JPS60213900A - Accumulating phosphor sheet - 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 [Field of the Invention] The present invention relates to a stimulable phosphor sheet used in a radiation image information recording and reproducing method using a stimulable phosphor. The present invention relates to a stimulable phosphor sheet with improved impact resistance.

[Background of the Invention] Conventionally, as a method of obtaining a radiation image as an image, the so-called radiography method uses a combination of a radiographic film having an emulsion layer made of a silver salt photosensitive material and an intensifying screen. is being used.

In recent years, as an alternative to the radiographic method mentioned above,
For example, a method for recording and reproducing radiation image information using a stimulable phosphor, as described in Japanese Patent Laid-Open Publication No. 55-12145, has been developed and is attracting attention. This method involves absorbing radiation transmitted through the subject or radiation emitted from the subject into a stimulable phosphor, and then exciting this phosphor with electromagnetic waves (excitation light) such as visible light or infrared light. The radiation energy stored in the 4-phosphor is emitted as fluorescence (exhaustive luminescence), and this fluorescence is read photoelectrically to obtain an electrical signal. Based on this electrical signal, a radiation image of the subject or subject can be created. Information is reproduced as visual images, numerical values, symbols, etc.

The above radiation image information recording and reproducing method has the advantage that a radiation image with a rich amount of information can be obtained with a much lower radiation dose than when conventional radiography is used. Therefore, this radiographic image information recording and reproducing method has a very high utility value especially in direct medical radiography such as X-ray photography for the purpose of medical diagnosis.

When carrying out the radiation image information recording and reproducing method, the stimulable phosphor is generally used as a stimulable phosphor sheet (a radiation image It is also called a conversion panel and is usually used in the form of a rectangular or square sheet. Further, a protective film made of a transparent plastic material is provided on the surface of the phosphor layer for the purpose of preventing physical deterioration and chemical alteration of the phosphor layer.

A stimulable phosphor sheet does not ultimately record image information by itself, but temporarily carries image information in order to provide an image, etc. to a separately prepared final recording medium as described above. It is. Therefore, the stimulable phosphor sheet can be used repeatedly, and such repeated use becomes extremely economical.

” - Repeated use of stimulable phosphor sheets can be achieved by equipping a mobile station such as an X-ray vehicle with a radiation image information recording/reading device that uses stimulable phosphor sheets for mass medical examinations, etc. This is particularly advantageous when traveling to various locations to perform X-ray photography. That is, it is inconvenient to load a large number of SA phosphor sheets on a mobile station, and there is a limit to the number of sheets that can be loaded on a vehicle such as an X-ray vehicle. Therefore, xl! under conditions that allow repeated use of the stimulable phosphor sheet!
The radiation image information for each subject is recorded on each stimulable phosphor sheet, and the image information signal obtained by reading it is transferred to a recording medium with a large storage requirement such as a magnetic tape. If the phosphor sheets are recycled, radiation images of a large number of objects can be obtained with a small number of stimulable phosphor sheets, which is extremely useful in practice. Furthermore, by combining the cyclical reuse of this stimulable phosphor sheet with continuous imaging, rapid imaging in mass medical examinations becomes possible, which has an extremely large practical effect.

In addition, when reusing the stimulable phosphor sheet,
Normally, after obtaining the desired image information by reading the radiation energy accumulated in the stimulable phosphor sheet, the remaining radiation energy is read, for example, as described in
A step of release and removal is added by the method disclosed in Japanese Patent Publication No. 56-12599. Such a method enables efficient cyclical reuse of the stimulable phosphor sheet.

Therefore, when the radiation image information recording and reproducing device described above is mounted on a mobile station such as an X-ray imaging vehicle, radiation is irradiated to the subject, and then a stimulable phosphor sheet is exposed to the radiation, so that the radiation of the subject is An image recording unit that stores and records an image on the stimulable phosphor sheet, an image reading unit that reads the radiation image stored and recorded on the stimulable phosphor sheet, and emits radiation energy remaining in the stimulable phosphor sheet after the reading operation. It is desirable that an erasing section for removing the stimulable phosphor sheet in preparation for the next recording operation and a conveying means for sequentially circulating the stimulable phosphor sheet to each of these sections are combined into one device. Furthermore, the radiation image information recording and reproducing apparatus having such a configuration has various advantages and is convenient in practice, not only when installed in a mobile station such as an X-ray imaging vehicle, but also when installed in a hospital or the like.

