JPH043058B2

JPH043058B2 -

Info

Publication number: JPH043058B2
Application number: JP57113852A
Authority: JP
Priority date: 1982-07-02
Filing date: 1982-07-02
Publication date: 1992-01-21
Also published as: JPS595549A

Description

【発明の詳細な説明】発明の技術分野本発明は放射線を用いて医療診断または工業用
検査に用いる放射線像増強管装置に関する。さら
に詳しくは電子管の内部に第１の螢光面を用いて
放射線像を光像に変換し、光電面により光像を電
子像に、該電子像を適当な増倍手段により増倍
し、そして第２の螢光面により光像に変換し、さ
らに光導電面で光像を電荷像に変換し、この電子
像を電子ビーム走査により時系列的に読取つて電
気信号出力を得る新しい放射線像増強管装置に関
するものである。発明の技術的背景と問題点第１図は、従来の放射線像増強管装置の１例を
示す。１は放射線像増強管の真空容器で、放射線
９の入射方向から順に、放射線入射窓２、胴部
３、錐部４、出力部５よりなる。そしてこれらは
いずれも軸対象で、放射線入射窓２の有効面は円
形である。放射線入射窓２に内部には放射線像を
電子像に変換する放射線像変換パネル６が内蔵さ
れている。放射線像変換パネル６は、第２図に示
すようにアルミニウム基板１７上に例えば沃化セ
シウムからなる螢光面１８、酸化アルミニウム、
酸化インジウム等の保護膜１９、光電面２０を順
次形成したもので、放射線９は螢光面１８で光に
変換され、この光は光電面２０によつて光電子８
に変換される。光電子８は放射線像変換パネル６
とグリツド電極１５および陽極１６によつて形成
された電子レンズによつて加速・集束作用を受
け、出力螢光面７によつて明るい光像に変換され
る。そして出力螢光面７に形成された光像は１対
のレンズ１０，１１からなるタンデムレンズ系に
よつて、１２で示すような光路をとりテレビカメ
ラ１３に入射し、出力端子１４より電気信号とし
て取り出される。このような従来の装置の場合、放射線像変換パ
ネル６とグリツド電極１５、陽極１６とは軸対称
の静電レンズを形成するため、放射線像変換パネ
ル６の形状は、放射線入射窓２方向に突き出た球
面である。このため有効面が角形に出来ない、糸
巻歪が大きい、周辺部の輝度が中心部に比し低く
なる傾向をもち、また全長が長いと言つた不都合
がある。特に大視野の有効面を必要とする場合こ
れらの不都合は顕著になる。また撮像管の解像度は必らずしもよくないの
で、装置全体の解像度が悪い。さらにタンデムレンズ系、テレビカメラ１３と
結び付けることによつて、はじめて電気信号が取
り出せるので、調整も複雑であり価格的にも高価
なものとなる。発明の目的本発明は上述の如く、従来の放射線像増強管装
置の不都合を除去して、性能の優れた新しい放射
線像増強管装置を提供するものである。即ち本発明の特長は下記の如くなる。 ○イ角形有効面にすることが出来る。 ○ロ放射線像を直接電気信号として時系列的に取
り出すことが出来る。 ○ハ糸巻歪が非常に少ない。 ○ニ中心と周辺の輝度一様性が良い。 ○ホ小形、軽量である。 ○ヘ高解像度である。発明の概要径大部とコーン部を介してそれに対向する部分
が径小部からなる真空容器を備え、放射線像を第１の螢光面で光像に変換し、該
光像を光電面で電子像に変換する放射線像変換
パネル、上記光電子を増倍する手段、光透過ガラス基板の放射線入射側に電子線を
透過する遮光膜と電子線照射で発光する第２の
螢光面を順に形成し、他面に光導電面を有して
電子像を蓄積電荷像に変換する光電変換パネ
ル、上記電荷像を読取るための読取電子ビームが
光電変換パネルにほゞ垂直入射するような電界
形成手段、とを、径大部に放射線入射側から所定の間隔で順
次に配置し、径小部には読取電子ビームを発生せ
しめる電子銃と集束手段、偏向手段とを備え、径
大部面に入射した放射線像を電気信号に変換する
ことを特徴とした放射線像増強管装置であつて、
実質的に近接集束形イメージ管と撮像管とを一体
化したような装置である。即ち、角形を含めた任意の平面形状の放射線像
