JP2008197495A - X-ray imaging film and production method, x-ray imaging method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new X-ray photographing film capable of reliably photographing moire fringes without using a diffraction grating. <P>SOLUTION: An X-ray imaging unit 11 is placed in a position at an approximate Talbot distance L from a diffraction grating for Talbot and is a unit for imaging X-rays diffracted by the diffraction grating for Talbot. The X-ray imaging unit 11 comprises an X-ray imaging film 20 for imaging an X-ray image (X-ray Talbot image) and a shutter 30 placed in a position right before this X-ray imaging film 20 on a light path thereof. The X-ray imaging film 20 is obtained by alternately arranging stripe-shaped photosensitive parts 21 formed of a material having photosensitivity to X-rays and stripe-shaped non-photosensitive parts 22 formed of a material not substantially having photosensitivity to X-rays. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for imaging X-rays.

  Conventionally, in X-ray imaging, an image having an X-ray absorption contrast, that is, an X-ray absorption level by a subject is obtained as a contrast. X-ray absorption generally increases as the atomic number increases, that is, the heavier the element. When a living body is a subject, the elements constituting the living body are mainly elements having a relatively small atomic number, such as hydrogen (H), carbon (C), nitrogen (N), and oxygen (O), that is, light elements. Therefore, the X-ray image of the living body does not have much contrast. Therefore, a substance containing an element with a large atomic number is used as a contrast agent in X-ray imaging of a living body. For example, barium sulfate is used as a contrast agent in X-ray imaging of digestive organs such as the stomach and colon. However, the contrast medium cannot be used for all tissues, and the burden on the living body is large.

  Therefore, in recent years, a phase contrast method has been studied and developed in which X-rays are treated as waves and an image is obtained in which the difference in the speed with which the waves travel through the subject is taken as contrast. In the phase contrast method, for example, an X-ray interferometer is used, and a transmission image of a subject is obtained by detecting an X-ray phase shift caused by passing through the subject. This phase contrast method is expected to improve the sensitivity by about 1000 times compared to the case where a transmission image of a subject is obtained by the X-ray absorption contrast, thereby reducing the X-ray irradiation amount to, for example, 1/100 to 1/1000. There is also an advantage that it becomes possible.

  As one of such phase contrast methods, for example, a method using a Talbot interferometer has been proposed in, for example, Patent Document 1 and Non-Patent Document 1.

FIG. 8 is an explanatory diagram showing a schematic configuration of the X-ray imaging apparatus described in Patent Document 1. As shown in FIG. In FIG. 8, an X-ray imaging apparatus 1000 described in Patent Document 1 includes an X-ray source 1001, a phase-type first diffraction grating 1002 that diffracts X-rays emitted from the X-ray source 1001, and a first diffraction grating. An amplitude-type second diffraction grating 1003 that forms an image contrast by diffracting the X-rays diffracted by 1002, and an X-ray image detector 1004 that detects X-rays in which image contrast is generated by the second diffraction grating 1003, And the first and second diffraction gratings 1002 and 1003 are set to the conditions that constitute the Talbot interferometer. This condition is expressed by the following equations 1 and 2. Equation 2 assumes that the first diffraction grating 1002 is a phase type diffraction grating.
l = λ / (a / (L + Z1 + Z2)) (Formula 1)
Z1 = (m + 1/2) × (d ² / λ) (Formula 2)

  Here, l is a coherent distance, λ is an X-ray wavelength (usually a center wavelength), and a is an aperture diameter of the X-ray source 1001 in a direction substantially perpendicular to the diffraction member of the diffraction grating. Yes, L is the distance from the X-ray source 1001 to the first diffraction grating 1002, Z1 is the distance from the first diffraction grating 1002 to the second diffraction grating 1003, and Z2 is from the second diffraction grating 1003. The distance to the X-ray image detector 1004, m is an integer, and d is the period of the diffractive member (the period of the diffraction grating, the grating constant, the distance between the centers of adjacent diffractive members).

