JPS62211600A - Radiation picture conversion panel with light scattering layer - 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 specifically, it provides a radiation image with a high practical level of sharpness and C/sensitivity. This invention relates to a radiation image conversion panel.

[Background of the invention]

Radiographic images such as the X#1iilliI image are often used for disease diagnosis. In order to obtain this x#1vJi image, the X-rays that have passed through the subject are irradiated onto the phosphor phase (phosphor screen), thereby producing visible light, which is then used in the same way as when taking a normal photograph. So-called radiography is used, in which a film using silver salt is irradiated and developed. However, in recent years, methods have been devised to directly extract images from the phosphor phase without using a film coated with silver salt. This method involves making a phosphor absorb the radiation that has passed through the copying material, and then exciting this phosphor with, for example, light or thermal energy, so that the second phosphor absorbs the radiation energy accumulated by the absorption into the phosphor ( There is a method in which the fluorescent light is emitted as stimulated luminescence (stimulated luminescence), and this fluorescence is detected and imaged. Specifically, for example, U.S. Patent No. 3,859,527 and Japanese Patent Application Laid-open No. 55-12144 disclose a radiation image conversion method using a stimulable phosphor and using visible light or infrared rays as stimulable excitation light. There is. This method uses a radiation image conversion panel in which a stimulable phosphor phase is formed on a support, and radiation that has passed through the object is applied to the stimulable phosphor phase of this radiation image conversion panel to visualize various parts of the object. A latent image is formed by accumulating radiation energy corresponding to the radiation transparency,
Thereafter, by scanning this photostimulable phosphor phase with photostimulation excitation light, the radiation energy accumulated in each part is released.
This is converted into light, and an image is obtained from an optical signal based on the intensity of this light. This final image may be reproduced as a hard copy or on a CRT. Now, the radiation image conversion panel having a stimulable phosphor phase used in this radiation image conversion method is similar to the case of the above-mentioned radiography using a fluorescent screen.
It is required that the i-yield and the light conversion rate (both of which are hereinafter referred to as "radiation sensitivity") are high, and the image has good graininess and high sharpness. However, in general, a radiation image conversion panel having a stimulable phosphor phase is produced by coating a dispersion containing a granular stimulable phosphor with a grain size of about 1 to 30 μm and an organic binder on a support or a carrier. Since it is produced by drying, the packing density of the stimulable phosphor is low (50% filling rate), and it is necessary to increase the layer thickness of the stimulable phosphor phase in order to sufficiently increase the radiation sensitivity. Ta. On the other hand, the image sharpness in the radiation image conversion method tends to be higher as the layer thickness of the photostimulable phosphor phase in the radiation image conversion panel becomes thinner. It was necessary to thin the phosphor phase. In addition, the graininess of the image in the radiation #1liI image conversion method is caused by local fluctuation cm quantum mottle of the radiation quantum number or structural disorder (structural mottle) of the stimulable phosphor phase of the radiation image conversion panel. Therefore, when the layer thickness of the R-stimulable phosphor phase becomes thinner, the number of radiation quanta absorbed by the R-stimulable phosphor phase decreases, resulting in an increase in quantum mottles, and structural disorder becomes apparent and the structure Mottle may increase, resulting in a decrease in image quality. Therefore, in order to improve the graininess of the image, the 1j11-exhaustive fluorescent 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 phase. The radiation image conversion panels have been made with some trade-off between sensitivity to radiation, graininess, and sharpness. In other words, in conventional radiation image conversion panels, the sharpness of the image rapidly decreases as the stimulable phosphor phase thickness increases due to the large scattering and diffusion of 11 [excitation light] by the stimulable phosphor particles, resulting in a decrease in sensitivity. Although there may be conditions where both sharpness and sharpness are bad, it is difficult to find conditions where both are good. By the way, it is well known that the sharpness of images in conventional radiography is determined by the spread of instantaneous emission (emissions during radiation irradiation) of the phosphor in the fluorescent screen. The sharpness of images in radiation image conversion methods using stimulable phosphors is not determined by the spread of stimulated luminescence of the stimulable phosphors in the radiation image conversion panel; This is not determined by the spread of the emission of the phosphor, but depends on the spread of the stimulated excitation light within the panel.This is because in this radiation image conversion method, the radiation image conversion panel Since the radiographic image information accumulated in is retrieved in a time-series manner, all of the stimulated luminescence due to the stimulated excitation light irradiated at a certain time (ti) is preferably captured and the stimulated light emitted by the stimulated excitation light is irradiated at that time. However, if the stimulable excitation light spreads within the panel due to scattering, etc., and the stimulable phosphor existing outside the irradiated pixel (xLyi) This is because if the above pixel (xLyi) is also excited, the output from a wider area than the image will be recorded as the output from the pixel (xLyi).Therefore, for a certain time (Li)
The time (
If only the light is emitted from the pixel (xiyyi) on the panel that was truly irradiated with the stimulated excitation light at ti), the sharpness of the image obtained will be affected no matter how wide the light is emitted. There is no. Under these circumstances, several methods have been attempted to improve the above-mentioned drawbacks of radiation image conversion panels having a stimulable phosphor phase in which a stimulable phosphor is dispersed in a binder. For example, JP-A-56-11393 discloses a method in which a metal light-reflecting layer is provided at the interface of one layer of a stimulable phosphor phase prepared by dispersing a stimulable phosphor in a binder. According to this method, the stimulable phosphor phase in the portion of the stimulable phosphor phase that enters inside from the interface on the incident side of the stimulable excitation light is changed into a metal light reflecting layer. The layer thickness of the stimulable phosphor layer can be made thinner, thereby suppressing the spread of the stimulable excitation light within the stimulable phosphor phase, resulting in highly sharp radiation images. However, although this method can suppress the spread (scattering) of the stimulable excitation light within the layer by the thinning of the stimulable phosphor phase,
l1II that reached the metal light reflecting layer while being scattered within the layer
! Since the stimulated excitation light has almost no directivity, it is reflected depending on the angle of incidence of the stimulated excitation light on the metal reflective layer, returns to the stimulated phosphor phase side, and is repeatedly scattered again.
