JP2002071815A - X-ray image fluorograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve X-ray transmittance of grids for scattered X-ray removal of an X-ray image fluorograph, improve an MTF by reducing scattered components inside scintillators, and to realize an image with no fringes and moire fringes of the grid without using a moving grid. SOLUTION: The scintillators 3 such as phosphors shaped like a divided band or a grid are arranged adjacent to photoelectric transducing elements 1 of an X-ray image detecting part 10 used in the X-ray image fluorograph and directly above insensitive body portions 9a between respective photoelectric transducing elements 1. The grids 11 for scattered X-ray removal are arranged adjacent to the scintillators 3, and X-ray absorbing members 4 inside the grids for scattered X-ray removal are arranged directly above the insensitive body portions 9a between the same photoelectric transducing elements 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus, and more particularly to an X-ray digital imaging apparatus having a grid for removing scattered radiation and a phosphor.

[0002]

2. Description of the Related Art Heretofore, a film / screen method has been most commonly used as an X-ray imaging method. In this method, an image is taken by combining a photosensitive film and a phosphor sensitive to X-rays.

In this method, a sheet of a rare-earth phosphor that emits light when irradiated with X-rays is held in close contact with both surfaces of a photosensitive film, and the X-rays transmitted through a subject are converted into light by the phosphor. Instead, the light is captured by a photosensitive film. The image is visualized by developing the film.

As a second method of X-ray photography, a method called computed radiography (CR) has been put to practical use. In this method, a latent image is read out by irradiating with excitation light after temporarily storing a transmission image of radiation as a latent image in a phosphor.

[0005] Radiation (X-ray, α-ray, β
Radiation, gamma rays, electron beams, ultraviolet rays, etc.), a part of the radiation energy is accumulated in the phosphor. It is known that when this phosphor is irradiated with excitation light such as visible light, the phosphor emits stimulated emission according to the stored energy. Phosphors exhibiting such properties are called storage phosphors (stimulable phosphors).

As a system for X-ray image photographing using the CR method, a radiation image information recording / reproducing system using a stimulable phosphor is known.
Nos. 429 and 56-11395. In this system, first, radiation image information of a subject such as a human body is temporarily recorded on a sheet of a stimulable phosphor,
The sheet is scanned with excitation light such as laser light to emit stimulating light. Then, based on an image signal obtained by photoelectrically reading the stimulated emission light, a radiation image of the subject is output as a visible image on a recording material such as a photographic photosensitive material or a display device such as a CRT.

[0007] As a third X-ray imaging method, a method using a semiconductor sensor is also known.

In an X-ray imaging system using this semiconductor sensor, an image is recorded over an extremely wide radiation exposure area as compared with a radiographic system using silver halide photography. This is a practical advantage. That is, in a system using a semiconductor sensor, a radiation image is converted into a recording material such as a photographic photosensitive material or a display device such as a CRT using an electric signal obtained by reading and converting X-rays having a very wide dynamic range by a photoelectric conversion unit. Output as a visible image. As a result, a radiation image that is not affected by the change in the radiation exposure amount is output.

FIG. 6 is a diagram showing an example of a radiographic image capturing system using the above-described semiconductor sensor.

Reference numeral 103 denotes an X-ray image photographing device having a built-in X-ray detection sensor 104. In this device, X-rays emitted from the X-ray generator 101 and transmitted through the subject 102 are detected by an X-ray detection sensor 104 having a detection surface on which a plurality of photoelectric conversion elements are two-dimensionally arranged. The image signal output from the detecting means 104 is output to an image processing means 107.
And an X-ray image of the subject is output to the monitor 108.

In the above three types of X-ray imaging methods,
In some cases, a grid for removing scattered X-rays (grid) is used. This grid is for removing scattered X-rays generated inside a subject such as a human body by X-ray irradiation.
It is used between the wire tube and a detector such as a film just before the detector. When imaging is performed using this grid, the contrast of the X-ray image is improved.

