JPS6199900A - Radiation image conversion panel - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a radiation image conversion panel using a stimulable phosphor, and particularly to a radiation image conversion panel using a stimulable phosphor.

This invention relates to a radiation image storage panel with improved chemical durability.

(Prior Art) Conventionally, the so-called tlltJJ radiography method, which combines a radiographic film having an emulsion layer made of a silver salt photosensitive material and an intensifying screen, has been used to obtain a radiographic image. In recent years, due to problems such as the depletion of silver resources, a method of imaging 1IIIi ray images without using silver salts has become desirable.

One of the methods of converting tJJm* without using silver salt is
The method described in US Pat. No. 3,859,527 and the like is attracting attention. This radiation image one-line method is a stimulable phosphor (a phosphor that emits light when excited by electromagnetic waves selected from visible light and infrared rays after being exposed to radiation; here, radiation refers to X-rays and α-rays).

Refers to electromagnetic waves or particle beams such as β rays, γ rays, high-1 energy neutron beams, electron beams, vacuum line 1wc external rays, etc. ), which uses a radiation image conversion panel with a radiation image conversion panel of 0.
After that, the panel is scanned with electromagnetic waves selected from visible light and infrared rays (hereinafter referred to as [excitation light-1)], time series 1NOC is extracted as stimulable luminescence, and this is electrically processed to create an image. It is something that becomes.

[The radiation image conversion panel used in the radiation image conversion method described above has at least a phosphor layer comprising a stimulable phosphor dispersed in a suitable binder. When the phosphor layer is self-supporting, 1.1. Although the phosphor layer itself can serve as a radiation image conversion panel, generally the phosphor layer is provided on a suitable support to construct a radiation image conversion panel.

In this way, a radiation image conversion panel in which a phosphor layer is provided on a support is used to store and record image information by irradiating it with rays of light, and then it is read out. Japanese Unexamined Patent Publication No. 11392/1983 (Patent Application No. 8/1983
As described in No. 7799, Mei No. 1, the residual radiation image is erased and reused. In each of these steps or between customer steps, the radiation image conversion panel is usually transported by a transport means such as a belt or roller, but during this transport, the surface of the phosphor layer is easily damaged, and these scratches cause noise during reading. Therefore, it is especially necessary to prevent this damage.

That is, this radiation image conversion panel is used, for example, to record a patient's radiation image in medical diagnosis, and to read it, sub-scanning at an extremely fine pitch is performed, for example, by laser scanning, and the recording is performed.

Although the reading resolution is said to be extremely high, scratches on the surface of the phosphor layer as described in - lower the reading and recording resolution and become noise, which greatly reduces the diagnostic performance of the image. Furthermore, due to repeated contact with various conveying means such as endless belts in the device, the stimulable phosphor may be chemically affected and deteriorated, which may reduce the performance of radiation image conversion. There is also.

(Objective of the Invention) Therefore, an object of the present invention is to provide a radiation image conversion panel which is free from scratches and has good durability.

(Structure of the Invention) The radiation image conversion panel 13 of the present invention shown in FIG. layer 131 and protective film 13
2 are laminated in this order, and if necessary, an undercoat layer is provided between the support 130 and the phosphor layer 131.
, is characterized in that the adhesion I between the support 130 and the phosphor layer 131 is oriented in the direction I.

It goes without saying that the Fa retaining film 132 is made of a material that is physically and chemically more durable than the surface of the phosphor layer 131. Specifically, a plastic film is used.

(Effects of the Invention) The radiation image conversion panel according to the present invention has L of the phosphor layer.
Since the protective film is provided on the panel, the surface of the phosphor layer is physically and chemically protected during transportation of the panel, and high resolution is maintained during storage recording and reading.

(Actual I11! Embodiment) Hereinafter, the configuration of the radiation image conversion panel of the present invention will be explained in detail.

The stimulable phosphor used in the radiation image conversion panel of the present invention is a phosphor that exhibits stimulated luminescence when irradiated with excitation light from radiation as described above, but from a practical standpoint, it is preferable to 300~ by excitation light of 500~soonm
It is a phosphor that exhibits aoo'ns stimulated luminescence. Examples of the stimulable phosphor used in the radiation image storage panel of the present invention include:) U.S. Pat. No. 3,859,527;
SrS:Ce as described in i.

8m, Sr S:Elj, 3s, I-ax
02 S:'Etl'.

