JPH06100680B2 - Radiation image conversion panel manufacturing method - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a radiation image conversion panel using a stimulable phosphor, and more particularly to a method of manufacturing a radiation image conversion panel having high sensitivity to radiation.

[Conventional background]

Radiation images such as X-ray images are often used for disease diagnosis. In order to obtain this X-ray image, X-rays that have passed through the subject are irradiated onto the phosphor layer (fluorescent screen), thereby generating visible light, and this visible light is used in the same way as when taking a normal photograph. A so-called radiograph in which a film using salt is irradiated and the film is developed is used. However, in recent years, a method of directly taking out an image from the phosphor layer without using a film coated with silver salt has been devised. As this method, the radiation that has passed through the subject is absorbed by the phosphor, and then the phosphor is excited by, for example, light or thermal energy so that the radiation energy accumulated by the absorption by the phosphor is emitted as fluorescence. , There is a method of detecting this fluorescence and imaging. Specifically, for example, U.S. Pat. No. 3,859,527 and JP-A-55-1214.
No. 4 discloses a radiation image conversion method using a stimulable phosphor and using visible light or infrared light as stimulated excitation light. This method uses a radiation image conversion panel in which a stimulable phosphor layer is formed on a support, and the radiation that has passed through the subject is applied to the stimulable phosphor layer of this radiation image conversion panel to apply the radiation to each part of the subject. A latent image is formed by accumulating the radiation energy corresponding to the radiation transmittance, and thereafter, the stimulable phosphor layer is scanned with stimulable excitation light to radiate the accumulated radiation energy of each part to generate a latent image. Convert it to light,
An image is obtained by an optical signal depending on the intensity of this light. This final image may be played back as a hard copy or on a CRT. Also in a radiation image conversion panel having a stimulable phosphor layer used in this radiation image conversion method, high radiation sensitivity and good image graininess as in the radiographic method using the fluorescent screen described above, and Image sharpness is required to be high. However, in the radiation image conversion panel and the fluorescent screen, the high radiation sensitivity of the radiation image conversion panel means that the radiation energy has a high efficiency of absorbing and accumulating so that the radiation energy can be stimulated and emitted later by the excitation light. The high radiation sensitivity of the fluorescent screen means that the efficiency of converting the radiation energy into light is high, and the absorption of radiation energy reduces the amount of conversion into light immediately. There are different natural laws. Regarding the radiation sensitivity of the radiation image conversion panel, a radiation image conversion panel having a conventional stimulable phosphor layer supports a dispersion liquid containing a granular stimulable phosphor having a particle size of about 1 to 30 μm and an organic binder. Since it is created by coating on the body or protective layer and drying, the filling density of the stimulable phosphor is low (filling ratio 50%), and the layer thickness of the stimulable phosphor layer is sufficient to increase radiation sensitivity. Had to be thicker. On the other hand, the sharpness of the image in the radiation image conversion method tends to be higher as the layer thickness of the stimulable phosphor layer of the radiation image conversion panel is smaller. It was necessary to thin the luminescent phosphor layer. Further, the graininess of the image in the radiation image conversion method is determined by the spatial fluctuation of the radiation quantum number (quantum mottle), the structural disorder of the stimulable phosphor layer of the radiation image conversion panel (structural mottle), or the like. Therefore, as the layer thickness of the stimulable phosphor layer becomes thinner, the number of radiation quantum absorbed in the stimulable phosphor layer decreases and the quantum mottle increases, or structural disorder becomes apparent and the structure mottle increases. As a result, the image quality is degraded. Therefore, in order to improve the graininess of the image, the stimulable phosphor layer needs to be thick. That is, as described above, in the conventional radiation image conversion panel, the sensitivity to radiation and the graininess of the image, and the sharpness of the image show the opposite tendency to the layer thickness of the stimulable phosphor layer. The radiation image conversion panels have been made at the trade-off between radiation sensitivity and some degree of graininess and sharpness. Regarding the difference between the fluorescent screen and the radiation image conversion panel described above, the sharpness of the image in the radiographic method depends on the instantaneous light emission of the phosphor in the fluorescent screen (light emission during irradiation).
It is well known that it is determined by the spread of