FIG. 7 is a sectional view of the above-mentioned grid. X-rays are emitted from the upper direction A. 110 is
A foil having a high X-ray absorptivity and usually made of lead. 11
Reference numeral 1 denotes an intermediate substance between foils, which is made of aluminum, paper, wood, synthetic resin, carbon fiber reinforced resin, or the like having a low X-ray absorption rate. Reference numeral 112 denotes a member that covers the foil 110 and the intermediate substance 111, and is made of aluminum or the like. The cross section of another portion perpendicular to the paper has the same structure. That is, the foil 110 is continuous in a belt shape in a direction perpendicular to the paper surface.

The use of the above-described grid prevents a decrease in resolution due to X-rays scattered in the body of the subject.
That is, the primary light incident parallel to the foil 110 passes through the grid, but the scattered X-rays incident on the grid with a certain inclination with respect to the foil 110 are absorbed by the foil 110 and do not pass through the grid.

The foil 110 has a cover 112 at the center just below the X-ray source, which is a light source, as shown at 110a.
Perpendicular to and towards the periphery, 110b,
In many cases, 110c is inclined toward the center, that is, toward the X-ray source. In the case of using this convergent grid, it is necessary to image the distance between the grid and the X-ray source and the center thereof. On the other hand, some grids do not tilt the foil,
This is called a parallel grid.

As an index indicating the degree of scattered radiation removal of the grid, a number called a grid ratio is used. In FIG. 7, the grid ratio is determined by the distance L1 between the adjacent foils 110 at the center of the grid and the height L2 of the foil 110.
In general, the distance between the foils is represented as 1. For example, the grid ratio of the grid shown in FIG. 7 is expressed as (L2 / L1): 1.

The grid generally has a grid ratio of 6:
1,8: 1,10: 1,12: 1,14: 1 etc. are used. The higher the grid ratio, the higher the ability to remove scattered radiation, but the so-called tilt due to the tube,
Injuries increase.

The number of foils per cm is expressed as grid density (lines / cm). When the grid ratio is increased at the same grid density, the ability to remove scattered radiation is improved, but the thickness of the intermediate substance 111 is increased and the X-ray transmittance is reduced.

FIG. 8 is an X-ray imaging apparatus used for X-ray imaging by the radiation imaging system shown in FIG.
It is sectional drawing of a line image detection part and a grid. 120 is
In the X-ray image detection unit, the photoelectric conversion element 1
21 are arranged two-dimensionally. 123, which is adjacent to the photoelectric conversion element 121, is a phosphor. When the phosphor 123 is irradiated with X-rays, the fluorescent substance is excited in the phosphor 123 and emits fluorescence having a wavelength close to the spectral sensitivity wavelength region of the photoelectric conversion element 121.

Reference numeral 130 denotes a grid similar to that shown in FIG. The grid 130 includes a foil 131 such as lead having a high X-ray absorption, an intermediate substance 132 made of aluminum or the like having a low X-ray absorption, and a cover member 133. X
The primary light 134 of the line passes through the grid and passes through the phosphor 123.
Leads to. On the other hand, the scattered radiation component 135 of X-rays is incident on the foil 131 at a certain angle, not parallel to the foil 131, and is absorbed by the foil 131.

The grid 130 is supported by a pointing mechanism (not shown) so that it can move in the B or C direction. Then, the grid 130 moves in the B or C direction during photographing by a driving mechanism and a control unit (both not shown). Therefore, the image obtained by the X-ray image detection unit 120 does not include grid stripes detected when the grid is fixed, moiré stripes generated due to a difference in pitch between the grid foil and the pixel, and the like. .

Further, an X-ray flat panel detector provided with a fixed grid is disclosed in Japanese Patent Application Laid-Open No. 9-75332.
This discloses that a lead portion of a grid is formed in an insensitive portion of an X-ray flat panel detector.

[0022]

However, in the above-mentioned conventional X-ray imaging apparatus, it is necessary to reduce the dose of X-rays to be applied at the time of imaging to reduce the amount of exposure to the subject.
There is a big problem in achieving both good and good images.