  In the X-ray imaging apparatus 1000 having such a configuration, the subject 1010 is disposed between the X-ray source 1001 and the first diffraction grating 1002, and X-rays are irradiated from the X-ray source 1001 toward the first diffraction grating 1002. Is done. This irradiated X-ray produces a Talbot effect at the first diffraction grating 1002 to form a Talbot image. This Talbot image is acted on by the second diffraction grating 1003 to form an image contrast of moire fringes. This image contrast is detected by the X-ray image detector 1004. The moire fringes are modulated by the subject 1010, and the amount of modulation is proportional to the angle at which the X-ray is bent by the refraction effect of the subject 1010. For this reason, the subject 1010 and its internal structure can be detected by analyzing the moire fringes.

Here, the Talbot effect means that when light enters the diffraction grating, the same image as the diffraction grating (self-image of the diffraction grating) is formed at a certain distance. It is called a distance L, and this self-image is called a Talbot image. When the diffraction grating is a phase type diffraction grating, the Talbot distance L is Z1 represented by the above formula 2 (L = Z1). In the Talbot image, an inverted image appears at an odd multiple of L (= (2m + 1) L, m is an integer), and a normal image appears at an even multiple of L (= 2 mL).
International Publication No. WO2004 / 058070 Pamphlet Kaoru Hyakusei, “Recent Developments of X-ray Phase Imaging”, Medical Imaging Technology, Vol. 24, No. 5, November 2006

The first diffraction grating 1002 used in the X-ray imaging apparatus 1000 is a grating that is sufficiently coarser than the wavelength of the X-ray to form an X-ray Talbot image, for example, the lattice constant is about the X-ray wavelength. It needs to be 20 times or more. Since the wavelength of X-rays is generally about 10 ⁻¹² m to 10 ⁻⁸ m, the grating constant of the first diffraction grating 1002 is about 10 ⁻¹¹ m to 10 ⁻⁷ m. It becomes several μm. Since the Talbot image is a self-image of the first diffraction grating 1002, that is, when the incident X-ray is parallel light, it is an image having the same pattern as the grating pattern of the first diffraction grating 1002. When it can be regarded as a point light source, the grating of the first diffraction grating 1002 expanded according to the ratio of the distance from the X-ray source 1001 to the first diffraction grating 1002 and the distance from the X-ray source 1001 to the second diffraction grating 1003. This is a pattern image, and the Talbot image is also a striped pattern with a period of several μm. For this reason, in order for the Talbot image to generate moire fringes by the second diffraction grating 1003, the grating constant of the second diffraction grating 1003 is also several μm.

  On the other hand, when the second diffraction grating 1003 is formed of an amplitude type (absorption type) diffraction grating, in order to absorb sufficient X-rays that function as an amplitude type diffraction grating, the diffraction member of the second diffraction grating 1003 is used. Even when a heavy element such as gold (Au) is used, a thickness of several tens to several hundreds μm is required.

  Therefore, as shown in FIG. 9, the diffraction member of the second diffraction grating 1003 has a width of several μm (for example, 4 μm) and a thickness of several tens to several hundreds of μm (for example, 100 μm). For this reason, it is necessary to form the diffractive member with a high aspect ratio, and it is not easy to manufacture the second diffraction grating 1003.

  Even if the second diffraction grating 1003 can be manufactured, the X-rays emitted from the X-ray source 1001 spread radially because the X-ray source 1001 is a substantially point light source. For this reason, as shown in FIG. 9, in the central region of the second diffraction grating 1003, the X-ray of the Talbot image is incident substantially parallel to the diffraction member, so that a moire is generated by the Talbot image and the second diffraction grating 1003. However, in both side regions of the second diffraction grating 1003, the X-rays of the Talbot image are obliquely incident on the diffraction member, so that the moire image by the Talbot image and the second diffraction grating 1003 is blurred or completely moire. Does not occur.

  On the other hand, even when the second diffraction grating 1003 is formed of a phase-type diffraction grating, in order to give the X-ray a sufficient phase change that functions as a phase-type diffraction grating, the diffraction member of the second diffraction grating 1003 Even when a heavy element such as gold (Au) is used, a thickness of several tens of μm is required. For this reason, the same inconvenience as in the amplitude type diffraction grating occurs in the phase type diffraction grating.

  Further, in order to avoid such inconvenience due to the second diffraction grating 1003, a method of directly capturing a Talbot image without using the second diffraction grating 1003 can be considered. However, it is extremely difficult to capture a Talbot image having a period of several μm with the resolution of a photosensitive material of a general X-ray film. Furthermore, for a chest X-ray, a digital image sensor such as a CCD having a size of 17 inches × 14 inches and a resolution of 4000 dots × 3000 dots is known, but the pixel size is about 110 μm. In addition, even such an image sensor cannot capture a Talbot image with a period of several μm.

