JPS6275400A - Manufacture of radiation picture conversion panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a radiation image conversion panel using a stimulable phosphor, and more particularly to a method for manufacturing a radiation image conversion panel that is highly sensitive to radiation.

[Conventional background]

Radiographic images such as X-ray images are often used for disease diagnosis. In order to obtain this X-ray image, the X-rays that have passed through the object are irradiated onto a phosphor layer (phosphor screen), thereby producing visible light, which is then irradiated with silver in the same way as when taking ordinary photographs. So-called radiography is used, which is made by exposing and developing a film using salt. However, in recent years, methods have been devised to directly extract images from the phosphor layer without using a film coated with silver 1. This method involves making a phosphor absorb the radiation that has passed through the copying material, and then exciting the phosphor with, for example, light or heat energy, so that the phosphor converts the radiation energy M multiplied by the absorption into fluorescence. There is a method of emitting light, detecting this fluorescence, and creating an image. Specifically, for example, U.S. Pat.
No. 5-12144 discloses a radiation image conversion method using a stimulable phosphor and using visible light or infrared rays as stimulable excitation light. This method uses a radiation image conversion panel in which a stimulable phosphor layer is formed on a support, and radiation that has passed through the object is applied to the stimulable phosphor layer of this radiation image conversion panel to visualize various parts of the object. What is the radiation energy that corresponds to the radiolucency? ! ('l) to form a latent image, and then scan this 111-exhaustive phosphor layer with a bright p4. excitation light to radiate M-multiplied radiation energy from each part and convert it into light, An image is obtained by an optical signal depending on the intensity of this light.This final image may be reproduced on a computer or on a CRT.Used in this radiation image conversion method A radiation image conversion panel having a stimulable phosphor layer has a radiation absorption rate and a light conversion rate (hereinafter referred to as "radiation sensitivity") in the same way as in the case of radiography using a fluorescent screen described above. It goes without saying that the image quality is high, and the image graininess is good.
Moreover, high sharpness is required. However, in general, a radiation image conversion panel having an X1ll stimulable phosphor layer is prepared by coating a dispersion containing a stimulable phosphor in particles with a grain size of about 1 to 30 μm and an organic binder on a support or a protective layer. Since it is created by drying, the filling density of the stimulable phosphor is low (filling rate 50%), and it was necessary to increase the layer thickness of the stimulable phosphor layer in order to obtain sufficiently high radiation sensitivity. . On the other hand, the sharpness of the image in the radiation image conversion method tends to be higher as the layer j7 of the photostimulable phosphor layer of the radiation image conversion panel becomes thinner. It was necessary to make the phosphor layer thinner. In addition, the graininess of the image in the radiation image conversion method may be due to local fluctuations in the number of radiation quanta (quantum mottles) or fatal disturbances in the stimulable phosphor layer of the radiation image conversion panel.
