JP2005283261A

JP2005283261A - Radiation detector

Info

Publication number: JP2005283261A
Application number: JP2004096190A
Authority: JP
Inventors: Junichi Suzuki; 準一鈴木; Shinya Nagafune; 伸也長舟; Haruyuki Fujino; 治之藤野
Original assignee: Shimadzu Corp
Current assignee: Shimadzu Corp
Priority date: 2004-03-29
Filing date: 2004-03-29
Publication date: 2005-10-13
Anticipated expiration: 2024-03-29
Also published as: JP4442278B2

Abstract

PROBLEM TO BE SOLVED: To fix a detector body to a casing in the form not impeding light irradiation for detection characteristic improvement and not damaging a charge reading substrate. SOLUTION: In this radiation detector, the detector body 2 is fixed to the casing 8 across a support stand 7 for supporting the detector body 2 from the back side of the charge reading substrate 5, and the whole detector body 2 is supported by the support stand 7, and thereby the charge reading substrate 5 is prevented from being damaged, because the state wherein the whole detector body 2 is supported by the charge reading substrate 5 is removed. In addition, since the detector body 2 is supported by the support stand 7 having a translucent plate body 7A which is a light passage where light for detection characteristic improvement passes, the light irradiation for detection characteristic improvement is not impeded. Resultantly, the detector body 2 can be fixed to the casing 8 in the form not impeding the light irradiation for detection characteristic improvement and not damaging the charge reading substrate 5. COPYRIGHT: (C)2006,JPO&NCIPI

Description

この発明は、バイアス電圧印加用の共通電極が表面に形成されていると共に入射放射線を直接電荷に変換する放射線有感体が透光性を有する電荷読み出し用基板に搭載されている検出器本体と、この検出器本体を収容する筐体とを備えている直接変換タイプの放射線検出器に係り、特に放射線検出器の検出器本体を筐体に対し固定するための技術に関する。 The present invention relates to a detector main body on which a common electrode for applying a bias voltage is formed on a surface, and a radiation sensitive body that directly converts incident radiation into electric charge is mounted on a translucent charge readout substrate. In particular, the present invention relates to a direct conversion type radiation detector including a housing for housing the detector body, and more particularly to a technique for fixing the detector body of the radiation detector to the housing.

最近、医用Ｘ線撮像装置などでは被検体からの透過Ｘ線等の放射線を検出する放射線検出器としてフラットパネル型の二次元放射線検出器が使用されている。このフラットパネル型の二次元放射線検出器（以下、適宜「検出器」と略記）には間接変換タイプと直接変換タイプとがある。 Recently, a flat panel type two-dimensional radiation detector is used as a radiation detector for detecting radiation such as transmitted X-rays from a subject in a medical X-ray imaging apparatus or the like. The flat panel type two-dimensional radiation detector (hereinafter abbreviated as “detector” as appropriate) includes an indirect conversion type and a direct conversion type.

前者の間接変換タイプの検出器の場合、図８に示すように、光シンチレータ６２と光電変換膜６３が電荷読み出し用基板６４に搭載されている検出器本体６１を備えていて、入射放射線が上側の光シンチレータ６２でいったん光に変換され、変換光が下側の光電変換膜６３で電荷に変換されると共に、光電変換膜６３で生じた電荷が電荷読み出し用基板６４によって読み出されるので、放射線は二段で検出されることになる。検出器本体６１は裏面を接着剤で基台（図示省略）に接合したうえで筐体（図示省略）に収容固定されている（例えば特許文献１参照。）。 In the case of the former indirect conversion type detector, as shown in FIG. 8, an optical scintillator 62 and a photoelectric conversion film 63 are provided with a detector main body 61 mounted on a charge readout substrate 64, and the incident radiation is on the upper side. The light scintillator 62 converts the light into light once, and the converted light is converted into charges by the lower photoelectric conversion film 63, and the charge generated in the photoelectric conversion film 63 is read by the charge reading substrate 64, so that the radiation is It will be detected in two stages. The detector main body 61 is accommodated and fixed in a housing (not shown) after the back surface is bonded to a base (not shown) with an adhesive (see, for example, Patent Document 1).