変換パネルで、Ｘ線→光→光電子変換を行ない、
１段または複数段の近接集束形イメージ管、また
はマイクロチヤンネルプレートの原理を用いて、
前記光を増倍し、この光を光導電膜に入射せしめ
て撮像管の原理により光電変換パネルから電気信
号として時系列的に取り出すものである。発明の実施例第３図は本発明の一実施例で、第４図、第５図
はその要部拡大図である。真空容器１００は径大部が放射線入射窓１０
２、胴部１０３よりなり径小のネツク部１０５と
の間はコーン部１０４で接続されている。放射線
入射窓１０２としてはガラスでもよいが、アルミ
ニウム、チタニウム、鉄合金の薄板が耐気圧に強
く、放射線透過もよいので望ましい。径大部の内
部には、放射線入射窓１０２側から順に放射線像
変換パネル１０６、光電変換パネル１０７、２枚
のメツシユ電極１０８，１０９が互いに近接して
配置されている。放射線像変換パネル１０６は、
例えば、厚さ0.5mmのアルミニウム基板１５０、
厚さ200μｍの沃化セシウム蒸着膜よりなる第１
の螢光面１５１、酸化アルミニウム、酸化インジ
ウム等よりなる保護膜１５２、Sb−Cs，Sb−Cs
−Ｋ，Sb−Cs−Ｋ−Na等よりなる光電面１５３
が順次形成されている。今放射線９、例えばＸ線が放射線入射窓１０２
を透過して入射すると、上記第１の螢光面１５１
により光に変換され、この光は保護膜１５２を透
過して光電面１５３に達し、光の強弱に応じた光
電子１５４を放出する。次に放射線像変換パネル１０６から距離ｄだけ
離れて光電変換パネル１０７が配置されている。
光電変換パネル１０７は光フアイバープレートま
たは厚さ100〜300μｍの超薄形ガラス板よりな
る。光伝達ガラス基板１６０の放射線像変換パネ
ル１０６側に、電子線で発光する例えば（Zn，
Cd）SiAg，ZnS：Cu，Cl等の硫化物螢光体から
なる第２の螢光面１６１と、メタルバツク層１６
５、光しや光膜１６９が被着され、他面には光導
電面１６８が形成されている。遮光膜１６９は第２の螢光面の光の一部がメタ
ルバツク層１６５を透過してそれと対向する光電
面１５３を刺激してノイズ成分の光電子を放出さ
せるのを防止するのが目的である。光しや光膜と
しては炭素の蒸着膜、10^-1torr程度の圧力のアル
ゴン雰囲気中でアルミニウムを蒸着することによ
つて得られる黒アルミニウム膜等が用い得る。光導電膜としては用途に応じて種々のものがあ
るが、例えば東芝カルニコン（商品名）撮像管に
使用されているものは、透明導電膜１６２，
CdSe膜１６３、As₂S₃膜１６４が順次被着されて
いる。今放射線像変換パネル１０６の光電面１５３と
光電変換パネル１０７の第２の螢光面１６１間の
距離をｄ、その間に印加される電圧をＶとする
と、光電変換パネル１０７の第２の螢光面１６１
での解像度Ｒ（lp／mmで表わす）と、輝度増倍度
BMは次の関係にある。Ｒ＝Ｋ√Ｖ／ｄ BM＝K′（Ｖ−V₀）ⁿ ここでＫ，K′は定数、V₀はメタルバツク層１
６５と光しや光膜１６９との厚さで決まる定数で
一般に３〜10KVであり、ｎは第２の螢光面１６
１の特性によつて決まる定数で一般には0.5〜1.5
の間にある。しかるにｄを小さくすればする程解像度は良く
なるが、両電極間の耐電圧が悪くなる。またＶを
大きくすればする程解像度輝度増倍率は向上する
が、耐電圧が悪くなる関係を有する。以上のことを勘案してｄとＶを決める必要があ
るが、一例としてｄ＝３mm，Ｖ＝10KVとした場
合、解像度は約30lp／mm、輝度増倍度は50倍とな
る。上記のように光電子増倍手段により輝度増倍さ
れた第２の螢光面１６１の光１６７は、フアイバ
ープレート１６０を通して他面に形成された光導
電面１６８に伝達される。光導電面１６８は光の
強弱に応じて抵抗値が変化しその表面に電荷像を
蓄積する。第６図は第５図に示す光電変換パネル１０７の
他の実施例で、第５図のフアイバープレート１６
０の代りに、厚さが100〜300μｍの薄いガラス板
１６６を用いたもので、ガラス板厚が充分に薄け
れば、解像度の劣化を最小限に抑えて第２の螢光
面１６１の光１６７を光導電面１６８へ伝達す
る。一方、ネツク部１０５の内部には電子銃１１０
が内蔵されており、こゝで発生した電子ビーム１
１１は集束コイル１１２、偏向ヨーク１１３の作
