JPS59211263A - Radiation image detecting method - Google Patents

Abstract

PURPOSE:To eliminate a problem of adverse influence affected to the quality of a picture occurred in a mechanical carriage of a panel or a detector by photoelectrically reading out an intensity light via a photosensitive element, thereby shortening the detecting time in a radiation image converting method utilizing the intensity fluorescent unit, and simplifying the detection. CONSTITUTION:A photosensitive element 1 is, for example, formed of a photodiode 4 of a photoreceptor, and an MOS5 of a transfer unit. Radiation passed through an object is incident to a fluorescent layer side of a radiation image detector, and an electromagnetic wave of an exciting wavelength range of an intensity fluorescent unit contained in a fluorescent layer 3 is emitted. Then, the accumulated image of the radiation energy formed on the layer 3 is radiated as fluorescent (intensity light emission). This fluorescent light is proportional to the strong and weak radiation energy absorbed to the layer 3. Only the emitted fluorescent light is passed through the layer 2 of the filter to be photosensed by the photodiode 4 of the element 1, thereby generating a signal charge in the photodiode 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation image detection method. More specifically, the present invention relates to a radiation image detection method that utilizes a combination of a stimulable phosphor and a photosensitive element.

Traditionally, the so-called radiographic method, which combines a radiographic film with an emulsion layer made of a silver salt photosensitive material and an intensifying screen, has been used to detect a radiation image of a subject and obtain it as an image. has been done. As an alternative to the conventional radiographic method described above, for example, a stimulable phosphor as described in U.S. Pat. Radiographic image conversion methods utilized are known.

In this method, radiation transmitted through the subject or radiation emitted from the subject is absorbed into a stimulable phosphor, and then this phosphor is exposed to electromagnetic waves (excitation light) such as visible light and infrared rays in a time-series manner. By exciting the phosphor, the radiation energy accumulated in the phosphor becomes fluorescent (stimulated luminescence)
The radiation image detection method consists of emitting a stimulable phosphor and detecting this fluorescence.So far, the radiation image detection method has been performed using a radiation image converter containing a stimulable phosphor. It has been proposed to use a panel (stimulable phosphor sheet) and photoelectrically read out the energy image of radiation accumulated in the radiation image conversion panel using a radiation image reading device. In addition, in radiation image reading devices, a photomultiplier tube is usually used as a photodetector, as disclosed in Japanese Patent Application Laid-open No. 56-11395. First, a light guide sheet is installed to collect the fluorescence emitted from the surface of the radiation image conversion panel and guide it to the photodetector.

In other words, the radiation that has passed through the subject (l, N) is absorbed by the phosphor layer of the channel (radiation image conversion), and the radiation image of the subject or subject is formed on the channel. It is formed as an accumulated image of radiation energy. Next, the accumulated image formed on this panel is excited by electromagnetic waves (excitation light) such as visible light and infrared rays in a radiation image reading device, and is emitted as stimulated luminescence (fluorescence). The emitted fluorescence is guided through a light-guiding sheet, then photoelectrically read by a photomultiplier tube and converted into an electrical signal.The obtained electrical signal is used to create a radiation image of the subject or subject. can do.

The radiation image conversion method has the advantage that it is possible to obtain a radiation image rich in information with a much lower exposure dose than when conventional radiography is used. Therefore, this radiation image conversion method has a very high utility value especially in direct medical radiography such as X-ray photography for the purpose of medical diagnosis.

However, reading of the radiation image conversion panel has conventionally been carried out by irradiating the panel with light with a small beam diameter, such as a laser beam, in chronological order, that is, by scanning (main scanning or sub-scanning) with the laser beam. At this time, the fluorescence emitted from the panel is detected using a photodetector such as a photomultiplier tube and converted into an electrical signal. This readout operation takes a considerable amount of time (several tens of seconds). ).