Image sharpness is not significantly improved due to the excitation over the II-exhaustive fluorescence range. In addition, in JP-A-56-12600, the above-mentioned JP-A-56-12600
1I instead of the metal light reflective layer disclosed in No. 11393.
A method is disclosed in which a white pigment light-reflecting layer is provided on one side of a stimulable phosphor phase dispersed in a qI-stimulable fluorescent dye. According to this method, the v# exhaustible phosphor phase is converted into a white pigment reflective layer by changing the part of the stimulable phosphor phase that enters the interior from the excitation light incident side surface into a white pigment reflective layer. The layer thickness of the phase can be made thinner, thereby making it possible to suppress the spread of the photostimulable excitation light within the photostimulable phosphor phase, resulting in a radiation image with high sharpness. However, this method also uses a part of the stimulable phosphor phase, which is made by dispersing a stimulable phosphor, which is a type of white pigment, in a binder.
It is simply replaced with a white pigment light-reflecting layer formed by dispersing a white pigment in a binder. Therefore, although this method has the effect of suppressing the spread (scattering) of the photostimulable excitation light within the layer to the extent that the thickness of the photostimulable phosphor layer can be reduced, the white pigment light-reflecting layer The stimulated excitation light that reaches the stimulable phosphor layer is diffusely reflected on the surface of the white pigment light-reflecting layer, or is scattered inside the white pigment light-reflecting layer, reflected to the stimulable phosphor phase, and then scattered again within the stimulable phosphor phase. Since the stimulable phosphor is excited over a wide range, image sharpness is not significantly improved. As mentioned above, the conflict between sensitivity to radiation and image sharpness in conventional radiation image exchange panels has hardly been improved, and improvement has been strongly desired. After extensive research, we received a special patent application in 1986-2.
No. 74596 discloses a radiation image conversion panel having a photostimulable phosphor phase, in which the photostimulable phosphor phase is composed of a phosphor phase having a bonded form, and the stimulable phosphor phase We have proposed a radiation image conversion panel characterized by having a light scattering layer on the interface side of one of the layers of the phosphor phase. According to the invention, it is possible to provide a radiation image information panel that provides an image with higher sharpness than a conventional radiation image conversion panel when compared with a conventional radiation image conversion panel having the same radiation sensitivity; When compared with conventional radiation mva image conversion panels in sharpness, it is possible to provide a radiation image conversion panel that is more sensitive to radiation than conventional radiation image conversion panels. In this invention, although the reciprocity between the radiation sensitivity and image sharpness of the radiation image conversion panel described above has been considerably improved, it is still not sufficient, and further improvement has been desired.

[Object of the present invention]

In view of the above points, it is an object of the present invention to achieve the following by comparing radiation image conversion panels with the same radiation sensitivity.
It is an object of the present invention to provide a radiation image conversion panel that provides a more beautiful and sharper image than a nm image conversion panel. Another object of the present invention is to provide a radiation image conversion panel that has significantly higher sensitivity to radiation than conventional radiation image conversion panels when comparing radiation image conversion panels with the same sharpness.

[Structure of the invention]

The object of the present invention is to provide a radiation image conversion panel having a light scattering layer at the interface of one of the layers of the photostimulable phosphor phase, based on the findings obtained through repeated research in accordance with the above object. This is achieved by a radiation image conversion panel characterized in that the phosphor phase is composed of a fluorescent phase having a bonded form, and the light scattering layer is colored with a coloring agent. In the aspect of the present invention, the phosphor phase, which is formed by joining the stimulable phosphor phases, has striae in the Kashiwara direction, and the stimulable phosphor phase has striae in the Kashiwara direction, giving directionality to the stimulable phosphor and the stimulated luminescence. It is preferable to give. Furthermore, it is practically preferable that the layer structure is laminated in the following order: support, light scattering layer, and stimulable phosphor phase. Further, the light scattering layer is formed by having a fine interface where the refractive index varies optically, for example, a pigment layer made of fine particles or a layer having a rough surface at the interface. Furthermore, the light scattering layer is preferably colored with a coloring agent that absorbs at least a portion of the 11f [excitation light]. The present invention will be explained in detail below. The present invention improves the radiation sensitivity and image sharpness of a radiation image conversion panel by providing a colored light scattering layer at the interface between one of the stimulable phosphor phases and the I layer of the radiation image conversion panel. It is something that will be realized. As mentioned above, the sharpness of the image of the radiation image conversion panel is controlled by the scattering of the stimulable excitation light within the stimulable phosphor phase. Therefore, in order to improve the sensitivity to radiation and the sharpness of images, it is necessary to improve the directionality of stimulated excitation light and/* or stimulated luminescence within the photostimulable phosphor phase, and to add a light scattering layer. It is traditionally effective to combine both of the following: reducing the thickness of the stimulable phosphor phase by increasing the radiation sensitivity. By providing the layer, the extraction efficiency of lII! excitation light to the outside is increased and improved.In addition, the sharpness of the image is improved by improving the directivity of the I1I excitation light and by increasing the aforementioned sensitivity. By making the stimulable phosphor phase a thin layer, the scattering of the stimulable excitation light within the stimulable phosphor phase is suppressed and improved. The light scattering layer reflects the stimulated luminescence efficiently and increases the efficiency of extracting the stimulated luminescence to the outside, but at the same time, the light scattering layer also brings about the same effect on the luminescence l!-excitation light. A part of the Xl!I-excited excitation light incident on the phosphor phase reaches the light-scattering layer and is diffusely reflected on the surface of the light-scattering layer, or the Xl!I-excited excitation light scattered inside the light-scattering layer returns to the aforementioned luminescence. Exhaustive phosphor N