On the other hand, the sharpness of the image in the radiation image conversion method using the stimulable phosphor described above is not determined by the spread of the stimulated emission of the stimulable phosphor in the radiation image conversion panel, that is, the radiation There is also the difference that it is not determined by the spread of the emission of the phosphor as in the photographic method, but is determined by the spread of the stimulated excitation light in the panel. This difference is that in the radiation image conversion method, since the radiation image information accumulated in the radiation image conversion panel is taken out in time series, the stimulated emission due to the stimulated excitation light irradiated at a certain time (ti) does not occur. It is recorded as the output from the pixels (xi, yi) on the panel that were all illuminated and stimulated by excitation light at that time, but if the excitation light is scattered in the panel, etc. If the stimulable phosphor existing outside the irradiation pixel (xi, yi) is also excited, the output from the pixel (xi, yi) above will be recorded as the output from the pixel above (xi, yi). Due to Therefore, the stimulated emission due to the stimulated excitation light irradiated at a certain time (ti) is changed to the pixel (xi, y) on the panel that was actually irradiated with the stimulated excitation light at that time (ti).
If only the light emitted from i) has any spread, the sharpness of the obtained image will not be affected. Under these circumstances, some methods have been devised to improve the sharpness of radiographic images. For example, JP-A-55-14644
No. 7, a method of mixing a white powder in the stimulable phosphor layer of the radiation image conversion panel, the radiation image conversion panel described in JP-A-55-163500, the stimulable excitation wavelength region of the stimulable phosphor And the like so that the average reflectance in the above is smaller than the average reflectance in the stimulated emission wavelength region of the stimulable phosphor. However, these methods are not preferable methods because the sensitivity inevitably decreases remarkably when the sharpness is improved. In view of the above-mentioned drawbacks and reciprocity between properties, the present applicant discloses a radiation image conversion panel containing no binder in the stimulable phosphor layer and a method for producing the same in JP-A-59-196365. is suggesting. According to this, since the stimulable phosphor layer of the radiation image conversion panel does not contain a binder, the filling rate of the stimulable phosphor layer is significantly improved and the stimulable excitation light of the stimulable phosphor layer is also increased. Further, the directivity of stimulated emission is improved, 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 improved. Now, the radiation image conversion panel not containing the binder can be manufactured by various vapor phase deposition methods such as a sputtering method, a CVD method and a vapor deposition method, but the vapor deposition method is the most preferable method in consideration of the production cost and the like. Can be said. However, when the stimulable phosphor layer is formed by a resistance heating method that is generally performed in the vapor deposition method, a plurality of substances constituting the stimulable phosphor for a certain crucible temperature, the vapor pressure is different, A substance having a higher vapor pressure is preferentially evaporated. Therefore, the composition of the stimulable phosphor layer formed on the support does not match the composition of the stimulable phosphor charged in the crucible, and the sensitivity to radiation of the radiation image conversion panel is reduced, which is a serious drawback. It became clear that there is. That is, the method of vapor-depositing the stimulable phosphor brings various advantages as described above, but by degrading the vaporization condition of the phosphor when forming a layer of the stimulable phosphor, Fall into a big trap. For example, according to the research of the present inventors regarding the RbBr: Tl stimulable phosphor using Tl as an activator, the emission intensity of the phosphor is 6th.
Is Tl content as shown in FIG its composition ratio as 10 ^-2 ~10 ⁰ mol% of In the range instantaneous light emission intensity is constant and as long as common phosphor Tl content is Osamu' constant width You don't have to be very careful about it. However, the stimulated emission that controls the death of the radiation image conversion panel according to the present invention has a peak at around 3 × 10 ^-2 mol%, and the intensity is greatly reduced before and after that. Therefore, when vapor-depositing a stimulable phosphor by a vapor deposition method or the like, the vapor pressures of the activator and the stimulable phosphor matrix are different from each other. When the activator is vapor-deposited on the panel support before or behind the phosphor matrix and the activator concentration varies in the thickness direction in the stimulable phosphor layer and deviates from the optimum concentration, The purpose of imparting the desired activity is to cause the symptoms of poisoning by the activator. By the way, the vapor pressure of RbBr shows 1mmHg at 777 ℃ and Tl.
Br exhibits 10 mmHg at 522 ° C and has a large difference in vapor pressure. I have no interest in this point, and I often see examples of activating stimulable phosphor layers that have poor performance despite the optimum activator concentration overall.