用を受けて前記径大部に内蔵された光電変換パネ
ル１０７方向へ向う。この際光電変換パネル１０
７の電子銃１１０側に２枚のメツシユ電極１０
８，１０９を設け、電子銃のカソード（図示せ
ず）電圧に対し、例えば第１メツシユ電極１０９
に＋8KV、第２メツシユ電極１０８に第１メツ
シユ電極１０９よりは高い電圧＋10KVを印加す
る。偏向ヨーク１１３で偏向され第１メツシユ電
極１０９で加速された読取電子ビーム１１１は、
第７図に示すように第１メツシユ電極１０９と第
２メツシユ電極１０８との間の加速電界によつ
て、第２メツシユ電極１０８を透過した後は第２
メツシユ電極１０８にほぼ直角方向に曲げられて
いる。この様子を第７図に示す。そして光導電面１６８に対しほゞ垂直に入射
し、光導電面１６８の表面に形成された電荷像に
対応した電気信号が、光導電面１６８の出力端子
１１５より取出せる。尚光導電面１６８の透明導
電膜１６２に印加されている電圧は数10Vであ
る。上記２ケのメツシユ電極のピッチは読取電子ビ
ーム１１１の大きさに対して充分小さく、かつ電
子ビーム透過の良いものが良く、一例としてニツ
ケル、タングステン、銅等を材料とした50〜500
メツシユが適当である。メツシユ電極はさらに増
設してもよい。このように本発明では放射線像変換パネル１０
６と光電変換パネル１０７とが平面であり、この
間で近接集束を行なうので、有効面を角形にする
ことが出来る。さらに上記読取電子ビーム１１１は径小のネツ
ク部１０５で発生せしめ偏向ヨーク１１３を使つ
て、有効面全体を走査し、かつ２ケのメツシユ電
極を設けてこの間に加速電界を作つて、光導電面
１６８に入射する読取電子ビーム１１１を垂直入
射させるので全面均一な画像読出しが出来る。第８図は本発明の別の実施例で、光電変換パネ
ルを２ケ用いて光電子増倍を２段設けたものであ
る。電子銃１１０側の光電変換パネル２０２は第
３図に示す光電変換パネル１０７と全く同一であ
るが、放射線入射窓１０２側の光電変換パネル２
０１ではガラス基板の電子銃側に光電面２０６を
形成している。また２ケの光電変換パネル２０
１，２０２の間隔と印加電圧に関しても第３図の
放射線像変換パネル１０６と光電変換パネル１０
７の場合と全く同じである。放射線像変換パネル
１０６より放出された第１の光電子２０３は第１
の光電変換パネル２０１の螢光面２０５を光らし
光増倍を行なう。この光は他面に形成された光電
面２０６に導かれて第２の光電子２０４を放出す
る。そしてこの光電子２０４は第２の光電変換パ
ネル２０２の螢光面２０７を光らし光増倍を行な
う。この光が他面に形成された光導電膜２０８を
刺激し、その表面に電荷像を形成する。この電荷
像は読取ビーム１１１によつて出力端子１１５よ
り電気信号として読出される。この方式は近接集束形イメージ管の輝度増倍を
２回くり返すので全体の輝度増倍度は50×50＝
2500倍となる。しかし解像度は若干悪くなる。光電子増倍のためにマイクロチヤンネルプレー
トを用いてもよい。マイクロチヤンネルプレート
は、例えば直径50μｍのガラス細管の内壁に二次
電子放出均質例えばPbO膜が形成されたもので、
その長さ方向に連続的に電圧が印加されているの
で、その低電圧側に入射した電子は上記ガラス細
管内壁で二次電子増倍され、高電圧側に出てくる
時には数百倍から数万倍に増倍されている。しか
るにこのようなガラス細管をフアイバープレート
のように束ねることにより、一面に入射した光電
子像は、増倍されて他面より光電子像として放出
される。このマイクロチヤンネルプレートを放射
線像変換パネルに近接して設け光電子を増倍して
放出するように構成することができる。発明の効果上記したように本発明は有効面が角形で従来方
式のようなタンデムレンズ系とテレビカメラが不
要なので装置全体を考えると著しく小形軽量であ
り、放射線像を直接電気信号として取り出し、テ
レビモニターでの透視や画像処理装置と接続して
診断能の高い画像を高速で再構成することが出来
るので、Ｘ線を用いた医療診断用として特に有効
である。従来のＸ線螢光増倍管装置と比較して次のよう
な利点がある。入力面が平面にできるので、糸巻歪、輝度一
様性が優れている。また同一最大径に対して有
効面が広くとれる。入力有効面を角形にすることができるので、
