JPS61142499A - Radiation image conversion panel and manufacture thereof - 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 radiation image conversion panel that provides a highly sharp radiation image and a method for manufacturing the same. [Prior art]

Radiographic images such as XMI images are often used for disease diagnosis. This X#! In order to obtain an image, X-rays that have passed through the subject are irradiated onto a phosphor layer (fluorescent screen).
This generates visible light, which is then irradiated onto a film using silver salt to develop it, in the same way as when taking ordinary photographs, in what is called radiography. However, in recent years, methods have been devised to directly extract images from the phosphor layer without using a film coated with silver salt. In this method, the radiation transmitted through the object is absorbed by a phosphor, and then this phosphor is excited with light or thermal energy, so that the phosphor emits the radiation energy accumulated by the absorption as fluorescence. However, there is a method to detect and image these fluorescens. 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 R-excitation light. This method uses a radiation image conversion panel with a stimulable phosphor layer formed on a support, so radiation that has passed through the object is applied to the stimulable phosphor layer of this radiation image conversion panel to visualize each part of the object. A latent image is formed by multiplying the radiation energy corresponding to the radiation transmittance M, and then the radiation energy accumulated in each part is radiated by scanning this This is converted into light, and an image is obtained using 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 Miii image conversion panel having a stimulable phosphor layer used in this radiation image conversion method has a radiation absorption rate and a phosphor conversion rate (both of which are Including "radiation sensitivity" below
It goes without saying that the image quality is high, the graininess of the image is good, and the sharpness is also high. something is required. However, in a radiation image conversion panel having a stimulable phosphor layer, a dispersion containing a particulate stimulable phosphor with a particle size of about 1 to 30 μm and an organic binder is coated on a support or a protective layer.・Since it is formed by drying, the packing density of the stimulable phosphor is low (nine term ratio 50%), and in order to obtain sufficiently high radiation sensitivity, the stimulable phosphor must be used as shown in Figure 5 (turtle). It was necessary to increase the thickness of the layers. As is clear from the figure, the layer thickness of the X11-exhaustive phosphor layer is 20
At 0 μ-, the adhesion resistance amount of stimulable phosphor is 50 mg/c,
z, and the radiation sensitivity increases linearly up to a layer thickness of 350 μl and saturates above 450 μl. The reason why the radiation sensitivity becomes saturated is that when the stimulable phosphor layer becomes too thick, Elf exhaustion occurs inside the stimulable phosphor layer due to the amount of stimulable luminescence between the stimulable phosphor particles. This is because the light does not come out to the light emitting part. On the other hand, the sharpness of the image in the radiation image conversion method is as shown in FIG.
The thinner the layer thickness of the stimulable phosphor layer of the image conversion panel, the higher the sharpness, and in order to improve the sharpness, it was necessary to make the stimulable phosphor layer thinner. In addition, the graininess of the image in the radiation m* image conversion method is caused by local fluctuations of the radiation #1 quantum failure (fi quantum mottles) or structural 6L fluctuations (structural fluctuations) of the stimulable phosphor layer of the radiation #1 image conversion panel. As the layer thickness of the stimulable phosphor layer becomes thinner, the number of radiation quanta absorbed by the stimulable phosphor layer decreases and the quantum mottle increases.
) ltN structural disturbances become apparent and structural mottles increase, resulting in a decrease in image quality. Therefore, in order to improve the graininess of the image, /! of the stimulable phosphor layer is necessary. It needed 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 trends depending on the layer thickness of the stimulable phosphor layer. Said radiation image conversion panels have been discouraged by their sensitivity to radiation H and by some sacrifice in 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 light emission (light emission during radiation irradiation) of the phosphor in the fluorescent screen. Radiation using exhaustible phosphor#
! The sharpness of the image in the image conversion method is not determined by the spread of the stimulated luminescence of the stimulable phosphor in the radiation image conversion panel, but rather by the spread of the luminescence of the phosphor as in radiography. 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 stored in the radiation image conversion panel is converted into a time series. ), therefore, the stimulated luminescence due to the stimulated excitation light irradiated at a certain time (ti) is preferably fully illuminated and the image 1t(x+wy+ ), but if the stimulable excitation light spreads within the panel due to scattering etc. and also excites the stimulable phosphor that exists outside the irradiated pixel (xi + yi), the above-mentioned (xLyi) is the output from a pixel that is wider than that pixel! This is because you will be ignored. Therefore, certain II
The photostimulable fluorescence caused by the photostimulative excitation light irradiated on the fil(ti) is that the photostimulable excitation light is truly irradiated at that time (ti) and only light is emitted from the pixel (in 1tyi) on the panel. If so, the sharpness of the image obtained is not affected no matter how wide the light emission is. Under these circumstances, several methods have been devised to improve the sharpness of radiographic images.