In addition, when reading out a radiation image conversion panel, in order to detect fluorescence emitted in time series from each group of phosphor particles on the radiation image conversion panel irradiated with excitation light, the panel is usually exposed to excitation light. (sub-scanning or main-scanning).

Therefore, the operation for detecting (reading) the radiation image stored in the radiation image conversion panel is complicated.

Furthermore, if a light-guiding sheet or the like is used in combination with a photomultiplier tube to efficiently detect fluorescence emitted from a radiation image conversion panel, the readout device becomes complicated and operational problems arise. is likely to occur.

Therefore, the main object of the present invention is to provide a radiation image detection method in which the above-mentioned problems in radiation image conversion methods using stimulable phosphors are solved or the drawbacks are reduced. It is something to do.

The above purpose is to detect the radiation transmitted through the subject or emitted from the subject by using a photodetecting member consisting of a large number of photosensitive elements regularly arranged two-dimensionally and a phosphor containing a stimulable phosphor. radiation energy is absorbed by a phosphor layer of a radiation image detector having a laminate of layers, and then the phosphor layer is irradiated with electromagnetic waves to release the radiation energy accumulated in the phosphor layer as photostimulated light. This can be achieved by the radiation image detection method of the present invention, which comprises photoelectrically reading this stimulated light using the photosensitive element.

That is, according to the studies of the present inventors, using a radiation image detector having a photodetecting member made of a large number of photosensitive elements and a phosphor layer made of a stimulable phosphor provided on the photodetecting member, Radiation such as X-rays transmitted through the subject or emitted from the subject is incident on the phosphor layer of this detector, and the energy of the radiation is absorbed by the stimulable phosphor in the phosphor layer. By irradiating the phosphor layer with light in the excitation wavelength range of the stimulable phosphor, the fluorescence (n-primary emission) emitted from the phosphor layer is received by the photosensitive element of the detector and converted into an electrical signal. It has been found that image information regarding a radiation image of a subject or a subject can be directly obtained as an electrical signal.

Therefore, according to the radiation image detection method of the present invention, compared to the radiation image readout methods proposed so far, since a photosensitive element integrated with a phosphor layer is used as a photodetector, Radiation image information can be obtained as electrical signals for each pixel of a large number of photosensitive elements under irradiation with excitation light, and therefore the detection time of a radiation image can be significantly shortened.

Furthermore, the radiation image detector used in the present invention is provided with a large number of photosensitive elements regularly arranged two-dimensionally so as to cover one surface of the phosphor layer, and under irradiation with excitation light. The fluorescence emitted from the surface of the phosphor layer is detected at each pixel of the photosensitive element adjacent to the phosphor layer.In other words, there is no need to move the panel during the readout operation of the radiation image line image conversion panel. Image detection is simplified.

Furthermore, unlike conventional methods, there is no need to install a light-guiding sheet to collect the fluorescent light emitted from the panel surface, so the readout device can be downsized, making it possible to capture the radiation image as described above. In the reading operation of the conversion panel, it is possible to eliminate problems such as adverse effects on image quality caused by mechanical transportation of the panel or detector.

This also means that even when the intensity of radiation transmitted through or emitted from an object is weak, the radiation image can be detected with high sensitivity, for example in measurements such as autoradiography. can also be used effectively.

The present invention will be explained in detail below.

The radiation image detector used in the present invention basically consists of a photodetecting member in which a large number of photosensitive elements are regularly arranged in a two-dimensional manner, and a phosphor layer provided on the photodetecting member. be.

The photodetecting member has a large number of photosensitive elements arranged regularly in the horizontal direction to form a plane. The photosensitive element used in the photodetecting member includes, for example, a light receiving part for receiving fluorescence emitted from a phosphor layer, and a time series output of electric charges obtained by photoelectric conversion in the light receiving part as an electric signal. A known solid-state image sensor using an amorphous semiconductor or the like can be used as the photosensitive element.