SIl and Zu, CdS: Mn, X (
However, X is halogen) , II) Japanese Patent Application Laid-Open No. 1983-12
Publication No. 142 (Patent Application No. 53-84740 Mei III)
7, nS: Cu, Pb, 3a described in
O-x AQ,z O3: Ell (However, 0.8
<x <10) Oyo UMX-0, X Si 02
: A (However, M is MQ, Ca, Sr, Zn,
Cd or Ba, A4. iCe, ,Tb
, Fu, 'l+n, Pb, T9J, Bi or Mnt', x 0.5≦x≦2.5)
, 1ii) Japanese Patent Application Laid-Open No. 12143/1983 (Patent Application No. 1983)
-84742 Akira 11) (13at
-X-y, M(lx, Cay) FX:a E
u 2+ (where X is at least one of C9J and Br, × and V are o < x + y ≦ 0.6 and XV% 0, and a is 10th edition ≦ a ≦ 5 × 104), M Japanese Patent Application Publication No. 55-12144 (Patent Application No. 1983)
-84743 specification) LnOX:xA (
However, LO is at least one of La, Y, Gd and lu, X is at least one of C and 3r, A is at least one of Ce and Tb, and × is Q
<x<0.1), ■) Japanese Patent Application Laid-Open No. 55-12145 (described in Japanese Patent Application No. 53-84744, Patent Application No. 1) (Bat-X).

Mmx) FX:y A (However, vK is Mu, C
a, Sr.

70 and Cd, X is C9,
At least one of Br and l, Δ is Eu, Tb
, Ce, Tm, oy, pr, 1-1n, Nd, Yb and Er, X[;10≦X≦0
．． 6. V is 0≦V≦0.2t''). Among these phosphors, if), 1ii), m)
The phosphors of and V) exhibit significantly higher luminescence than the phosphors of i), and are therefore preferable. phosphors are preferred. However, the radiation l1lII! of the present invention! The stimulable phosphor used in the conversion panel is not limited to the phosphors mentioned above, but any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light. Needless to say, it's a good thing.

The smaller the average particle diameter of the commonly used phosphor 1!1 phosphor, the smaller the average particle size of the resulting radiation image conversion panel.
However, as the average particle diameter becomes too large, the culm impression tends to improve, but the grain size 11 tends to decrease. Taking these things into consideration, the stimulable phosphor used in the present invention is generally appropriately selected from those having an average particle diameter of 0.1 to 10,071. Preferably, those having an average particle diameter of 1 to 30 μm are used. In addition, the amount of stimulable phosphor to be used is decided as appropriate from the point of view of providing the radiation image conversion panel with the necessary number of recording and output capacities, and from the point of view of economic efficiency. The radiation image conversion panel 1 is set to have 3 to 300 rays per crJ.

The phosphor layer of the radiation image storage panel of the present invention is prepared by dispersing the stimulable phosphor described above in a suitable binder to prepare a coating solution, and applying the resulting coating solution uniformly by a conventional coating method. It is made by forming a layer. Binders include, for example, proteins such as gelatin, polysaccharides such as dextran or gum arabic, polyvinyl butyral,
Polyvinyl acetate, Nitrocell [1-su, Ethylcellulose.

Vinylidene chloride-vinyl chloride copolymer, polymethyl methacrylate-1~, vinyl chloride-vinyl acetate copolymer,
Binders commonly used in layer formation are used, such as polyurethane, cellulose acetate butyrate, polyvinyl alcohol, and the like. Generally, the binder is used in an amount of 0.01 to 1 part by weight per part by weight of the stimulable phosphor.

However, in terms of the sensitivity and sharpness of the f/Jjm image conversion panel that can be obtained, it is preferable to use a small amount of binder, and from the viewpoint of ease of application, a range of 0.03 to 0.2 parts by weight is recommended. The thickness of the phosphor layer is generally set within the range of 10 μm to 1 μm.

In the radiation image storage panel of the present invention, a support for supporting a phosphor layer as described above is used. Supports made from various materials such as various polymers, glass, wool, cotton, paper, and metal can be used, but as information recording materials, flexible bamboo sheets or rolls can be used. It is preferable to use a material that can be processed into From this point,
For example, plastic film such as cell[1-STER film, polyester film, poly]nytylene terephthalate film, polyamide film, polyimide film, triacetate film, polyh-bonate film, general paper and, for example, for photography. Base paper, printing base paper such as coated paper or A1-paper, Baryta paper, Resin2-1-paper, Bell L-Spec R1 No. 78461
Paper sized with polysaccharide etc. as described in No. 5 Akira Am, pigment paper containing pigments such as titanium dioxide.