That is, when the grid is made of a laminate of an X-ray absorbing heavy metal such as lead and a light metal such as aluminum foil,
There is a problem that the X-ray intensity reaching the X-ray detector is reduced. One of the causes of the decrease in the X-ray intensity is that the X-rays reaching the X-ray detector 120 shown in FIG.
You have to go through 2.

As described above, a material such as aluminum having a high X-ray transmittance is used for the intermediate material, but the transmittance is naturally not 100% even if it is high. For example, the grid density representing the number of foils per 1 cm is 40 pieces / cm,
When the grid ratio is 10: 1, assuming that the thickness L4 of the lead foil 131 shown in FIG.
Has a thickness L3 of 207 μm (= (1 cm / 40) −L4).
And the height L5 of the intermediate substance 132 is 2070 μm (=
L3 × 10). When the intermediate material 132 is made of aluminum, the thickness becomes about 2 mm, and the transmittance of the primary X-ray light is about 70%. Therefore, 30% of the X-ray intensity is lost. When viewed from the X-ray incident direction, the foil 1
Since the lead 31 does not transmit about 17% (= L4 / (L3 + L4)) of the X-ray, the total transmittance is about 60% (= 0.7 × ( 1-
0.17)), and the X-ray intensity decreases at a very large rate.

Japanese Patent Application Laid-Open No. 9-75332 discloses a method in which a lead foil is formed on an insensitive portion of an X-ray flat panel detector in order to improve the absorption of X-rays by a grid. Generally, the size of one pixel of the X-ray flat panel detector is preferably at least 200 μm or less in order to maintain good resolution. On the other hand, in order to improve the sensitivity of the X-ray flat panel detector, it is desired that the area of the effective detection unit (radiation sensitive unit) of the imaging pixel unit is as large as possible. Therefore, the width of the dead portion corresponding to between pixels is reduced.

Therefore, the thickness of the lead foil of the grid provided in the dead area usually needs to be about 20 μm to 80 μm. However, this thinness reduces the mechanical strength of the grid. In particular, when a gap is provided between grids, the mechanical strength is significantly reduced. Further, when a load of a subject such as a human is applied on the X-ray flat panel detector as in the case of cassette imaging, the grid is deformed, and the shadow of the grid appears in the captured image, and a good image is obtained. No.

Further, in the conventional X-ray imaging apparatus, the phosphor has a continuous plane shape covering all the photoelectric conversion elements. Therefore, in FIG. 8, the primary light 134 of the X-ray that has passed through the grid reaches the phosphor 123, and the fluorescence 136 generated in the phosphor 123 goes in various directions. Therefore, the fluorescent light 136 may reach not only the photoelectric conversion element 121a immediately below the place where the light is emitted but also another adjacent photoelectric conversion element 121b.

Therefore, although the incident scattered radiation component can be removed by the grid 130, the phosphor 1
The scattered radiation component in 23 cannot be removed,
There is a problem that the MTF of an image is reduced.
In addition, when the thickness of the phosphor 123 is increased in order to increase the signal intensity of the photoelectric conversion element and the intensity of the emitted light is increased, this tendency is further increased, and the sensitivity of the X-ray imaging apparatus is improved. Would be an obstacle.

Therefore, the present invention reduces the amount of decrease in the X-ray intensity when passing through the grid while removing the X-ray scattered radiation component by the grid as before, and without reducing the image quality. To reduce the exposure dose, reduce the scattered component in the phosphor, reduce the crosstalk between the photoelectric elements, improve the MTF, and obtain a good image without grid streaks or moire fringes. That is the task.

Further, the present invention eliminates the need for a mechanism for moving the grid, and provides a stable, inexpensive, maintenance-free device without moving parts, and increases the load-bearing strength of the grid by incorporating a grid reinforcing resin. Another object is to make the grid reinforcing resin an adhesive resin, to further increase the load-bearing strength, and to improve the reliability of cassette photographing.