48447, a method of mixing white powder into the stimulable phosphor layer of the radiated JtIII image conversion panel, JP-A No. 1983-
The average reflectance in the stimulated excitation wavelength region of the photostimulable phosphor of the radiation #i image conversion panel described in No. 163500 is the E
l! Exhaustible phosphor phosphor [This is a method of coloring the phosphor so that the average reflectance in the exhaustible emission wavelength region is lower than the average reflectance. However, in these methods, improving the sharpness inevitably leads to a drastic decrease in sensitivity, and therefore cannot be said to be a preferable method. On the other hand, the present applicant has already received
Radiation # using a stimulable phosphor as described above in No. 5
Ii [! ii) A radiation image conversion panel in which the stimulable phosphor layer does not contain a binder is proposed as a new radiation image conversion panel that improves the drawbacks of conventional image conversion panels. 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 is sharply improved, and the phosphor layer of the stimulable phosphor layer is also improved. Therefore, the sensitivity of the radiation image conversion panel to radiation and the graininess of the image are improved, and at the same time, the sharpness of the image is also improved. However, in the radiation image conversion method, the sensitivity,
The demand for image quality that does not impair graininess (and has excellent sharpness) is becoming more and more severe.

[Object of the Invention] The present invention relates to the above-mentioned proposed radiation image conversion panel using a stimulable phosphor, and further improves the same.
An object of the present invention is to provide a radiation #il image conversion panel that has improved sensitivity to radiation and provides images with high sharpness. Another object of the present invention is to provide a radial edge image conversion panel that provides images with improved graininess and high sharpness. Another object of the present invention in addition to the above object is to provide a method for manufacturing a radiation image conversion panel that satisfies the above object. [Structure of the Invention] The object of the present invention is to provide a radiation #! having a stimulable phosphor layer.
In the image conversion panel, a large number of micro tile-like plates distributed on the surface of the support, a #IIIA net surrounding and dividing each of the micro tile-like plates, and a #IIIA mesh extending in the thickness direction on the micro tile-like plates. The present invention is achieved by a radiation image conversion panel characterized by having a stimulable phosphor layer having a fine columnar block structure of a stimulable phosphor, and a manufacturing method for embodying the structure of the image conversion panel. Next, the present invention will be specifically explained. FIG. 1(A) is a sectional view in the thickness direction of a radiation M image conversion panel (hereinafter sometimes referred to as a panel for clarity) of the present invention. Figure (b) shows the micro tile-like plate and the #IIR net surrounding and dividing the micro tile-like plate when the stimulable phosphor layer having the fine columnar block structure is not yet provided. FIG. 6(e) is a cross-sectional view in the thickness direction of the support having only the micro tile-like plates without the ma-net provided thereon. The distribution pattern of the micro tile-like plate on the support may be arbitrary. Examples of the distribution pattern of the micro tile-like plate are shown in FIG. 2 as (a), l, (b) and (c). . Note that the same symbols in FIG. 1 and FIG. 1:IS2 are functionally synonymous with each other. In FIG. 1, 10 is a panel of the present invention, l1ij is a micro tile-like plate each having a thickness of d on the support surface, (lli
j) is a gap in the form of a crack, groove or depression surrounding the micro tile-like plate. 12ij is formed by filling the above (llij) and partitions each 1lij with #! of height h.
I#! 1512 rope rice, and it is preferable that h≧d. 13ij is each fine columnar block of stimulable phosphor deposited on the fine tile plate 11ij, (13i
j) is the gap between the thin columnar blocks 13ij. 13
111 exhaustive phosphor 1f having a fine columnar block structure according to the present invention by ij and (13ij)! i13 is formed. 15 is a protective layer that is preferably provided. 14 is a support. The average diameter of the micro tile-like plate 11ij is 1 to 400μ.
llij is preferred, and the average gap (llij) is 0.
It is preferable that it is 01 to 20 μ-. The thickness of the stimulable phosphor 7113 varies depending on the sensitivity of the panel to radiation, the type of stimulable phosphor, etc.
