JPS6111685A - Radiation image reading device - Google Patents
Radiation image reading deviceInfo
- Publication number
- JPS6111685A JPS6111685A JP13354084A JP13354084A JPS6111685A JP S6111685 A JPS6111685 A JP S6111685A JP 13354084 A JP13354084 A JP 13354084A JP 13354084 A JP13354084 A JP 13354084A JP S6111685 A JPS6111685 A JP S6111685A
- Authority
- JP
- Japan
- Prior art keywords
- radiation image
- layer
- voltage
- phosphor
- transparent electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/24—Measuring radiation intensity with semiconductor detectors
- G01T1/246—Measuring radiation intensity with semiconductor detectors utilizing latent read-out, e.g. charge stored and read-out later
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- Molecular Biology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Measurement Of Radiation (AREA)
- Nuclear Medicine (AREA)
Abstract
Description
【発明の詳細な説明】
(al産業上の利用分野
本発明は放射線像読み取り装置に関するもので、特に医
療用等に広範囲に利用されている放射線画像処理装置で
あり、通常のX線撮影等で瞬間的に照射された放射線像
を一旦記憶させ、次に記憶した放射線像を、電子ビーム
を走査して時系列信号として読み出すようにした、高速
、高感度、高解像度の放射線像の読み取り装置である。DETAILED DESCRIPTION OF THE INVENTION (AlIndustrial Field of Application) The present invention relates to a radiation image reading device, and in particular is a radiation image processing device that is widely used for medical purposes. A high-speed, high-sensitivity, high-resolution radiation image reading device that temporarily stores an instantaneously irradiated radiation image and then reads out the stored radiation image as a time-series signal by scanning an electron beam. be.
山)従来の技術
放射線像を時系列信号として読み取る方式には幾つかの
種類があるが、第1に、帯電させた放射線感光体に放射
線像を照射し、その後の帯電電位分布を非接触で読み取
る潜像読み取り方式と、第2に、放射線照射により感光
体中に発生したキャリアを誘電体層との界面にトラップ
させ、光走査によってそのトラップ電荷を開放した際に
流れる変位電流を検知するE L ’I C(Elec
trophotographic Light 5ca
nned Image Converter)方式、第
3に輝尽を示す螢光体に放射線像を照射し、その後光走
査した際に、輝尽でできる光を検知するIP(Imag
ing Plate)方式があるが、第1の潜像読み取
り方式と、第2のELuC方式は感度と解像度が低く、
又応答速度も遅いという欠点があり、第3のIP方式は
感度や解像度は良好であるが、応答速度が遅いという欠
点があり、その改善が要望されている。M) Conventional technology There are several types of methods for reading radiation images as time-series signals.The first method is to irradiate a radiation image onto a charged radiation photoreceptor and measure the subsequent charging potential distribution without contact. The second method is E, which traps carriers generated in the photoreceptor due to radiation irradiation at the interface with the dielectric layer and detects the displacement current that flows when the trapped charges are released by optical scanning. L'I C (Elec
trophotographic Light 5ca
The third method is the IP (Imaging Converter) method, which detects the light produced by photostimization when a radiation image is irradiated onto a phosphor that exhibits photostimization and then scanned with light.
ing plate) method, but the first latent image reading method and the second ELuC method have low sensitivity and resolution;
It also has the disadvantage of slow response speed, and although the third IP method has good sensitivity and resolution, it has the disadvantage of slow response speed, and there is a desire to improve this.
(C1発明が解決しようとする問題点
本発明は上記従来の問題点を解決するために、ELIC
方式とE L (Electro luminesce
nce)技術を組み合わせることにより、従来の画像読
み取り方式の欠点である感度や応答及び解像度について
高速応答で高感度であり高解像度の画像読み取り装置を
提供することにある。(C1 Problem to be solved by the invention) In order to solve the above-mentioned conventional problems, the present invention
Method and E L (Electro luminesce)
nce) technology, it is an object of the present invention to provide an image reading device that has high speed response, high sensitivity, and high resolution in terms of sensitivity, response, and resolution, which are disadvantages of conventional image reading methods.