An example of such a solid-state image sensor is MOS (Met
al Oxide Sem1conductor)
, CCD (Charged Coupled De
vice), BB D (Bucket Brig
adeDevice), CI D (Charg
Sensors such as e15olated device) can be mentioned. Among these, particularly preferable is MOS
It is. In addition, photoconductive materials used in this solid-state image sensor include amorphous silicon Ca-5i), Zn
Examples include O, CdS, and the like.

A phosphor layer is provided on this photodetecting member with an insulating layer interposed therebetween. Examples of the material for the insulating layer include light-transmitting and insulating materials such as glass and transparent polymer materials. This insulating layer.

It is desirable to have a function as a filter that transmits only light in the wavelength range of stimulated luminescence and cuts light in the wavelength range of excitation light. Such a function as an optical filter can be imparted to the insulating layer by, for example, coloring the insulating layer with a coloring agent having optical selective transparency as described above.

Alternatively, a filter layer having light transmittance as described in "2" may be provided between the insulating layer and the phosphor layer.

The phosphor layer is usually a layer consisting of a binder containing and supporting stimulable phosphor particles in a dispersed state.

The stimulable phosphor used in the present invention is a phosphor that exhibits stimulated luminescence when irradiated with radiation and then with excitation light as described above, but from a practical point of view, the wavelength is 40.
300 to 5 by excitation light in the range of 0 to 800 nm.
It is desirable that the phosphor be a phosphor that exhibits stimulated luminescence in a wavelength range of 0.00 nm.

Examples of such stimulable phosphors include U.S. Pat.
SrS:Ce described in 859,527
, Sm, SrS:Eu.