It is preferably 1000μ, and more preferably 20 to 800μ. Incidentally, the gap (13ij) referred to in the present invention includes the case where the surface of the stimulable phosphor layer is merely a crack that does not provide a substantial gap.Therefore, the fine columnar block structure includes a fine polygonal pyramidal block. Contains structure. Further, an adhesive layer for assisting the adhesion of the stimulable phosphor, or a reflective layer or an absorbing layer for stimulated excitation light and/or stimulated luminescence may be provided on the micro tile-like or V-wire network, if necessary. It's okay. Based on the above-mentioned stimulable phosphor layer having a fine columnar block structure that is optically independent from each other! - When the excitation light is incident, the excitation light is repeatedly reflected on the inner surface of the columnar block due to the light guiding effect of the fine columnar block structure, and does not dissipate to the outside (reaching the bottom of the columnar block and being absorbed, or It is reflected and exits in the columnar direction of the columnar block while repeating reflection on the inner surface of the columnar block.Therefore, the sharpness of the image due to stimulated luminescence is steadily increased while increasing the chance of stimulated excitation.Radiation image of the present invention In a conversion panel, a stimulable phosphor is a phosphor that is first irradiated with light or high-energy radiation and then stimulated (stimulated excitation) thermally, mechanically, chemically, or electrically. It refers to a phosphor that exhibits stimulated luminescence corresponding to the irradiation amount of light or high-energy radiation, but from a practical standpoint, it is preferably a phosphor that exhibits stimulated luminescence with stimulated excitation light of 500 n- or more. 1. The stimulable phosphor used in the radiation image conversion panel of the present invention is, for example, BaSO4:AX (where A is Dy, Tb and V T
The least of m (both are one type, X is o, oot≦x
<1 mol%. ) Phosphor represented by C, JP-A-48-
Mg5Q described in No. 80488, :Ax (where A is either HO or ν1, and 0.001≦X≦1
Phosphor expressed as mol%), JP-A-48-804
SrS○, which is described in No. 89 and has ν:A x (However, A
is at least one of D y t T b and Tl11
The species X is 0.001≦×1 mol%. ), Na2SO+-CaSO4 and VBI described in JP-A-51-29889
At least one of Mn, Dy and Tb in LS 04 etc.
Phosphor with added seeds, described in JP-A No. 52-30487
BeO, LiF MgSO< and Ca
Phosphors such as Fz, described in Japanese Patent Application Laid-Open No. 53-39277 a
L i 2 B 40 : Cu IAg
phosphors such as those described in Japanese Patent Application Laid-Open No. 54-47883 (
Lizo ・(B 202)X:Cu(IushiX
is 2<x≦3), and L izo ・(B 20 z)
x: Cu+Ag (where x is 2×≦3)′:! SrS:Ce, Sm, SrS:Eu, Sm, t,
a2o2S: EuwS- and (Z n t Cd )
Examples include a phosphor represented by S: M n + X (where X is /10 den). Also, JP-A-55-12
ZnS:Cu, Pb phosphor described in No. 142,
A barium aluminate phosphor whose general formula is represented by B ao ・xA 1,0 *:E u (however, 0.8≦X≦10), and a barium aluminate phosphor whose general formula is M ” O・xS io 2:A
(However, Ml is Mg+CavSr=Zn, Cd or Ba, A is Ce-Tb, Eu. TmtPbtTI, at least one of Bi and Mn, and X is 0.5≦X≦2. 5) is mentioned. Also, the general formula is (Bi Mg Ca )FX:eEu”1
-x-yxy (where X is at least one of Br and CI,
X+F and e are respectively O'<x+y≦o, e, xy≠
0 and 101≦e≦5X10-”) is described in JP-A-55-12144.The general formula is L no X : xA (However, Ln is at least one of La, Y, Gd and Lu,
b is a number satisfying 0<x<0.1), the general formula described in JP-A-55-12145 is S rt Z at least one of n and Cd, X at least one of CI, Br, and engineering; A is EutTbtCe+T
mtDy+PrtHo+Nd, at least one of Yb and Er, where X and y are 0≦X≦0.6 and 0≦y
The general formula for the phosphor represented by ), which represents a number satisfying the condition of ≦0.2, is BaFX:xce*yA (where X is CI, Br, and At least one of A is I n, T I, Gd
, 8 wheels, and at least one of Zr, and X and y are 0<x≦2X10-' and O<7≦5X, respectively.
10-” phosphor represented by ), JP-A-55-1
The general formula described in No. 60078 is MxFX-xA
:yLn (However, Ml is M gt Ca+ B at S re
At least 1!11 of Z n and Cd, A is B
e Os M g Ot Ca Ov Sro *B
to-ZnO, A I20 z-Y *02-LazO
x-I n20 sts io ztT io ztZ
ro ztGeo,, S no ,, N b. 0, at least one of TazOs and VThoz!