+dj問題点を解決するための手段
本発明によれば、この問題点は、第1透明電極と誘電体
と放射線感光体と螢光体と第2透明電極と透明基板とが
順次積層されてなる放射線読み取り素子を用いて、上記
第1透明電極と第2透明電極とに電圧を印加しながら前
記第1透明電極側から放射線像を照射し、次に上記印加
電圧の極性を反転させて上記第1透明電極側からビーム
光を走査して上記放射線像に対応する上記螢光体からの
光を光検知器で検知することを特徴とする放射線像読み
取り装置と、上記光検知器と螢光体層との間に上記螢光
体から発光する光のみを通過させるフィルターを配して
なることを特徴とする放射線像読み取り装置と、上記螢
光体が透明であることを特徴とする放射線像読み取り製
置を提供することによって達成できる。+dj Means for Solving the Problem According to the present invention, this problem can be solved by sequentially laminating a first transparent electrode, a dielectric, a radiation photoreceptor, a phosphor, a second transparent electrode, and a transparent substrate. Using a radiation reading element, a radiation image is irradiated from the first transparent electrode side while applying a voltage to the first transparent electrode and the second transparent electrode, and then the polarity of the applied voltage is reversed to 1. A radiation image reading device, characterized in that a light beam is scanned from a transparent electrode side and a photodetector detects light from the phosphor corresponding to the radiation image, and the photodetector and the phosphor. A radiation image reading device characterized in that a filter is disposed between the layer and a filter that allows only light emitted from the phosphor to pass through, and a radiation image reading device characterized in that the phosphor is transparent. This can be achieved by providing a preparatory facility.
te1作用
本発明はELICの電荷蓄積効果と、この蓄積電荷で螢
光体を高速、高感度に発光させる効果を利用するよう考
慮したものである。te1 Effect The present invention is designed to take advantage of the charge accumulation effect of ELIC and the effect of causing a phosphor to emit light at high speed and with high sensitivity using this accumulated charge.
即ち最初に照射放射線量に応じて感光体中に発生した自
由キャリアを誘電体との界面にトラップさせておき、E
LIC方式では次にレーザ走査によって、このトラップ
電荷を開放させ、この際に外部回路を流れる変位電流を
検知することにより放射線像の読み取りをするものであ
るが、この方法では誘電体の電気容量と感光体の電気抵
抗によるCR時定数が大きいために、応答速度が遅くな
り、又トラップ電荷量が少ないため低感度になるという
問題があるために、本発明ではこの対策として、移動速
度の遅いトラップ電荷を電界によって加速して螢光体層
に入れて発光させ、それを光電子増倍管で大幅に増幅す
る方式であるため、応答速度が速く、感度や解像度も大
幅に増大するものである。That is, first, free carriers generated in the photoreceptor according to the irradiation radiation dose are trapped at the interface with the dielectric material, and E
In the LIC method, the trapped charges are then released by laser scanning, and the radiation image is read by detecting the displacement current flowing through the external circuit. Since the CR time constant due to the electrical resistance of the photoreceptor is large, the response speed is slow, and the amount of trap charge is small, resulting in low sensitivity. In the present invention, as a countermeasure to this problem, a trap with a slow moving speed is used. This method accelerates charges using an electric field and enters a phosphor layer to emit light, which is then greatly amplified using a photomultiplier tube, resulting in fast response speed and greatly increased sensitivity and resolution.
(f)実施例
本発明の実施例として、第1図乃至第3図に素子の構成
と動作を示しているが、放射線の種類としてはX線を用
いた場合について説明する。(f) Example As an example of the present invention, the structure and operation of an element are shown in FIGS. 1 to 3, and a case will be described in which X-rays are used as the type of radiation.