As the thickness of the stimulable phosphor layer becomes thinner, the number of radiation quanta absorbed by the 111-stimulable phosphor layer decreases, and the quantum mottle increases. This becomes obvious and causes an increase in VT distortion, resulting in a deterioration in image quality. Therefore, in order to improve the graininess of images, the stimulable phosphor layer needs to be thick. That is, as mentioned above, in the conventional radiation image conversion panel, the sensitivity to radiation, the graininess of the image, and the sharpness of the image exhibit completely opposite tendencies with respect to the layer thickness of the stimulable phosphor layer. The radiation image conversion panels have been made with some degree of trade-off between sensitivity to radiation, graininess, and sharpness. By the way, it is well known that the sharpness of images in conventional radiography is determined by the spread of instantaneous emission (emission of light during radiation irradiation) of the phosphor in the fluorescent screen. The sharpness of the image in the radiation image conversion method using a stimulable phosphor is not determined by the spread of stimulated luminescence of the stimulable phosphor in the radiation image conversion panel; rather than being determined by the spread of the emission of
It depends on the spread of the stimulated excitation light within the panel. This is because in this radiation image conversion method, the radiation image information accumulated in the radiation image conversion panel is extracted in a time series manner, so that the stimulated luminescence due to the stimulated excitation light irradiated at a certain time (ti) is Preferably, it is recorded as the output from the pixel (x++yi) on the panel that is fully illuminated and irradiated with stimulated excitation light at that time,
If the stimulated excitation light spreads within the panel due to scattering, etc., and exists outside the irradiated pixel (xi, yi), 11! This is because if the exhaustible phosphor is also excited, the output from the pixel (gi, yi) will be recorded from a wider area than the image. Therefore, at a certain time (i)
If the V$ exhaustion due to the fl exhaustion excitation light irradiated at that time is only the light emission from the pixel (x++yi) on the panel that was truly irradiated with the IXII exhaustion excitation light at that time (ti), then No matter how widespread the light emission is, it has no effect on the sharpness of the image obtained. Under these circumstances, several methods have been devised to improve the sharpness of radiographic images. For example, JP-A-55-1
Method of incorporating white powder into the stimulable phosphor layer of a radiation image conversion panel described in No. 46447, JP-A-55-163
The radiation image conversion panel described in No. 500 has an average reflectance in the stimulated excitation wavelength region of the stimulable phosphor that is 6 times higher than the average reflectance in the stimulated emission wavelength region of the stimulable phosphor
This is a method of coloring so that it becomes smaller. However, in these methods, improving the sharpness inevitably leads to a noticeable decrease in sensitivity, and therefore cannot be said to be a preferable method. In view of the above-mentioned drawbacks and incompatibility between characteristics, the present applicant has proposed a radiation image conversion panel that does not contain a binder in the stimulable phosphor layer and a method for manufacturing the same in Japanese Patent Application No. 196365/1983. According to this, since the stimulable phosphor layer of the radiation image conversion panel does not contain a binder, the filling rate of the stimulable phosphor layer is significantly improved, and I
The directionality of luminescence and stimulated luminescence of the El II exhaustible phosphor phosphor layer is improved, and the sensitivity of the radiation image conversion panel to radiation and the granularity of the image are improved.At the same time, the sharpness of the image is also improved. . Now, the radiation image conversion panel that does not contain the above-mentioned binder can be manufactured by various vapor deposition methods such as sputtering, CVD, and vapor deposition, but vapor deposition is the most preferable method considering manufacturing costs. I can say that. However, when the stimulable phosphor layer is formed by the resistance heating method commonly used in the vapor deposition method, the vapor pressures of the plurality of substances constituting the stimulable phosphor for a certain crucible temperature are different. Substances with high vapor pressure evaporate preferentially. For this reason, the composition of the stimulable phosphor layer formed on the support does not match the composition of the stimulable phosphor charged in the crucible, which is a serious drawback in that the sensitivity of the radiation image conversion panel to radiation decreases. It became clear that there is. In other words, the method for depositing the stimulable phosphor in a vapor phase is as follows:
As described above, this method brings about many advantages, but when forming a layer of stimulable phosphor, neglecting the vaporization conditions of the phosphor causes a major drawback. For example, according to the present inventors' research on RbBr:TQ stimulable phosphors using TQ as an activator, the emission intensity of the phosphors is as shown in FIG.
…In the range of oQ%, the instantaneous luminescence intensity is constant and T
As long as the Q content falls within a certain range, there is no need to pay close attention to the composition ratio of the general phosphor. However, the stimulated luminescence, which is critical to the radiation image conversion panel according to the present invention, has a peak around 3X10-2+aoQ%, and the intensity decreases significantly before and after that peak. Therefore, when vapor-phase depositing a stimulable phosphor using a vapor deposition method, due to the difference in vapor pressure between the activator and the stimulable phosphor matrix, the evaporation source of the activated stimulable phosphor is If the activator is deposited on the panel support before or after the phosphor matrix, and the activator concentration varies in the thickness direction in the stimulable phosphor layer and deviates from the optimum concentration, the activator The original purpose of imparting activation turns into symptoms of toxicity due to the activator. By the way, the vapor pressure of the old [BrL7] is 116 at 777℃.