[Object of the Invention]

The present invention relates to the above-mentioned proposed method for producing a radiation image conversion panel using a stimulable phosphor, and further improves the method. The object of the present invention is to prepare a stimulable phosphor composition and to prepare it. The present invention provides a method for producing a radiation image conversion panel which has a composition substantially equal to that of the stimulable phosphor and is highly sensitive to radiation. Still another object of the present invention is to provide a method for producing a radiation image conversion panel which has good graininess and sharpness and which has the advantages of the vapor deposition method, and which is highly sensitive to radiation. .

[Constitution of the invention]

The present invention has a stimulable phosphor layer on a support, or a protective layer on the stimulable phosphor layer, and the stimulable phosphor layer is irradiated with a radiation carrying image information. In the method for producing a radiation image conversion panel, which stores and records image information in and then emits stimulated luminescence carrying stored image information when stimulated excitation light is incident, in the vacuum chamber of the vapor deposition device, the support or After arranging the material to be vapor-deposited in the protective layer and the evaporation dish so as to face each other so as to have a predetermined interval, the inside of the vacuum chamber is set to a predetermined vacuum degree, the evaporation dish is heated, and the evaporation source is applied to the evaporation dish. The material is supplied from the storage container little by little so as not to accumulate, and evaporated, and the deposition rate is
Characterized in that the thallium-activated rubidium halide stimulable phosphor is vapor-deposited on the object to be vapor-deposited under the control of 10 ² to 10 ⁷ Å / min to form the stimulable phosphor layer. A method of manufacturing a radiation image conversion panel according to claim 1, wherein the above object is achieved by this configuration. The present invention will be described in detail below. FIG. 1 is a schematic sectional view of an example of a flash vapor deposition apparatus used in the present invention. 1 is a bell jar (vacuum tank), 4 is a support on which a stimulable phosphor is to be deposited, 5 is a storage container for containing a stimulable phosphor (evaporation source) 7 for evaporation, and 6 is flash vapor deposition, that is, an evaporated substance. For vapor deposition by a method of continuously or intermittently supplying a small amount of an evaporated substance to an evaporation dish heated to a temperature sufficiently higher than the melting point of Evaporating substance so that the evaporated substance does not accumulate on the evaporation dish. An evaporation dish, 8 is a supply device for supplying the stimulable phosphor (evaporation source) 7 to the evaporation dish 6 in a fixed amount, 9 is a current introduction line for introducing electric power for heating the evaporation dish 6, 11 Is a main valve, 10 is an auxiliary valve, and 12 is a leak valve, which is used in conjunction with an exhaust device (not shown) to develop and maintain a predetermined degree of vacuum in the bell jar 1. In the present invention, when using the vapor deposition apparatus, it is preferable that the stimulable phosphor that is first evaporated is uniformly dissolved or formed into a small lump such as flakes, pellets, or columns by pressing or hot pressing. It may remain as it is. In addition, it is preferable to perform degassing treatment together when the stimulable phosphor is molded. Further, the evaporation source 7 does not always have to be a stimulable phosphor, and may be a mixture of stimulable phosphor raw materials. First, after the evaporation source material 7 is charged into the storage container 5, the support 4 is installed so as to face the evaporation source 6. The interval is set to about 10 to 40 cm according to the average range of the stimulable phosphor. The support 4 may be heated to 50 to 350 ° C. by the heater 3. The surface of the vapor-deposited substrate of the support 4 is formed by a series of Japanese Patent Application No. 59-266913.