11, Ln is E, Tb, Ce, TmtDytPrtHo
, Nd, Yb5ErtS theory, and Gd (both are one type, X is at least one type of CI, Br, and I, and X and y are each 5 X 10-'≦X
This number satisfies the conditions of ≦0.5 and VO<y≦0.2. ) A rare earth element-activated divalent metal fluorohalide phosphor with the general formula ZnS:A-(ZnwCd)S
:A, CdS :A%ZnS :A, X and (/CdS
: A, X (where A is Cu v A g t A u or Mn, and X is a halogen). phosphor, general formula (1) or (II) described in JP-A-57-148285, general formula (1) x? 1 (PO4)z'NXz:yA
General formula (II) Mko(PO,)!・yA (where M and N are Mg, Ct, Sr, BatZn, respectively)
and (/Cd, X is F, CI. At least one of Br+ and I, A is Eul T
beCetTmtDytPrtHo*NdtErtS
b* Represents at least one of TlvMn and Sn;
Further, X and Vy are numbers that satisfy the condition 0<x≦6.0≦y≦1. ), a phosphor represented by general formula (III)
or (■) general formula (I[[) nReX5・+*A
X'2:xEu general formula (IV) nReX3・mA
X'2: xEu, ysm (wherein, Re is La, Gd, Y
, at least one of Lu, A is an alkaline earth metal,
At least one of Ba, Sr, and Ca, X and rlX'
I! F, CI, B "Represents at least one of the following,
Moreover, X and y are lXl0-'<x<3
0-', IX 10-'<y< IX
It is a number that satisfies the condition of 10-1, and n/+s is I
10-'<n/items<7X10-'), and the general formula %: It is a kind of alkali metal, and MX is B
erMg*CawSryBatZn*CdyCu and N
At least one divalent metal selected from i is Sc, Y, La, Ce, Pr, Nd, Pm, Ss, E
u, Gd, Tb. Dy, Ho, ErtTstYb, Lu, A'l, Ga,
and In, XtX' and X'' are at least one type of halogen selected from F, CI, Br, and 1/I. A is Eu,
TbtCetTmtDytPrtHotNd, Yb5E
rtS theory, LuwS+*tYtTl+Na+Ag+Cu
and M. Also, a is a numerical value in the range of O≦a<0.5, and b is a value in the range of O≦b
C is a numerical value in the range of <o, s, and C is a numerical value in the range of 0<c≦0.2. ) and the like can be mentioned. In particular, alkali halide phosphors are preferred because they facilitate the formation of a stimulable phosphor layer by methods such as vacuum evaporation and sputtering. However, the stimulable phosphor used in the radiation #I image conversion panel of the present invention is not limited to the above-mentioned phosphor, and when irradiated with radiation and then irradiated with stimulable excitation light, the stimulable phosphor emits stimulable fluorescence. Any phosphor may be used as long as it shows the phosphor. The radiation image conversion panel of the present invention may be a stimulable phosphor layer group consisting of one or more stimulable phosphor layers containing at least one kind of the above-mentioned stimulable phosphors; The stimulable phosphors contained in each stimulable phosphor layer may be the same or different. In the radiation #1 image conversion panel of the present invention, various polymeric materials, deposits, etc. can be used as the support. Particularly in terms of handling as an information recording material, it is preferable that the flexible sheet or paper 1 be one that can be processed with a web plate.From this point of view, example 1! Plastic films such as cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film, aluminum, iron + Wg
A metal sheet made of chromium 1 or the like or a metal sheet having a coating layer of the metal oxide is preferred. The layer thickness of these supports varies depending on the material of the support used, but is generally 80 μII to 1000 μ-II.
from the viewpoint of handling, more preferably 80 μ-
~500μ-. The radiation R image conversion panel of the present invention generally includes the above-mentioned 1! The stimulable phosphor layer group is physically present on the surface exposed to the stimulable fluorescent light. It is preferable to provide llFM. This protective layer may be formed by directly applying a coating solution for the protective layer on the stimulable phosphor layer. Cellulose acetate may be used as a material for the protective WIN layer on the exhaustible phosphor layer. Typical protective layer materials such as Nitrocellulose, polymethyl methacrylate, polyvinyl butyral, polyvinyl reformal, carbon 17 carbonate, polyester, polyethylene terephthalate, polyethylene, vinyl chloride + 7 densine, nylon, etc. It will be done. Moreover, this protective layer can be formed by vacuum evaporation method, snow (lid method, etc.), S iC=S io z*s iN , A I20
- It may be formed by laminating inorganic substances such as 1° These hold, l! The layer thickness is general moss 0.1μ~10
Preferably around 0μ theory. Next, one trick ν1 of the panel manufacturing method of the present invention will be explained. The present invention is shown in FIG.
The manufacturing process proceeds in this order. Step (C): Micro tile-like plate 11ij and gap (11i
Distribution pattern D The stimulable phosphor is distributed on the surface of a support such as a plastic film, a metal sheet, or a metal sheet with a metal oxide coating layer, and the surface of the micro tile-like plate is deposited thereon in a subsequent step. Preferably, it is a dielectric material or semiconductor material that has good adhesion affinity with the material and has electrical ground detectability.
Therefore, one method is to meet the above conditions and coat the surface of the support with various resist resins commonly used in photolithography that can form the distribution pattern. In this case, if a metal sheet having a metal oxide coating layer is used as the support, it will have good adhesion affinity with the resist resin. Techniques for laminating metal oxides on metal surfaces, which are commonly used in the technical field of
Physically, an RF ion plating method, an RF sputtering method, a vacuum evaporation method, or the like can be used. As the resist resin, various positive and negative type renost resins such as 7 otoresist, deep ultraviolet ray nost, and electron beam resist t x si resist can be used. For example, 7
Otrenostok (as a fat, esterification reaction of lotus 7/n 7note or benzoquin/an azide to Nopopok resin is mentioned.) First, apply the renost resin to a support and form a micro tile-like plate pattern. By baking, developing, and etching using a wet or dry method to a depth where the surface of the support is exposed, a desired distribution pattern layer 11 of fine tile-like plates and gaps can be obtained. When using an aluminum plate as a support in addition to the photolithography method using photolithography, it is possible to easily create a micro tile-like plate by sealing the porous aluminum oxide produced on the surface by anodizing, followed by heat treatment. The method applied to the present invention is a method commonly used in the field of aluminum surface treatment technology.The anodizing treatment of the surface of the aluminum support can be performed, for example, with a The side of the thick aluminum plate on which the stimulable phosphor is to be deposited is soaked in an 8% oxalic acid solution for about 2 hours.
When a current of A/cm' is applied, an anodic oxidation coating layer made of porous fluorite oxide is formed. Next, the coating layer is washed with water and then boiled in boiling water for about 1 hour, so that the porous aluminum oxide absorbs crystal water and expands to form a coating layer consisting of dense crystals. This operation is the so-called sealing process. When heat treatment is performed at 250° C. or higher after the sealing treatment, the aluminum oxide containing the crystal water loses the crystal water and forms seed lines, forming micro tile-like plates surrounded by gaps created by shrinkage cracks and isolated from each other. A putter is formed that looks like it has been smeared off the pad. At this time, the thickness of the aluminum oxide coating layer is preferably several μm or more, and if it is thin, the micro tile-like plate tends to be very light, so it is necessary to optimally select the conditions for the anodization process. In this way, the vapor phase deposition of the stimulable phosphor is
Or a chemically favorable island-like micro-section [1 (tile-like plate) surrounded by fine streaks, grooves, depressions or cracks in which vapor phase deposition is difficult to progress can get. Step (b): $I#l is constructed by surrounding each of #I wire net 1 and 2 micro tile-like plates 11ij with 1M12ij and filling the gap (llij).
The material for the net 12 is preferably a material with different exhaustible fluorescent phosphor conditions and/or different physical properties such as thermal expansion. Practically speaking, metal is preferable. For example, it is created by a known electroplating method. Therefore, when a dielectric plastic is used as a support, a conductive layer of metal or indium oxide or the like is provided on the surface by vacuum evaporation or other method, and the above step (c) is carried out, and the conductive layer is exposed by etching. I need to let it happen. The same applies to the case of receipts containing metal oxide-covered M chips. The support under the above conditions is subjected to air plating in a conventional manner to form a thin mesh 12 made of, for example, nickel or chromium. At this time, in order to conveniently deposit the stimulable phosphor as fine columnar blocks on the micro tile-like plate 11ij, the brightness h of the thin wire 12ij of the thin wire lAl2 is determined by the thickness d of the micro tile-like plate from the surface of the conductive support. It is better if it is greater than or equal to . Step (t): XIII stimulable phosphor layer 13 having a fine columnar block structure As a method for forming the stimulable phosphor layer having a fine columnar block structure, a vapor deposition method is used to ensure the formation of the columnar blocks. It is most preferable from the viewpoint of performance and sensitivity. A first method of vapor phase deposition is a vacuum evaporation method. In this method, first, the support is placed in a vapor deposition apparatus, and then the inside of the apparatus is evacuated to a vacuum level of about 10-'Torr.6 Next, at least one of the stimulable phosphors is resistance heated. The stimulable phosphor is deposited on the surface of the support to a desired thickness by heating and emitting it by a method such as a method or an electro-a beam method. As a result, a stimulable phosphor layer containing no binder is formed, but it is also possible to form the stimulable phosphor layer in multiple steps in the vapor deposition process. 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, a protective layer is optionally provided on the side of the stimulable phosphor layer opposite to the support, and the radiation image conversion panel of the present invention is manufactured. Note that a step may be taken in which the support is provided after forming the stimulable phosphor layer on the protective layer. In addition, in the vacuum evaporation method, the stimulable phosphor raw material is codeposited using a plurality of resistance heaters or an electron beam, and the desired stimulable phosphor is synthesized on the support while the stimulable phosphor is simultaneously evaporated. It is also possible to form a phosphor layer. Furthermore, in the vacuum evaporation method, the object to be evaporated (support or protective layer) may be cooled or heated as necessary during evaporation, or the stimulable phosphor layer may be heat-treated after evaporation. Good too. A second method is a sputtering method. In this method, like the vapor deposition method, the support is placed in a sputtering device, the inside of the device is once evacuated to a vacuum level of about 10-' Torr, and then a non-containing gas such as Ar or Ne is used as a sputtering gas. Activated γ gas is introduced into the sputtering equipment and heated to 10-'Tor.
The gas pressure is set to about r. Next, the stimulable phosphor is made tarded and sputtered to deposit the stimulable phosphor on the surface of the support to a desired thickness. In the sputtering process, it is possible to form the stimulable phosphor layer in multiple steps as in the vacuum evaporation method, or it is possible to form the stimulable phosphor layer in multiple steps at the same time by using multiple terded layers each made of a different stimulable phosphor. Alternatively, it is also possible to form a stimulable phosphor layer by sequentially sputtering the tarded materials. After the sputtering is completed, a protective layer is preferably provided on the opposite side of the stimulable phosphor layer from the support side, if necessary, similarly to the vacuum evaporation method, and the radiation image conversion panel of the present invention is manufactured. Note that a step may be taken in which the support is provided after forming the stimulable phosphor layer on the protective layer. In the sputtering method, a plurality of stimulable phosphor raw materials are used as a target and sputtered simultaneously or sequentially to synthesize the desired stimulable phosphor on a support and at the same time produce stimulable phosphor. It is also possible to form a body layer. In addition, in the sputtering method, 02
．． Reactive sputtering may be performed by introducing a gas such as H2. Furthermore, in the sputtering method, the material to be deposited (support or protective layer) may be cooled or heated as necessary during sputtering, and the stimulable phosphor layer may be heat-treated after sputtering. Good too. A third method is the CVD method. This method involves decomposing a target photostimulable phosphor or an organometallic compound containing a photostimulable phosphor raw material with energy such as heat or high-frequency power, thereby producing a photostimulable material on a support that does not contain a binder. Obtain a fluorescent phosphor layer. FIG. 3 (,) shows t! corresponding to the unit thickness of the stimulable phosphor layer of the radiation image conversion panel of the present invention obtained by the vapor deposition method. ! [This shows an example of the relationship between the amount of attached exhaustible phosphor and radiation sensitivity. Since the stimulable phosphor layer formed by the vapor deposition method according to the present invention does not contain a binder, the adhesion resistance (filling rate) of the stimulable phosphor is lower than that of the conventional stimulable phosphor coated layer. The thickness of the stimulable phosphor layer is approximately twice that of the stimulable phosphor layer, and the radiation absorption rate per unit thickness of the stimulable phosphor layer is improved, resulting in high sensitivity to radiation and improved graininess of the image. Furthermore, the l*exhaustible phosphor layer formed by the vapor deposition method has excellent transparency, and has high transmittance to stimulated excitation light and stimulated luminescence.
A by conventional coating method! It is possible to increase the thickness of the exhaustible fluorescent phosphor layer, resulting in higher sensitivity to radiation. An example of the sharpness of the panel of the present invention having a stimulable phosphor layer with a fine columnar block structure obtained as described above is shown in the third example.
Shown in Figure (b). Due to the light guiding effect of the fine columnar block structure, the panel of the present invention exhibits the characteristics of conventional panels because the stimulated excitation light is repeatedly reflected on the inner surface of the columnar block and is less likely to be dissipated outside the columnar block! @5 As is clear from the comparison with Figure (b), it is possible to improve the sharpness of the image and to reduce the decrease in sharpness due to an increase in the layer thickness of the stimulable phosphor. The radiation image conversion panel of the present invention is schematically shown in FIG.
Provides excellent sharpness, graininess and sensitivity. That is, in FIG. 4, 41 is a radiation generating device. 42 is a subject, 43 is a radiation image conversion panel of the present invention,
44 is a stimulated excitation light source, 45 is a photoelectric conversion device that detects stimulated luminescence emitted from the radiation am image conversion panel, and 46 is a device that reproduces the signal detected by 45 as an image.47 is a device that reproduces the reproduced image. The display device 48 is a filter that separates stimulated excitation light and stimulated luminescence and allows only stimulated luminescence to pass through. Note that the elements after 45 are not limited to the above, as long as they can reproduce the optical information from 43 as an image in some form.As shown in FIG. 4, the radiation from the radiation transmission image fi41 Radiation enters the #lW image conversion panel 43 of the present invention through the subject 42. This incident radiation is absorbed by the stimulable phosphor layer of the radiation #1 image conversion panel 43, and its energy is accumulated to accumulate a radiation transmission image. The radiation image conversion panel 43 of the present invention has a stimulable phosphor layer, in which an image is formed, and this accumulated image is excited with the stimulable excitation light from the stimulable excitation light source 44 to emit it as tIII stimulated luminescence. has a fine columnar block structure, which suppresses the photostimulation excitation light from diffusing in the stimulable phosphor layer during scanning with the above-mentioned ll! exhaustion excitation light.Emitted photostimulation Since the strength of the light emission is proportional to the amount of accumulated radiation energy, this optical signal is photoelectrically converted by a photoelectric conversion device W145 such as a photomultiplier tube, and the image reproduction device i
46 as an image and displaying it on the image display device 47.

【Example】

Next, the present invention will be explained by examples. Example 1 A 500 .mu.-thick aluminum plate was anodized, sealed and heated by the method described above to obtain a surface structure in which the tile-like plates were separated from each other by fine grooves and packed together. The average diameter of the tile-like plate is 63μ, and the thickness d is 10
It was mu. Subsequently, the aluminum plate subjected to the above treatment was nickel plated to form a #1 wire network that surrounded the micro tile-like plates and partitioned them, and was used as a support. The height h of the fine wire network was 16μ. Next, this support was placed in an evaporator, and the alkali-11-ride stimulable phosphor (
0.9RbB r ・0. ICsF: 0. OIT I
) and set it on the resistance heating electrode, and then the evaporator was evacuated to a degree of vacuum of 2×10-' Torr. Next, a current was applied to the tungsten board, and the alkali/1-ride stimulable phosphor was evaporated using the resistance heating method. The thickness of the stimulable phosphor layer on the support is 300 μm.
The radiation image conversion panel A of the present invention was obtained by depositing until the thickness reached -. After irradiating the thus obtained radiation image conversion panel A of the present invention with X-rays at a tube voltage of 80 KVp using Ion R,
Stimulated excitation is performed using He-Ne laser light (633 nm), and the stimulated luminescence emitted from the stimulable phosphor layer is photoelectrically converted by a photodetector (photomultiplier tube), and this signal is converted into an image by an image reproducing device. It was then reproduced and recorded on silver halide film. The sensitivity of the radiation image conversion panel A to X#1 was investigated based on the signal magnitude, and the modulation transfer function (MTF') and graininess of the image were investigated from the obtained images, which are shown in Table 1. In Table 1, the sensitivity to X Rl: H is shown as a relative value, with the #iii image conversion panel A of the present invention being taken as 100. *The modulation transfer amount fi (MTF) is the value when the spatial frequency is 2 cycles/lll1, and the granularity is (
Good, average, bad) are indicated by (○, Δ+X), respectively. Example 2 In Example 1, the layer thickness of the stimulable phosphor layer was changed to 150 μ-
A radiation image conversion panel B of the present invention was obtained in the same manner as in Example 1 except for the following. The thus obtained radiation image conversion panel B of the present invention was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Example 3 In Example 1, the average diameter of the tile-like plate of the support was 11
A radiation image conversion panel C of the present invention was obtained in the same manner as in Example 1, except that the 5 μm paste was used. The radiation image conversion panel C of the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Example 4 In Example 1, the thickness h of the fine wire network of the support was 11 μI.
A radiation image conversion panel D of the present invention was obtained in the same manner as in Example 1 except for the following. The radiation image conversion panel D of the present invention was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Example 5 In Example 1, an aluminum plate with a thickness of 500 μm was treated as a support in the same manner as in Example 1 to form an arm net that surrounded and partitioned the microtiles on the surface of the aluminum plate. After that, remove the metal aluminum to 0
．． A radiation #tm image conversion panel E of the present invention was obtained in the same manner as in Example 1, except that a support was vacuum-deposited to a thickness of 1 μm. By depositing metal aluminum thinly in this manner, the surface of the tile-like plate of the support is blackened. The radiation image conversion panel E of the present invention was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Example 6 In Example 1, an aluminum plate with a thickness of 500 μm was treated as a support in the same manner as in Example 1, and the micro tile-like plates on the surface of the aluminum plate were surrounded and partitioned. ! The radiation #Il image conversion panel F of the present invention was prepared in the same manner as in Example 1, except that after forming, metal aluminum was vacuum-deposited to a thickness of 1μ+1.
I got it. By depositing metal aluminum thickly in this way, the reflectance of the tile-like plate surface of the support is approximately 20%.
Improved. The radiation image conversion panel F of the present invention was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Example 7 In Example 1, 7 Otrenost resin was applied to a 500 μM thick aluminum plate as a support. A radiation image conversion panel of the present invention was obtained in the same manner as in Example 1, except that the pattern of the micro tile-like plate was printed, developed, and further dried to form a micro-tile-like plate. The size of the micro tile-like plate was a square of 100 μA on each side, and the thickness d was 10 μA. Also, the width of the gap is 10μ. Met. The thus obtained radiation #X image conversion panel G of the present invention was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Comparative Example 1 Alkali halide stimulable phosphor (0,9RbBr・0,
ICsF: 00OIT l) 8 parts by weight and I for polyvinyl butyral! ′! ? 1 part by weight and 5 parts by weight of a solvent (cyclohexanone) were mixed and dispersed to prepare a coating solution for a stimulable phosphor layer.This coating solution was then placed horizontally. It was coated uniformly on a black polyethylene naphthalate film as a support with a thickness of 300 μm and air-dried for 30 μm.