胸部、腹部等への診断領域が拡がる。放射線像を時系列的な電気信号として、直接
取出すことができる。装置全体として従来装置よりも小形軽量にで
きる。解像度が優れている。 DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a radiation image intensifier tube device that uses radiation for medical diagnosis or industrial testing. More specifically, a first fluorescent surface is used inside the electron tube to convert a radiation image into a light image, a photocathode converts the light image into an electron image, the electron image is multiplied by a suitable multiplication means, and A new radiation image enhancement system that converts the electron image into a light image using the second fluorescent surface, converts the light image into a charge image using the photoconductive surface, and reads this electron image in time series using electron beam scanning to obtain an electrical signal output. This relates to pipe equipment. Technical Background and Problems of the Invention FIG. 1 shows an example of a conventional radiation image intensifier tube device. Reference numeral 1 denotes a vacuum container of a radiation image intensifier tube, which consists of a radiation entrance window 2, a body part 3, a cone part 4, and an output part 5 in order from the direction of incidence of radiation 9. All of these are axially symmetrical, and the effective surface of the radiation entrance window 2 is circular. A radiation image conversion panel 6 for converting a radiation image into an electronic image is built into the radiation entrance window 2. As shown in FIG. 2, the radiation image conversion panel 6 has a fluorescent surface 18 made of, for example, cesium iodide, aluminum oxide,
A protective film 19 such as indium oxide and a photocathode 20 are sequentially formed. Radiation 9 is converted into light by the fluorescent surface 18, and this light is converted into photoelectrons 8 by the photocathode 20.