[0031]

According to the present invention, there is provided a laminate comprising a sensor having a two-dimensional array of photoelectric conversion elements formed on a substrate, a phosphor layer and an X-ray transmission layer. And a grid body partitioned into the two-dimensional array by an X-ray absorber, and an X-ray imaging apparatus having the grid body mounted on the sensor, wherein the phosphor layer is formed by each of the photoelectric conversion elements. The X-ray transmission layer is stacked on the light receiving surface, the X-ray transmission layer is stacked on the X-ray incidence surface of each of the phosphor layers, and the X-ray absorber is located in a gap between the photoelectric conversion elements. It is arranged perpendicular to the light receiving surface of the conversion element.

Here, the X-ray absorber is positioned above the gap between the photoelectric conversion elements, and is arranged perpendicularly to the light receiving surface of the photoelectric conversion element at the center of the sensor.
The sensor may be replaced with one that is gradually inclined toward the center of the sensor as it goes toward the periphery of the sensor.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 respectively show X in Embodiment 1.
It is sectional drawing and a top view of an X-ray image detection part used for a X-ray imaging apparatus. Reference numeral 10 denotes an X-ray image detection unit. The X-ray image detection unit 10 includes an insulating substrate 2, a photoelectric conversion element 1, and a reference numeral 11.
It consists of a part. 11 is a grid and a phosphor part.

The plurality of photoelectric conversion elements 1 are two-dimensionally distributed in a plane perpendicular to the paper surface. Photoelectric conversion element 1
Are formed on the insulating substrate 2 by a semiconductor process. Generally, a glass plate is used for the insulating substrate 2.
The glass plate is used because there is no chemical action with the semiconductor element forming the photoelectric conversion element 1 and the like, it withstands high temperature during the semiconductor process, the dimensions are stable, and the planar accuracy is good. For that reason. Reference numeral 9a denotes a gap between the adjacent photoelectric conversion elements 1, which is a non-sensitive portion having no sensitivity to incident light.

The grid and the phosphor section 11 are composed of a scintillator 3 such as a phosphor, a foil 4 and an intermediate substance 5.
The scintillator 3 is provided adjacent to the photoelectric conversion element 1. The foil 4 is a foil having a high X-ray absorptivity, and usually uses lead.

The intermediate material 5 is a resin for reinforcing the grid between the foils 4 and is made of a synthetic resin having a low X-ray absorption or a carbon fiber reinforced resin. It is preferable to use a plastic resin having high mechanical strength as a material of the synthetic resin.
For example, polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, polystyrene, or polyether sulfone is used. Further, it is preferable to use a UV-curable resin having a polyfunctional acrylic group, a thermosetting resin, a thermosetting epoxy resin, or the like, which has good adhesiveness to lead or the like as the material of the foil 4.

By using a resin having good adhesiveness to the foil 4 as a material of the intermediate substance 5, the adhesiveness between the foil 4 as an X-ray absorbing material and the intermediate substance 5 as a grid reinforcing resin is improved, As compared with the case where the material of the intermediate substance 5 is a resin material having no adhesive property such as polycarbonate, the mechanical strength of the grid 11 against external stress increases.

The foils 4, which are X-ray absorbing materials, are formed immediately above the dead portions 9a, and the thickness of the foil 4 and the width of the dead portions 9a are substantially the same. The scintillator 3 is divided by the foil 4. The intermediate substance 5 which is a grid reinforcing resin is formed immediately above the scintillator 3 between the adjacent foils 4.

FIG. 2 is a plan view seen from the direction D in FIG. Substantially square regions 1a and 1b represented by hatched portions
Denotes one pixel of the photoelectric conversion element 1, and 1 pixel shown in FIG.
a and 1b. The foil 4 and the intermediate substance 5 which is a grid reinforcing resin are formed continuously in the vertical direction on the paper of FIG. The photoelectric conversion elements 1 formed directly below the grid reinforcing resin 5 are substantially square and two-dimensionally distributed as described above. Therefore, the dead body portion 9b exists in the left-right direction of the paper substantially perpendicular to the dead body portion 9a immediately below the foil 4 shown in FIG.

Next, a case where X-rays are incident on the X-ray image detecting section 10 shown in FIGS. 1 and 2 will be described.