11 It g and TQBr is 10 at 522°C.
IIIIIIg, and there is a large difference in vapor pressure. There are no cases in which this point has been given much attention, and we often see examples of activated stimulable phosphor layers with poor performance despite having the optimum activator concentration for wire rods.

[Purpose of the invention]

The present invention relates to the method of manufacturing a radiation image conversion panel proposed above using a stimulable phosphor, and is intended to further improve this. It is an object of the present invention to provide a method for manufacturing a radiation image conversion panel having substantially the same composition of stimulable phosphors as the stimulable phosphor composition and having high sensitivity to radiation. Another object of the present invention is to provide a method for manufacturing a radiation image conversion panel that fully utilizes the advantages of vapor deposition, has good graininess and sharpness, and is highly sensitive to radiation. .

[Structure of the invention]

The inventors of the present invention have conducted extensive research into methods for manufacturing radiation image conversion panels having a stimulable phosphor layer, and have found that compounds with relatively low melting points, such as stimulable phosphors, can be produced using flash vapor deposition. By instantaneously heating the Xl1i stimulable phosphor and instantaneously vaporizing it, it is possible to form a stimulable phosphor layer without intentionally changing the composition of the stimulable phosphor and the composition after vapor deposition. I found out that it is possible. That is, the object of the present invention is achieved by a method for manufacturing a radiation image conversion panel, which comprises forming at least one stimulable phosphor layer on a support by flash vapor deposition. In the present invention, the flash evaporation method is a vapor deposition method in which the evaporating substance is continuously or intermittently supplied in small quantities onto an evaporating dish heated to a temperature sufficiently higher than the melting point of the evaporating substance, and evaporated instantly. By controlling the supply of the evaporation material so that the evaporation material does not stagnate, it is possible to substantially match the composition of the evaporation material as it is charged and the composition after evaporation. The present invention will be explained in detail below. FIG. 1 is a schematic cross-sectional view of one example of a flash vapor deposition apparatus used in the present invention. 1 is a belt jar (vacuum chamber); 4 is a support on which the stimulable phosphor is to be deposited; 5 is a storage container containing the stimulable phosphor (evaporation source) 7 to be evaporated; and 6 is a container for carrying out flash vapor deposition. 8 is a supply device for supplying the stimulable phosphor (evaporation source) 7 to the evaporation dish 6 in fixed amounts; 9 is a current lead-in line for introducing electric power to heat the evaporation dish 6; A main valve, 10 is an auxiliary valve, and 12 is a leak valve, which are used to create and maintain a predetermined degree of vacuum in the Pel Jar 1 in conjunction with an exhaust device (not shown). In the present invention, when using the vapor deposition apparatus, it is preferable that the stimulable phosphor to be evaporated is first dissolved uniformly or formed into small lumps such as lakes, pellets, and columns by pressing or hot pressing. may remain as a powder. When molding the stimulable phosphor, it is preferable to also perform desorption treatment. Further, the evaporative FA material 7 does not necessarily have to be a Ql-stimulable phosphor, and may be one mixed with a stimulable phosphor raw material. First, the evaporation source 7 is charged into the storage B container 5, and then the support 4 is placed facing the evaporation dish 6. The spacing is approximately 10 to 40 ca+, depending on the average range of the stimulable phosphor. Further, the support body 4 is heated to a temperature of 50 to 350 by the heater 3
It may be heated to ℃. Incidentally, the surface of the vapor-deposited substrate of the support 4 is
As described in No. 6913 to No. 59-266916, the stimulable phosphor may be processed to grow into fine columnar crystals. Next, the main valve 11 and the like are operated to remove the gas inside the Pel jar 1 and bring the vacuum level to about 10-4 to 10-' Torr.6 At this time, an inert gas such as argon may be mixed. Next, the evaporating dish 6 is sufficiently heated, and the supply device r is removed from the storage container 5.
Step a8, the stimulable phosphor 7 is supplied little by little to the evaporation dish 6 and evaporated, and the deposition is continued while monitoring the deposition rate and thickness using the film thickness monitor 2. When a predetermined thickness is reached, the deposition is stopped. In the present invention, the deposition rate varies depending on the stimulable phosphor and the intended characteristics, but is 102 to 10'^/
@i + a, more preferably 10'-10'
λ/ +a i n. If it is slower than 10'A/win, it takes too much time to produce the stimulable phosphor layer, which is undesirable, and if it is faster than 10'A/win, it becomes difficult to control the speed, which is not preferred. Alternatively, a plurality of storage containers filled with different evaporation sources 7 may be placed in the Pelger 1 and deposited sequentially to form a deposited layer consisting of a plurality of types of stimulable phosphors. FIG. 2 shows an example using another vapor deposition apparatus. In the apparatus, a plurality of evaporation dishes and storage containers are provided. This type is generally large in size and has a large deposition area, making it convenient for large-area deposition. In Figure 2, the same symbols as in Figure 1 represent objects with the same meaning. In the radiation image conversion panel according to the present invention, the stimulable phosphor refers to a stimulable phosphor that is stimulated by optical, thermal, mechanical, chemical, or electrical stimulation (stimulable phosphor) after being irradiated with the first light or high-energy radiation. It refers to a phosphor that exhibits photostimulated luminescence corresponding to the irradiation amount of initial light or high-energy radiation due to excitation), but from a practical standpoint, it preferably exhibits stimulated luminescence when stimulated with excitation light of 500 or more. It is a phosphor. Examples of the stimulable phosphor used in the radiation image conversion panel of the present invention include Ba5O, :^X (where ^ is Dy+Tb and T+n
at least one of the following, and X is 0.001≦x<1
It is mole%. ) Phosphor expressed by JP-A-48-80
Mg5O, described in No. 488, phosphor represented by ^× (where ^ is either I (o or Dy, and 0.001≦X≦1 mol%), JP-A-48-80489
SrSO4", ^X (however, ^ is Dy)
At least one of 1Tb and T+, and × is 0.
001≦x mol%. , ), NQ2S described in Japanese Patent Application Laid-Open No. 51-29889
O. Phosphor in which at least one of Mn, Dy and Tb is added to Ca5O, Ba5O1, etc., JP-A-52-30
DeO, LiF, Mg5o described in No. 487
, and phosphors such as CaF2, JP-A-53-39277
Phosphors such as Liz[1,0,:Cu, A81, etc. written in the No. 1, Li2O・(B20□)x:Cu (where X is 2<× ≦3
), and phosphors such as Li2O'' (B202)x:Cu+Ag (where 2×≦3), U.S. Pat.
SrS described in No. 527: Ce, Sm, SrS
:Eu, Sm, LazOzS:Eu, Srn and (Z
Examples include phosphors represented by n, Cd)S, Mn, and X (where X is a halogen). Also, JP-A-55-12142
The ZnS:Cu,Pb phosphor described in the above issue has a general formula of BaO.xAQ20. +: Eu (however, 0.8≦≦
10), and the general formula is MT, 0.xSi02:^ (however, MI is Mg, Ca
+Sr, Zn, Cd or B8 ^ is Ce, Tb, E
u, TUa, Pb, TQ, Bi, and Mn), at least lfi, and X satisfies 0.5≦x<2.5. ) Alkaline earth metal silicate phosphors represented by: Also, the general formula is (Bal x yMgxcay)FX:eEu''(
However, X is at least one of Br and Cu; y and e are numbers satisfying the following conditions, respectively: O<x+y≦0.6, xy≠O and 10-6≦e≦5X 10-”). , the general formula described in JP-A No. 55-12144 is Ce and/or Tb
, X represents a number that satisfies 0 x x 0.1. ), the general formula described in JP-A-55-12145 is (Bal x, MIx)FX:y^ (where Ml is at least one of Hg+Ca*5ryZn and Cd, X is at least one of CQ, Br and I, ^ is Eu, Tb*CetTm+Dy+P
At least one of r+HotNd, Yb and Er, x and y represent numbers satisfying the conditions 0≦X≦0.6 and 0≦y≦0°2. ) Phosphor expressed by JP-A-1983
The general formula described in -84389 is BaFX:x
Ce, y^ (however, X is at least 61 of CQ, Br and I, In = TQ, Gd, SL1+ and Zr
at least one of the following, and each of X and y is O<
x≦2X 10-' and o<y≦5X 10-2. , ), the general formula described in JP-A-55-160078 is HxFX.^:yLn (However, Ml is MH, Ca*Ba, Sr, Zn, and cd)
At least 61 of them are BeO, MHO, Ca0tS
rOyBaO+Zn0w＾q2o,,Y2O5゜La2
O3, In2O5, 5in2. TiO2, ZrO,,G
e02tsnozvNdzos. At least one of T11205 and Th02, L
nlj: Eu, Tb. Ce+Tm+DyyPr+Ho+Nd+Yb+Er*5
is at least one of I11 and Gd, and X is CQ
, Br, and I, and y and y are respectively 5X 10-'≦X≦0.5 and o<y≦0.
This is a number that satisfies the condition of 2. ) Rare earth element-activated divalent metal fluoro/%ride phosphor, whose general formula is Zn
S: ^, CdS: ^, (Zn, Cd) S: 8, ZnS:
^. X and CdS: A phosphor represented by ＾, Any of the following general formulas
At least one of Zn and Cd, X is F, CQ, [
At least one of lr and ■, ^ is Eu, Tb, C
e, Tm+Dy+Pr+lIo, Nd, YbtEr+S
b represents at least one of TQ, M++, and Sn. Also, y is 0<x≦6.0<x≦
This is a number that satisfies the condition of 1. ), a phosphor represented by one of the following general formula % formula %: (wherein, Re is at least one of Ln, Cd, Y, Lu, A is an alkaline earth metal, Ba, Sr, Ca) At least one kind, X and X' represent at least one kind among F, CQ, and Br, and X and y represent IX 10-
'<x< 3X 10-', lXl0-4<y<
IX 10-' is a number that satisfies the condition 11/II
l is LX 10-'< II/I11 < 7X 10
− satisfies the condition. ), and the following general formula 8 %: (However, Ml: l±Li, Ha, Rb, and Cs
At least one alkali metal selected from H
z is Be+Mgtca+Sr, l1lu, Zn, Cd,
At least 61 selected from Cu and old! ! It is a divalent metal. 14m+ Sc, Y, La, Ce, Pr
, Nd, Pm. S+atEu+Gd+TbyDy+IIo+Er, Tl
II+Yb, Luv^ (at least one trivalent metal selected from 1, Ga and In. X. X' and X7/ are F, CQ, [at least one selected from lr and l+7) 7% Cll There is a Shin. 1 Sat Eu, Tb+Ce, Tm+Dy+Pr, Ho, Nd
, Yb, Er, Gd, Lu, Sw, Y, TQ, Na, 8g, Cu, and M. Furthermore, a is a numerical value in the range of 0≦a<0.5, 1) is a numerical value in the range of 0≦1]・ζ0.5, and C is a numerical value in the range of 0≦1]・ζ0.5.
There are numbers in the range of 0.2. ) and the like can be mentioned. However, the photostimulable phosphor used in the radiation image conversion panel according to the present invention is not limited to the above-mentioned phosphor.
Any phosphor may be used as long as it exhibits $-exhaustive luminescence. The radiation image conversion panel according to the present invention comprises one or more stimulable phosphors containing at least one type of stimulable phosphor.
It may be a group of stimulable phosphor layers consisting of lI stimulable phosphor layers. Furthermore, the stimulable phosphors contained in each stimulable phosphor layer may be the same or different. The layer thickness of the stimulable phosphor layer of the radiation image conversion panel according to the present invention varies depending on the radiation sensitivity of the radiation image conversion panel, the type of stimulable phosphor, etc., but is 10 μm to 10 μm.