Sm, Th0z:E r, and La2O2S:E
Phosphors expressed by compositional formulas such as u and Sm, JP-A-55
ZnS:Cu described in Publication No.-12142
, Pb, BaO*xAl2O3:Eu [however, 0.8
≦X≦10], and M2+0・xsi02:A [
However, M2+ is Mg, Ca, Sr, Zn, Cd, or Ba, and A is Ce, Tb, Eu, Tm, Pb, '
Tu, Bi, or Mn, and X is 0,5≦X≦2
．． A phosphor represented by a composition formula such as
1-z iy, M g z
, Ca y ) F X :aEu2
+[However, X is at least one of CJIJ and Brc7), and X and y are 0<x+y≦0.6,
Katsu x y b, with Ote, a is 10-≦a≦5X
A phosphor represented by the composition formula of lO'; LnO described in JP-A-55-12144;
X: xA [where Ln is La, Y, Gd, and Lu
X is at least one of C1 and Br, A is at least one of Ce and Tb, and X is O<x<0.1. The expressed phosphor is described in Japanese Patent Application Laid-open No. 55-12145 (B
at-X, M'' A is Eu, Tb, Ce, Tm, DV,
At least one of Pr, Ho, Nd, Yb, and Er, where X is O≦X≦0.6, and y is O≦y≦
A phosphor represented by the composition formula:
FX@xA: yLn [However, M seal is Ba, Ca
, S r, Mg, Zn, and Cd, A is Bed, MgO, CaO1S ro, Bad
, ZnO, Au203, Y2O3, La2O3, In2
o3, S i02, TM01, Z F02, GeO2,
S n02, Nb2O5, Ta205, and Tho2
At least one of the following, Ln is Eu, Tb, Ce, T
m, Dy, Pr, Ho, Nd, Yb, Er,
At least one of Sm and Gd, X is Cl
, Br, and I, and xs
, y and y are each expressed by the composition formula 5X10-' (x≦0.5, and 0xy≦0.2), which is described in JP-A-56-116777. (B
ar-x, M”x) F 2 ・aB aX2
:yEu, zA [However, Ml [ is at least one of beryllium, magnesium, calcium, strontium, zinc, and cadmium, X is chlorine, bromine,
and at least one of iodine, A is at least one of zirconium and scandium, and a
, x, y, and 2 are each 0.5≦a≦1.25.
0≦X≦1, io-"≦y≦2x10-", and O<z≦10-", a phosphor represented by the composition formula:
It is described in Japanese Patent Application Laid-open No. 57-23673 (
Ba1- x , M”)c) F 2 *
aBaX 2 :yEu, zB [However, Ml is beryllium, magnesium, calcium, strontium,
At least one of zinc and cadmium, or at least one of chlorine, bromine, and iodine, and a, x, y, and 2 are each 0.5≦a≦1.2
5.0≦X≦1,104≦y≦2×10−”, and 0
<z≦2
1-x9M-density A is at least one of arsenic and silicon, and a, x, y, and 2 are each 0.5≦
a≦1.25, O≦X≦1.101≦y≦2×io-'
, and O<z≦5X10-1], M”OX : xCe [where Mm is Pr , Nd, Pm, Sm, Eu, Tb, Dy, Ho, E
At least one trivalent metal selected from the group consisting of r, Tm, Yb, and Bi; 1. x is C1 and Br
Either or both of these, and X is 0
phosphor represented by the composition formula <x<0.1], B a 1- x M x /2 L x described in Japanese Patent Application No. 1989-89875 filed by the present applicant.
y2 F X :, E u2+ [However, M is L
represents at least one alkali metal selected from the group consisting of i, Na, Ni', Rb, and Cs; L is S;
c, Y, La, Ce, Pr, Nd, Pm, S
m, Gd, Tb, Dy, Ha, Er, Tm, Yb, L
represents at least one trivalent metal from the group consisting of u, AfL, Ga, In, and Tl;
represents at least one halogen selected from the group consisting of , Br, and ■; and X is 10-2≦X≦0
．． 5, y is o<y≦0.1] A phosphor represented by the composition formula: BaFX*xA, described in Japanese Patent Application No. 137374/1987 by the applicant: yEu2+ [However, X is at least one halogen selected from the group consisting of C1, Br, and ■; A is a fired product of a tetrafluoroboric acid compound; and X is io-"
≦X≦o, t, y are O x y≦0.1] A phosphor represented by the composition formula BaFX*xA described in Japanese Patent Application No. 158048/1983 filed by the present applicant: yEu'' [where X is at least one halogen selected from the group consisting of CgL, Br, and I; A is monovalent or divalent hexafluorosilicic acid, hexafluorotitanic acid, and hexafluorozirconic acid. It is a fired product of at least one compound selected from the group of hexafluoro compounds consisting of metal salts; and X is lo-6≦X≦0゜1
, y is o<y≦0.1]; , X and X′ are C1, Br, and I, respectively.
A phosphor represented by the composition formula: at least one of M "F X @ X N a X ' stated in the specification
:yEu':zA [However, yIN is Ba, Sr,
and at least one alkaline earth metal selected from the group consisting of Ca; X and X' are each C9
, Br, and ■: A is at least one halogen selected from the group consisting of ■, Cr, Mn, Fe, C
o, and at least one transition metal selected from Ni; and X is O<x≦2, and y is o<y≦0.2.
, and Z is 0<z≦10-] A phosphor represented by the composition formula M"FX・a M "X"
2.CMTIIX'' 3. X A: y Eu
2+[However, M"j: at least one kind of alkaline earth metal selected from the group consisting of Ba, Sr, and Ca; MI is at least one kind selected from the group consisting of Li, Na, Rb, and Cs M” is at least one divalent metal selected from the group consisting of Be and Mg; MI is AJJ, Ga, In
, and at least one trivalent metal selected from the group consisting of Tl; A is a metal oxide;
r, and at least one halogen selected from the group consisting of
"° is at least one kind of halogen selected from the group consisting of F, C, Br, and I; and a is O.
≦a≦2, b is O≦b≦10”, C is O≦C≦10-2
, and a +' b + c≧to-'; X is 0
<x≦0.5, y is o<y≦0.2, and the like can be mentioned.

Note that the stimulable phosphor used in the present invention is not limited to the above-mentioned phosphors, but any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light. There may be.