Since the X-ray primary light 6 is incident on the foil 4 substantially in parallel, the primary light 6 passes through the intermediate substance 5 which is a grid reinforcing resin, reaches the scintillator 3, and inside the scintillator 3, a photoelectric conversion element is formed. The fluorescent light 8 having a wavelength sensitive to 1 is emitted. Although the fluorescent light 8 is emitted at various angles, it is absorbed by the foil 4 and does not reach another photoelectric conversion element 1 adjacent in the left-right direction. On the other hand, the X-ray scattered ray component 7 is not parallel to the foil 4 but is incident at a certain angle, so that it is absorbed by the foil 4 and does not reach the photoelectric conversion element 1.

As shown in FIG. 2, the foil 4 is continuous in the vertical direction of FIG. 2, so that the X-ray scattered ray component 7 and the scattering of the scintillator 3 are not shielded in the cross section shown in FIG.
However, most of the scattering is achieved by making the continuous direction of the grid foil (vertical direction in FIG. 2) substantially coincide with the body axis of the subject, as used in a normal film or screen-based imaging method. Line components are removed.

To summarize the first embodiment, since the foil 4 exists only on the insensitive portion 9a between the photoelectric conversion elements 1,
X-rays incident on the scintillator 3 on the photoelectric conversion element 1 are not blocked. Therefore, the conventional apparatus does not suffer from the problem of a decrease in the X-ray transmittance determined by the ratio (opening ratio) of the thickness of the intermediate substance to the thickness of the foil. For example, when the grid ratio described in the description of the conventional device is 10: 1, the thickness of the lead foil is 43 μm, and the thickness of the intermediate material is 207 μm.
About 17% (= 43 / (43 + 207)) of X-rays are not transmitted. That is, the aperture ratio is 83%. In contrast, in the present embodiment, the aperture ratio is 100% while forming the grid portion. Therefore, even when the same photoelectric conversion element is used, the sensitivity is improved by about 20% (= 100/83), and the exposure dose to the subject is suppressed.

In addition, by removing not only the scattering of the incident X-ray but also the scattering of the emitted fluorescent light, so-called crosstalk between the photoelectric elements is reduced. Therefore,
MTF is improved and a good image is obtained.

In the first embodiment, the scintillator 3 is formed continuously in the vertical direction in FIG. 2. However, the scintillator 3 has a substantially square shape, The shape excluding the upper scintillator 3 may be used. In this case, the MTF in the vertical direction is also improved.
If the above-mentioned grid ratio is about 3: 1 or more, scattered radiation can be removed satisfactorily.

FIG. 3 is a sectional view of the X-ray image detecting section 20 used in the X-ray image photographing apparatus of the second embodiment. 1 and 2
The same reference numerals denote the same members.

The difference between the first embodiment shown in FIGS. 1 and 2 and the second embodiment shown in FIG. 3 lies in the shape of the grid portion 21. As shown in FIG. 1, in the first embodiment, the grid 1
While the foils 4 in 1 are parallel grids arranged in parallel to each other, in Embodiment 2 shown in FIG. 2, the grid portion 21 is a so-called converging grid.

That is, the foil 23a near the center line 26 is
Although perpendicular to the detection surface of the photoelectric conversion element 1a, the foil 23 inclines from the perpendicular 25 of the detection surface toward the center line 26 toward the periphery. The angle θ between the peripheral foil 23b and the center line 26 is 0 near the center line 26, but increases as the distance from the center line 26 in the left-right direction increases. In FIG. 3, the extension line above the foil 23 intersects at one point above the center line 26.

The X-ray image detector 20 of the second embodiment described above
If an X-ray tube is arranged at the intersection of the extension lines of the foils 23 and photographed with an X-ray image photographing device using
A so-called unbleached image is obtained by the foil 23b of the grid 21. That is, a good image without a decrease in light intensity in the peripheral portion can be obtained.

FIG. 4 is a sectional view of the X-ray image detecting section 30 used in the X-ray image photographing apparatus according to the third embodiment. 1 and 2
The same reference numerals denote the same members.

The X-ray image detecting section 30 shown in FIG. 4 is a modification of the X-ray image detecting section 10 shown in FIG. 1, and has a fluorescent reflection layer 4a provided on the surface of the X-ray absorbing material 4. is there.