No. 59 to 266916, the stimulable phosphor may be processed so as to grow into fine columnar crystals. Next, the main valve 11 and the like are operated to remove the gas inside the bell jar 1 and bring the vacuum degree to about 10 ⁻⁴ to 10 ⁻⁶ Torr. At this time, an activated gas such as argon may be mixed. Next, the evaporation dish 6 is sufficiently heated, and the stimulable phosphor 7 is gradually supplied from the storage container 5 to the evaporation dish 6 by the supply device 8 to evaporate, and the deposition rate and the deposition thickness are monitored by the film thickness monitor 2. While proceeding with vapor deposition, the vapor deposition is stopped when it reaches a predetermined thickness. In the present invention, the vapor deposition rate is 10 ² to 10 ⁷ Å / min, more preferably 10 ³ to 10 ⁶ Å / min, though it depends on the stimulable phosphor and the target characteristics. 10 ² Å / mi
If it is slower than n, the production of the stimulable phosphor tank takes too long, which is not preferable, and if faster than 10 ⁷ Å / min, it is not preferable because the control of the speed becomes difficult. Further, a plurality of storage containers containing different evaporation sources 7 may be installed in the bell jar 1 and sequentially deposited to form a deposited layer composed of a plurality of types of stimulable phosphors. FIG. 2 shows an example in which another vapor deposition device is used. The apparatus is provided with a plurality of evaporation dishes and storage containers. This type is generally large in size and has a large vapor deposition area, which is convenient for vapor deposition of a large area. Incidentally, in FIG. 2, the same reference numerals as those in FIG. In the radiation image conversion panel according to the present invention, the stimulable phosphor means a stimulus (stimulation of photo, thermal, mechanical, chemical or electrical after the first light or high energy radiation is emitted. Excitation) refers to a phosphor that exhibits stimulated emission corresponding to the dose of the first light or high-energy radiation, but from a practical point of view, a phosphor that exhibits stimulated emission by stimulated excitation light of 500 nm or more is preferable. Is. The stimulable phosphor used in the radiation image conversion panel according to the present invention,
Thallium activated rubidium halide. This stimulable phosphor is a monovalent alkali metal such as rubidium, F, Cl, B.
It contains halogen and thallium selected from r. The radiation image conversion panel according to the present invention may be a stimulable phosphor layer group composed of one or more stimulable phosphor layers containing at least one kind of the stimulable phosphor described above.
The stimulable phosphor contained in each stimulable phosphor layer may be the same or different. The layer thickness of the stimulable phosphor layer of the radiation image conversion panel according to the present invention varies depending on the radiation sensitivity of the radiation image conversion panel, the type of the stimulable phosphor, and the like, but is 10 μm to 1000 μm.
It is preferably selected from the range of m, 20 μm to 800 μm
More preferably, it is selected from the range. FIG. 3 shows the layer thickness of the stimulable phosphor of the radiation image conversion panel according to the present invention, and the relationship between the amount of the stimulable phosphor attached to the layer thickness and the radiation sensitivity. Since the stimulable phosphor layer of the radiation image conversion panel according to the present invention does not contain a binder as in the conventional panel, the adhesion amount (filling rate) of the stimulable phosphor is the same as that of the conventional radiation image conversion panel. It is about twice, and the radiation absorptivity per unit thickness of the stimulable phosphor layer is improved, and the sensitivity to radiation is higher than that of the conventional radiation image conversion panel, and the graininess of the image is improved. Further, since the stimulable phosphor layer of the radiation image conversion panel according to the present invention does not contain a binder, it has excellent directivity, and has high transmittance for stimulated excitation light and stimulated emission, which is conventionally It is possible to make the layer thickness thicker than that of the radiation image conversion panel described above. Furthermore, since the stimulable phosphor layer of the radiation image conversion panel according to the present invention has excellent directivity as described above, the scattering of the stimulable excitation light in the stimulable phosphor layer is reduced, and the image Sharpness is significantly improved. As the support used in the radiation image conversion panel according to the present invention, various polymer materials, glass, metals and the like are used, and cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film. A plastic film such as, a metal sheet of aluminum, iron, copper, chromium or the like, or a metal sheet having a coating layer of the metal oxide is preferable. The surface of these supports may be a smooth surface, may be a matte surface for the purpose of improving the adhesiveness with the stimulable phosphor layer, and may be provided with a reflection layer or an absorption layer. Further, the surface of the support may be an uneven surface 21 as shown in FIG. 4 (a), or a tile-shaped plate 23 isolated as shown in FIG. 4 (b).