is converted to The photoelectron 8 is the radiation image conversion panel 6
The electron beam is accelerated and focused by the electron lens formed by the grid electrode 15 and the anode 16, and is converted into a bright optical image by the output fluorescent surface 7. The light image formed on the output fluorescent surface 7 takes an optical path as shown by 12 through a tandem lens system consisting of a pair of lenses 10 and 11, and enters the television camera 13, where it is sent as an electrical signal from the output terminal 14. is extracted as. In the case of such a conventional device, since the radiation image conversion panel 6 , the grid electrode 15, and the anode 16 form an axially symmetrical electrostatic lens, the shape of the radiation image conversion panel 6 is such that it protrudes in the direction of the radiation entrance window 2. It is a spherical surface. For this reason, there are disadvantages such as the effective surface cannot be made into a square shape, pincushion distortion is large, the brightness at the periphery tends to be lower than that at the center, and the overall length is long. These disadvantages become particularly noticeable when a large field of view is required. Furthermore, since the resolution of the image pickup tube is not necessarily good, the resolution of the entire device is poor. Further, since electric signals can only be extracted by connecting the tandem lens system and the television camera 13, the adjustment is complicated and the price is high. OBJECTS OF THE INVENTION As described above, the present invention provides a new radiation image intensifier tube device with excellent performance by eliminating the disadvantages of the conventional radiation image intensifier tube device. That is, the features of the present invention are as follows. ○B Can be made into a square effective surface. ○B Radiographic images can be directly extracted as electrical signals in time series. ○C There is very little pincushion distortion. ○D Good brightness uniformity between center and periphery. ○E It is small and lightweight. ○F High resolution. Summary of the Invention A vacuum vessel is provided with a large-diameter portion and a small-diameter portion opposite to the cone portion through a cone portion, a radiation image is converted into a light image by a first fluorescent surface, and the light image is converted by a photocathode. A radiation image conversion panel that converts into an electron image, a means for multiplying the photoelectrons, a light-shielding film that transmits the electron beam, and a second fluorescent surface that emits light when irradiated with the electron beam are sequentially formed on the radiation incident side of the light-transmitting glass substrate. and a photoelectric conversion panel having a photoconductive surface on the other side to convert an electron image into an accumulated charge image, and an electric field forming means such that a reading electron beam for reading the charge image is almost perpendicularly incident on the photoelectric conversion panel. , and are sequentially arranged at a predetermined interval from the radiation incident side in the large diameter part, and the small diameter part is equipped with an electron gun for generating a reading electron beam, focusing means, and deflection means, and the electron beam is incident on the large diameter part. A radiation image intensifier tube device characterized by converting a radiation image into an electrical signal,
It is essentially a device that integrates a close focusing image tube and an image pickup tube. That is, X-ray → light → photoelectron conversion is performed using a radiation image conversion panel of any planar shape, including rectangular shapes.
Using the principle of one or more stages of closely focused image tubes or microchannel plates,
The light is multiplied, the light is made incident on a photoconductive film, and is extracted in time series as an electrical signal from a photoelectric conversion panel using the principle of an image pickup tube. Embodiment of the Invention FIG. 3 shows an embodiment of the present invention, and FIGS. 4 and 5 are enlarged views of the main parts thereof. The large diameter portion of the vacuum container 100 is the radiation entrance window 10.
2. A cone portion 104 connects the body portion 103 to a small diameter neck portion 105. Although glass may be used as the radiation entrance window 102, thin plates made of aluminum, titanium, or iron alloys are preferable because they are resistant to pressure and have good radiation transmission. Inside the large-diameter portion, a radiation image conversion panel 106 , a photoelectric conversion panel 107 , and two mesh electrodes 108 and 109 are arranged close to each other in order from the radiation entrance window 102 side. The radiation image conversion panel 106 is
For example, an aluminum substrate 150 with a thickness of 0.5 mm,
The first layer is made of cesium iodide vapor deposited film with a thickness of 200 μm.
A protective film 152 made of aluminum oxide, indium oxide, etc., Sb-Cs, Sb-Cs
-K, photocathode 153 made of Sb-Cs-K-Na, etc.
are formed sequentially. Now radiation 9, for example X-rays, is transmitted to the radiation entrance window 102.
When it enters the first fluorescent surface 151
This light is transmitted through the protective film 152, reaches the photocathode 153, and emits photoelectrons 154 depending on the intensity of the light. Next, a photoelectric conversion panel 107 is arranged at a distance d from the radiation image conversion panel 106 .