  The present invention is a new X-ray capable of reliably capturing moire fringes without using a diffraction grating in order to overcome various problems that occur when imaging X-rays via an amplitude type or phase type diffraction grating. An object is to provide an imaging film, a manufacturing method thereof, an X-ray imaging method, and a system.

  An X-ray imaging film according to one aspect of the present invention is formed of a first portion formed of a material having photosensitivity to X-rays and a material having substantially no photosensitivity to X-rays. The second portion is periodically arranged to have a pattern corresponding to a diffraction grating (claim 1).

  In the conventional film-type imaging technique, X-ray moire fringes that are manifested by passing through an amplitude-type or phase-type diffraction grating are imaged with an X-ray imaging film. On the other hand, according to the above-described configuration of the present invention, the first portion formed of a material having sensitivity to X-rays and the material having substantially no sensitivity to X-rays are formed. Since the X-ray imaging film has a pattern corresponding to the diffraction grating formed by the second portion, when an X-ray stripe image is incident on the film, the X-ray stripe pattern and the first portion on the film The first portion is exposed only at the portion where the pattern matches. This photosensitive portion exhibits moire fringes because the first portion and the second portion constitute a pattern corresponding to a diffraction grating. Therefore, moire fringes can be imaged without using a diffraction grating.

  In the above configuration, it is desirable that the pattern is a diffraction grating pattern having a one-dimensional period. Alternatively, the pattern is preferably a diffraction grating pattern having a two-dimensional period.

  When a two-dimensional period is adopted, it is desirable that the periodic structure is a square lattice arrangement or a triangular lattice arrangement.

  According to another aspect of the present invention, there is provided a method for producing an X-ray imaging film, comprising: forming a photosensitive layer made of a material having photosensitivity to X-rays on one side of a film base; And a step of stacking diffraction gratings, and a step of irradiating photosensitive light to the photosensitive layer through the diffraction gratings.

  According to this configuration, using an actual diffraction grating as a mask material, an unexposed portion corresponding to the pattern and an exposed portion can be created, and an X-ray imaging having a photosensitive layer pattern corresponding to the diffraction grating. The film can be easily manufactured.

  In this case, an amplitude diffraction grating for X-rays is used as the diffraction grating, and X-rays are used as the photosensitive light (Claim 6), or X-rays and A material having photosensitivity to both visible light is used, an amplitude type diffraction grating for visible light is used as the diffraction grating, and visible light is used as the photosensitive light (claims). Item 7) is desirable.

  Another method for producing an X-ray imaging film according to the present invention is a material having photosensitivity to X-rays on one side of a film substrate formed of a material that is substantially non-photosensitive to X-rays. Is applied to a pattern corresponding to a diffraction grating by an ink jet method (claim 8).

  According to this configuration, an X-ray imaging film having a photosensitive layer pattern corresponding to a diffraction grating can be easily manufactured using an ink jet head or the like.

  An X-ray imaging method according to still another aspect of the present invention is an X-ray imaging film according to any one of claims 1 to 4 disposed on an imaging plane, and an X-ray Talbot image is formed on the imaging plane. (Claim 9).

  An X-ray imaging system according to still another aspect of the present invention includes: an X-ray source that emits X-rays; a Talbot diffraction grating that generates a Talbot effect by the X-rays emitted from the X-ray source; And the X-ray imaging film is disposed at a position substantially separated from the Talbot diffraction grating by the Talbot diffraction grating. ).

  According to these configurations, the Talbot image generated by the Talbot diffraction grating is incident on the X-ray imaging film. Moire fringes are imaged by an X-ray imaging film having a photosensitive layer pattern corresponding to a diffraction grating. Accordingly, moire fringes can be imaged without using an amplitude type or phase type diffraction grating.

  According to the X-ray imaging film and manufacturing method, X-ray imaging method, and system of the present invention, a moire fringe is not generated by an amplitude type diffraction grating, but a photosensitive layer pattern corresponding to the diffraction grating is formed on the film itself. In this configuration, moire fringes are exposed to a portion where the X-ray stripe pattern and the pattern coincide with each other. Therefore, it is possible to reliably capture moire fringes without using a diffraction grating.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of an X-ray imaging system 1 according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the configuration of the X-ray imaging unit 11.

  The X-ray imaging system 1 includes an X-ray imaging unit 11, a diffraction grating 12 (Talbot diffraction grating), and an X-ray source 13. Further, in this embodiment, the X-ray imaging system 1 supplies power to the X-ray source 13. Controls the operation of the X-ray power supply unit 14, the shutter control unit 15 that controls the shutter operation of the X-ray imaging unit 11, the system control unit 16 that controls the overall operation of the X-ray imaging apparatus X, and the X-ray power supply unit 14. The X-ray control unit 17 is configured to control the X-ray emission operation in the X-ray source 13.

  The X-ray source 13 is a device that emits X-rays and emits X-rays toward the diffraction grating 12. The X-ray source 13 emits X-rays when, for example, a high voltage supplied from the X-ray power supply unit 14 is applied between the cathode and the anode, and electrons emitted from the cathode filament collide with the anode. Device.

  The diffraction grating 12 is a transmission type diffraction grating that generates a Talbot effect by X-rays emitted from the X-ray source 13. The diffraction grating 12 includes a flat substrate made of a material that transmits X-rays and a plurality of diffraction members formed on one surface of the substrate. Each of the plurality of diffractive members has a linear shape extending in one direction (in FIG. 1, the normal direction to the paper surface), and is disposed at a predetermined interval in a direction orthogonal to the one direction. This predetermined interval is fixed in this embodiment. That is, the plurality of diffractive members are arranged at equal intervals in a direction orthogonal to the one direction. For example, glass is used for the substrate of the diffraction grating 12, and gold (Au) is used for the diffraction member. The diffraction grating 12 is configured to satisfy the conditions for causing the Talbot effect, and has a grating sufficiently coarser than the wavelength of X-rays emitted from the X-ray source 13, for example, a grating constant (diffraction grating period) d. It is a phase type diffraction grating which is about 20 times or more the wavelength of the X-ray. The first diffraction grating 12 may be an amplitude (absorption) diffraction grating that performs the same function.

  The X-ray imaging unit 11 is a unit for film-imaging X-rays that are arranged at a position approximately L Talbot distance L away from the diffraction grating 12 and diffracted by the diffraction grating 12. As shown in FIG. 2, the X-ray imaging unit 11 is disposed at an X-ray imaging film 20 for imaging an X-ray image (X-ray Talbot image) and a position immediately before the X-ray imaging film 20 on the optical path. And a shutter 30.

  As shown in a plan view in FIG. 3, the X-ray imaging film 20 includes a striped photosensitive portion 21 (first portion) formed of a material having photosensitivity to X-rays, and Thus, stripe-shaped non-photosensitive portions 22 (second portions) formed of a material having substantially no photosensitivity are alternately arranged. The photosensitive portion 21 and the non-photosensitive portion 22 are formed in a pattern of a one-dimensional periodic structure (striped structure) corresponding to an amplitude type diffraction grating. That is, the photosensitive portions 21 and the non-photosensitive portions 22 are provided with widths and intervals corresponding to the slits and the light shielding portions of the amplitude type diffraction grating. For example, the X-ray imaging film 20 is configured with a periodic structure in which photosensitive portions 21 having a width of several μm to several tens of μm and non-photosensitive portions 22 having a width of several μm to several tens of μm are alternately arranged.

  For the photosensitive part 21, various types of conventionally known photosensitive materials for X-ray imaging such as silver halide can be used. The non-photosensitive portion 22 is not particularly limited, and can be made of an appropriate material that has substantially no sensitivity to X-rays. An example of a method for manufacturing such an X-ray imaging film 20 will be described later.

  The shutter 30 is for exposing the X-ray imaging film 20 to X-rays for an appropriate exposure time. For example, a focal plane shutter can be adopted. The shutter 30 is controlled by the shutter control unit 15 to be “open” for a predetermined exposure time.

  Such X-ray imaging unit 11 and diffraction grating 12 have their arrangement positions set to conditions that constitute the Talbot interferometer expressed by the above-described Expression 1 and Expression 2.