By the way, if physical deterioration such as scratches occurs on the surface of a stimulable phosphor sheet (the surface of the sheet facing the phosphor layer), the quality of the image obtained from the sheet or the accuracy of the image information will drop significantly. There is a tendency to Therefore, when selecting a means for transporting the stimulable phosphor sheet, sufficient consideration must be given to avoid damaging the surface of the stimulable phosphor sheet. In consideration of these points, a belt conveyor using a flexible sheet material has conventionally been used as a means for conveying a stimulable phosphor sheet.

However, even when using a belt conveyor etc.
When passing through the connecting section of two belt conveyors, the images are transferred from various positions (for example, 1 image recording section 1, image reading section, erasing section, and if necessary, a stimulable phosphor sheet storage section provided on the conveyance path). The front end of the stimulable phosphor sheet often collides with various members when moving onto the belt conveyor or from the belt conveyor to various positions, and such collisions cause the stimulable phosphor sheet to The phosphor layer may undergo physical deterioration.

Conventionally, as a means to avoid direct impact of these bullets on the phosphor layer, measures such as providing the end of the phosphor layer inside the end of the support have been proposed. However, it is still not a sufficient improvement. In particular, in the radiation image information recording and reproducing apparatus that circulates and reuses the stimulable phosphor sheet as described above, the sheet is transported frequently, so physical deterioration of the stimulable phosphor sheet becomes noticeable in a short period of time. There is a tendency to

[Summary of the Invention] The present invention provides a stimulable phosphor sheet with particularly improved impact resistance.

The present invention provides a stimulable phosphor sheet having a structure in which a substrate, a support, a phosphor layer containing a stimulable phosphor and a binder, and a protective film are laminated in this order, the stimulable phosphor sheet comprising at least The front end and/or rear end of the phosphor layer and the support body are arranged inside the corresponding front end and/or rear end of the base body with respect to the transport direction of the body sheet, and the stimulable phosphor The present invention provides a stimulable phosphor sheet characterized in that the front end and/or rear end of the sheet is covered and protected by a film-like polymeric substance.

The present invention also provides a stimulable phosphor sheet having a structure comprising a substrate, a support, a phosphor layer containing a stimulable phosphor and a binder, and a protective film in this order, the stimulable phosphor sheet comprising at least The front end and/or rear end of the phosphor layer and the support are located inside the corresponding front and/or rear end of the base with respect to the transport direction of the fluorescent phosphor sheet, and The front end and/or rear end of the body layer is protected by an embedded member installed in the space formed by the phosphor layer and the side edges of the support layer being arranged inside. The present invention also provides a stimulable phosphor sheet characterized by the following.

Note that in the present invention, the rear end of the stimulable phosphor sheet is protected because the stimulable phosphor sheet does not necessarily move in one direction. Preferably, both the front and rear ends are protected.

[Detailed Description of the Invention] The present invention will be described in detail below with reference to the male drawings.

The stimulable phosphor sheet of the present invention has a front end portion and/or a rear end portion (a front end portion and/or a rear end portion of the phosphor layer based on the transport direction of the stimulable phosphor sheet).
Special care is taken to protect the phosphor layer from the mechanical shocks that are likely to occur from the front and/or rear ends of the stimulable phosphor sheet during transport.

Examples of typical configurations of the stimulable phosphor sheet provided by the present invention are shown in FIGS. 1a, 1b, and 1c of the accompanying drawings.

The structure of the stimulable phosphor sheet of the present invention can be divided into the following two types. That is, (I) the side edges of the phosphor layer and the support are arranged inside the corresponding front and/or rear ends of the substrate, and the front and/or rear ends of the stimulable phosphor sheet (n) the phosphor layer and the side edges of the support are arranged inside the corresponding front and/or rear ends of the substrate; , and the front end and/or rear end of the phosphor layer is protected by an embedded member installed in the space formed by the phosphor layer and the support layer being placed inside the side edge force Z. A stimulable phosphor sheet.

It is.

A preferred example of the configuration of CI) above is shown schematically in FIGS. 1a and 1b. That is, Figures 1a and 1b
In the figure, the number 11 represents the base, 12 represents the support, and 13
14 represents a phosphor layer, and 14 represents a protective film. The base body 11 and the support body 12 are usually bonded together using an adhesive. In this way, by configuring the stimulable phosphor sheet so that the base 11 protrudes outward from the phosphor layer 13 and the support 12 at its front and rear ends,
Mechanical applied to the end of the stimulable phosphor sheet! !
It becomes possible to suppress physical or chemical deterioration of the phosphor layer due to impact, friction, etc. to some extent. Further, a structure in which the front end and/or rear end of the phosphor layer and the front end and/or rear end of the support body are aligned has the advantage that it is very easy to manufacture.