It may be a structure that is spread. In the case of FIG. 4 (a), the photostimulable phosphor layer is subdivided by the uneven surface 21 as shown in the sectional view of FIG. 4 (c), so that the sharpness of the image is further improved. In the case of FIG. 4 (b), the stimulable phosphor layer is deposited while maintaining the contour of the tile plate 23 of the support,
As a result, the photostimulable phosphor layer is composed of the columnar blocks 25 of the photostimulable phosphor separated by the cracks 26 as shown in the sectional view of FIG. 4 (d), so that the sharpness of the image is further improved. To do. Further, these supports may be provided with an undercoat layer on the surface on which the stimulable phosphor layer is provided for the purpose of improving the adhesiveness with the stimulable phosphor layer. The layer thickness of these supports varies depending on the material of the support used, etc., but is generally 80 μm to 20 μm.
00 μm, more preferably 80 μm from the viewpoint of handling
It is m to 1000 μm. In the radiation image conversion panel according to the present invention, a protective layer for physically or chemically protecting the stimulable phosphor layer is generally provided on the surface on which the stimulable phosphor layer is exposed. May be. This protective layer may be formed by directly coating the protective layer coating solution on the stimulable phosphor layer, or by forming a protective layer separately formed in advance on the stimulable phosphor layer. Good. As the material for the protective layer, usual materials for the protective layer such as cellulose acetate, nitrocellulose, polymethylmethacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyester, polyethylene terephthalate, polyethylene, vinylidene chloride and nylon are used. Further, this protective layer may be formed by laminating inorganic substances such as Sic, SiO ₂ , SiN, and Al ₂ O ₃ by vapor deposition or sputtering. Generally, the thickness of these protective layers is preferably about 0.1 μm to 100 μm. The stimulable phosphor according to the present invention may contain other metal as long as the amount of the metal does not impair the effects of the present invention. The radiation image conversion panel according to the present invention provides excellent sharpness, graininess and sensitivity when used in the radiation image conversion method schematically shown in FIG. That is, in FIG. 5, 31 is a radiation generator, 32 is a subject, 33 is a radiation image conversion panel according to the present invention, 34 is a stimulated excitation light source, and 35 is
Is a photoelectric conversion device that detects stimulated fluorescence emitted from the radiation image conversion panel, 36 is a device that reproduces the signal detected in 35 as an image, 37 is a device that displays the reproduced image, and 38 is stimulated It is a filter that separates excitation light and stimulated fluorescence and transmits only stimulated fluorescence. It should be noted that after 35, any optical information from 33 can be reproduced as an image in some form, and is not limited to the above. As shown in FIG. 5, the radiation from the radiation generator 31 enters the radiation image conversion panel 33 according to the present invention through the subject 32. The incident radiation is absorbed by the photostimulable phosphor layer of the radiation image conversion panel 33, the energy is accumulated, and an accumulated image of a radiation transmission image is formed. Next, this accumulated image is excited by stimulated excitation light from the stimulated excitation light source 34 and emitted as stimulated emission. Radiation image conversion panel
33, since the stimulable phosphor layer does not contain a binder and the transparency of the stimulable phosphor layer is high, during the scanning with the stimulable excitation light, the stimulable excitation light is stimulated. The diffusion in the fluorescent layer is suppressed. Since the intensity of the stimulated emission emitted is proportional to the amount of accumulated radiation energy, this optical signal is photoelectrically converted by the photoelectric conversion device 35 such as a photomultiplier tube, and reproduced as an image by the image reproduction device 36. By displaying with the image display device 37, the radiation transmission image of the subject can be observed.

【Example】

Next, the present invention will be described with reference to examples. Example 1 As a support, a chemically strengthened glass having a thickness of 500 μm was placed in the vapor deposition device shown in FIG. Next, the alkali halide stimulable phosphor (RbBr: 0.0006Tl) powder was put into the storage container 5 as an evaporation source, and then the vaporizer was evacuated to a vacuum degree of 5 × 10 ⁻⁶ Torr. Next, while heating and holding the support at 150 ° C., electric power is introduced into the evaporation dish 6 to heat the evaporation dish, and then the alkali halide stimulable phosphor powder is supplied from the storage container 5 little by little to the evaporation dish. The stimulable phosphor was vapor-deposited. In order to obtain the target stimulable phosphor layer, the vapor deposition rate was detected by a film thickness monitor, and the vapor deposition rate was controlled to be 10 ⁵ Å / min. When the layer thickness of the stimulable phosphor layer reached 300 μm, vapor deposition was terminated to obtain a radiation image conversion panel A by the manufacturing method of the present invention. The thus obtained radiation image conversion panel A according to the present invention was irradiated with 10 mR of X-ray having a tube voltage of 80 KVp, and then stimulated by He-Ne laser light (633 nm) to radiate from the stimulable phosphor layer. The stimulated emission thus generated was photoelectrically converted by a photodetector (photomultiplier tube), and this signal was reproduced as an image by an image reproducing device and recorded on a silver salt film. From the size of the signal,
The sensitivity of the radiation image conversion panel A to X-rays was investigated.
Shown in the table. In Table 1, the sensitivity to X-rays is shown as a relative value with the radiation image conversion panel A according to the present invention as 100. Example 2 A radiation image conversion panel B according to the present invention was obtained in the same manner as in Example 1, except that the vapor deposition apparatus was changed to the type shown in FIG. The radiation image conversion panel B according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are also shown in Table 1. Example 3 Example 1 was repeated except that an alkali halide stimulable phosphor raw material (a mixture of 1 mol of RbBr and 0.0006 mol of TlBr) was used as the evaporation source instead of using the alkali halide stimulable phosphor. A radiation image conversion panel C according to the present invention was obtained in the same manner as in. The radiation image conversion panel C according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are also shown in Table 1. Comparative Example 1 As a support, a chemically strengthened glass having a thickness of 500 μm was placed in an evaporator. Next, put the alkali halide stimulable phosphor (RbBr: 0.0006Tl) in the molybdenum boat for resistance heating,
Set on the resistance heating electrode, then exhaust the vaporizer and
The vacuum degree was × 10 ^-6 Torr. Next, a current is passed through a molybdenum boat while heating and holding the support at 150 ° C., the alkali halide stimulable phosphor is evaporated by a resistance heating method, and the vapor deposition rate is detected by a film thickness monitor. The vapor deposition rate is 10 ⁵ Å / A radiation image conversion panel P by a comparative manufacturing method was obtained by depositing the layer on the support until the layer thickness became 300 μm while controlling the concentration to be min. The comparative radiation image conversion panel P thus obtained was evaluated in the same manner as in Example 1, and the results are also shown in Table 1. As is clear from Table 1, the radiation image conversion panels A, B, and C manufactured by the manufacturing method of the present invention have the same graininess and sharpness as the radiation image conversion panel P manufactured by the comparative manufacturing method, but the X-ray sensitivity is about the same. It was three times higher. This is because the vapor pressure of TlBr that is an activator during formation of the stimulable phosphor layer is RbBr.
Since it is significantly different from the vapor pressure of Tl was not doped with a target concentration of Tl to the stimulable phosphor layer formed in Comparative Example, in the example, depending on the time of vapor deposition,
This is because a stimulable phosphor layer having a target activator concentration was obtained. Example 4 In Example 1, the deposition rate of the stimulable phosphor was 3 × 10 ⁶ Å /
A radiation image conversion panel D according to the present invention was obtained in the same manner as in Example 1 except that the control was performed so that the value was min. The radiation image conversion panel D according to the present invention thus obtained was evaluated in the same manner as in Example 1, and the results are shown in Table 2. In Table 2, the sensitivity to X-rays is shown as a relative value with the radiation image conversion panel A according to the present invention as 100. As is clear from Table 2, the radiation image conversion panel D according to the present invention showed the same high X-ray sensitivity as the radiation image conversion panel A according to the present invention.

【The invention's effect】

As a means for forming a vapor deposition deposition layer that faithfully copies the stimulable phosphor composition that exhibits the design characteristics, a flash vapor deposition method that instantly heats and vaporizes the stimulable phosphor of the composition is adopted,
It is possible to eliminate the performance deviation between the design and the product, improve the assurance of quality, and achieve a stable and reliable production process.

[Brief description of drawings]

1 and 2 are schematic sectional views of an example of a flash vapor deposition apparatus used in the present invention. FIG. 3 shows the sensitivity characteristics of the radiation image conversion panel obtained by the present invention. FIG. 4 illustrates the shape of the vapor deposition substrate surface of the support. FIG. 5 is a diagram for explaining the radiation image conversion method. FIG. 6 is a diagram showing the Tl concentration dependence of the instantaneous emission intensity and the stimulated emission intensity in the stimulable phosphor (RbBr: Tl). 1 …… Bell jar 2 …… Film thickness monitor 3 …… Support body heater 4 …… Support body 5,5 ′ …… Storage container 6,6 ′ …… Evaporation dish 7,7 ′ …… Evaporation source Fluorescent material) 8 …… Supply device 9 …… Current introduction line 11 …… Main valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumio Shimada No. 1 Sakura-cho, Hino-shi, Tokyo Konishi Roku Photo Industrial Co., Ltd. Judge Tamura (56) Reference Japanese Patent Laid-Open No. 62-47599 (JP, A) KOSHO 52-20818 (JP, B1)

Claims (1)

[Claims] 1. A stimulable phosphor having a stimulable phosphor layer on a support, or a protective layer on the stimulable phosphor layer, which is irradiated with radiation carrying image information. In a method of manufacturing a radiation image conversion panel that stores and records image information in a layer, and then emits stimulated luminescence carrying stored image information when stimulated excitation light is incident, the support is provided in a vacuum chamber of a vapor deposition apparatus. Alternatively, after the deposition target of the protective layer and the evaporation dish are arranged so as to face each other at a predetermined interval, the inside of the vacuum chamber is set to a predetermined degree of vacuum, the evaporation dish is heated, and the evaporation dish is evaporated. The source material is supplied from the storage container little by little so as not to accumulate, and evaporated, and the deposition rate is
Characterized in that the thallium-activated rubidium halide stimulable phosphor is vapor-deposited on the object to be vapor-deposited under the control of 10 ² to 10 ⁷ Å / min to form the stimulable phosphor layer. Method for manufacturing radiation image conversion panel.