However, the stimulable phosphor needs to be used in combination with a photosensitive element so that the wavelength range of its stimulated luminescence overlaps the light absorption wavelength range of the photoconductive material used in the light receiving part of the photosensitive element. That is, the photostimulable phosphor and photoconductive material used in the present invention must be selected so that at least a portion of the emission wavelength region of stimulated light overlaps at least a portion of the light absorption wavelength region of the photoconductive material. Must be. For example, when α-3t is used as the photoconductive material, the stimulable phosphor is preferably a phosphor having a stimulated emission wavelength around 600 nm. In addition, divalent europium-activated alkaline earth metal fluoride halide phosphors (
When using a phosphor having a stimulated emission wavelength in the near-ultraviolet to visible region, such as (emission peak wavelength is about 390 nm), ZnS and CdS are used as photoconductive materials.
is preferred.

Examples of binders for the phosphor layer include proteins such as gelatin, polysaccharides such as dextran, or natural polymeric substances such as gum arabic; and polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, and vinylidene chloride/chloride. Vinyl copolymer, polymethyl methacrylate, vinyl chloride/vinyl acetate copolymer, polyurethane, cellulose acetate butyrate,
Examples of binders include synthetic polymeric substances such as polyvinyl alcohol and linear polyester.

For example, the phosphor layer can be formed by forming an insulating layer (
or a single layer of filters).

First, the above-mentioned stimulable phosphor particles and binder are added to a suitable solvent (e.g., lower alcohol, ketone, ester, ether) and mixed thoroughly, so that the phosphor particles are dissolved in the binder solution. Prepare a uniformly dispersed coating solution.

The mixing ratio of the binder and the stimulable phosphor particles in the coating solution depends on the characteristics of the intended radiation image detector, the type of photosensitive element,
Although it varies depending on the type of phosphor particles, in general, the mixing ratio of the binder and phosphor particles is from ■=1 to 1:100 (
weight ratio), and especially l:8 to l:1:
It is preferable to select from a range of 40 (weight ratio).

The coating liquid contains a dispersant to improve the dispersibility of the phosphor particles in the coating liquid, and a dispersant to improve the bonding force between the binder and the phosphor particles in the phosphor layer after formation. Various additives, such as plasticizers, may be mixed to make the material more durable.

A coating solution containing the stimulable phosphor particles and a binder prepared as described in Section 2 is then uniformly applied to the surface of the insulating layer to form a coating film of the coating solution. This coating operation can be carried out using conventional coating means such as a doctor blade, roll coater, knife coater, etc. Then, the formed coating film is gradually heated and dried to complete the formation of the phosphor layer on the insulating layer. The thickness of the phosphor layer varies depending on the characteristics of the intended radiation image detector, the type of phosphor particles, the mixing ratio of the binder and the phosphor particles, and is usually 20 gm to 1 mm. However, this layer thickness is 50 to 500
It is preferable to set it as pm.

Note that the phosphor layer does not necessarily need to be formed by directly applying a coating liquid to the insulating layer as described above; for example,
Separately, a phosphor layer is formed by coating and drying a coating liquid on a sheet such as a glass plate, metal plate, or plastic sheet, and then this is pressed onto an insulating layer or by using an adhesive. The insulating layer and the phosphor layer may be bonded together.

Further, the phosphor layer does not necessarily need to be formed by dispersing stimulable phosphor particles in a binder.

For example, it may be formed by depositing stimulable phosphor particles on the insulating layer by vacuum deposition or the like.

Preferably, a transparent protective film is provided on the phosphor layer to protect the phosphor layer from physical impact and chemical alteration. The protective film may be made of, for example, a cellulose derivative such as cellulose acetate or nitrocellulose; or polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate,
Polyvinyl acetate, vinyl chloride/vinyl acetate copolymer,
It is formed from synthetic polymeric substances such as polyethylene terephthalate, polyethylene, vinylidene chloride, and polyamide. The thickness of the protective film is preferably about 3 to 20 pm.