  The system control unit 16 is a device that controls the operation of the entire X-ray imaging system 1 by controlling each unit of the X-ray imaging system 1, and includes, for example, a microprocessor and its peripheral circuits. The system control unit 16 controls the X-ray emission operation in the X-ray source 13 via the X-ray power source unit 14 by transmitting and receiving control signals to and from the X-ray control unit 17, and the shutter control unit 15 The control signal is transmitted / received between them to control the opening / closing operation of the shutter 30 of the X-ray imaging unit 11. Under the control of the system control unit 16, X-rays are emitted toward the subject S, and an image generated thereby is captured by the X-ray imaging film 20 of the X-ray imaging unit 11.

  Then, the example of the manufacturing method of the X-ray imaging film 20 which has the photosensitive pattern corresponded to a diffraction grating is shown. 4A to 4D are schematic views illustrating a method for manufacturing the X-ray imaging film 20 according to the first embodiment.

  As shown in FIG. 4A, first, a photosensitive agent 210 having photosensitivity to X-rays and visible light is applied to one surface of a film base 23 to a predetermined thickness by a screen printing method or the like. Then, a film base material in which a layer of the photosensitive agent 210 is formed on the entire surface of one side of the film base 23 is prepared by applying a drying process or the like.

  Next, as shown in FIG. 4B, an amplitude-type diffraction grating 24 for visible light in which stripe-shaped light shielding portions 241 and light transmitting portions 242 are alternately arranged is prepared, and the diffraction grating 24 is placed on the film. It is superimposed on the layer of the photosensitive material 210 of the base material. Then, as shown in FIG. 4C, a light source 25 capable of sensitizing the photosensitive agent 210 is prepared, and light for light is emitted from the light source 25 through the diffraction grating 24. As the light source 25, since the photosensitive agent 210 is sensitive to X-rays and visible light, a light source that emits visible light that is easy to handle can be used.

  When such light irradiation is performed, a portion corresponding to the translucent portion 242 of the solid-coated photosensitive agent 210 is exposed, but a portion corresponding to the light shielding portion 241 remains unexposed. . Therefore, as shown in FIG. 4D, there is an X-ray imaging film 20 in which the unexposed portion is periodically formed as the photosensitive portion 21 and the photosensitive portion is formed as the non-photosensitive portion 22 in accordance with the pattern of the diffraction grating 24. Manufactured.

  In the above manufacturing method, an X-ray amplitude type diffraction grating may be used as the diffraction grating 24, and a light source that generates X-rays may be used as the light source 25.

  According to these manufacturing methods, the photosensitive part 21 and the non-photosensitive part are obtained by performing one or several visible light amplitude diffraction gratings or X-ray amplitude diffraction gratings and performing the photosensitive process as described above. The X-ray imaging film 20 having a pattern corresponding to a diffraction grating in which 22 and 22 are periodically arranged can be easily mass-produced.

  FIG. 5 is a schematic diagram showing a method for manufacturing the X-ray imaging film 20 according to the second embodiment. This manufacturing method is a method in which the photosensitive portion 21 is directly applied by an inkjet method. As shown in FIG. 5, a material having photosensitivity to X-rays is jetted from an inkjet nozzle onto one surface of a film substrate 26 formed of a material that is substantially non-photosensitive to X-rays. . An arrow indicated by a symbol J in the drawing schematically shows the photosensitive agent ejected from the nozzle.

  A plurality of inkjet nozzles are one-dimensionally arranged at a pitch corresponding to the grating constant of the amplitude type diffraction grating, and the nozzle array and the film substrate 26 are moved relative to each other, so that the photosensitive agent is the film substrate 26. It is applied to the surface in stripes. As a result, the photosensitive portions 21 are formed in a one-dimensional cycle, and non-photosensitive portions 22 formed by exposing the surface of the film base 26 are formed between the photosensitive portions 21.

  A single inkjet nozzle is used instead of the nozzle array as described above, and the single nozzle is sequentially moved according to the formation pattern of the photosensitive portion 21 to be formed, and the photosensitive portion is formed on the film substrate 26. 21 patterns may be drawn.

  Next, the operation of the X-ray imaging system 1 according to this embodiment will be described. When the subject S is disposed between the X-ray source 13 and the diffraction grating 12 and the user of the X-ray imaging system 1 instructs the imaging of the subject S from an operation unit (not shown), the system control unit 16 A control signal is output to the X-ray control unit 17 to irradiate X-rays toward the X direction. 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 13, and the X-ray source 13 emits X-rays and irradiates the subject S with X-rays.