The photoelectric conversion panel 107 is made of an optical fiber plate or an ultra-thin glass plate with a thickness of 100 to 300 μm. For example , (Zn,
Cd) SiAg, ZnS: A second phosphor surface 161 made of a sulfide phosphor such as Cu, Cl, and a metal back layer 16
5. A light film 169 is applied, and a photoconductive surface 168 is formed on the other side. The purpose of the light-shielding film 169 is to prevent a portion of the light from the second fluorescent surface from transmitting through the metal back layer 165 and stimulating the photocathode 153 facing it to emit photoelectrons as noise components. As the light source or film, a carbon vapor deposited film, a black aluminum film obtained by vapor depositing aluminum in an argon atmosphere at a pressure of about 10 ^-1 torr, etc. can be used. There are various types of photoconductive films depending on the application, but for example, the ones used in Toshiba Calnicon (trade name) image pickup tubes are transparent conductive films 162,
A CdSe film 163 and an As ₂ S ₃ film 164 are sequentially deposited. Now, if the distance between the photocathode 153 of the radiation image conversion panel 106 and the second fluorescent surface 161 of the photoelectric conversion panel 107 is d, and the voltage applied therebetween is V, then the second fluorescent surface of the photoelectric conversion panel 107 Surface 161
resolution R (expressed in lp/mm) and brightness multiplication
BM has the following relationship. R=K√V/d BM=K'(V-V ₀ ) ^nHere , K and K' are constants, and V ₀ is the metal back layer 1.
It is a constant determined by the thickness of the second fluorescent surface 165 and the second fluorescent surface 169, and is generally 3 to 10 KV.
A constant determined by the characteristics of 1, generally 0.5 to 1.5
It's between. However, the smaller d is, the better the resolution becomes, but the withstand voltage between the two electrodes becomes worse. Further, as V increases, the resolution and brightness multiplication factor improves, but the withstand voltage deteriorates. It is necessary to decide d and V by taking the above into consideration. For example, if d=3 mm and V=10 KV, the resolution will be about 30 lp/mm and the brightness multiplication will be 50 times. The light 167 from the second fluorescent surface 161 whose brightness has been multiplied by the photoelectron multiplier as described above is transmitted through the fiber plate 160 to a photoconductive surface 168 formed on the other surface. The resistance value of the photoconductive surface 168 changes depending on the intensity of light, and a charge image is accumulated on its surface. FIG. 6 shows another embodiment of the photoelectric conversion panel 107 shown in FIG.
0, a thin glass plate 166 with a thickness of 100 to 300 μm is used, and if the glass plate is sufficiently thin, the light from the second fluorescent surface 161 can be minimized with deterioration of resolution. 167 to a photoconductive surface 168 . On the other hand, an electron gun 110 is provided inside the network portion 105.
is built in, and the electron beam 1 generated here
11 is directed toward a photoelectric conversion panel 107 built in the large diameter portion under the action of a focusing coil 112 and a deflection yoke 113. At this time, the photoelectric conversion panel 10
Two mesh electrodes 10 are placed on the electron gun 110 side of 7.
8, 109, for example, the first mesh electrode 109 is connected to the cathode (not shown) voltage of the electron gun.
A voltage of +8 KV is applied to the second mesh electrode 108, and a voltage of +10 KV, which is higher than that of the first mesh electrode 109, is applied to the second mesh electrode 108. The read electron beam 111 is deflected by the deflection yoke 113 and accelerated by the first mesh electrode 109.
As shown in FIG. 7, the accelerating electric field between the first mesh electrode 109 and the second mesh electrode 108 causes the second mesh electrode to pass through the second mesh electrode 108.
It is bent in a direction substantially perpendicular to the mesh electrode 108. This situation is shown in FIG. Then, an electric signal corresponding to the charge image incident on the photoconductive surface 168 approximately perpendicularly and formed on the surface of the photoconductive surface 168 can be extracted from the output terminal 115 of the photoconductive surface 168 . Note that the voltage applied to the transparent conductive film 162 on the photoconductive surface 168 is several tens of volts. The pitch of the above two mesh electrodes should be sufficiently small relative to the size of the reading electron beam 111 and have good electron beam transmission.For example, a mesh electrode made of nickel, tungsten, copper, etc.
Metsuyu is appropriate. Further mesh electrodes may be added. In this way, in the present invention, the radiation image conversion panel 10
6 and the photoelectric conversion panel 107 are flat, and since close focusing is performed between them, the effective surface can be made into a rectangular shape. Further, the reading electron beam 111 is generated by a small-diameter neck portion 105 and scans the entire effective surface using a deflection yoke 113, and two mesh electrodes are provided to create an accelerating electric field between them. Since the reading electron beam 111 is vertically incident on the reading electron beam 168, uniform image reading can be performed over the entire surface. FIG. 8 shows another embodiment of the present invention, in which two photoelectric conversion panels are used to provide two stages of photoelectron multiplication. The photoelectric conversion panel 202 on the electron gun 110 side is exactly the same as the photoelectric conversion panel 107 shown in FIG .