Next, regarding the radiation image detection method of the present invention, an example of a partial vertical sectional view of the radiation image detector shown in FIG. 1 of the accompanying drawings and an overall circuit diagram of the radiation image detector shown in FIG. This will be explained in detail with reference to the following.

FIG. 1 is a longitudinal cross-sectional view of one pixel of a radiation image detector comprising a photodetecting member and a phosphor layer provided on the photodetecting member.

In FIG. 1, the radiation image detector is composed of, in order, a photosensitive element 1, an insulating layer 2, and a phosphor layer 3 made of a stimulable phosphor. The photosensitive element 1 has a photodiode 4 which is a light receiving part and a MOS which is a transfer part: FET (Meta
l Oxide Sem1conductor: F
ieldEffect Transistor)
It consists of 5. The photodiode 4 includes, in order, a metal layer 6 of ground such as aluminum, a P-type α-Si:H layer 7,
It consists of an i-type α-3i:H layer 8 and a transparent electrode layer 9 of tin dioxide (Sn02). Also, MOS: FET5 is
Metal layers 1O111 such as aluminum provided at both ends, and α-3i :H provided in order inside these metal layers.
It consists of a layer 12, an insulating layer 13 of silicon (Si02), and a transfer electrode 14 of aluminum or the like. This metal layer 1
1 is the drain, which is connected to the transfer register.

On the other hand, the transfer electrode 14 is a gate and is connected to a scanning pulse generator. The insulating layer 2 has such a light transmittance that it transmits only light in the wavelength range of stimulated luminescence emitted from the phosphor layer 3 and cuts light in the wavelength range of excitation light.

FIG. 2 is a schematic circuit diagram of a light sensing member of a radiation image detector. One pixel 21 corresponds to that shown in FIG. 1, and is composed of a light receiving section 22 and a transfer section 23. Each transfer section is
scan pulse generator 24 and transfer register 25, respectively.
It is connected to the.

The transfer register 25 is provided with an output terminal 26 .

First, the radiation that has passed through the object (or, if the object itself emits radiation, that is, the object, the radiation emitted from the object) is made incident on the phosphor layer side of the radiation image detector. That is, radiation having strengths and weaknesses corresponding to the radiographic image of the subject enters from below in FIG. The incident radiation is absorbed by the phosphor layer 3.

That is, on the phosphor layer 3, an image of accumulated radiation energy (a kind of latent image) corresponding to a radiation image of the subject is formed.

Next, when the radiation image detector is irradiated with electromagnetic waves in the excitation wavelength range of the stimulable phosphor contained in the phosphor layer from the phosphor layer 3 side, the accumulated radiation energy image formed on the phosphor layer 3 is , emitted as fluorescence (stimulated luminescence). This fluorescence is proportional to the intensity of radiation energy absorbed by the phosphor layer 3.

Only the emitted fluorescence passes through the insulating layer 2, which also serves as a filter, and is received by the photodiode 4 of the photosensitive element 1, which is a photodetecting member, and a signal charge is generated in the photodiode 4. In this way, a signal charge is generated in each pixel of a large number of photosensitive elements of the radiation image detector, which is proportional to the luminance of fluorescence, that is, the intensity of the radiation incident on the phosphor layer of the detector.

Next, in the circuit diagram shown in FIG. 2, when the scan pulse generator 24 sends a transfer pulse to each pixel in the top row, each transfer unit in the top row has a single switch (in FIG. 1, the transfer electrode A state is reached in which a voltage is applied to 14 and a current flows between the metal layer IO and 11. That is, the signal charge generated in the photodiode 4 in FIG.
Transferred via T5. Therefore, the signal charges of each pixel in the top row are sent to the transfer register 25 simultaneously. Electric signals for each pixel are taken out in time series from the output terminal 26 of the transfer register 25.