Processed paper such as paper sized with polyvinyl alcohol or the like is particularly preferred. These supports may have a stepped undercoat layer on one side (the surface on which the phosphor layer is provided) for the purpose of holding the phosphor layer more closely. Conventional adhesives are used as the material for the undercoat layer. When forming a phosphor layer on a support or an undercoat layer, a coating solution containing a stimulable phosphor dispersed in a binder is applied directly onto the support or undercoat layer to form a fluorescent layer. The body layer may be formed first, or a separately formed phosphor layer may be adhered to the support or undercoat layer. In addition, when the support used is one that transmits excitation light, the resulting radiation image conversion panel can be irradiated with excitation light from the surface of the support opposite to the surface on the phosphor layer side. It becomes possible.

In particular, in the radiation image storage panel of the present invention, the other surface of the above-mentioned phosphor layer (the surface opposite to the surface on which the support is provided) is provided with a layer for physically or chemically protecting the phosphor layer. The protective film is layered.

This protective film is safe! The film-forming liquid may be applied directly onto the phosphor layer, or a protective film formed separately in advance may be adhered to the phosphor layer. As the material 1'+1 of the material 1'+1, Ni=nilulose'1-delcel [1-s, cellulose acetate, poly1 stel,
A conventional protective film material such as poly[Glenterenotale 1-] is used.

The radiation image conversion panel of the present invention is a radiation image converting panel shown schematically in FIG. Used in image conversion methods. That is, in FIG. 2, 11 is a radiation generating device, 12 is a subject, 13 is the IIi ray image conversion panel of the present invention, and 14 is an excitation source for emitting the latent radiation image of the Pi-based ray image conversion panel as fluorescence. 15 is a photoelectric conversion device that detects fluorescence emitted from the radiation image conversion panel; 16 is a device that reproduces the photoelectric conversion signal detected by 15 as an image; 1
7 is a device for displaying the reproduced image, 18 is a light source 14h
This is a filter for cutting off the reflected light of 11 and transmitting only the light emitted from the radiation image conversion panel 13. It should be noted that the elements after 15 are not limited to those described above, as long as they can reproduce the optical information from 13 as an image in some form.

As shown in FIG. 2, the subject 12 is placed between the radiation generating device 11 and the radiation image conversion panel 13 of the present invention,
When radiation is irradiated, the radiation passes through each part of the subject 12 according to changes in radiation transmittance, and the transmitted radiation 1it (that is, an image of the intensity of the radiation) enters the radiation image conversion panel 13 of the present invention. This incident transmission image is absorbed by the phosphor layer of the radiation image conversion panel 13, thereby generating a number of electrons or holes proportional to the fIItA dose absorbed in the phosphor layer, which are trapped in the phosphor. accumulated in the level. That is, an accumulation of radiographic images of 1 it (-second latent image) is formed. This latent image is then excited with light energy to become visible. That is, by scanning the phosphor layer with excitation light and expelling electrons or holes accumulated at the trap level,
The accumulated image is emitted as fluorescence. The strength of the emitted fluorescence is proportional to the number of accumulated electrons or holes, that is, the strength of the h'l copper wire energy absorbed by the phosphor layer of the radiation image conversion panel 13. A photoelectric conversion device 15 such as a photomultiplier tube converts the signal into a time-series electrical signal, which is transmitted to an image reproducing device 16 to reproduce it as an image, and an image display device 17 displays the image.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing the basic structure of the radiation image conversion panel of the present invention. FIG. 2 is a schematic explanatory diagram of a radiation image conversion method using the radiation image conversion panel of the present invention. 11...Radiation light! R-mounted vR12...Subject 1
3...Radiation image conversion panel 14...Light source 15...Photoelectric conversion device 16...Image reproduction' @ position 17...Image display device 18...Filter 130...Support 131・・・
・Phosphor layer 132...protection

Claims (1)

[Claims] (1) It has a phosphor layer formed by dispersing a stimulable phosphor in a binder, and after irradiating radiation having image information onto the phosphor layer and absorbing it into the stimulable phosphor. A radiation image conversion method comprising scanning the phosphor layer with excitation light, extracting the radiation energy accumulated in the stimulable phosphor in time series as stimulated luminescence, and electrically processing it to form an image. In the radiation image conversion panel used in A radiation image conversion panel comprising a protective film.