However, with these structures alone, it may be difficult to sufficiently suppress physical or chemical deterioration of the phosphor layer. Therefore, in the present invention, the front end and/or rear end of the phosphor layer is Molecular substance coating layer 15 or adhesive layer 1
By attaching the polymer film 17 via the stimulable phosphor sheet 6, physical or chemical deterioration of the stimulable phosphor sheet is further prevented. Note that the front end, rear end, side edges, etc. of the base body 11 may be chamfered at the upper or lower edge thereof.

A preferred example of the configuration (II) above is schematically shown in FIG. 1c. That is, in Figure 1C, the number 1
1 is a base, 12 is a support, 13 is a phosphor layer, and 14 is a protective film. Base body 11 and support body 12
are usually joined with adhesive. Then, by installing the embedded member 18 made of a material such as a polymer substance in the space formed by placing the front end and rear end of the phosphor layer inside, the stimulable phosphor sheet is physically It is designed to sufficiently prevent physical or chemical deterioration. Note that the front end, rear end, and side edges of the base body 11 may be chamfered at the upper or lower edges.

Various materials for stimulable phosphor sheets are already known.
In manufacturing the stimulable phosphor sheet used in the present invention,
Any material can be selected and used from those materials.

For example, examples of supports include films of plastic materials such as cellulose acetate and polyethylene terephthalate, metal sheets such as aluminum foil, ordinary paper, baryta paper, resin-coated paper, and the like. Note that the surface of the support on which the phosphor layer is provided is
Other functional layers such as an adhesion-imparting layer, a light-reflecting layer, and a light-absorbing layer may be provided on the surface.

Further, the substrate can be made of the same or different material as the support, but in any case it is preferable that the material is selected from the above-mentioned support materials.

The phosphor layer is basically a layer in which particles of stimulable phosphor are dispersed in bangu. A large number of stimulable phosphors that can be used in [1]-1 are already known, and in the present invention, any one of these stimulable phosphors can be selected and used. Examples of known stimulable phosphors include divalent europium-activated alkaline earth metal fluorohalide phosphors (M"Fx:Eu"; where Mll is selected from the group consisting of Mg, Ca, and Ba). at least one alkaline earth metal, X is C
At least one halogen selected from the group consisting of I, Br and I); europium and samarium activated strontium sulfide phosphor (SrS:Eu, Sm)
; europium and samarium activated lanthanum oxysulfide phosphor (La202S:Eu, Sm); europium activated barium aluminum oxide phosphor (BaO・A2
03: Eu); Europium-activated alkaline earth metal silicate phosphor (M2+Oa Si 02: Eu;
However, M? is at least one alkaline earth metal selected from the group consisting of Mg, Ca and Ba);
X: Ce; provided that Ln is at least one rare earth element selected from the group consisting of La, Y, Gd and Lu, and X is at least one halogen selected from the group consisting of C1, Br and I) can be mentioned. However, the stimulable phosphor that can be used in the stimulable phosphor sheet of the present invention is not limited to those mentioned above, and any phosphor that exhibits stimulability can be used without particular restriction.

When producing the stimulable phosphor sheet of the present invention, a method of attaching a phosphor layer on a composite of a substrate and a support (on the surface of the support) obtained by bonding in advance using an adhesive or the like; Alternatively, a method can be used in which a phosphor layer is first attached to the surface of a support and then bonded to the base using an adhesive or the like.

A transparent protective film for physically and chemically protecting the phosphor layer is then provided on the surface of the phosphor layer. Examples of materials used for the transparent protective film include cellulose acetate, polymethyl methacrylate, polyethylene terephthalate, and polyethylene. The thickness of the transparent protective film is typically 0.1 to 20 pm.

The stimulable phosphor sheet is disclosed in Japanese Patent Application Laid-Open No. 55-16350.
It may be colored with a coloring agent as described in Japanese Patent Application Laid-Open No. 57-96300, etc., or it may be colored with a phosphor as described in Japanese Patent Application Laid-Open No. 55-146447. White powder may be dispersed in the layer.