  The irradiated X-ray passes through the diffraction grating 12, is diffracted by the diffraction grating 12, and forms a Talbot image T that is a self-image of the diffraction grating 12 at a position away from the Talbot distance L (= Z1). An X-ray imaging unit 11 is disposed at the image forming position of the X-ray Talbot image T.

  In this state, the system control unit 16 gives a control signal for opening the shutter 30 of the X-ray imaging unit 11 to the shutter control unit 15. In response to this, the shutter control unit 15 opens the shutter 30. Thereby, the X-ray imaging film 20 is exposed to the light beam of the X-ray Talbot image T. When a predetermined exposure time has elapsed, the shutter 30 is closed.

  By such an exposure operation, only the portion where the stripe pattern of the Talbot image and the stripe pattern of the photosensitive portion 21 of the X-ray imaging film 20 coincide with each other, the photosensitive portion 21 is exposed to X-rays. As a result, the Talbot image T (moire fringes) is developed on the X-ray imaging film 20.

  Here, since the subject S is disposed between the X-ray source 13 and the diffraction grating 12, the X-rays that have passed through the subject S are out of phase with the X-rays that do not pass through the subject S. For this reason, the X-ray incident on the diffraction grating 12 includes distortion in its wavefront, and the Talbot image is deformed accordingly. For this reason, visible moiré fringes generated by superimposing the X-ray Talbot image incident on the X-ray imaging film 20 and the one-dimensional periodic structure of the photosensitive portion 21 are modulated by the subject S. This modulation amount is proportional to the angle at which the X-ray is bent by the refraction effect by the subject S. Therefore, the subject S and its internal structure can be detected by analyzing the moire fringes.

  As described above, according to the X-ray imaging system 1 according to the embodiment, the moiré fringes are not generated in the diffraction grating, but the one-dimensional periodic structure of the photosensitive unit 21 corresponding to the diffraction grating is provided in the X-ray imaging film 20 itself. In this configuration, the moire fringes are developed at the portion where the X-ray stripe pattern and the pattern of the photosensitive portion 21 coincide with each other. Therefore, it is possible to reliably capture moire fringes without using a diffraction grating.

  That is, according to the above configuration, moire fringes are substantially generated by superimposing the stripe pattern of the X-ray Talbot image and the stripe pattern of the photosensitive portion 21. The stripes of the X-ray Talbot image are very fine stripes, and it is extremely difficult to capture a Talbot image with a period of several μm with the resolution of a general X-ray film photosensitive material. Since the X-ray imaging film 20 has the photosensitive portions 21 arranged at a fine pitch, the stripe pattern of the X-ray Talbot image can be enlarged using moire. For this reason, an X-ray Talbot image can be substantially picked up even if a general X-ray film photosensitive material that cannot normally resolve a striped pattern is used.

  In the above embodiment, it is desirable that the photosensitive part 21 and the diffraction grating 12 of the X-ray imaging film 20 have the same lattice constant, but they may be different. When the grating constant of the diffraction grating 12 is d1 and the grating constant of the periodic structure of the photosensitive portion 21 is d2, a moire fringe of d1 × d2 / (d2−d1) appears, and this moire fringe is analyzed in the same manner as described above. It is possible to detect the subject S and its internal structure.

  In the above-described embodiment, the subject is disposed between the X-ray source 13 and the diffraction grating 12, but the subject may be disposed between the diffraction grating 12 and the X-ray imaging unit 11.

  Further, in the above-described embodiment, the X-ray imaging film 20 has the example in which the photosensitive portion 21 is formed in the diffraction grating pattern having a one-dimensional period. However, the present invention is not limited to this. FIG. 6 is an explanatory view showing a diffraction grating pattern having a two-dimensional period of a square lattice arrangement. FIG. 7 is a diagram for explaining moire generated from a Talbot image by the pattern shown in FIG. FIG. 7A shows a Talbot image, and FIG. 7B shows a moire image. The pattern of the photosensitive portion 21 of the X-ray imaging film 20 may be a diffraction grating pattern having a two-dimensional period as described above, and the periodic structure may be a square lattice arrangement or a triangular lattice arrangement. In short, the pattern of the photosensitive portion 21 may be a pattern having a structure that causes moire by capturing a Talbot image.