The fluorescent light 8 generated by the scintillator 32 such as a fluorescent substance by the fluorescent reflecting layer 4a formed on the surface of the X-ray absorbing material 4 is scattered to the surroundings, but the fluorescent reflecting layer 4a opposite to the intermediate substance 5 is sandwiched. The light reflected by the sensor and reaching the light receiving portion 1a of the sensor increases. Further, if the fluorescent reflection layer 5a is provided on the outermost layer surface of the intermediate substance 5 which is a grid reinforcing resin, the fluorescence 8 generated from the scintillator 32 is less likely to diffuse from the inside surrounded by the reflection layer to the outside. . Therefore, the fluorescence extraction efficiency of the scintillator is improved.

According to the third embodiment, the scattered ray component of the fluorescent light is also efficiently sent to the sensor, and the X-ray flat sensor has higher sensitivity than that used in the first embodiment shown in FIGS.

In the above-described embodiment, a cover or an adhesive layer may be provided on the surface of the grid, between the grid and the phosphor, or between the phosphor and the photoelectric conversion element.

Next, the manufacturing method of the above-described embodiment will be described with reference to a specific example.

Example 1 As the foil 4 shown in FIG.
A 30 μm-thick lead foil serving as an X-ray absorbing material was
A polyethylene terephthalate having a thickness of 130 μm as a grid reinforcing resin is prepared. Further, as a phosphor coating paste for the scintillator 3, 80 parts by weight of gadolinium oxysulfide and terbium (containing 3%), 10 parts by weight of cellulose acetate, and 10 parts by weight of an ethyl cellosolve solvent are prepared.

As shown in FIG. 5 (a), polyethylene terephthalate 5, the end of which has been set, is superimposed on the surface of the lead foil 4 as an intermediate substance. Then, as shown in FIG. 5B, the first layer is formed by forming the phosphor 12 by screen printing using the above-described phosphor application paste 51 material. Next, with the solvent not drying completely,
As shown in FIG. 5C, a second-layer lead foil 4 is overlaid on the phosphor 12 and the intermediate substance 5 formed by screen printing, and then, the first surface of the second layer is placed on the other surface of the second layer. Polyethylene terephthalate 5 is overlaid so as to be in the same position as the layer.
Then, the phosphor 12 is formed by screen printing using the above-described phosphor application paste material, and a second layer is formed. By repeating this operation, as shown in FIG. 5D, a multi-layer grid base material is manufactured, and cut and polished to a predetermined size, thereby forming the grid 11 as shown in FIG. .

The completed grid containing the phosphor is
When stacked on the surface of a flat sensor made of a semiconductor photoelectric conversion element having a size of one pixel of 160 μm × 160 μm,
An X-ray image detector 10 used in the X-ray image photographing apparatus shown in FIG. 11 was formed.

[Example 2] Even if the grid reinforcing resin for the intermediate substance used in the production method of Example 1 was changed to Unidec 806 Dainippon Ink which is an ultraviolet curable resin,
An X-ray image detection unit 10 having a grid 11 as shown in FIG. 1 was formed. The mechanical strength of the grid of this example, that is, the deformation load of the grid when a load was applied vertically to the grid was twice that of Example 1. The adhesiveness between the foil 4 as an X-ray absorbing material and the intermediate substance 5 as a grid reinforcing resin was superior to that of Example 1.

[Example 3] As the X-ray absorbing material 4, a thin film of aluminum was formed on both sides of a surface of a lead foil having a thickness of 20 μm by 30 n.
An X-ray image detection unit 30 having a grid 31 as shown in FIG. Also, on the outermost surface of the grid,
An aluminum reflective film 5a was formed to a thickness of 30 nm. A direct current sputtering method was used for forming the aluminum thin film.

The X-ray image photographing apparatus using the manufactured X-ray image detecting section 30 has a smaller emission amount of the phosphor than the X-ray image photographing apparatus using the X-ray image detecting section 20 of the second embodiment. 1.
It has improved three times.

