element. The temperature adjusting member 63 is attached to the inner surface of the frame portion 61 and adjusts the temperature inside the storage member 6 to a set temperature range by increasing or decreasing the temperature inside the storage member 6 based on the temperature detected by the temperature sensor 62.

  Next, the operation of the Talbot-Lau interferometer of the present embodiment will be described. FIG. 9 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating and the first grating are parallel at a first distance. FIG. 10 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating is rotated around the second axis from a state parallel to the first grating. FIG. 11 is an explanatory diagram of the X-ray imaging unit in a state where the 0th grating is rotated around the third axis from a state parallel to the first grating.

  The subject S is placed between the 0th lattice 2 and the first lattice 3 by placing the subject S on the mounting table 114 for photographing.

  In this state, when the user (operator) of the Talbot-Lau interferometer 1 instructs the imaging of the subject S from an operation unit (not shown), the system control unit 162 of the processing unit 16 emits X-rays toward the subject S. A control signal is output to the X-ray controller 17 for irradiation. With this control signal, the X-ray control unit 17 causes the X-ray power supply unit 14 to supply power to the X-ray source 12, and the X-ray source 12 emits X-rays and irradiates the subject S with X-rays.

  The system control unit 162 includes a first power supply signal for operating the first piezoelectric element 51 of the vibration applying member 5, a second power supply signal for operating the second piezoelectric element 52 of the vibration applying member 5, and a second power supply signal for operating the vibration applying member 5. A third power supply signal for operating the third piezoelectric element 53 is transmitted to the first piezoelectric element 51, the second piezoelectric element 52, and the third piezoelectric element 53 in a superimposed manner. As a result, the first piezoelectric element 51, the second piezoelectric element 52, and the third piezoelectric element 53 operate, and the zeroth lattice 2 vibrates in the Z1-Z2 direction, and also rotates around the X axis 2a and the Y axis 2b. Vibrate.

  The irradiated X-ray passes through the first grating 3 via the 0th grating 2 and the subject S, is diffracted by the first grating 3, and is a Talbot which is a self image of the first grating 3 at a position separated by the Talbot distance. An image T is formed.

  The formed Talbot image T of X-rays is diffracted by the second grating 4 and generates moiré to form an image of moiré fringes.

  At this time, the predetermined distance between the 0th grating 2 and the first grating 3 is shifted, or the 0th grating 2 and the 1st grating 3 are not parallel, or the preset 1st grating 3 and the 2nd grating 3 If the distance between the first grating 3 and the second grating 4 is not correct, the image captured by the X-ray imaging unit 13 becomes unclear.

  For example, as shown in FIG. 10, when the 0th grating 2 rotates around the X axis 2a and is not parallel to the first grating 3 by being inclined, the image 13a captured by the X-ray imaging unit 13 becomes unclear. turn into. Also, for example, as shown in FIG. 11, when the 0th grating 2 rotates around the Y axis 2b and is not parallel to the first grating 3 because it is not parallel, the image 13a captured by the X-ray imaging unit 13 is unclear. Become. Further, although not shown, if the 0th grating 2 moves in the Z1-Z2 direction and shifts in distance from the first grating 3, the image 13a captured by the X-ray imaging unit 13 similarly becomes unclear.

  Such deviation or inclination of the distance between the two adjacent gratings 2, 3, 4 may occur, for example, when the entire Talbot-Lau interferometer is subjected to external vibration or temperature change.

  However, in this embodiment, the 0th lattice 2 vibrates in the Z1-Z2 direction by the first piezoelectric element 51, the second piezoelectric element 52, and the third piezoelectric element 53, and also rotates around the X axis 2a and the Y axis 2b. During the vibration, the 0th grating 2 comes to a position parallel to the first grating 3 at a first distance L4. Further, the vibration frequency of the 0th lattice 2 vibrated around the X axis 2a by the first piezoelectric element 51 and the vibration frequency of the 0th lattice 2 vibrated around the Y axis 2b by the second piezoelectric element 52 are relatively prime, that is, By not having a common divisor other than 1, no misoth motion (precession motion) or movement of the turret occurs, and during the vibration, the 0th lattice 2 is parallel to the 1st lattice 3 The time has come.

  Since the first grid 3 and the second grid 4 are sealed in the storage member 6 at a predetermined temperature while being fixed to each other, the first grid 3 and the second grid 4 are subject to external vibration or temperature change. Are also maintained in a parallel state at a second distance from each other. Therefore, at the position where the 0th grating 2 is parallel to the first grating 3 at the first distance, the first grating 3 and the second grating 4 are parallel to each other at the second distance. .

  When the zeroth grating 2 comes to a position parallel to the first grating 3 at a set distance during vibration, the first interference pattern 221 of the zeroth grating 2 and the second interference pattern 613 of the storage member 6 At regular intervals. In the present embodiment, the detection unit 131 detects an interference pattern generated by interference between the X-rays that have passed through the first interference pattern 211 and the X-rays that have passed through the second interference pattern 613. When the interference patterns detected by the detection unit 131 are at equal intervals, the system control unit 162 controls the X-ray imaging unit 13 via the camera control unit 15 to instruct the X-ray imaging unit 13 to perform imaging. Output a signal.

  In response to the control signal for instructing the imaging, the X-ray imaging unit 13 captures the image 13a of the moire fringe at the timing when the interference patterns are at equal intervals. Therefore, at this time, the image 13a detected by the X-ray imaging unit 13 is a clear image as shown in FIG.

  Then, the X-ray imaging unit 13 outputs an image signal of the image of the moire fringe to the processing unit 16 via the camera control unit 15. This image signal is processed by the image processing unit 161 of the processing unit 16.

  In the above embodiment, the second interference pattern 613 is formed on the storage member 6 that stores the first grid 3 and the second grid 4, and the first grid 3 is indirectly connected to the second grid via the storage member 6. Although the interference pattern 613 is provided, the invention is not limited to this mode and can be changed as appropriate. For example, by forming the second interference pattern 613 directly on one or both of the first grating 3 and the second grating 4, one or both of the first grating 3 and the second grating 4 are formed. May be provided with the second interference pattern 613.

  In the above embodiment, X-rays are used. However, visible light may be used instead of X-rays, and can be changed as appropriate.

  Although the present specification discloses various aspects of the technology as described above, the main technology is summarized below.

  A Talbot-Lau interferometer according to one aspect includes an interferometer main body having an X-ray source that emits X-rays, and a zeroth beam arranged along a first direction from the X-ray source and held by the interferometer main body. A lattice, a first lattice, a second lattice, and a vibration applying means for applying vibration to the zeroth lattice such that the zeroth lattice is at a position parallel to the first lattice at a predetermined first distance when vibrating. A member, wherein the 0th lattice is movable in the first direction, and is arranged around a second axis extending in a second direction orthogonal to the first direction, and between the first direction and the second direction. The interferometer is held by the interferometer main body so as to be rotatable about third axes extending in a third direction orthogonal to each other, and the first grating and the second grating are parallel to each other at a predetermined second distance from each other. In this state, the vibration applying members are fixed to each other. The vibrated in the first direction, to and vibrate in each of said second axis and said third axis.

  In such a Talbot-Lau interferometer, the first grating and the second grating are integrally fixed to each other in a state where they are parallel to each other at a second distance from each other. Even so, the first grating and the second grating can be kept parallel to each other at a second distance from each other.

  Even if the 0th grating changes its distance from the first grating due to vibration or temperature change or the parallel state shifts, the vibration applying member moves the 0th grating in the first direction. During the vibration, the 0th grid is separated from the first grid by a first distance by vibrating the first grid and the third grid while rotating about the second axis and the third axis. Sometimes it comes to the position of the parallel state. Therefore, the Talbot-Lau interferometer can obtain a clearer image of the subject if the subject is imaged at that position.

  In another aspect, in the above-mentioned Talbot-Lau interferometer, the vibration frequency for vibrating the 0th lattice around the second axis and the vibration frequency for vibrating the 0th lattice around the third axis are mutually different. Is prime.

  When a miso motion (precession motion) or a movement of the turret occurs, the 0th lattice is not parallel to the 1st lattice. Thus, as in the above configuration, the vibration frequency rotating about the second axis and the vibration frequency rotating about the third axis are relatively prime, that is, do not have a common divisor other than 1 with each other. The Talbot-Lau interferometer can prevent miso motion (precession motion) or turret motion.

  In another aspect, in the above-mentioned Talbot-Lau interferometer, the first grating and the second grating are sealed in a storage member so as to be able to adjust the temperature.

  In such a Talbot-Lau interferometer, since the first grating and the second grating are sealed inside the storage member so as to be able to adjust the temperature, it is ensured that they are parallel to each other at a second distance. Is maintained. Even if the first grid and the second grid are stored in the storage member, the subject is arranged between the zero grid and the first grid, so that there is no hindrance to imaging.

  In another aspect, in the above-described Talbot-Lau interferometer, an imaging unit is further provided on the opposite side of the second grating from the first grating in the first direction, and the zeroth grating is , A first interference pattern, at least one of the first grating and the second grating interferes with the first interference pattern when the zero grating is parallel to the first grating at the first distance. A second interference pattern, wherein the imaging section includes an imaging section main body and a detection section for detecting the interference, and the imaging section main body interferes with the first interference pattern based on a detection result of the detection section. The subject is imaged at a timing when the interference patterns with the second interference pattern are at regular intervals.

  In such a Talbot-Lau interferometer, the imaging unit main body captures an image of the subject based on the detection result of the detection unit, so that the state in which the 0th grating is parallel to the first grating with a first distance is easily achieved. In this state, the subject can be easily and reliably imaged.

  This application is based on Japanese Patent Application No. 2015-134258 filed on July 3, 2015, the contents of which are included in the present application.

  Although the present invention has been described above appropriately and sufficiently through the embodiments with reference to the drawings in order to express the present invention, it is easy for those skilled in the art to modify and / or improve the above-described embodiments. It should be recognized that it is possible. Therefore, unless a modification or improvement performed by those skilled in the art is at a level that departs from the scope of the claims set forth in the claims, the modification or the improvement will not be included in the scope of the claims. Is interpreted as being included in

  According to the present invention, a Talbot-Lau interferometer can be provided.

Claims (4)

An interferometer body having an X-ray source that emits X-rays, a 0-th grating, a first grating, and a second grating that are arranged along the first direction from the X-ray source and held by the interferometer body, A vibration imparting member that imparts vibration to the zeroth lattice so that the zeroth lattice comes to a position parallel to the first lattice at a predetermined first distance during vibration,
The zeroth lattice is movable around the second axis extending in a second direction perpendicular to the first direction, and is movable around the second direction, and is orthogonal to each of the first direction and the second direction. The interferometer main body is rotatably held around a third axis extending in three directions,
The first grid and the second grid are fixed to each other while being parallel to each other at a predetermined second distance from each other,
The vibration imparting member vibrates the zeroth lattice in the first direction, and vibrates around the second axis and around the third axis, respectively.
Talbot-Lau interferometer. The vibration frequency for vibrating the zero lattice about the second axis and the vibration frequency for vibrating the zero lattice about the third axis are disjoint.
The Talbot-Lau interferometer according to claim 1. The first grid and the second grid are sealed in a storage member so as to be temperature-adjustable.
The Talbot-Lau interferometer according to claim 1 or 2. An imaging unit is further provided on the opposite side of the second grating from the first grating in the first direction,
The 0th grating includes a first interference pattern,
At least one of the first grating and the second grating includes a second interference pattern that interferes with the first interference pattern when the zeroth grating is parallel to the first grating at the first distance.
The imaging unit includes an imaging unit body and a detection unit that detects the interference,
The imaging unit body captures an image of a subject at a timing when interference patterns between the first interference pattern and a second interference pattern that interfere with each other are at equal intervals based on a detection result of the detection unit.
The Talbot-Lau interferometer according to any one of claims 1 to 3.

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