It is preferably selected from the range of 00 μm, and from 20 μm to
More preferably, it is selected from the range of 800 μm. FIG. 3 shows the relationship between the layer thickness of the stimulable phosphor of the radiation image conversion panel according to the present invention, the adhesion resistance of the 111/3 phosphor corresponding to the layer thickness, and the radiation sensitivity. Since the stimulable phosphor layer of the radiation image conversion panel according to the present invention does not contain a binder unlike conventional panels, the adhesion resistance (filling rate) of the stimulable phosphor is lower than that of the conventional radiation image conversion panel. The radiation absorption rate per unit thickness of the stimulable phosphor layer is improved, resulting in not only higher sensitivity to radiation than conventional radiation image conversion panels, but also improved image granularity. In addition, since the stimulable phosphor layer of the radiation image conversion panel according to the present invention does not contain a binder, it has excellent directivity and has high transmittance to stimulated excitation light and stimulated luminescence. It is possible to increase the thickness of the upper layer of the radiation image conversion panel. Furthermore, radiation #i according to the invention! Since the stimulable phosphor layer of the image conversion panel has excellent directivity as described above, the number of stimulable excitation lights in the stimulable phosphor layer is reduced,
Image sharpness is significantly improved. Various polymeric materials, glasses, metals, etc. are used as the support for the radiation image conversion panel according to the present invention, and examples include cellulose acetate film, polyester film, polyethylene terephthalate film, polyimide film, polyimide film, triacetate film, and polycarbonate film. Preferred are plastic films such as, metal sheets made of aluminum, iron, copper, chromium, etc., or metal sheets having a coating layer of the metal oxide. The surface of these supports may be smooth, or may be matte for the purpose of improving adhesion to the stimulable phosphor layer, or may be provided with a reflective layer or an absorbing layer. Further, the surface of the support body may have an uneven surface 21 as shown in FIG. In the case of FIG. 4(a), the stimulable phosphor layer is subdivided by uneven surfaces 21 as shown in the cross-sectional view of FIG. 4(c), so that the sharpness of the image is further improved. In the case of Fig. f54 (b), the stimulable phosphor layer is deposited while maintaining the outline of the tile-like plate 23 of the support, so that the stimulable phosphor layer is deposited as shown in Fig. l'4 ( d
As shown in the cross-sectional view of ), the image is composed of columnar blocks 25 of stimulable phosphor separated by cracks 26, so that the sharpness of the image is further improved. Furthermore, these supports may be provided with a subbing layer on the surface on which the stimulable phosphor layer is provided, for the purpose of improving adhesion with the stimulable phosphor layer. The layer thickness of these supports varies depending on the material of the support used, but is generally 80 μm.
m to 2000 μm, more preferably 80 μto to 1000 μm from the viewpoint of handling. In the radiation image conversion panel according to the present invention, a protective layer for physically or chemically protecting the stimulable phosphor layer is generally provided on the surface where the stimulable phosphor layer is exposed. It's okay. This protective layer may be formed by directly applying a protective layer coating liquid onto the stimulable phosphor layer, or by adhering a separately formed protective layer onto the stimulable phosphor layer. good. Materials for the protective layer include cellulose acetate, nitrocellulose, polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate,
Conventional protective layer materials such as polyethylene, vinylidene chloride, nylon, etc. are used. In addition, this protective layer is made of SiC by vapor deposition method or sputtering method.
, SiO□, SiN, ^Q20. It may also be formed by laminating black iso materials such as. Generally, the N thickness of these protective layers is preferably about 0.1 μW to 100 μm. This radiation image conversion panel according to the present invention provides excellent sharpness, graininess and sensitivity when used in the radiation image conversion method schematically shown in FIG. That is, the fifth
In the figure, 31 is a radiation generating device, 32 is a subject, and 3
3 is a radiation image conversion panel according to the present invention, 34 is a stimulated excitation light source, and 35 is the radiation #Xii! ii A photoelectric conversion device that detects stimulated fluorescence emitted from the image conversion panel, 36 is 3
5 is a device for reproducing the detected signal as an image; 37 is a device for displaying the reproduced image; and 38 is a filter that separates stimulated excitation light and stimulated fluorescence and allows only stimulated fluorescence to pass through. It should be noted that the elements after 35 are not limited to the above, as long as they can reproduce the optical information from 33 as an image in some form. As shown in FIG. 5, radiation from a radiation generating device 31 passes through a subject 32 and enters a radiation image conversion panel 33 according to the present invention. This incident radiation is absorbed by the stimulable phosphor layer of the radiation image conversion panel 33, its energy is multiplied by M, and an accumulated radiation transmission image is formed. Next, this accumulated image is converted into I? from the photostimulating excitation light source 34? [Excited with exhaustion light and emitted as X111 exhaustion emission. In the radiation image conversion panel 33, the stimulable phosphor layer does not contain a binder and has a high fill stimulable phosphor layer, so when scanning with the above-mentioned stimulable excitation light, stimulable Diffusion of light in the stimulable phosphor layer is suppressed. Since the strength of the emitted stimulated luminescence is proportional to the amount of accumulated radiation energy, this optical signal is photoelectrically converted by a photoelectric conversion device 35 such as a photomultiplier tube, and the image reproduction device M36
By reproducing it as an image and displaying it on the image display device 37, it is possible to observe the radiation and IQ transmission image of the subject.

[Example] Next, the present invention will be explained with reference to an example. Example 1 A chemically strengthened glass having a thickness of 500 μIn was placed as a support in the vapor deposition apparatus shown in FIG. Next, an alkali halide stimulable phosphor (ItlJr: 0,0006 T) powder was placed in the storage container 5 as an evaporation source, and the evaporator was then evacuated to obtain a vacuum of 5×10-'Torr. Next, while heating and maintaining the support at 150'C, the evaporating dish 6
Electric power was introduced to heat the evaporation dish, and then the alkali halide stimulable phosphor powder was supplied little by little from the storage container 5 to the evaporation dish to deposit the stimulable phosphor. In order to obtain the desired stimulable phosphor layer, the deposition rate was detected by a film thickness monitor, and the deposition rate was controlled to be 0.58/Iain. The vapor deposition was terminated when the thickness of the stimulable phosphor layer reached 300 μm, and a radiation image conversion panel A was obtained by the manufacturing method of the present invention. The radiation image conversion panel A according to the present invention obtained in this way was subjected to a tube voltage of 80 K V l] x#i of 10 mR.
After irradiation, 1le-Ne laser light (633++u+
), the stimulated luminescence emitted from the stimulable phosphor layer is charged and converted by a photodetector (photomultiplier tube), this image is reproduced as an image by an image reproducing device, and the silver halide film is Recorded above. The sensitivity of the radiation image conversion panel A to X-rays was determined based on the signal magnitude and is shown in Table 1. In Table 1, the sensitivity to X-rays is shown as a relative value, with the radiation image conversion panel 8 according to the present invention being 100. Example 2 A radiation image conversion panel B according to the present invention was obtained in the same manner as in Example 1 except that the vapor deposition apparatus in Example 1 was changed to the type shown in FIG. The radiation image conversion panel B according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are also listed in Table f51. Example 3 In Example 1, instead of using an alkali/)ride stimulable phosphor as the evaporation source, an alkali halide stimulable phosphor raw material (RbBr 1 mol, TQBro, 0006) was used.
A radiation image conversion panel C according to the present invention was obtained in the same manner as in Example 1 except that a molar mixture) was used. The radiation image conversion Parnel C according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Comparative Example 1 A chemically reinforced lath with a thickness of 500 μm was placed in a vapor deposition apparatus as a support. Next, alkali halide stimulable phosphor (RbBr: 0.0006
TQ) and set it on a resistance heating electrode, and then the evaporator was evacuated to a vacuum of 5×10-' Torr. A current was applied to the molybdenum board while heating and holding the support at 150°C, and the alkali halide exhaustible phosphor was evaporated using a resistance heating method. The deposition rate was detected using a film thickness monitor, and the deposition rate was set to 105^/min. A radiation image conversion panel P according to a comparative manufacturing method was obtained by depositing the layer on the support until the layer thickness became 300 μm while controlling the following. The comparative radiation image conversion panel P thus obtained was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. @1 As is clear from Table 1, radiation image conversion panels ^, B, and C manufactured by the manufacturing method of the present invention have radiation #Ili! manufactured by the comparative manufacturing method. ! Compared to the i-image conversion panel P, the graininess and sharpness were the same, but the X-ray sensitivity was about three times higher. This is because the vapor pressure of TQBr, which is an activator, is significantly different from the vapor pressure of RI)Br when forming the stimulable phosphor layer. This is because a stimulable phosphor layer with the desired activator concentration was obtained during vapor deposition in the example, whereas Ti1l was not doped at the desired concentration. Example 4 In Example 1, the deposition rate of the stimulable phosphor was changed to 3×10
A radiation image conversion panel D according to the present invention was obtained in the same manner as in Example 1 except that the ratio was controlled to be 68/Iain. The radiation image conversion panel D according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are shown in Table 2. In Table 2, the sensitivity to X#l is expressed as a relative value, with radiation image conversion panel A according to the present invention being 100. Table 2 As is clear from Table 2, the radiation image conversion panel D according to the present invention exhibited high Xi sensitivity similar to the radiation image conversion panel A according to the present invention. Example 5 BaFBr: 0.00 as the evaporation source resource in Example 1
A radiation image conversion panel E according to the present invention was obtained in the same manner as in Example 1 except that 2Eu stimulable phosphor was used. The radiation image conversion panel E according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are shown in Table 3. In Table 3, the sensitivity to X-rays is shown as a relative value, with the radiation image conversion panel E according to the present invention being IOQ. Comparative Example 2 BaFBr: 0.00 as evaporation source resource in Comparative Example 1
A comparative radiation image conversion panel Q was obtained in the same manner as in Comparative Example 1 except that 2Eu stimulable phosphor was used. The comparative radiation image conversion panel Q thus obtained was evaluated in the same manner as in Example 1, and the results are also listed in Table 3. Table 3 As is clear from Table 3, the radiation image conversion panel E according to the present invention had higher sensitivity to X-rays than the comparative panel Q. [Effect of the invention] Create a stimulable phosphor that exhibits the designed characteristics! B: As a means of forming a vapor deposited layer that looks exactly like the actual product, we use a flash vapor deposition method that instantaneously heats and evaporates the stimulable phosphor with the same composition, eliminates performance deviations between design and product, and guarantees quality. In addition to improving performance, it is possible to achieve a stable and reliable production process.

[Brief explanation of drawings]

FIG. 111 and FIG. 2 are schematic cross-sectional views of an example of a flash evaporation device used in the present invention. FIG. 3 shows the sensitivity characteristics of the radiation image conversion panel that can be improved by the present invention. FIG. 4 illustrates the shape of the vapor deposition base surface of the support. FIG. 5 is a diagram illustrating a radiation image conversion method. FIG. 6 is a diagram showing the TQ concentration dependence of the instantaneous luminescence intensity and the stimulated luminescence intensity in a photostimulable phosphor (RbBr Near 1). DESCRIPTION OF SYMBOLS 1... Sarnoya, 2... Film thickness monitor 3... Support heater, 4... Support 5.
5'...Storage iL container 6,6'...Evaporation dish 7.7'...Evaporation rA material (stimulable phosphor) 8...
・Supply VC placement 9...Current introduction wire 11
...Main valve applicant Konishiroku Photo Industry Co., Ltd. Figure 1 Figure 3 o 100 200 'eD0
4G) 5 Right Seven Flashes yl-x> Figure 4 (a) (b) Figure 5 5K Procedural Amendment October 22, 1985

Claims (1)

[Claims] 1. A method for producing a radiation image conversion panel, comprising forming at least one stimulable phosphor layer on a support by a flash vapor deposition method.