In the embodiment described above, the grid section, the phosphor section, and the photoelectric conversion element section may be formed integrally. Also, after being formed as a separate body divided into certain parts,
They may be combined.

[0064]

According to the present invention described above, it is possible to reduce the amount of decrease in the X-ray intensity when transmitting through the grid while removing the X-ray scattered ray component by the grid as in the conventional case. Therefore, the exposure dose to the subject can be reduced without lowering the image quality.

Further, the scattering component in the scintillator can be reduced. Therefore, crosstalk between each photoelectric element is reduced, and the MTF is improved.

Further, a good image free of grid stripes and moire fringes can be obtained.

In addition, since a mechanism for moving the grid is not required, an inexpensive and maintenance-free stable device having no movable parts can be obtained.

Further, by adding the grid reinforcing resin, the load bearing strength of the grid increases.

Further, by using an adhesive resin as the grid reinforcing resin, the load bearing strength is further increased.

In addition, the reliability of cassette photographing is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a plan view of the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a third embodiment of the present invention.

FIG. 5 is a schematic view of a method for manufacturing a grid according to the present invention.

FIG. 6 is an explanatory diagram of an X-ray image photographing system.

FIG. 7 is a cross-sectional view of a conventional grid.

FIG. 8 is a cross-sectional view of a conventional grid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoelectric conversion element 2 Insulating substrate 3 Scintillator 4 X-ray absorption foil 5 Grid reinforcement resin 6 Primary light of X-ray 7 X-ray scattered ray component 8 Fluorescence 9 Insensitive part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuho Hiraoka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazumi Nagano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term in the corporation (reference) 2G088 FF02 GG19 GG20 JJ05 JJ15 JJ30

Claims (7)

[Claims] 1. A grid body comprising: a sensor having a two-dimensional array of photoelectric conversion elements formed on a substrate; and a laminate of a phosphor layer and an X-ray transmission layer divided by the X-ray absorber into the two-dimensional array. An X-ray imaging apparatus comprising the grid body on the sensor, wherein the phosphor layer is laminated on each light receiving surface of the photoelectric conversion element, and the X-ray transmission layer is The X-ray absorber is stacked on the X-ray incident surface of each phosphor layer, and the X-ray absorber is positioned above a gap between the photoelectric conversion elements and is arranged perpendicular to the light receiving surface of the photoelectric conversion element. X-ray imaging device. 2. A grid body in which a sensor having a two-dimensional array of photoelectric conversion elements formed on a substrate and a laminate of a phosphor layer and an X-ray transmission layer are divided into the two-dimensional array by an X-ray absorber. An X-ray imaging apparatus having the grid body mounted on the sensor, wherein the phosphor layer is stacked on each light receiving surface of the photoelectric conversion element, and the X-ray transmission layer is The X-ray absorbers are stacked on the X-ray incident surface of each phosphor layer, and the X-ray absorber is positioned above the gap between the photoelectric conversion elements, and is arranged perpendicularly to the light receiving surface of the photoelectric conversion element at the center of the sensor. An X-ray imaging apparatus characterized in that the X-ray imaging apparatus is arranged so as to be gradually inclined toward the center of the sensor toward the periphery of the sensor. 3. The X-ray image photographing apparatus according to claim 2, wherein the X-ray absorber is extended at one point so as to intersect at one point, and an X-ray light source is disposed at that position. 4. The X-ray image photographing apparatus according to claim 1, wherein a fluorescent reflection film is provided on an X-ray incident surface of the X-ray transmission layer. 5. A fluorescent reflection layer is provided in a section between the X-ray absorber and the laminate.
An X-ray image photographing apparatus according to any one of the above. 6. The X-ray imaging apparatus according to claim 1, wherein the X-ray transmission layer is an adhesive resin layer. 7. A length L2 of the laminate in a direction perpendicular to the substrate and a length L1 of the laminate in a direction parallel to the substrate, wherein a value of L2 / L1 is 3 or more and less than 10. 3. The X-ray imaging apparatus according to claim 1, wherein the X-ray imaging apparatus includes: