JP3070943B2 - Manufacturing method of radiation image conversion panel - Google Patents

Description

The present invention relates to a method for manufacturing a radiation image conversion panel,
More specifically, the present invention relates to a method for manufacturing a radiation image conversion panel having high image sharpness.

[Conventional technology]

For example, in the medical field, radiation images such as X-ray images are often used for diagnosing diseases.

Conventionally, as a method of forming a radiation image, X-rays transmitted through a subject are irradiated on a phosphor layer (fluorescent screen) to generate visible light, and this visible light is used in the same manner as when a normal photograph is taken. A so-called radiographic method of irradiating and developing a film using a silver salt has been generally used.

However, in recent years, as a method of taking out an image directly from the phosphor layer without using a film coated with a silver salt, the radiation transmitted through the subject is absorbed by the phosphor, and then the phosphor is excited by, for example, light or heat energy. Then, a method has been proposed in which radiation energy absorbed and accumulated in the phosphor is emitted as fluorescence, and the fluorescence is detected and imaged.

For example, U.S. Pat.No. 3,859,527, JP-A-55-121
No. 44 discloses a radiation image conversion method using a stimulable phosphor and using visible light or infrared light as stimulating excitation light. In this method, a radiation image conversion panel having a stimulable phosphor layer formed on a substrate is used. Forming a latent image by accumulating radiation energy corresponding to the radiation transmittance of each part of
Thereafter, the stimulable phosphor layer is scanned with stimulating excitation light to emit radiation energy accumulated in each part as stimulating light, and an optical signal based on the intensity of the light is photoelectrically converted, for example, to perform image reproduction. The image is formed by This final image is played as a hard copy or on a CRT.

A radiation image conversion panel having a stimulable phosphor layer used in such a radiation image conversion method has a radiation absorption rate and a light conversion rate (both of which are the same as in the case of the radiography method using a fluorescent screen described above). (Hereinafter referred to as “radiation sensitivity”), and the image must have good graininess and high sharpness.

However, the sharpness of the image tends to be higher as the thickness of the stimulable phosphor layer of the radiation image conversion panel is thinner. To improve the sharpness, the stimulable phosphor layer needs to be thinner. Was needed.

On the other hand, the granularity of the image is determined by the spatial fluctuation of the radiation quantum number (quantum mottle) or the structural disorder of the stimulable phosphor layer of the radiation image conversion panel (structural mottle). When the thickness of the body layer is reduced, the quantum number of radiation absorbed by the stimulable phosphor layer is reduced and the quantum mottle is increased, and the structural disorder is evident, the structural mottle is increased and the image quality is reduced. . Therefore, in order to improve the granularity of an image, it is necessary to increase the thickness of the stimulable phosphor layer.

As described above, in the conventional radiation image conversion panel, the radiation sensitivity and the granularity of the image and the sharpness of the image show a completely opposite tendency to the layer thickness of the stimulable phosphor layer. Granularity and sharpness have been produced with some compromise between each other.

Under such circumstances, some means for improving the sharpness of a radiographic image have been proposed. For example, means for mixing a white powder into the stimulable phosphor layer of the radiation image conversion panel (see Japanese Patent Application Laid-Open No. Sho 55-146447); Means for coloring the stimulable phosphor such that the average reflectance in the stimulable phosphor is smaller than the average reflectance in the stimulable emission wavelength region (Japanese Patent Laid-Open No.
55-163500). But,
Although these methods improve the sharpness, there is a problem that the radiation sensitivity necessarily decreases as a result.

On the other hand, as a technique for improving the conventional drawbacks in a radiation image conversion panel using a stimulable phosphor, the applicant of the present application has succeeded this surface structure to a support having a large number of fine uneven patterns on the surface. Means for forming a stimulable phosphor layer composed of a fine columnar structure grown in a direction substantially perpendicular to the support (hereinafter referred to as “fine columnar structure”) has been proposed by the applicant of the present application (Japanese Patent Application Laid-open No. 61
-142497).

[Problems to be solved by the invention]

However, in the technique of JP-A-61-142497 described above,
It is necessary to form a large number of fine uneven patterns on the surface of the support, but this uneven pattern is fixed to the support by the embossing method of embossing the support itself, light, heat, chemicals, and the like. After printing by gravure method or silk method using ink made of resin, it must be formed by printing method or photo-etching method of drying and curing treatment, so the process of forming the concavo-convex pattern is complicated, There is a troublesome problem.

The present invention relates to a radiation image conversion panel using a stimulable phosphor, and further improves the panel. It is an object of the present invention to improve radiation sensitivity and granularity and to provide a radiation image with high sharpness. An object of the present invention is to provide a method for manufacturing an image conversion panel.

[Means for solving the problem]

In order to achieve the above object, the present inventors have conducted intensive studies, and as a result, provided a pattern layer made of a material having a different thermal conductivity from the surface material of the support on the surface of the support, The present inventors have found that by depositing a stimulable phosphor on the side surface by a vapor deposition method, a stimulable phosphor layer having a fine columnar structure can be formed relatively easily, and the present invention Is completed.

Therefore, the method for producing a radiation image conversion panel of the present invention is directed to a method for producing a radiation image conversion panel having a stimulable phosphor layer on a support, wherein the surface material of the support is heat-sensitive on the surface of the support. A fine pattern layer made of a substance having a different conductivity is provided, and a stimulable phosphor layer is formed by depositing a stimulable phosphor on the surface on the pattern layer side by a vapor deposition method. .

 Hereinafter, the present invention will be described specifically.

In the present invention, as shown in FIGS. 1 and 2, the surface material of the support 1 of the radiation image conversion panel (hereinafter, abbreviated as “conversion panel” as appropriate) is attached to the surface material of the support 1 by heat. A pattern layer 2 made of a substance having a different conductivity is provided.

Assuming that the thermal conductivity of the surface material of the support 1 is Ks and the thermal conductivity of the pattern layer 2 is Kp, the ratio of the two at a temperature of 300 K satisfies 0.2> Ks / Kp or Ks / Kp> 5 is preferably satisfied.

As a constituent material of the support 1, various polymer materials, ceramics, glass, metal, and the like can be used. Specifically, a plastic film such as a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyamide film, a polyimide film, a triacetate cellulose film, and a polycarbonate film, a ceramic plate, a glass plate, a metal sheet such as aluminum, iron, copper, and chrome. And a metal sheet having a metal oxide coating layer.

The thickness of the support 1 varies depending on its material and the like, but is generally preferably 100 μm to 5 mm, and particularly preferably 200 μm to 2 mm for convenience of handling.

Further, the support 1 may have a configuration in which a light reflecting layer or a light shielding layer is provided on the surface of a non-metallic substrate such as a polymer material, glass, and ceramics. In this case, the thermal conductivity Ks of the surface material of the support 1 is determined by the thermal conductivity of the material constituting the light reflecting layer or the light shielding layer.

As a pattern material constituting the pattern layer 2, a metal, an organic insulating material, a photoresist material, or the like can be used. Specifically, a pattern layer 2 made of metal is provided on the surface of a support 1 made of glass or ceramics, and a pattern layer 2 made of an organic insulating material or a photoresist material is provided on the surface of the support 1 made of metal. Constitution,
A configuration in which a pattern layer 2 made of metal is provided on the surface of a support 1 made of PET (polyethylene terephthalate) or TAC (triacetate cellulose) can be adopted.

Although the form of the pattern layer 2 is not particularly limited, of the pattern layer 2 and the portion surrounded by the pattern layer 2,
Since fine columnar crystals of stimulable phosphor are selectively deposited on the lower thermal conductivity part, take into account the state of the stimulable phosphor layer with a fine columnar structure finally obtained. It is desirable to select the optimal form. Specifically, a lattice shape as shown in FIGS. 1 (a) and 1 (c), a hexagonal shape as shown in FIG. 1 (b), and an island-like shape corresponding to the negative / positive relationship, etc. Can be mentioned. The size of the portion having a high thermal conductivity is preferably 5 to 15 μm, and the size of the portion having a low thermal conductivity is preferably 30 to 50 μm.

The thickness of the pattern layer 2 is preferably 10 ² to 10 ⁵ Å, and in particular,
10 ³ 1010 ⁴ Å is preferred.

In the present invention, the support 1 provided with the pattern layer 2 on the surface obtained as described above is used, and a stimulable phosphor is deposited on the surface on the pattern layer 2 side by a vapor deposition method. Thus, a luminous stimulable phosphor layer having a fine columnar structure is formed.

Examples of the vapor deposition method as a means for forming the stimulable phosphor layer include a vacuum deposition method (hereinafter, simply referred to as “deposition method”), a sputtering method, a CVD method, an ion plating method, and the like.

In general, according to the vapor deposition method, a crystal surface where crystal growth is promoted and a surface where crystal growth is suppressed due to partial adsorption of an atmospheric gas or the like are generated. However, in the present invention,
Since the pattern layer 2 made of a material having a different thermal conductivity from the surface material of the support 1 is provided on the surface of the support 1,
Crystals of the stimulable phosphor grow selectively on portions having low thermal conductivity, and the surface where the crystal growth is promoted grows more and more in the direction in which evaporated molecules or atoms adhere.
On the other hand, the high thermal conductivity portion has a lower probability of vapor phase deposition of the phosphor material than the low thermal conductivity portion, so that crystal growth in the support plane direction is suppressed, and the stimulable phosphor is reduced. , And elongated cracks extending in the crystal growth direction, that is, the thickness direction of the stimulable phosphor layer, are generated. On the surface of the support 1 on which the pattern layer 2 is provided, a stimulable phosphor layer having a fine columnar structure having a large number of fine cracks in the thickness direction of the stimulable phosphor layer is provided. It is formed.

For example, when forming a stimulable phosphor layer by a vapor deposition method, the support 1 provided with the pattern layer 2 is placed in a vapor deposition apparatus, and then the inside of the vapor deposition apparatus is evacuated to a vacuum degree of about 10 ^-6 Torr. And Next, the support 1 provided with the pattern layer 2 is
By heating to a temperature of 0 ° C. or less, at least one kind of stimulable phosphor is heated and evaporated by a method such as a resistance heating method or an electron beam method, and the surface of the support 1 on the side where the pattern layer 2 is provided is provided. Then, a stimulable phosphor is deposited to a predetermined thickness.

As a result, a stimulable phosphor layer containing no binder is formed, but it is also possible to form the stimulable phosphor layer in a plurality of times in the vapor deposition step. In the evaporation step, co-evaporation can be performed using a plurality of resistance heaters or electron beams.

After the vapor deposition, a protective layer may be provided on the surface of the stimulable phosphor layer on the side opposite to the support side, if necessary, directly or via a gap.

In the vapor deposition method, the stimulable phosphor material is co-evaporated using a plurality of resistance heaters or electron beams, and the target stimulable phosphor is formed on the surface of the support on which the pattern layer is provided. Can be formed at the same time as forming the stimulable phosphor layer.

Further, in the vapor deposition method, at the time of vapor deposition, an object to be deposited (a support or a protective layer) may be cooled or heated as necessary. Further, the stimulable phosphor layer may be subjected to a heat treatment after the deposition is completed. In the vapor deposition method, O ₂ , H
Reactive deposition may be performed by introducing a gas such as ₂ .

For example, when forming a stimulable phosphor layer by a sputtering method, after arranging a support having a pattern layer in a sputtering apparatus in the same manner as in the vapor deposition method, the inside of the apparatus is once evacuated to 10 ^-6 Torr or less. The degree of vacuum is then set, and then an inert gas such as Ar or Ne is introduced into the sputtering apparatus as a gas for sputtering to a gas pressure of about 10 ^-3 Torr.

Next, the stimulable phosphor layer is deposited to a predetermined thickness on the surface of the support on the side where the pattern layer is provided by sputtering using the stimulable phosphor as a target.

In this sputtering step, it is also possible to form the stimulable phosphor layer in a plurality of times as in the case of the vapor deposition method.
Further, it is also possible to form a stimulable phosphor layer by simultaneously or sequentially sputtering a plurality of targets each using a different stimulable phosphor.

After the completion of the sputtering, a protective layer may be provided on the side opposite to the support side of the stimulable phosphor layer, if necessary, directly or via a gap as in the case of the vapor deposition method.

In the sputtering method, a plurality of stimulable phosphor raw materials are used as targets, and these are simultaneously or sequentially sputtered to synthesize a desired stimulable phosphor on the surface of the support on which the pattern layer is provided. At the same time, a stimulable phosphor layer can be formed. In the sputtering method, reactive sputtering may be performed by introducing a gas such as O ₂ or H ₂ as necessary.

Further, in the sputtering method, an object to be deposited (a support or a protective layer) may be cooled or heated as needed during sputtering. After the sputtering, the stimulable phosphor layer may be subjected to a heat treatment.

For example, when the stimulable phosphor layer is formed by a CVD method, the stimulable phosphor or the organometallic compound containing the stimulable phosphor material is decomposed by heat, energy such as high-frequency power, and the like. A stimulable phosphor layer containing no binder is formed on the surface on the side where the body pattern layer is provided.

The thickness of the stimulable phosphor layer varies depending on the intended radiation sensitivity of the radiation image conversion panel, the type of the stimulable phosphor, and the like, but is preferably 30 to 1000 µm, and particularly preferably 50 to 500 µm. When the thickness of the stimulable phosphor layer is too small,
The radiation absorptivity is reduced to lower the radiation sensitivity, the granularity of the image is reduced, and the spread of the stimulating light in the lateral direction is increased, so that the sharpness of the image is deteriorated.

In the step of forming the stimulable phosphor layer, the deposition rate of the stimulable phosphor layer is preferably 0.1 to 50 μm / min. If the deposition rate is too low, the productivity will be low, and if the deposition rate is too high, it will be difficult to control the deposition rate.

In the step of forming the stimulable phosphor layer, the temperature of the support when heating the support with a heater is preferably 400 ° C. or less.
If the temperature is too high, the sharpness of the image tends to decrease due to the progress of crystallization.

In the present invention, "stimulable phosphor" means, after being irradiated with the first light or high-energy radiation, optically, thermally,
Phosphor that emits photostimulated light corresponding to the amount of initial light or high-energy radiation when stimulated by mechanical, chemical, or electrical stimulation (stimulated excitation). Is preferably a phosphor that emits photostimulated light by photostimulated excitation light of 500 nm or more.

The following can be used as the stimulable phosphor constituting the stimulable phosphor layer.

(1) BaSO described in JP 48-80487 discloses _4: A _x (however, A is represented Dy, Tb, at least one Tm, x is 0.00
It represents a number satisfying 1 ≦ x <1 mol%. The phosphor represented by).

(2) MgSO ₄ : A _x described in JP-A-48-80488 (where A represents either Ho or Dy, and x is 0.001 ≦
x represents a number satisfying 1 mol%. The phosphor represented by).

(3) SrSO described in JP 48-80489 discloses _4: A _x (however, A is represented Dy, Tb, at least one Tm, x is 0.00
It represents a number satisfying 1 ≦ x <1 mol%. The phosphor represented by).

(4) Na ₂ SO ₄ , CaSO ₄ , Ba described in JP-A-51-29889
A phosphor obtained by adding at least one of Mn, Dy, and Tb to SO ₄ or the like.

(5) BeO, LiF, MgSO ₄ , C described in JP-A-52-30487
phosphor such as aF _2.

(6) Phosphors such as Li ₂ B ₄ O ₇ : Cu and Ag described in JP-A-53-39277.

(7) Li ₂ O · described in JP 54-47883 JP (B
₂ O ₂ ) _x : Cu (where x represents a number satisfying 2 <x ≦ 3), Li ₂ O · (B ₂ O ₂ ) _x : Cu, Ag (where x is 2 <x
Represents a number satisfying ≦ 3. ) And other phosphors.

(8) SrS: Ce, S described in U.S. Pat. No. 3,859,527
m, SrS: Eu, Sm, La 2 O 2 S: Eu, Sm (Zn, Cd) S: Mn, X ( provided that, X represents a halogen.) phosphor represented by.

(9) ZnS: Cu, Pb phosphor described in JP-A-55-12142.

(10) The general formula described in JP-A-55-12142 is BaO.xAl
_A barium aluminate phosphor represented by ₂ O ₃ : Eu (where x represents a number satisfying 0.8 ≦ x ≦ 10).

(11) The general formula described in JP- _A -55-12142 has M _A O.xSiO ₂ :
A (however, M _A represents Mg, Ca, Sr, Zn, Cd, and Ba, A is C
represents at least one of e, Tb, Eu, Tm, Pb, Tl, Bi, Mn, and x
Represents a number satisfying 0.5 ≦ x <2.5. The alkaline earth metal silicate-based phosphor represented by).

(12) The general formula described in JP-A-55-12142 (Ba _1-xy Mg
_x Ca _y ) FX: eEu ²⁺ (where X is at least one of Br and Cl)
X, y, and e represent 0 <x + y ≦ 0.6 and xy そ れ ぞ れ, respectively.
0, a number that satisfies 10 ⁻⁶ ≦ e ≦ 5 × 10 ⁻² . The phosphor represented by).

(13) LnOX: xA (where Ln represents at least one of La, Y, Gd, and Lu;
Represents at least one kind of Cl and Br, A represents at least one kind of Ce and Tb, and x represents a number satisfying 0 <x <0.1. The phosphor represented by).

(14) The general formula described in JP-A-55-12145 is represented by (Ba _1-x
(M _A ) _x ) FX: yA (where M _A represents at least one of Mg, Ca, Sr, Zn, Cd, X represents at least one of Cl, Br, I, and A is Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, represents at least one kind of Er, x, y are 0 ≦ x ≦ 0.6, 0 ≦ y ≦ 0.2
Represents a number that satisfies The phosphor represented by).

(15) The general formula described in JP-A-55-84389 is BaFX: xC
e, yA (where X represents at least one kind of Cl, Br, I, A represents at least one kind of In, Tl, Gd, Sm, Zr, x,
y represents a number satisfying 0 <x ≦ 2 × 10 ⁻¹ and 0 <y ≦ 5 × 10 ⁻² . The phosphor represented by).

(16) In formula described in JP 55-160078 Patent Publication No. · M _A FX
xA: yLn (where, M _A represents at least one of Mg, Ca, Ba, Sr, Zn, and Cd, and A is BeO, MgO, CaO, SrO, BaO, ZnO, Al ₂ O ₃ ,
Y ₂ O ₃ , La ₂ O ₃ , In ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , GeO ₂ , SnO ₂ , Nb ₂ O ₅ , Ta
₂ O _5, represents at least one of ThO _2, Ln is, Eu, Tb, Ce, Tm ,
X represents at least one of Dy, Pr, Ho, Nd, Yb, Er, Sm, and Gd;
Represents at least one of Cl, Br and I, and x and y represent 5 × 10 ⁻⁵
It represents a number that satisfies ≦ x ≦ 0.5 and 0 <y ≦ 0.2. A) a rare earth element-activated divalent metal fluorohalide phosphor represented by the formula:

(17) The general formula described in JP-A-55-160078 is ZnS: A, (Z
n, Cd) S: A, CdS: A, ZnS: A, X, CdS: A, X (where A is
Represents any of Cu, Ag, Au and Mn, and X represents halogen. The phosphor represented by).

(18) General formula [I] xM ₃ (PO ₄ ) ₂ · NX ₂ : yA described in JP-A-59-38278. General formula [II] M ₃ (PO ₄ ) ₂ · yA (where M , N represents at least one of Mg, Ca, Sr, Ba, Zn, and Cd, X represents at least one of F, Cl, Br, and I, and A represents Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Sb, Tl, M
represents at least one of n and Sn, and x and y are 0 <x ≦ 6, 0
Represents a number satisfying ≦ y ≦ 1. The phosphor represented by).

(19) General formula [III] nReX ₃ · mAX ′ ₂ : xEu described in JP-A-59-155487 General formula [IV] nReX ₃ · mAX ′ ₂ : xEu, ySm (where Re is La , Gd, Y, Lu
Represents at least one alkaline earth metal of Ba, Sr, Ca, X, X 'represents at least one of F, Cl, Br, x, y
Is 1 × 10 ⁻⁴ <x <3 × 10 ⁻¹ , 1 × 10 ⁻⁴ <y <1 × 10 ⁻¹
And n / m represents a number satisfying 1 × 10 ⁻³ <n / m <7 × 10 ⁻¹ . The phosphor represented by).

(20) The general formula aBaX ₂ · (1-a) BaY ₂ : bEu ²⁺ described in JP-A-2-58593 (wherein X and Y are at least one of F, Cl, Br and I Represents X
≠ Y, and a and b represent numbers satisfying 0 <a <1,10 ⁻⁵ <b <10 ⁻¹ . ) A phosphor represented by.

(21) JP formula described in JP _{61-72087 M A X · aM B X} '2 · bM C X "3: cA ( However, M _A is, Li, Na, K, Rb , and Cs represents at least one alkali metal, M _B is, Be, Mg, Ca, Sr , Ba, Zn, Cd, Cu, Ni
Of represents at least one divalent metal, M _C is, Sc, Y, La,
Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, In
X, X ′, X ″ represents at least one trivalent metal of
Represents at least one halogen of F, Cl, Br, I;
u, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, C
u, represents at least one metal of Mg, a, b, c is 0 ≦ a
<0.5, 0 ≦ b <0.5, and 0 <c ≦ 0.2. An alkali halide phosphor represented by).

In the present invention, in particular, this alkali halide phosphor can be preferably used.

However, in the present invention, the phosphor is not limited to the above, and other phosphors may be used as long as the phosphor exhibits stimulable fluorescence when irradiated with radiation and then irradiated with stimulating excitation light. it can.

FIG. 3 is a schematic diagram of a radiation image conversion apparatus configured using a radiation image conversion panel obtained by the manufacturing method of the present invention, 3 is a radiation generator, 4 is a subject, 5 is a radiation image conversion panel, 6 Is a photostimulated excitation light source, 7 is a photoelectric conversion device for detecting photostimulated emission emitted from the radiation image conversion panel 5, 8 is a reproducing device for reproducing a signal detected by the photoelectric conversion device 7 as an image, and 9 is a reproducing device. Reference numeral 8 denotes a display device for displaying the reproduced image, and reference numeral 10 denotes a filter that separates stimulated excitation light and stimulated emission and transmits only stimulated emission.

In the radiation image conversion apparatus shown in FIG. 3, the radiation R from the radiation generation apparatus 3 enters the radiation image conversion panel 5 through the subject 4. The incident radiation RI is absorbed by the stimulable phosphor layer of the radiation image conversion panel 5 and its energy is accumulated, thereby forming an accumulation image of the radiation transmission image. Next, the accumulated image is excited by stimulating light from the stimulating light source 6 and emitted as stimulating light.

Since the intensity of the emitted stimulating luminescence is proportional to the amount of accumulated radiation energy, this optical signal is photoelectrically converted by a photoelectric conversion device 7 such as a photomultiplier tube, and reproduced as an image by a reproduction device 8, By displaying the image on the display device 9, a radiation transmission image of the subject 4 can be observed.

As described above, in the production method of the present invention, a pattern layer made of a material having a different thermal conductivity from the surface material of the support is provided on the surface of the support, and the stimulable phosphor is provided on the surface on the pattern layer side. Is deposited by a vapor deposition method to form a stimulable phosphor layer, so that a stimulable phosphor layer having a fine columnar structure can be obtained easily and reliably. Therefore, according to the obtained conversion panel, it is possible to form a radiation image that sufficiently satisfies not only the radiation sensitivity and the granularity of the image but also the sharpness of the image.

〔Example〕

Hereinafter, examples of the present invention will be described together with comparative examples, but the present invention is not limited to these embodiments.

Example 1 As shown in FIG. 4, the surface of a support 1 made of a crystallized glass plate having a thickness of 1.0 mm and having a smooth surface was 3000 mm thick.
In the pattern shape shown in FIG. 1A, the interval a is 50 μm and the line width b is 5 μm.
The m-patterned pattern layer 2 was formed by an evaporation method.

The thermal conductivity Ks of the surface material (crystallized glass plate) of the support 1 is 1.5 W / m · K, and the thermal conductivity Kp of the pattern layer 2
Is 237 W / m · K.

The support 1 on which the pattern layer 2 is provided is placed in a vapor deposition apparatus, and RbBr: Tl (a material of a stimulable phosphor) is placed in a vapor deposition source container.
And the deposition source container was placed in a deposition apparatus.

The inside of the deposition apparatus is evacuated, and the support 1 having the pattern layer 2
Is heated by a heater arranged on the back surface side, the temperature of the entire support 1 is set to 100 ° C., Ar gas is introduced into the vapor deposition apparatus, and the atmospheric pressure is 1 × 10 ⁻⁶ Torr. Set to.

Under the above conditions, the stimulable phosphor in the evaporation source container was evaporated by resistance heating and deposited on the surface of the support 1 on the side of the pattern layer 2 to obtain a layer having a fine columnar structure having a thickness of 100 μm. The stimulable phosphor layer was formed, and the conversion panel A was manufactured.

The deposition rate of the stimulable phosphor layer was controlled so as to be 2 μm / min.

The cross section and surface shape of the stimulable phosphor layer of the conversion panel A obtained as described above were measured by SEM (scanning electron microscope).
As a result, cracks were present in the thickness direction of the stimulable phosphor layer along the fine pattern layer 2 provided on the support, and a good stimulable phosphor layer having a fine columnar structure was formed. It had been.

After irradiating the conversion panel A with X-rays having a tube voltage of 80 kV for 10 mR, it is stimulated with semiconductor laser light (wavelength 780 nm) and stimulated by a photodetector (photoelectron). The signal was reproduced as an image by a reproducing device, the modulation transfer function (MTF) of the image was examined from the obtained image, and the sharpness of the image was evaluated. When the value of 1 was taken as 100, the value was as high as 120 (relative value), confirming that the sharpness of the image was high. The modulation transfer function (MTF) has a spatial frequency of 2
It is the value at the time of cycle / mm.

Example 2 In Example 1, the support 1 was changed to a support made of an aluminum plate having a thickness of 1.0 mm, and the pattern layer 2 was
It is made of a gold (Au) film with a thickness of 3000 mm, with an interval a of 30 μm,
A conversion panel B was manufactured in the same manner as in Example 1, except that the line width b was changed to a grid-like pattern layer having a thickness of 10 μm.

The thermal conductivity Ks of the surface material (aluminum plate) of the support 1 is 36 W / m · K, and the thermal conductivity Kp of the pattern layer 2 is
Is 315 W / m · K.

This conversion panel B is used in the same manner as
When observed by M, cracks were present as in Example 1, and a stimulable phosphor layer having a good fine columnar structure was formed.

When the sharpness of the conversion panel B was evaluated in the same manner as in Example 1, the sharpness was evaluated as high as 110 (relative value), indicating that the sharpness was high.

Example 3 In Example 1, the support 1 was replaced with a 0.3 mm thick C.P.
Except that the support was changed to a support made of ET (carbon polyethylene terephthalate), and the pattern layer 2 was changed to a grid-like pattern layer made of an aluminum film having a thickness of 3000 mm, with an interval a of 30 μm and a line width b of 10 μm. The conversion panel C was manufactured in the same manner as in Example 1.

The thermal conductivity Ks of the surface material (C · PET) of the support 1
Is 0.2 W / m · K, and the thermal conductivity Kp of the pattern layer 2 is 237 W
/ m · K.

The conversion panel C was subjected to SE in the same manner as in Example 1.
When observed by M, cracks were present as in Example 1, and a stimulable phosphor layer having a good fine columnar structure was formed.

When the sharpness of the conversion panel C was evaluated in the same manner as in Example 1, the conversion panel C showed a high value of 120 (relative value), and it was confirmed that the sharpness was high.

Example 4 In Example 1, the support 1 was changed to a support made of an aluminum plate having a thickness of 0.3 mm.
5,000 mm thick photoresist material with spacing a
The conversion panel D was manufactured in the same manner as in Example 1 except that the pattern panel was changed to an island-shaped pattern layer having a line width of 5 μm and a line width b of 50 μm.

The thermal conductivity Ks of the surface material (aluminum) of the support 1 is 237 W / m · K, and the thermal conductivity Kp of the pattern layer 2 is
0.2 W / m · K.

This conversion panel D is subjected to SE in the same manner as in the first embodiment.
When observed by M, cracks were present as in Example 1, and a stimulable phosphor layer having a good fine columnar structure was formed.

When the sharpness of the conversion panel D was evaluated in the same manner as in Example 1, the conversion panel D showed a high value of 115 (relative value), and it was confirmed that the sharpness was high.

Example 5 A conversion panel E was manufactured in the same manner as in Example 1, except that the pattern layer was changed to a hexagonal pattern as shown in FIG. 1 (b).

This conversion panel E is subjected to SE in the same manner as in the first embodiment.
When observed by M, cracks were present as in Example 1, and a stimulable phosphor layer having a good fine columnar structure was formed.

In addition, when the sharpness of the conversion panel E was evaluated in the same manner as in Example 1, the value was as high as 120 (relative value), and it was confirmed that the sharpness was high.

Example 6 A conversion panel F was manufactured in the same manner as in Example 1, except that the pattern layer was changed to a lattice-like pattern shape as shown in FIG. 1 (c).

This conversion panel F is subjected to SE in the same manner as in the first embodiment.
When observed by M, cracks were present as in Example 1, and a stimulable phosphor layer having a good fine columnar structure was formed.

When the sharpness of the conversion panel F was evaluated in the same manner as in Example 1, the conversion panel F showed a high value of 120 (relative value), and it was confirmed that the sharpness was high.

Comparative Example 1 In Example 1, except that the pattern layer 2 was not provided,
A conversion panel a for comparison was manufactured in the same manner as in Example 1.

Regarding the conversion panel a, SE is performed in the same manner as in the first embodiment.
When observed by M, no cracks occurred,
The fine columnar structure was insufficient.

When the sharpness of the conversion panel a was evaluated in the same manner as in Example 1, it was 100 (relative value), which was inferior to that of the conversion panel A of Example 1.

Table 1 summarizes the contents of the above Examples and Comparative Examples.

As is clear from Table 1 above, the conversion panels A to F obtained in the examples are much superior in sharpness to the conversion panel a obtained in the comparative example.

Further, regarding the conversion panels A to F obtained in the examples,
When the radiation sensitivity and granularity were evaluated, all were satisfactory.

〔The invention's effect〕

As described in detail above, according to the production method of the present invention, a pattern layer made of a material having a different thermal conductivity from the surface material of the support is provided on the surface of the support, The stimulable phosphor is deposited by vapor deposition to form a stimulable phosphor layer, so that the stimulable phosphor can be deposited selectively in relatively low thermal conductivity areas. As a result, cracks (cracks) occur in the thickness direction of the stimulable phosphor layer, and a stimulable phosphor layer having an excellent fine columnar structure is obtained. Accordingly, it is possible to relatively easily manufacture a radiation image conversion panel capable of forming a radiation image that sufficiently satisfies not only the radiation sensitivity and the granularity of the image but also the sharpness of the image.

[Brief description of the drawings]

1 (a), (b) and (c) are plan views each showing a state in which a pattern layer is provided on the surface of a support, FIG. 2 is a longitudinal sectional end view of FIG. 1 (a), and FIG. The figure is an explanatory view schematically showing the radiation image conversion apparatus, and FIG. 4 is an end view of the support and the pattern layer according to the example. DESCRIPTION OF SYMBOLS 1 ... Support body 2, ... Pattern layer 3 ... Radiation generator 4, ... Subject 5 ... Radiation image conversion panel 6 ... Stimulation excitation light source 7, Photoelectric conversion device 8 ... Reproduction device, 9 …… Display device 10 …… Filter

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G21K 4/00

Claims (1)

(57) [Claims] 1. A method of manufacturing a radiation image conversion panel having a stimulable phosphor layer on a support, wherein the support has a fine surface made of a material having a different thermal conductivity from a surface material of the support. A method for producing a radiation image conversion panel, comprising: providing a pattern layer; and depositing a stimulable phosphor on the surface on the pattern layer side by a vapor deposition method to form a stimulable phosphor layer.