第1図において、パイレフクスガラス等の透明電極1が
あり、その上に順次インジューム錫(ITo)の第2の
透明電極2、その上にスパッター等で硫化亜鉛と銅(Z
nS:Cu)の螢光体層3を20μmの厚みで形成し、
次にセレン(≦e)のX線感光体層4を60μmの厚み
に真空蒸着で形成して、これを恒温槽で70℃の温度で
30分の熱処理を行い、更に誘電体バリ4レン層5を5
μm程度の厚みで設け、最後に第2の透明電極として半
透明の金電極6を蒸着によって0.1μ拍の厚みで形成
することにより素子が完成する。In Fig. 1, there is a transparent electrode 1 made of Pyrex glass, etc., on which a second transparent electrode 2 made of indium tin (ITo) is sequentially applied, and on top of that, zinc sulfide and copper (Z
A phosphor layer 3 of nS:Cu) was formed with a thickness of 20 μm,
Next, an X-ray photoreceptor layer 4 of selenium (≦e) is formed to a thickness of 60 μm by vacuum evaporation, and this is heat-treated at a temperature of 70° C. for 30 minutes in a constant temperature oven, followed by a dielectric burr 4 layer. 5 to 5
The device is completed by forming a semi-transparent gold electrode 6 as a second transparent electrode to a thickness of about 0.1 μm by vapor deposition.
この素子にX線像の書込みをする場合には、電源7で素
子のITO層2と半透明電極6間に半透明電極6が正に
なるように50ボルト乃至300ボルトの電圧を印加し
、半透明電極6側から矢印のようにX線像8を照射する
と、X線は主としてX線感光体N4に吸収され、自由電
子とホールが発生し、このホールは電界によって螢光体
N3の方向に移動して行って、やがて特に高抵抗では4
ない螢光体層3を貫通して第2の透明電極2に入射され
る。When writing an X-ray image on this element, a voltage of 50 to 300 volts is applied between the ITO layer 2 and the semi-transparent electrode 6 of the element using the power supply 7 so that the semi-transparent electrode 6 becomes positive. When an X-ray image 8 is irradiated from the semi-transparent electrode 6 side as shown by the arrow, the X-rays are mainly absorbed by the X-ray photoreceptor N4, generating free electrons and holes, which are directed toward the phosphor N3 by the electric field. , and eventually, especially at high resistance, it becomes 4.
The light passes through the phosphor layer 3 and enters the second transparent electrode 2.
一方、電子は誘電体パリレンN5との界面に達してトラ
ンプされるが、このトラップ電荷9の量はX線照射量に
比例するもので電源切断後も長時間保存されてメモリに
なる。On the other hand, the electrons reach the interface with the dielectric parylene N5 and are tramped, but the amount of this trapped charge 9 is proportional to the amount of X-ray irradiation and is stored for a long time even after the power is turned off and becomes a memory.
第2図はそのトラップ電荷9が電源切断後もメモリとし
て残存している状態を示しているが、−般に感光体とし
てセレンを用いる場合が、トラップ電荷9のメモリ性が
ホールより電子の方が良好な特性を有している。Figure 2 shows a state in which the trapped charge 9 remains as a memory even after the power is turned off. Generally, when selenium is used as a photoreceptor, the memory property of the trapped charge 9 is better for electrons than for holes. has good properties.
第3図はX線像の読み出しを説明する模式図であるが、
第2電源10によりX線書込み時と反対の極性の、IT
O層2と半透明電極6間に50ボルト乃至300ボルト
の電圧を印加し、半透明電極6側からX線感光体層4の
バンドギャップより小なるフォトンエネルギーををする
ヘリウム、ネオン()IeNe)レーザ光11を、矢印
のようにガルバノミラ−12で走査するが、この際には
ハンド間遷移による自由キアリアの発生がなく、トラッ
プ電荷8の開放でのみが行われる。FIG. 3 is a schematic diagram explaining the readout of an X-ray image.
With the second power supply 10, the IT
A voltage of 50 volts to 300 volts is applied between the O layer 2 and the semitransparent electrode 6, and photon energy smaller than the band gap of the X-ray photoreceptor layer 4 is emitted from the semitransparent electrode 6 side. ) The laser beam 11 is scanned by the galvanometer mirror 12 as shown by the arrow, but at this time, free chiaria is not generated due to transition between hands, and only the trapped charges 8 are released.
この開放された電子は電界で加速され、螢光体層3に注
入されて、矢印で示すルミネッセンス13が誘起される
が、素子の透明基板1に接触させて配したフィルタ14
によって、レーザ光11の光成分をカットし、ルミネッ
センス13のみを光電子増倍管15に入力することによ
り、X線照射量に応じた信号を得ることができる。These released electrons are accelerated by an electric field and injected into the phosphor layer 3, inducing luminescence 13 shown by the arrow.