In 01, a photocathode 206 is formed on the electron gun side of the glass substrate. In addition, 2 photoelectric conversion panels 20
1, 202 and the applied voltage, the radiation image conversion panel 106 and the photoelectric conversion panel 10 in FIG.
This is exactly the same as in case 7. The first photoelectrons 203 emitted from the radiation image conversion panel 106 are
The fluorescent surface 205 of the photoelectric conversion panel 201 is illuminated to perform light multiplication. This light is guided to a photocathode 206 formed on the other surface and emits second photoelectrons 204. The photoelectrons 204 illuminate the fluorescent surface 207 of the second photoelectric conversion panel 202 and perform light multiplication. This light stimulates the photoconductive film 208 formed on the other side, forming a charge image on its surface. This charge image is read out as an electrical signal from an output terminal 115 by a reading beam 111. In this method, the brightness multiplication of the close focusing image tube is repeated twice, so the total brightness multiplication is 50 x 50 =
It becomes 2500 times. However, the resolution will be slightly worse. Microchannel plates may be used for photomultiplication. A microchannel plate is, for example, a glass tube with a diameter of 50 μm, with a homogeneous secondary electron emitting film, such as PbO film, formed on the inner wall of the glass tube.
Since a voltage is continuously applied in the length direction, the electrons that enter the low voltage side are multiplied by secondary electrons on the inner wall of the glass tube, and when they come out to the high voltage side, they are multiplied several hundred times to several times. It has been multiplied ten thousand times. However, by bundling such glass tubes like a fiber plate, a photoelectron image incident on one side is multiplied and emitted as a photoelectron image from the other side. This microchannel plate can be arranged close to the radiation image conversion panel and configured to multiply and emit photoelectrons. Effects of the Invention As described above, the present invention has a rectangular effective surface and does not require a tandem lens system and a TV camera as in the conventional system, so the device as a whole is extremely small and lightweight. It is particularly effective for medical diagnosis using X-rays because images with high diagnostic performance can be reconstructed at high speed by connecting to a fluoroscope on a monitor or an image processing device. It has the following advantages compared to conventional X-ray fluorescence multiplier devices. Since the input surface can be made flat, pincushion distortion and brightness uniformity are excellent. Furthermore, the effective surface area can be widened for the same maximum diameter. Since the input effective surface can be made into a square shape,
The diagnostic area expands to include the chest and abdomen. Radiographic images can be directly extracted as time-series electrical signals. The entire device can be made smaller and lighter than conventional devices. Excellent resolution.

[Brief explanation of drawings]

第１図は従来の放射線像増強管装置の説明図、
第２図はその放射線像変換パネルの構造説明図、
第３図は本発明の一実施例を示す放射線像増倍管
の構成図、第４図、第５図は各々その要部拡大
図、第６図は第５図に示す光電変換パネルの別の
実施例を示し、第７図は第３図に示す読取電子ビ
ームの軌道説明図、第８図は本発明の他の実施例
を示す構成図である。１００……真空容器、９……放射線、１０６…
…放射線像変換パネル、１１４……光電子、１０
７……光電変換パネル、１１１……読取ビーム、
１０８，１０９……メツシユ電極、１１０……電
子銃、１１５……信号出力端子、１１２……集束
コイル、１１３……偏向ヨーク。 Fig. 1 is an explanatory diagram of a conventional radiation image intensifier tube device;
Figure 2 is an explanatory diagram of the structure of the radiation image conversion panel.
Fig. 3 is a block diagram of a radiation image intensifier tube showing an embodiment of the present invention, Figs. 4 and 5 are enlarged views of the main parts thereof, and Fig. 6 is an illustration of a photoelectric conversion panel shown in Fig. 5. FIG. 7 is an explanatory diagram of the trajectory of the reading electron beam shown in FIG. 3, and FIG. 8 is a configuration diagram showing another embodiment of the present invention. 100 ...vacuum container, 9...radiation, 106 ...