When providing a coating layer of a film-forming polymeric substance on the front end and/or rear end of a stimulable phosphor sheet, apply a coating solution prepared by dissolving any film-forming polymeric substance in a solvent. □ Utilize methods such as applying to the side edge and then drying to remove the solvent, or applying a polymer substance-forming raw material to the side edge and reacting at that position to form a coating film. can do. There are no particular restrictions on such film-forming polymeric substances, but for example,
Polyurethanes, acrylic resins, and mixtures of acrylic resins and vinyl chloride/vinyl acetate copolymers as disclosed in Japanese Patent No. 8-68746 can be used.

In addition, examples of the polymer film provided at the front end and/or rear end of the stimulable phosphor sheet include cellulose acetate, polymethyl methacrylate, and polyethylene terephthalate, which are listed above as examples of materials used for the transparent protective film. , polyethylene, etc., but are not particularly limited to these. The adhesive layer can be provided by attaching any adhesive to the polymer film or stimulable phosphor sheet.

The embedded member installed in the space formed by the front end and/or rear end of the phosphor layer of the stimulable phosphor sheet being placed inside may be made of any material. The formed embedded member can be used. Usually, after an adhesive layer is provided on the front and/or rear end of the phosphor layer of the stimulable phosphor sheet, the surface of the support, the embedded member, etc. , an embedded member is attached to the space. Note that the embedded member may be adhered to either the end of the phosphor layer or the surface of the support, but may be adhered to both.

Examples of the material for the embedded member include self-shape retaining materials such as polymeric substances and metals.
Polymeric substances are preferred. Examples of preferable polymeric substances include, but are not particularly limited to, cellulose acetate, polymethyl methacrylate, polyethylene terephthalate, and polyethylene, which were mentioned above as examples of materials used for the transparent protective film. isn't it. The polymeric material can be molded into an embedded member by any molding means. Alternatively, the embedded member can also be formed by filling the space with a solution containing a polymeric substance and then drying it. Furthermore, after filling the space with the raw material of the polymeric substance, a polymerization reaction may occur at that position, thereby forming the embedded member.

The polymer material embedded member used in the present invention does not need to be particularly transparent.

The side edges of the stimulable phosphor sheet of the present invention may also be provided with the impact protection structure and various protection members as described above, but this is not essential.

The stimulable phosphor sheet of the present invention provides sufficient protection as described above and is particularly resistant to shocks such as collisions. It is particularly suitable for use in information recording and reproducing devices.

[Brief explanation of the drawing]

FIG. 1a, FIG. ib, and FIG. 1c are diagrams schematically showing the structure of the stimulable phosphor sheet of the present invention. 11 two substrates, 12: support, 13: phosphor layer, 14: protective film, 15: coating layer of film-like polymeric substance 16: adhesive layer, 1
7: Polymer substance film, 18: Embedded member, Patent applicant: Fuji Photo Film Co., Ltd. Agent, Patent attorney: Yasuo Yanagawa

Claims (1)

[Scope of Claims] 1. A stimulable phosphor sheet having a structure in which a substrate, a support, a phosphor layer containing a stimulable phosphor and a binder, and a protective film are laminated in this order, the sheet comprising at least The front end and/or the rear end of the phosphor layer and the support are arranged inside the corresponding front and/or rear end of the base with respect to the transport direction of the stimulable phosphor sheet, and A stimulable phosphor sheet, characterized in that a front end and/or a rear end of the stimulable phosphor sheet are covered and protected with a film-like polymeric substance. 2. The stimulable fluorescence according to claim 1, wherein the front end and/or rear end of the stimulable phosphor sheet is covered and protected by a coating layer of a film-like polymeric substance. body sheet. 3. The stimulable phosphor according to Section 4, Paragraph 1 of the Claims, characterized in that the front end and/or rear end of the stimulable phosphor sheet is covered and protected by adhesion of a polymer film. body sheet. 4. A stimulable phosphor sheet having a structure in which a substrate, a support, a phosphor layer containing a stimulable phosphor and a binder, and a protective film are laminated in this order, at least the stimulable phosphor sheet The front end and/or rear end of the phosphor layer and the support body are arranged inside the corresponding front end and/or rear end of the substrate, and the front end and the rear end of the phosphor layer A stimulable fluorescence characterized in that the rear end portion is protected by an embedded member installed in a space formed by arranging the side edges of the phosphor layer and the support layer inside. body sheet. (7) The stimulable phosphor sheet according to claim 1i, wherein the embedded member is made of a polymeric substance.