By cutting the optical component of the laser beam 11 and inputting only the luminescence 13 to the photomultiplier tube 15, a signal corresponding to the amount of X-ray irradiation can be obtained.
正確に制御された速度で素子を水平方向に移動させ、こ
れと垂直方向にガルバノミラ−12によってビーム走査
を繰返して一画面のX線像が時系列信号で読み出され、
この信号は逐次画像処理器16のメモリに入力される。The element is moved horizontally at a precisely controlled speed, and beam scanning is repeated vertically using a galvanometer mirror 12 to read out one screen of X-ray images as time-series signals.
This signal is sequentially input to the memory of the image processor 16.
画像処理器I6では、一部拡大表示や、諧調性の向上の
ために濃淡強調、空間周波数処理等の計算機処理がなさ
れるが、−回のX線撮影で多量の情報が得られる。The image processor I6 performs computer processing such as partially enlarged display, gradation emphasis, and spatial frequency processing to improve gradation, but a large amount of information can be obtained by - times of X-ray imaging.
尚、この素子は使用した最後に、素子全面に強い可視光
を照射することによりメモリが消失するので反復して使
用することが可能である。Furthermore, at the end of use, the memory of this device is erased by irradiating the entire surface of the device with strong visible light, so it can be used repeatedly.
上記の実施例は特定の条件の場合について説明したが、
例えば照射像はX線に限定するものではなく、γ線や可
視光等の電磁波、更に各種粒子線にも適用が可能であり
、又感光体の材料もセレンに限らず、照射光線の種類に
応じて、それに適した感光体を選定することができ、例
えばX線やγ線の場合には酸化鉛(PbO)等を使用す
ることができる。Although the above example described the case of specific conditions,
For example, the irradiation image is not limited to X-rays, but can also be applied to electromagnetic waves such as gamma rays and visible light, as well as various particle beams, and the material of the photoreceptor is not limited to selenium, but can also be applied to the type of irradiation light. Accordingly, a suitable photoreceptor can be selected. For example, lead oxide (PbO) or the like can be used in the case of X-rays or γ-rays.
螢光体については、ZnS:Cuは一例に過ぎず、Zn
S;Cu、AI + ZnS:Ag、AI + BaF
Br:Eu2+その他の多くのELを発光する螢光体が
適用可能であるが、但しレーザの走査光源の波長とは離
れた発光波長であることが必要であって、これによりフ
ィルタにより十分に選別ができる。Regarding phosphors, ZnS:Cu is just one example;
S; Cu, AI + ZnS: Ag, AI + BaF
Br:Eu2+ and many other phosphors that emit EL can be applied, but it is necessary that the emission wavelength is different from the wavelength of the laser scanning light source, so that it can be adequately selected by a filter. I can do it.
この螢光体は熔融や、スパッタリングをした後のアニー
リング等により透明化を行うと、感度が大幅に向上する
。If this phosphor is made transparent by melting or annealing after sputtering, the sensitivity will be greatly improved.
螢光体を透明化する必要性は、ルミネッセンスが感光体
近傍の螢光体層で多く発生するが、螢光体層の透明性が
良好でないと散乱や吸収により光電子増倍管の側に達す
るまでに減衰するからである。The need to make the phosphor transparent is that most of the luminescence is generated in the phosphor layer near the photoreceptor, but if the phosphor layer is not transparent, it may reach the photomultiplier tube through scattering or absorption. This is because it will attenuate by then.
更に、螢光体層に銅のような導電体を適当量ドーピング
して、螢光体層を低抵抗化することにより感光体や螢光
体中の不要な電荷が迅速に消滅するため応答速度や解像
度が一段と向上するという利点がある。Furthermore, by doping the phosphor layer with an appropriate amount of a conductor such as copper to lower the resistance of the phosphor layer, unnecessary charges in the photoreceptor and phosphor disappear quickly, increasing the response speed. This has the advantage of further improving resolution.
(g)発明の効果
以上詳細に説明したように本発明の放射線像読み取り装
置を採用することにより、高速応答で高感度であり、高
解像度の画像読み取りに供し得るという効果大なるもの
がある。(g) Effects of the Invention As explained in detail above, by employing the radiation image reading device of the present invention, there are great effects in that it has high-speed response, high sensitivity, and can be used for high-resolution image reading.