It is reflected to gA. The V$excitation light reflected by this light scattering layer expands in the stimulable phosphor phase,
Therefore, the sharpness of the image deteriorates. According to studies by the present inventors, by coloring the light scattering layer of the radiation image conversion panel with a coloring agent that selectively absorbs the stimulated excitation light, the brightness r! - It has been found that deterioration of image sharpness due to reflection of excitation light can be significantly prevented. That is, by coloring the light scattering layer itself, the colored light scattering layer can efficiently absorb only excess stimulated excitation light without reducing the reflectance of stimulated luminescence. In the present invention, a phosphor phase having a bonded form is provided to the stimulable phosphor phase, and striae, that is, a portion with non-uniform refractive index, is formed in the thickness direction of the layer. For example, providing directionality of stimulated excitation light or stimulated luminescence in the layer thickness direction by creating crack interfaces, gaps, etc. is generally achieved by forming a stimulable phosphor by a vapor deposition method. Figure 1 (,) shows a stimulable phosphor phase consisting of fine columnar crystals formed by bonding with one vapor deposition method and having gaps and cracks as striae in the layer thickness direction. Fig. 2 shows an electron micrograph of the cross-sex layer, and Fig. 3(b) schematically shows the light directivity in the layer, that is, the light guiding effect of the layer. In the same figure (1,), each fine columnar crystal aira
2. Due to the light guiding effect of a3..., the stimulated excitation light 11 or the stimulated luminescence 12 is repeatedly totally reflected at the crystal interface and proceeds in the layer thickness direction. As a result, the photostimulable excitation light 11 incident on the radiation image conversion panel is not scattered and diffused in the photostimulable phosphor phase 13, and the directivity is improved. Similarly, the directionality of stimulated luminescence is also improved. As the vapor phase deposition method of the phosphor, a vapor deposition method, a sputtering method, an ion blating method, and others can be used. In the first vapor deposition method, the support is first placed in a vapor deposition apparatus, and then the apparatus is evacuated to a temperature of 10-'Torr.
The degree of vacuum should be approximately Next, at least one of the stimulable phosphors is heated and evaporated by a resistance heating method, an electron beam method, or the like to deposit the stimulable phosphor on the surface of the support to a desired thickness. As a result, a stimulable phosphor phase containing no binder is formed, but it is also possible to form the stimulable phosphor phase in multiple steps in the vapor deposition step. Further, in the vapor deposition step, it is also possible to co-evaporate using a plurality of resistance heaters or an electro beam. After the vapor deposition is completed, if necessary, the stimulable phosphor phase is kept on the side opposite to the support side. The radiation image conversion panel of the present invention is manufactured by providing LIvi. Incidentally, a step may be taken in which a support is provided after forming the stimulable phosphor phase on the protective fill eyebrows. In addition, in the above vapor deposition method, the stimulable phosphor raw material is co-evaporated using a plurality of resistance heaters or an electron beam, and the desired stimulable phosphor is synthesized on the support while 11I is exhausted at the same time. It is also possible to form a phosphor phase. Furthermore, in the vapor deposition method, the object to be vapor deposited (support or protective layer) may be cooled or heated as necessary during vapor deposition, and the stimulable phosphor phase may be heat-treated after vapor deposition. In addition, in the vapor deposition method, 0
□=HtkJ gas may be introduced to perform reactive vapor deposition. In the sputtering method as the second method, the support is placed in the sputtering device as in the vapor deposition method, and then the inside of the device is once evacuated to a degree of vacuum of about 10-' Torr.
Next, ArrNe was used as a gas for sputtering.
etc. into the sputtering equipment. The gas pressure is set to about 10-' Torr. Next, the stimulable phosphor phase is deposited on the surface of the support to a desired thickness by sputtering the stimulable phosphor as tarded. In the sputtering process, it is possible to form the stimulable phosphor phase in multiple steps as in the vapor deposition method, or it is possible to form the stimulable phosphor phase simultaneously or simultaneously using multiple tarded layers each made of a different stimulable phosphor. It is also possible to sequentially sputter the tarded material to form a stimulable phosphor phase. After sputtering is completed, the radiation image conversion panel of the present invention is manufactured by providing a protective layer on the side of the stimulable phosphor phase opposite to the support, if necessary, in the same manner as in the vapor deposition method. In addition, Ho 1! After forming the stimulable phosphor phase on the layer,
A step of providing a support may also be taken. In the above sputtering method, a plurality of stimulable phosphor raw materials are used as tarded materials, and these are sputtered simultaneously or sequentially to synthesize the desired 711f1 stimulable phosphor on a support and at the same time produce stimulable phosphor. It is also possible to form a body phase. In the sputtering method, 0, . Reactive sputtering may be performed by introducing a gas such as 82 or the like. Furthermore, in the sputtering method, the object to be deposited (support or protective layer) may be cooled or heated as necessary during sputtering. Further, the stimulable phosphor phase may be heat-treated after sputtering. A third method is the CVD method. Moreover, there is an ion blating method as a fourth method. The layer thickness of the stimulable phosphor phase in the radiation image conversion panel of the present invention varies depending on the radiation sensitivity of the intended radiation image conversion panel, the type of stimulable phosphor, etc., but is 30 μM.
It is preferable to select from the range of ~1000 μL, and 40 μL.
More preferably, it is selected from the range of μ, W to 800 μl. If the layer thickness of the stimulable phosphor phase is less than 30μ particles, the radiation absorption rate will be extremely reduced, the radiation sensitivity will deteriorate, the graininess of the image will deteriorate, and the stimulable phosphor phase will become transparent. This is not preferable because the lateral spread of the stimulable excitation light in the stimulable phosphor phase tends to increase steadily, and the sharpness of the image tends to deteriorate. Further, in manufacturing the radiation image conversion panel of the present invention, the deposition rate of the stimulable phosphor phase is 0.05 μm min to 300 μm min.
Preferably it is μl/min. Deposition rate is 0.05μ
If the deposition rate is less than 1/min, the productivity of the radiation image conversion panel of the present invention will be low (unpreferable).If the deposition rate exceeds 300 μl/min, it will be difficult to control the ttb stacking speed, which is undesirable. The light scattering layer according to the invention is provided on the side opposite to the side surface of the lfI stimulable phosphor phase on which the photostimulable excitation light is incident.The light scattering layer may be provided directly on the surface of the photostimulable phosphor phase. Alternatively, the light scattering layer may be provided via a subbing layer to enhance the adhesion between the light scattering layer and the stimulable phosphor phase.The light scattering layer may include a pigment layer, a porous metal layer, a grained layer, etc. A calendar having an interface or layer capable of scattering light such as a metal layer, ceramic layer, glass layer or opal glass layer is used.The light scattering layer other than the pigment layer can also be in the form of a support. The stimulable phosphor can be vapor-phase deposited on the light-scattering surface side.If a separate support is used, it can be attached before vapor-phase deposition, or the light-scattering layer can be attached to the support after vapor-phase deposition. When the light-scattering layer is a pigment layer, the vapor phase deposition method may be used for pigments that can be deposited in a vapor phase, or the pigment layer may be suspended in a binder. A pigment paint may be applied.As the pigment, a pigment having a high reflectance to luminescence is preferable, and from this point, a white pigment is particularly preferable.
As an example of the preferred white pigment, TIO, (af'
-S type, /”F le type), M g 012PbCO
a ・Pb(Oll)2, Ba5O,,^1!0. ,M
"FX (however, Hz is at least one of B&, Sr, and Ca, and X is at least one of C1 and Br), CaCO3, ZnO-5bzOt, 5
iOz, Zr0z, NL+20s, Litopone (BaSO
< + Zn5), silicon filv magnesium, basic lead silicate, basic lead phosphate, aluminum silicate, etc. These white pigments have a strong hiding power and a large refractive index, so they easily scatter stimulated luminescence by reflecting or refracting light, which reduces the sensitivity of the resulting radiation image conversion panel. Improve. Stimulable phosphors for radiation image conversion panels include divalent europium-activated alkaline earth metal fluoride/rhodanide phosphors, rare earth element-activated rare earth oxyhalide phosphors, and thallium-activated alkali halide phosphors. When using a stimulable phosphor that exhibits stimulated luminescence even in the near-ultraviolet region such as
, anatase-type Ti0t, Mg0JZPbCO* *
Pb(OH)2, Ba5On and ^120. is preferred. When used as a pigment paint, the average particle size of the pigment is 0.
．． 05 to 50 µl is preferred, and 0.1 to 10 µl is more preferred. A number of resins can be used and provided. The thickness of the light scattering layer according to the present invention is generally preferably 2 to 100 μm, and preferably has an average reflectance of 50% or more, and further 70% or more, for light in the stimulated emission wavelength region. The colorant used to color the light scattering layer in the linear image conversion panel of the present invention absorbs at least a portion of the stimulated excitation light for causing the photostimulable phosphor to stimulate luminescence. Depending on the type of stimulable phosphor used, the average reflectance of the radiation image conversion panel for light in the stimulated excitation wavelength region may be lower than the average reflectance for light in the stimulated emission wavelength region. It is preferable to have a light absorption characteristic that is smaller than the ratio. From the point of view of image sharpness, the coloring agent is a stimulable phosphor,
It is better to have a high absorption rate for light in the 8rIh luminescence wave is range (a small average reflectance of the radiation image conversion panel for light in this wavelength range). It is better that the absorption rate of the region is small (the average reflectance of the radiation image conversion panel for light in the wavelength range is large). More specifically, the average reflectance of a light scattering layer colored with a coloring agent to light in the stimulated emission wavelength range is 20% of the average reflectance of an uncolored equivalent 6LM to light in the same wavelength range. More preferably, it is 60% or more, and the average reflectance of the light-scattering layer colored with a coloring agent to light in the wavelength region of the stimulated excitation light is the same as that of an equivalent light-scattering layer that is not colored. The average reflectance for light is preferably 95% or less, and more preferably 80% or less. In addition, the reflectance in this invention means the reflectance calculated|required with the integrating sphere type spectrophotometer. The colorant may be organic or non-organic! Any coloring agent may be used, but in terms of hue, blue to green coloring agents are useful. There are 8! The color M is Zapon 7 Earth Blue 3G (
Hoechst), Nistrol Prill Blue N-3RL (
(manufactured by Sumitomo Chemical), D&C Blue No. 1 (Nassicinal Aniline M), Spirit Blue (manufactured by Hodogaya Chemical), Oil Blue No. 603 (manufactured by Orient), Kitten Blue A (Chiba Iggy!! Ri, Eisenka) Chironpuru G
LH (Hodogaya Chemical!! Ri, Lake Blue AFH (manufactured by Kyowa Sangyo), Brimodianin 6 G X (manufactured by 1i Hata Sangyo)
, Prill Acid Green f3BH (manufactured by Hodogaya Chemical),
Cyan Blue BNR8 (manufactured by Toyo Ink), Lionol Blue SL (manufactured by Toyo Ink), etc. are used. Also, color index No. 2441L23160.74
180.74200.22800.23150.231
55.24401.14880.15050.1576
0.15707.17941,74220.13425
．． 13381.13420, 11836.74140.
Organic metal complex salt coloring agents such as 74380 and Fu4350.74460 may also be mentioned. Inorganic colorants include ultramarine blue, cobalt blue, cerulean blue, chromium oxide, and Tio2-Zn. Examples include -Coo-NiO pigments. The colored light-scattering layer according to the present invention can be prepared, for example, by adding the white pigment, coloring agent, and binder to a suitable solvent, thoroughly mixing and dispersing to prepare a coating solution, and applying the obtained coating solution to the support described below. It is formed on the support (or on the stimulable phosphor phase) by uniformly coating it on the body surface (or on the stimulable phosphor phase surface) and drying it. The mixing weight ratio of the binder to the pigment in the coating solution is 0.
A value of about 02 to 0.5 is practical. In addition, the mixing weight ratio of the binder to the coloring agent in the coating solution is practically about 106 to 10 when the coloring agent is a dye, and 104 to 0.1 when the coloring agent is a pigment. The thickness of the 0-colored optical drilling layer is preferably 2 to 100 μl, which is a practical level. In the radiation image conversion panel of the present invention, for the purpose of further improving the sharpness of the obtained image, the radiation image conversion panel may be colored on the side where the stimulated excitation light is incident rather than the light scattering layer. In the present invention, the coloring applied to the side where the bright rL excitation light enters rather than the light scattering layer of the radiation image conversion panel is applied to the entire layer of the stimulable phosphor phase, or to the surface layer of the layer, The coating is applied to the layer portion close to the light-scattering layer, the undercoat layer, the retention Ia layer, or two or more of these. Alternatively, a colored layer may be provided on the layer surface or between the layer and the light scattering layer. As the coloring agent used for the coloring, the coloring agent used for coloring the light scattering layer can be applied. In the radiation image conversion panel of the present invention, <Stimulated excitation) refers to a phosphor that exhibits stimulated luminescence corresponding to the irradiation dose of initial light or high-energy radiation, but from a practical standpoint, preferably 500 n
The stimulable phosphor used in the radiation image conversion panel of the present invention, which is a phosphor that exhibits stimulated luminescence by stimulable excitation light of m or more, is, for example, Ba504 described in JP-A-48-80487. :A x (A is Dy, T
at least one of b and Tm, and X is o, oo
i≦x<1 mol%. ), MgSO4:AX described in JP-A-48-80488 (where A is either Ho or Dy, and 0.001
≦51 mol%), JP-A-48
SrSO<:A x described in No.-80489
(However, A is at least IWL of Dy, Tb and Ta.
and X is o, ooi≦x<1 mol%. ), Nl12S O<, Ca5O< and B a S described in JP-A-51-29889
A phosphor in which at least one of M n *D y and Tb is added to O< etc., BeOtL iF tMgS O4 and CaF x 44 phosphor described in JP-A-52-30487, JP-A-Sho 53-39277
L listed in the issue! zB 40 t:c u-A
phosphors such as Lizo ・(B 20 z)x:Cu (However, X
is 2<x≦3), and L izo ・(8202)X:
Phosphors such as Cus A g (where X is 2<x≦3), SrS described in U.S. Pat. No. 3,859,527:
Ce+8m1SrS”, Eu, Sm5La202S:E
Examples include a phosphor represented by u*Smut/(Zn*Cd)S:MntX (where X is halogen). In addition, Z +IS described in Japanese Patent Application Laid-Open No. 55-12142
:CLltpb phosphor, general formula is Bao-xA 1z
Barium flumate phosphor represented by O, :E u (0°8≦X≦10), and V fi formula is Mlo x
siOz:A((IiLMxl;t:M g w Ca
w S ry Z n w Cd or Ba and A
is Ce, T b. E ut T ut P t) + T L B i and V
At least one type among M n, and x is 0.5≦x
<2.5. ) Alkaline earth metal silicate-based phosphors represented by: Further, the general formula is (Ba1-X, MgxCa,)FX: eEu'' (where X is at least one of Br and CI, and Xt
7 and e are 0<x+y≦0.6, xy≠0 and (
/10-'≦e≦5X10-''), the general formula of the alkaline earth fluorohalide phosphor described in JP-A-55-12144 is L++OX: xA (However, Ln is at least one of La, Y, Gd, and Lu, X is C1 and tF/or Br, A is Ce and/or Tb, and X is a number satisfying 0<x<0.1. The general formula of the phosphor described in JP-A-55-12145 is (B al-xM ''x)F X :yA (where Ml is M g t Cat S r *Z n and t/C
At least one of d, the sentence is C1, Br and (/I
A is E u * T b v
Ce t T 01 t D y t P r +
At least one of HosNd, Yb and VEr
First, X and y satisfy the following conditions: 0≦≦0.6 and O≦y≦0.2. Phosphor represented by ), JP-A-55-8438
The general formula described in No. 9 is B aF X :xCe
eyA (However, X is at least one of C1, Br, and 1; A is at least one of In, T I, G d, S Ia, and Zr; ×≦2XIQ-' and o<y≦5X10-''), V# Kaisho 55-160078
The general formula described in the issue is M”F
Ln (However, Ml is M gv'c at B ILt S r
At least one of y Z n and (/Cd, A is B
eOyMgo*CaO, 5rO=B aO, Z no
-A 1203-Y to s-L a2o s-1n
20,, S ioz, TiO2, Zr0i, GeO2,
SnO,, NQzO5゜T a 20 s and V T I
+ at least one of 02, Ln is Eu, Tb,
CetTm, DytPrtHo, NdtYb, Er, S
is at least one of seagull and Gd, and X is Cj!
, Br and I, i), and (
/y is 5x10-s≦X≦0,5 and VO<y≦, respectively
This is a number that satisfies the condition of 0.2. ) rare earth element-activated divalent metal fluorohalide phosphor, whose general formula is Z
nS:A, CdS:A, (Zn,Cd)S:A. ZnS: A, X and CdS: A, X (However, A is Q u
HA g +Au or Mn, and X is halogen. ), any of the following general formula % formula % described in JP-A-57-148285:) (where M and N are each M ffv Cay S
rt B at least one of Zn and Cd, X
is F, CI. At least one of Brs and Engineering, A is E us T
b. CtyTIIItDysP r*HotNd, Y+LE
r+s b*Tj! represents at least one of tMn and 1/Sn, and X and y are O≦6.0≦y
This is a number that satisfies the condition of ≦1. ) phosphor,
Any of the following general formulas nReX*・mAX',
:xEunReX s ・mA X' 2:xE u
tys@(wherein, Re is at least one of Lm, Gd, Y, Lu, A is an alkaline earth metal, Ba, Sr,
At least one of Ca, X and X' are F s Ce
= B represents at least one type of r, *ta, ×
and y is IXto-'<to<3 X10-1. I
It is a number that satisfies the condition Xl0-4<y<I Xl0-1, and n/IIl is IX10-'< n7m
<7 X 10-1), and the following general formula % formula %: (However, M town, at least one selected from Li, Na, Rb, and 1/Cs is an alkali metal of Ml
is B e y Mg t C a v S r y B
at Z n *Cd t At least one divalent metal selected from Cu and Ni. M is Sc, Y,
La, Ce, Pr, Ncl, Pw-8+a, Eu, Gd
, T.I.). Dy, Ho, Er, Tm, YbtLu*A1. It is at least one kind of trivalent metal selected from Ga+ and In. X. X′ and x” are at least one kind of halogen selected from F, C1, Br and Engineering. A is E us T b. CetTmtDytPr, HotNdtYb, Er, G
d, Lu, Srat1 'l, r 1 t N a t
A g * At least one metal selected from Cu and Mg. Further, a is a numerical value in the range of 0≦a<0.5, b is a numerical value in the range of 0≦b<0.5, and C is a numerical value in the range of O<c≦0.2. ) and the like can be mentioned. Especially for alkali halide phosphors, use methods such as vapor deposition and sputtering! It is preferable because it is easy to phase the illuminating fluorescent phosphor. However, the stimulable phosphor used in the radiation image conversion panel of the present invention is not limited to the above-mentioned phosphor,
Any phosphor may be used as long as it exhibits stimulated fluorescence when irradiated with radiation and then irradiated with excitation light. The radiation m[image conversion panel of the present invention may be a stimulable phosphor phase group composed of one or more stimulable phosphor phases containing at least one type of the above-mentioned stimulable phosphors. Also, the stimulable phosphors contained in each stimulable phosphor phase may be the same or different. In the radiation MAWI image changing panel of the present invention, a support for supporting the light scattering layer or the stimulable phosphor phase when the light scattering layer or the stimulable phosphor phase does not have self-supporting ability. is provided. Various polymeric materials, glass, metals, etc. are used as the support, and include plastic films such as cellulose acetate film, polyester film, polyethylene terephthalate film, holly7mid film, polyimide film, triacetate film, and polycarbonate film, aluminum sheet,
A metal sheet such as an iron sheet or a copper sheet, or a metal sheet having a coating layer of the metal oxide is preferred. The surfaces of these supports may be smooth or matte for the purpose of improving adhesion with the stimulable phosphor phase or light scattering layer. (a
) may be an uneven surface 21 as shown in FIG. is ff
As shown in the cross-sectional view of FIG. t2 (C), the image is subdivided by the uneven surface 21, so that the sharpness of the image is further improved. Second
In the case of Figure (b), the stimulable phosphor phase is deposited while maintaining the contour of the tile-like plate 23 of the support, so that as a result, the stimulable phosphor phase is second! ! As shown in the cross-sectional view I(d), the image is composed of columnar blocks 25 of stimulable phosphor separated by cracks 26, thereby further improving the sharpness of the image. Furthermore, these supports may be provided with a subbing layer on the surface on which the stimulable phosphor phase or light scattering layer is provided for the purpose of improving adhesion with the stimulable phosphor phase or light scattering layer, or ,
The layer thickness of these supports varies depending on the material of the support used, but is generally 80 μm to 2000 μm, more preferably 80 μm to 1000 μm from the viewpoint of handling.
It is m. In the radiation image conversion panel of the present invention, generally, the photostimulable phosphor phase group is physically or chemically applied to the surface opposite to the surface on which the light scattering layer of the photostimulable phosphor phase is provided. A safeguard may be provided to protect the This protective layer may be formed by directly applying the coating solution for the storage layer 1 onto the stimulable phosphor phase, or by adhering a separately formed protective layer on the stimulable phosphor phase. Good too. Materials for the protective layer include cellulose acetate, nitrocellulose, polymethyl methacrylate, and polyvinyl butyral. Common protective layer materials such as polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate, polyethylene, vinylidene chloride, nylon, etc. are used. In addition, this protective layer is made using a vapor deposition method. S iC, S io 21 by sputtering method etc.
SiN. It may also be formed by laminating Kuroiso materials such as A12031. The thickness of these protective layers is generally preferably about 0.1 μm to 100 μm. The radiographic image conversion panel of the present invention provides excellent sharpness, graininess and sensitivity when used in the radiographic image conversion method shown schematically in FIG. That is, in the ptS3 diagram, 31 is the radiation generating device, 32 is the subject, and 33
4 is a radiation image conversion panel of the present invention, 44 is a stimulated excitation light source, 34 is a photoelectric conversion device that detects stimulated luminescence emitted from the radiation image conversion panel, and 36 is a device that reproduces the signal detected by 35 as an image. device, 37 is a device for displaying reproduced images, 38 is 11! Separate the excitation light and the stimulated emission, l! This is a filter that transmits I-exhaust luminescence. 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. 3, the radiation from the radiation generating device 31 passes through the copying body 32 and enters the radiation image conversion panel 33 of the present invention. This incident radiation is absorbed by the V$ exhaustible phosphor phase of the radiation image conversion panel 33, and its energy is accumulated to form an accumulated image of the emission MIIA transmission image. It is excited with the stimulated excitation light from 34 and is emitted as stimulated luminescence. The radiation image conversion panel 33 of the present invention does not contain a binder in the stimulable phosphor phase and has high directivity, so that it can be easily scanned by the stimulable excitation light. , diffusion of photostimulable excitation light in the photostimulable phosphor phase is suppressed. *In addition, the radiation image conversion panel 33 of the present invention has a colored light scattering layer,
Since at least a portion of the photostimulated excitation light is absorbed, scattering of the photostimulated excitation light in the light confusion 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 fi3
6, reproduce it as an image and display it on the image display device r! 137, the radiographic image of the copy can be observed.

[Example] Next, the present invention will be explained with reference to an example. Example 1 Toluene and ethanol were added to a mixture of barium fluoride bromide (BaFBr) particles, a blue pigment (Lionol Blue ER, manufactured by Toyo Ink.), and polyurethane, and the mixture was sufficiently stirred and mixed using a homogenizer to dissolve the fluoride. The barium bromide particles and the pigment are uniformly dispersed, the binder, the barium fluorobromide and the pigment have a mixing specific strength of C1:10:0.3 (weight ratio), and a viscosity of 25 to 35 PS (at 25°C). ) coating solution @
Manufactured. Next, chemically strengthened glass (support, thickness: 400μ)
was placed horizontally, and the coating solution was uniformly applied thereon using a doctor blade. Then, the support on which the coating film was formed was placed in the coating solution in a dryer, and the temperature inside the dryer was gradually raised from 25° C. to 100° C. to dry the coating film. In this way, 11! Thickness is about 30
A colored light-scattering layer was formed. Next, an alkaline pallite stimulable phosphor (RbBr: 0,00067N) was placed in a water-cooled crucible in which the support on which the colored light-scattering layer was formed was placed in a vapor deposition device, and pressed to form the shape of the crucible. It was molded into. The evaporator was then evacuated and the vacuum level was set to 5×10-'Toor while the support was heated and maintained at 100°C.
Power was supplied to the ED gun to vaporize the stimulable phosphor. In order to obtain the desired stimulable phosphor phase, the deposition rate was detected by a film thickness monitor and controlled to be 5 μIIIZ. The electron beam also scanned the surface of the stimulable phosphor in the crucible in a raster pattern. Vapor deposition was terminated when the layer thickness of the stimulable phosphor phase reached 200 μm to obtain a radiation image conversion panel of the present invention comprising a support, a colored light-scattering layer, and a stimulable phosphor phase. Furthermore, by changing the N thickness of the stimulable phosphor phase in the range of 100 to 400 μl, various radiation image changing panels consisting of a support, a color, a light scattering layer, and a stimulable phosphor phase can be created. I made an NR. The radiation image conversion panel of the present invention (Evaluated by the radiation intensity test and image sharpness test described below)
The results are shown as a curve in FIG. (1) Radiation! Sensitivity test Radiation image conversion panel W voltage 80K V I3 x
After irradiating #X with 1011IR, semiconductor laser light (7
80 nm), and the stimulated luminescence emitted from the stimulable phosphor phase is photoelectrically converted with a photodetector (photomultiplier tube).
The sensitivity of the radiation image conversion panel to X-rays was investigated based on the magnitude of this signal. Note that the sensitivity to X-rays is 100 μl for the radiation image conversion panel of the present invention with a photostimulable phosphor phase thickness of 200 μl.
It is shown as a relative value. (2) Image sharpness test The radiation image conversion panel of the present invention thus obtained was irradiated with X#X with a tube voltage of 80 KVp for 10 aiR, and then photostimulated with semiconductor laser light (780r++++). [The stimulated luminescence emitted from the exhaustible phosphor phase is photoelectrically converted by a photodetector (photomultiplier tube), and this signal is reproduced as an image by an image reproducing device. From the obtained image, the image is modulated. The transfer function (MTF) was investigated. The modulation transfer function (MTF") is the value when the spatial frequency is 7 am for 2 cycles. Example 2 Instead of the blue pigment used in Example 1, a polymethine dye (IR820, manufactured by Nippon Kayaku Co., Ltd.) was used. ) was used, and the mixing ratio of the binder, barium fluorobromide, and colorant was 1:10:
0,0! In the same manner as in Example 1 except that (weight ratio) The radiation image conversion panel B of the present invention was evaluated for radiation #i sensitivity and image sharpness in the same manner as in Example 1, and the results are shown as curve B in Figure 4. Example 3 In Example 1 Instead of using a support coated with a light-scattering layer, the surface was grained, and this was colored with the polymethine dye used in Example 2 to form a colored light-scattering layer. An aluminum plate made of sand grains,
Various radiographic image conversion panels C of the present invention were manufactured which were composed of a 1I exhaustible phosphor phase. The radiation #1iii image conversion panel C of the present invention is Example 1
The radiation sensitivity and image sharpness were evaluated in the same manner as above, and the results are shown as curve mC in FIG. Comparative Example 1 In the same manner as in Example 1, except that the stimulable phosphor phase was directly deposited on the chemically strengthened glass, various types of chemically strengthened glass and Ql-stimulable phosphor phases were prepared. A comparative radiation aWi image conversion panel P was manufactured. The comparative radiation image conversion panel P was evaluated for radiation #i sensitivity and image sharpness in the same manner as in Example 1, and the results are shown as curve P in FIG. Comparative Example 2 Toluene and ethanol were added to a mixture of barifum fluoride bromide (BaFBr) particles, blue pigments (Lionol Blue ER, Toyo Ink I), and polyurethane, and then thoroughly stirred and mixed using a homogenizer. The particles of barium fluoride bromide and the pigment are uniformly dispersed, the mixing ratio of the binder, barium fluoride bromide and the pigment is 1:10:0.3 (fl quantity ratio), and the viscosity is 25 to 85 PS (25 ℃）coating solution to T
Made by I4. Next, chemical reinforcement is applied to the lath (support, thickness: 250 μm)
was placed horizontally, and the coating solution was uniformly applied thereon using a doctor blade. After coating, the support on which the coating film was formed was placed in a dryer, and the temperature inside the dryer was gradually raised from 25° C. to 100° C. to dry the coating film. In this way, the layer thickness is about 30μ on the special holiday.
1 colored light scattering layer was formed. Next, alkali halide stimulable phosphor (RbBr:0.
Methyl ethyl ketone was added to a mixture of particles of 0006TZ) and linear polyester If resin, and the degree of nitrification was further increased to 11.
．． A dispersion containing phosphor particles in a dispersed state was prepared by adding 5% nitrocellulose.Next, tricresyl phosphate, n-butanol, and methyl ethyl ketone were added to this dispersion, and then a propeller mixer was used to prepare a dispersion containing phosphor particles in a dispersed state. Thoroughly stir and mix to prepare a coating solution in which the phosphor particles are uniformly dispersed, the mixing ratio of binder and phosphor is 1:20 (weight ratio), and the viscosity is 25 to 35 PS (25°C). did. This coating solution was applied on the colored light scattering layer by the same operation as above, and then dried to a layer thickness of approximately ZOO.
A V$ exhaustive phosphor phase was formed on the μ shoulder. In this manner, a comparative radiation-1 light-emitting panel consisting of a support, a colored light-scattering layer, and a stimulable phosphor phase was produced. Furthermore, by changing the layer thickness of the stimulable phosphor phase in the range of 100 to 400μ, the support, the colored light scattering layer,
Various comparative radiographic image conversion panels Q were prepared consisting of an Xl11 exhaustible phosphor phase. The radiation sensitivity and image sharpness of the comparative radiation image conversion Hennel Q were evaluated in the same manner as in Example 1, and the results are shown as curve Q in FIG. Comparative Example 3 In Example 3, various comparative samples were prepared in the same manner as in Example 1 except that they were not colored with a blue pigment, and the chemical reinforcement consisted of a lath, a light scattering layer, and a stimulable phosphor phase. radiation#
A XaEiI image conversion panel R was manufactured. The radiation sensitivity and image sharpness of the comparative radiation image conversion panel R were evaluated in the same manner as in Example 1, and the results were evaluated in the fourth example.
It is shown as curve R in the figure. As is clear from FIG. 4, the radiation image conversion panels A, B, and C of the present invention are different from the conventional radiation image conversion panels P, Q, and
Compared to R, if the radiation sensitivity is the same, the image sharpness is high; conversely, if the image sharpness is the same, the radiation sensitivity is high. [Effects of the Invention] As mentioned above, by using fine columnar crystals formed by bonding exhaustible phosphor phases and having striae in the layer thickness direction and having a frost columnar dA effect, the layer interfaces of the layers are colored. By providing a light scattering layer, it was possible to further improve both sensitivity and sharpness, which were contradictory.

[Brief explanation of drawings]

Fig. fB1 is an explanatory diagram of the phase of the stimulable phosphor of the present invention, and the same figure (,) is an electron micrograph of a layer consisting of microcrystals formed by the vapor deposition method, and the same figure (
b) is a schematic cross-sectional view showing the light directivity of the layer; 2(a) and 2(b) show examples of the shape of the layer surface on which the V$ exhaustible phosphor of the support according to the present invention is deposited, and FIG. 2(c)
and (d) shows a cross section when a stimulable phosphor phase is formed on the layer surface. FIG. 3 is a schematic diagram of the radiation conversion method employed in the present invention. ! Figure 164 shows the radiation image conversion panels of the present invention^, D, and C.
FIG. 3 is a diagram showing the relationship between relative sensitivity and image sharpness in radiation image conversion panels P, Q, and R for comparison. 21 and 22...Support 23...Tile plate Z4 and 25...Stimulable phosphor phase 27...Colored light scattering layer 26...Crack 31
...Radiation generating device 32...Subject 33.
・Radiation image conversion panel 34 ・Photostimulation excitation light source 38 ・Filter applicant Konishi Roku Photo Industry Co., Ltd. Engraving of the drawings (no changes to the contents) Figure 1 Figure 2 (a) (b) Qz, α... *! 4 claws - 11 Gensho Ki 1 Ice island 11... GB external excitation tag 12... 4 road back tag 13... ・ SaiCυhaζ・V Lord, *r Figure 3 Figure 4 Phase arc 6 Good procedure amendment June 18, 1986

Claims (5)

[Claims] (1) In a radiation image conversion panel having a light scattering layer at the interface of one of the stimulable phosphor layers, the stimulable phosphor layer has a phosphor phase formed by bonding. 1. A radiation image conversion panel comprising: a radiation image conversion panel, wherein the light scattering layer is colored with a coloring agent. (2) The radiation image conversion panel according to claim 1, wherein the light scattering layer is colored with a colorant that absorbs at least a portion of the stimulated excitation light. (3) The light scattering layer has an average reflectance of the stimulable phosphor for light in the stimulated excitation wavelength range that is smaller than an average reflectance of the stimulable phosphor for light in the stimulated emission wavelength range. The radiation image conversion panel according to claim 1 or 2, which is colored with a coloring agent. (4) Claims 1 to 3 are characterized in that the phosphor phase formed by bonding the stimulable phosphor layer has striae in the layer thickness direction. The radiation image conversion panel according to any one of. (5) The radiation image conversion panel is characterized in that the support, the light scattering layer, and the stimulable phosphor layer are laminated in this order. The radiographic image conversion panel described.