...Radiation image conversion panel, 114...Photoelectron, 10
7...Photoelectric conversion panel, 111...Reading beam,
108, 109...mesh electrode, 110...electron gun, 115...signal output terminal, 112...focusing coil, 113...deflection yoke.

Claims

[Scope of Claims] 1. A vacuum vessel formed by successively forming a large-diameter portion, a cone portion, and a small-diameter portion each having an entrance window made of a material that transmits radiation; a radiation image conversion panel provided inside the entrance window and sequentially comprising a first fluorescent surface that is excited by incident radiation and converts it into an optical image and a photocathode that converts the optical image into an electronic image; a second phosphor surface that is disposed in close proximity to the photocathode of the radiation image conversion panel and emits light when excited by photoelectrons emitted from the photocathode; a photoelectric conversion panel comprising a light shielding film that blocks light on the image conversion panel side and transmits photoelectrons from the photocathode, and a photoconductive surface that receives light emitted from a second fluorescent screen; an electron gun that is installed in the small diameter part of the container and generates a reading electron beam; and an electron beam for vertical incidence that forms an electric field such that the electron beam emitted from the electron gun is perpendicularly incident on the photoconductive surface of the photoelectric conversion panel. A radiation image intensifier device comprising: an electrode; and a deflection device configured to deflect and scan the electron beam, and configured to extract an electrical signal corresponding to a radiation image from the photoelectric conversion panel. 2 The radiation image conversion panel consists of a first panel made of a flat aluminum substrate on which cesium iodide phosphor is vapor-deposited.
A radiation image intensifier tube device according to claim 1, comprising a phosphor screen, a protective film deposited on the phosphor screen, and a photocathode formed on the protective film. 3. The photoelectric conversion panel has a light-transmissive substrate, a second fluorescent screen is provided on the surface of the substrate on the radiation image conversion panel side, and a photoconductive surface is provided on the surface of the substrate on the electron gun side. The radiation image intensifier tube device according to scope 1. 4 The two substrates of both panels are placed parallel to each other, a photocathode is formed on one of their opposing surfaces, and a second fluorescent screen that emits light by electron beam irradiation is provided on the other side with a light shielding surface on the photocathode side. the photocathode and the second phosphor screen are provided with a film, the mutual distance between the photocathode and the second phosphor screen is maintained at 10 mm or less, and a positive potential of 5 Kv or more is applied to the second phosphor screen with respect to the photocathode. The radiation image intensifier tube device according to claim 1, 2, or 3, wherein the radiation image intensifier tube device is configured to obtain photoelectron multiplication accompanied by a proximity focusing effect of photoelectrons. 5. Claim 1 comprising a plurality of sets of photoelectric conversion panels arranged so that a second phosphor screen closely faces the photocathode surface of the radiation image conversion panel from the radiation entrance window side to the electron gun side. The radiation intensifier tube device described in Section 1. 6. The radiation intensifier tube device according to claim 1, wherein a microchannel plate having a photoelectron multiplication function is provided in close proximity to a radiation image conversion panel. 7. Claim 1 or 3 in which the light-transmissive substrate of the photoelectric conversion panel is made of an optical fiber plate or a thin plate glass having a thickness of 100 μm to 300 μm.
The radiation intensifier tube device described in Section 1. 8. The radiation image intensifier tube device according to claim 1, wherein the electron beam vertical incidence electrode comprises at least two mesh electrodes arranged on the photoelectric conversion panel at a predetermined interval. 9. The radiation image intensifier tube device according to claim 8, wherein the plurality of mesh electrodes are such that the mesh electrode potential on the photoelectric conversion panel side is maintained at a higher potential than the mesh electrode potential on the electron gun side. 10. The radiation image intensifier tube device according to claim 1, wherein the radiation entrance window is formed of a thin plate selected from aluminum, titanium, or an iron alloy. 11. The radiation image intensifier tube device according to claim 1, wherein the effective surface of the radiation entry window is square.