  For example, a two-dimensional periodic diffraction grating pattern is configured by arranging dots serving as diffraction members at equal intervals in two linearly independent directions. As shown in FIG. 3, the square lattice arrangement is configured by arranging dots serving as diffraction members at equal intervals in two orthogonal directions so that the unit lattice is square. Although not shown in the figure, the triangular lattice arrangement is configured by arranging dots serving as diffractive members at equal intervals in two directions that are 60 degrees from each other so that the unit lattice is a regular triangle. Such a dot portion may be constituted by the photosensitive portion 21 or the non-photosensitive portion 22.

  In the X-ray imaging film 20 having such a two-dimensional period, for example, as shown in FIG. 7A, a plurality of shadows extending linearly in one direction are formed at equal intervals in a direction orthogonal to the one direction. For example, as shown in FIG. 6, when the X-ray imaging film 20 having a photosensitive portion 21 having a periodic lattice arrangement of a square lattice is exposed to the striped Talbot image, which is slightly inclined from the one direction, as shown in FIG. The moire fringes shown in FIG. 7B can be developed on the X-ray imaging film 20.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Accordingly, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not limited to the scope of the claims. To be construed as inclusive.

It is explanatory drawing which shows the structure of the X-ray imaging system which concerns on embodiment of this invention. It is explanatory drawing which shows the structure of the X-ray imaging unit in embodiment. It is a top view of the X-ray imaging film in embodiment. It is a schematic diagram which shows the manufacturing method of the X-ray imaging film which concerns on 1st Embodiment. It is a schematic diagram which shows the manufacturing method of the X-ray imaging film which concerns on 2nd Embodiment. It is explanatory drawing which shows the diffraction grating of the two-dimensional period of a square lattice arrangement | sequence. It is a figure for demonstrating the moire which arises from a Talbot image with the diffraction grating shown in FIG. It is explanatory drawing which shows schematic structure of the X-ray imaging device of patent document 1. FIG. It is a top view for demonstrating the 2nd diffraction grating and moire image in the X-ray imaging device which concerns on background art.

Explanation of symbols

1 X-ray imaging system 11 X-ray imaging unit 12 Diffraction grating (Talbot diffraction grating)
13 X-ray source 20 X-ray imaging film 21 Photosensitive part (first part)
22 Non-photosensitive part (second part)
23 Film substrate 30 Shutter

Claims (10)

  A first portion made of a material having photosensitivity to X-rays and a second portion made of a material having substantially no photosensitivity to X-rays are periodically arranged. An X-ray imaging film having a pattern corresponding to a diffraction grating.   The X-ray imaging film according to claim 1, wherein the pattern is a diffraction grating pattern having a one-dimensional period.   The X-ray imaging film according to claim 1, wherein the pattern is a diffraction grating pattern having a two-dimensional period.   The X-ray imaging film according to claim 3, wherein the two-dimensional periodic structure is a square lattice arrangement or a triangular lattice arrangement. Forming a photosensitive layer made of a material sensitive to X-rays on one side of a film base;
Stacking diffraction gratings on the photosensitive layer;
Irradiating photosensitive light toward the photosensitive layer through the diffraction grating, and a method for producing an X-ray imaging film. As the diffraction grating, an X-ray amplitude diffraction grating is used,
6. The method for producing an X-ray imaging film according to claim 5, wherein X-rays are used as the light for photosensitive. As the photosensitive layer, a material having sensitivity to both X-rays and visible light is used,
As the diffraction grating, an amplitude type diffraction grating for visible light is used,
The method for producing an X-ray imaging film according to claim 5, wherein visible light is used as the light for photosensitive. On one side of a film substrate formed of a material that has substantially no photosensitivity to X-rays,
A method for producing an X-ray imaging film, wherein a material having photosensitivity to X-rays is applied to a pattern corresponding to a diffraction grating by an inkjet method. The X-ray imaging film according to any one of claims 1 to 4 is disposed on an imaging plane,
An X-ray imaging method, wherein an X-ray Talbot image is formed on the imaging surface. An X-ray source emitting X-rays;
A Talbot diffraction grating that produces a Talbot effect by X-rays emitted from the X-ray source;
An X-ray imaging film according to any one of claims 1 to 4,
The X-ray imaging system, wherein the X-ray imaging film is disposed at a position substantially separated from the Talbot diffraction grating by a Talbot distance.

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