A 0 μ-thick stimulable phosphor layer was formed. Comparative radiation image conversion panel P obtained in this way
was evaluated in the same manner as in Example 1, and the results are also listed in Table 1. Comparative Example 2 A comparative radiation image conversion panel Q was obtained in the same manner as in Comparative Example 1 except that the thickness of the stimulable phosphor layer was increased to 150 μm. Comparative radiation mg image conversion panel Q obtained in this way
were evaluated in the same manner as in Example 1, and the results are shown in Table 1. As is clear from Table 1, radiation image conversion panels A to G of the present invention were compared to the comparative radiation image converting panels A to G having corresponding photostimulable phosphor layer thicknesses.
1 Image conversion panel P. Compared to Q, the X#i sensitivity was about twice as high, but the image graininess was excellent. This is because the radiation image conversion panel of the present invention does not contain a binder in the stimulable phosphor layer, and the filling rate of stimulable phosphor is higher than that of comparative panels, and the X-ray absorption rate is good. It is. In addition, the radiation Mll image conversion panels A to G of the present invention are sharper despite having higher X#I sensitivity than comparative radiation image conversion panels P and Q having corresponding stimulable phosphor layer thicknesses. They were also superior in terms of sex. This is the radiation 114. of the present invention. In the M image conversion panel, cracks are created in the stimulable phosphor layer due to the gaps in the support, and this causes t! This is because the i-stimulable phosphor layer is made into a fine columnar block structure in which it is subdivided, and the dispersion of the He-Ne laser, which is the stimulable excitation light, in the stimulable phosphor layer is suppressed and reduced. . Effects of the Invention 1 As mentioned above, according to the present invention, since the stimulable phosphor layer has a fine columnar block structure, the diffusion of 8L of the stimulable excitation light in the stimulable phosphor layer is reduced. The sharpness of the image can be significantly reduced, resulting in improved image sharpness. Furthermore, according to the present invention, the decrease in image sharpness due to an increase in the stimulable phosphor layer is small, so by increasing the stimulable phosphor layer, radiation sensitivity can be increased without reducing image sharpness. It is possible to improve. Further, according to the present invention, the decrease in image sharpness due to an increase in the stimulable phosphor layer is small, so by increasing the stimulable phosphor layer thickness, the image sharpness can be improved without decreasing the image sharpness. It is possible to improve graininess. Further, according to the present invention, it is possible to stably manufacture the radiation image conversion panel of the present invention at low cost. The present invention has extremely great effects and is industrially useful.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of the support surface during the manufacturing process of the radiation image conversion panel and V51 of the present invention. FIG. 2 is a plan view showing an example of the distribution pattern of the micro tile-like plates. FIG. 3(,) is a diagram showing the stimulable phosphor layer thickness, adhesion resistance, and sensitivity to radiation in a radiation image conversion panel according to an example of the present invention, and FIG. 3(b) is a diagram showing the radiation sensitivity in the radiation image conversion panel. FIG. 2 is a diagram showing an exhaustible phosphor layer and a solar transfer function (MTF). FIG. 4 is a schematic diagram of the radiation #lH image conversion method used in the present invention.
Figure (a) is a diagram showing the photostimulable phosphor layer and adhesion resistance in the conventional radiation #i [image conversion panel] and sensitivity to radiation, and (b) is a diagram showing the sensitivity to radiation in the conventional radiation #1iii image conversion panel. The thickness of the stimulable phosphor layer, the adhesion resistance, and the spatial frequency are modulated by 2 cycles/temperature (MTF).
). 10... Panel 11... Distribution pattern layer 11ij... Micro tile-like plate (llij)... Gap 12... Fine R mesh 12ij... Wire 13... Stimulable phosphor layer 13ij... Fine columnar block 14... Support 15... Protective layer agent Patent attorney Field 1)a Parent Fig. 1 Fig. 2 Fig. 3 0 200 40
0 Ivy 74ζn-n Figure 4 Figure 5 (b) Procedural amendment March 14, 1985

Claims (1)

[Scope of Claims] 1) In a radiation image conversion panel having a stimulable phosphor layer on a support, a large number of micro tile-like plates and thin lines surrounding and dividing each of the micro tile-like plates are provided. 1. A radiation image conversion panel comprising a net and a stimulable phosphor layer having a fine columnar block structure of stimulable phosphor extending in the thickness direction on the micro tile-like plate. 2) In a method for producing a radiation image conversion panel having a stimulable phosphor layer, a large number of micro tile-like plates and a fine wire network surrounding and dividing each of the micro tile-like plates are formed on the support surface. A method for manufacturing a radiation image conversion panel, further comprising depositing a stimulable phosphor on the micro tile-like plate in the thickness direction and stretching the stimulable phosphor to form a stimulable phosphor layer having a fine columnar block structure.