第1図は本発明の素子の断面図、
第2図は素子のメモリの状態を説明する模式断面図、
第3図は読み取り装置の模式断面図である。
図において、
1は透明基板、 2は第2の透明電極3は螢光
体層、 4はX線感光体層、5は誘電体パリレ
ン層、 6は半透明の金電極、7は電源、 ・
8はX線像、9はトラップ電荷、 10は電源
、11はレーザ光、 12はガルバノミラ−1
13はルミネッセンス、14はフィルタ、15は光電子
増倍管、 16は画像処理器、をそれぞれ示す。FIG. 1 is a sectional view of the device of the present invention, FIG. 2 is a schematic sectional view illustrating the memory state of the device, and FIG. 3 is a schematic sectional view of a reading device. In the figure, 1 is a transparent substrate, 2 is a second transparent electrode 3 is a phosphor layer, 4 is an X-ray photoreceptor layer, 5 is a dielectric parylene layer, 6 is a semi-transparent gold electrode, 7 is a power source,
8 is an X-ray image, 9 is a trapped charge, 10 is a power source, 11 is a laser beam, 12 is a galvanometer mirror 1
13 is a luminescence device, 14 is a filter, 15 is a photomultiplier tube, and 16 is an image processor.
Claims (3)
第2透明電極と透明基板とが順次積層されてなる放射線
像読み取り素子の、上記第1透明電極と第2透明電極と
に電圧を印加しながら前記第1透明電極側から放射線像
を照射し、次に上記印加電圧の極性を反転させて上記第
1透明電極側からビーム光を走査して上記放射線像に対
応する上記螢光体からの光を光検知器で検知することを
特徴とする放射線像読み取り装置。(1) The first transparent electrode and the second transparent electrode of a radiation image reading element in which the first transparent electrode, the dielectric, the radiation photoreceptor, the phosphor, the second transparent electrode, and the transparent substrate are laminated in sequence. A radiation image is irradiated from the first transparent electrode side while applying a voltage to the area, and then the polarity of the applied voltage is reversed and a beam of light is scanned from the first transparent electrode side to generate the radiation image corresponding to the radiation image. A radiation image reading device characterized by detecting light from a phosphor with a photodetector.
発光する光のみを通過させるフィルターを配してなるこ
とを特徴とする特許請求の範囲第(1)項記載の放射線
像読み取り装置。(2) A filter according to claim (1), characterized in that a filter is disposed between the photodetector and the phosphor layer to allow only the light emitted from the phosphor to pass through. Radiographic image reading device.
請求の範囲第(1)項記載の放射線像読み取り装置。(3) The radiation image reading device according to claim (1), wherein the phosphor is transparent.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13354084A JPS6111685A (en) | 1984-06-27 | 1984-06-27 | Radiation image reading device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13354084A JPS6111685A (en) | 1984-06-27 | 1984-06-27 | Radiation image reading device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6111685A true JPS6111685A (en) | 1986-01-20 |
Family
ID=15107198
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP13354084A Pending JPS6111685A (en) | 1984-06-27 | 1984-06-27 | Radiation image reading device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6111685A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2616992A1 (en) * | 1987-06-19 | 1988-12-23 | Thomson Csf | ADVANCED SENSITIZATION MEMORY VISUALIZATION SYSTEM AND METHOD USING THE SAME |
KR100873580B1 (en) | 2007-07-10 | 2008-12-11 | 주식회사 오킨스전자 | Apparatus for flat x-ray inspection |
-
1984
- 1984-06-27 JP JP13354084A patent/JPS6111685A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2616992A1 (en) * | 1987-06-19 | 1988-12-23 | Thomson Csf | ADVANCED SENSITIZATION MEMORY VISUALIZATION SYSTEM AND METHOD USING THE SAME |
EP0299813A1 (en) * | 1987-06-19 | 1989-01-18 | Thomson-Csf | System for visualizing a latent image, and method of applying it |
KR100873580B1 (en) | 2007-07-10 | 2008-12-11 | 주식회사 오킨스전자 | Apparatus for flat x-ray inspection |
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