In this way, from the top row to the bottom row in Figure 2,
A transfer pulse is sent from the scanning pulse generator 24 to each column,
Electrical signals from each pixel in each column having radiation image information are outputted from the output terminal 26 in time series.

The electric signal output from the radiation image detector is amplified by an amplifier and reproduced as an image by an image reproduction device. The electrical signal obtained here may be subjected to image processing such as spatial frequency processing, gradation processing, averaging processing, reduction processing, and enlargement processing, if desired. Then, the obtained image may be recorded on a recording medium or displayed on an image display device. As a recording medium,
For example, it is possible to use a method that records optically by scanning a photographic light-sensitive material with a laser beam or the like, or a method that records on a heat-sensitive recording material using heat rays. Further, as the image display device, display devices based on various principles can be used, such as one that displays electronically on a CRT or the like, or one that records a radiation image displayed on a CRT or the like on a video printer or the like. Further, this radiation image information of the subject may be recorded and stored on a magnetic tape or the like.

In addition, in the radiation image detector used in the present invention, as a photosensitive element, one pixel has approximately 200 pLmX 20
07tm size can be used. If the size of the radiation image detector is, for example, about the same size as a conventional radiation intensifying screen (430 mm x 354 mm), it will be composed of 2150 x 1750 pixels. As a material for a uniform photosensitive element that forms such a large area, α
-3i is preferable, and it is desirable that the area of the light receiving part is as large as possible. In a radiation image detector having the structure and size as described above, the pulse output from the scanning pulse generator is preferably about 3 kHz, for example.

However, the radiation image detector used in the present invention and the photosensitive element included therein are not limited to the above-mentioned size. Furthermore, the radiation image detector used in the present invention is not limited to the detectors exemplified above,
It can take any form as long as it has a phosphor layer containing a stimulable phosphor and a large number of regularly arranged two-dimensionally arranged photosensitive elements for reading the stimulable light from this phosphor layer. It is possible.

Furthermore, the radiation image detection method of the present invention is not limited to the method exemplified above. Before the main operation, a preliminary operation by irradiating weak electromagnetic waves may be performed in order to measure the amount of photostimulated light, and based on the results of this preliminary operation, the amplification factor of the obtained electric signal can be set, and the reproduced image It is also possible to set processing conditions.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial vertical sectional view of a radiation image detector used in the radiation image detection method of the present invention. l: photosensitive element, 2: insulating layer, 3: phosphor layer, 4: photodiode, 5: MOS: FET, 6: metal layer,
7: p-type α-Si:H layer, 8: i-type α-3t:H layer, 9
: transparent electrode layer, 10.11: metal layer, 12: α-3t
: H layer, 13: Insulator layer, 14: Transfer electrode FIG. 2 is a schematic circuit diagram of a radiation image detector used in the radiation image detection method of the present invention. 21 pixel, 22: Light receiving section, 23: Transfer section 24: Scanning pulse generator, 25: Transfer register, 26: Output terminal Patent applicant Fuji Photo Film Co., Ltd. Agent Patent attorney Yasuo Yanagawa

Claims (1)

[Claims] l. A laminated layer consisting of a light-detecting member made of a large number of photosensitive elements arranged in a regular two-dimensional manner and a phosphor layer containing a stimulable phosphor, which detects radiation transmitted through or emitted from an object. After the radiation energy is absorbed into the phosphor layer of a radiation image detector having a body, the phosphor layer is irradiated with electromagnetic waves to release the radiation energy stored in the phosphor layer as photostimulated light. A radiation image detection method comprising photoelectrically reading light with the photosensitive element. 2゜The photosensitive element is composed of a light receiving section and a transfer section, and the light receiving section is a photodiode and the transfer section is a MOS)
2. The radiation image detection method according to claim 1, wherein the radiation image detection method is a radiator. 3. The radiation image detection according to claim 1 or 2, wherein the phosphor layer contains a divalent europium-activated alkaline earth metal fluorohalide phosphor. Method.