後者の直接変換タイプの検出器の場合、図９に示すように、バイアス電圧印加用の共通電極７２が表面に形成されていると共に入射放射線を直接電荷に変換する放射線有感体としての半導体膜７３が電荷読み出し用基板７４に搭載されている検出器本体７１を備えていて、入射放射線が半導体膜７３で直に電荷に変換されると共に、半導体膜７３で生じた電荷が電荷読み出し用基板７４によって半導体膜７３の裏面側に二次元マトリックス配列で設けられている個別電極（図示省略）毎に読み出されるので、放射線が一段で検出できる（例えば特許文献２参照。）。 In the case of the latter direct conversion type detector, as shown in FIG. 9, a common electrode 72 for applying a bias voltage is formed on the surface, and a semiconductor film as a radiation sensitive body that directly converts incident radiation into electric charge. 73 includes a detector main body 71 mounted on a charge readout substrate 74, and incident radiation is directly converted into charges in the semiconductor film 73, and the charges generated in the semiconductor film 73 are converted into charges in the charge readout substrate 74. Is read out for each individual electrode (not shown) provided in a two-dimensional matrix arrangement on the back side of the semiconductor film 73, so that radiation can be detected in a single stage (see, for example, Patent Document 2).

ただ、直接変換タイプの検出器は、電荷読み出し用基板７４で電荷が読み出された後も読み出し切れずに入射放射線により生じた電荷が半導体膜７３の内に滞留することによって、検出感度が変動したり、残留出力が発生したりするという難点があった。 However, in the direct conversion type detector, the detection sensitivity fluctuates because the charge generated by the incident radiation stays in the semiconductor film 73 without being completely read after the charge is read by the charge reading substrate 74. Or a residual output occurs.

そこで、本件出願人が先に提出した特願2002-253819 号において、半導体膜７３に向けて放射線検出中に個別電極（分割電極）側から光を照射することにより半導体膜７３の内に入射放射線で生じた電荷が滞留することで起こる検出感度の変動や残留出力の発生を抑える直接変換タイプの検出器を案出した。 Therefore, in Japanese Patent Application No. 2002-253819 previously filed by the present applicant, incident radiation is incident on the semiconductor film 73 by irradiating the semiconductor film 73 with light from the individual electrode (divided electrode) side during radiation detection. We have devised a direct conversion type detector that suppresses fluctuations in detection sensitivity and residual output caused by the retention of the charge generated by the.

また、本件出願人が提出した別の特願2003−058487号において、半導体膜７３に向けて放射線検出中に個別電極（分割電極）側から検出特性改善用の光を照射することによってダイナミックレンジが狭められるのを、電荷読み出し用基板７４から電荷を読み出した後に設定されたゲイン値（ゲイン設定値）に応じて信号処理する電気信号処理回路のゲイン設定値の増加、減少に応じて検出特性改善用の光の強度を増加、減少することにより防止することを案出した。
特開２０００−１１２３６９号公報（第４頁５欄〜第６頁７欄，図３）特開２００２−３１１１４４号公報（第６頁〜第８頁，図１〜図５） Further, in another Japanese Patent Application No. 2003-058487 filed by the present applicant, the dynamic range is increased by irradiating the semiconductor film 73 with light for improving detection characteristics from the individual electrode (divided electrode) side during radiation detection. What is narrowed is improvement in detection characteristics as the gain setting value of the electric signal processing circuit that performs signal processing in accordance with the gain value (gain setting value) set after reading out the charge from the charge reading substrate 74 increases or decreases. It was devised to prevent it by increasing or decreasing the light intensity.
JP 2000-112369 A (page 4, column 5 to page 6, column 7, FIG. 3) JP 2002-31144 A (pages 6 to 8, FIGS. 1 to 5)

しかしながら、上記特願2002-253819 号と特願2003−058487号の両出願に係る検出器の場合、検出器本体７１を筐体（図示省略）に収容して電荷読み出し用基板７４の周縁部のところを筐体に取り付けることで検出器本体７１を筐体に対して固定し、電荷読み出し用基板７４で電荷検出器本体７１全体を支えなければならない。 However, in the case of the detectors according to both Japanese Patent Application Nos. 2002-253819 and 2003-058487, the detector main body 71 is accommodated in a casing (not shown) and the peripheral portion of the charge readout substrate 74 is However, the detector main body 71 must be fixed to the casing by attaching it to the casing, and the entire charge detector main body 71 must be supported by the charge readout substrate 74.

電荷読み出し用基板７４は、普通、厚みが０．７ｍｍ程度の薄いガラス基材を用いているので、機械的に堅牢であるとは言い難い。それでも電荷読み出し用基板７４の場合、半導体膜７３の搭載域は半導体膜７３ごと樹脂モールドが施せるので、機械的に補強できるのであるが、電荷読み出し用基板７４の周縁部はフレキシブルプリント配線板等による電気接続域や集積回路搭載域となっていて、接続異常時や回路故障時のリペア（補修）などのために樹脂モールドが施せないので、機械的な補強ができず、電荷読み出し用基板７４の周縁部のところで破損が起こるのを心配しなければならない。 Since the charge readout substrate 74 usually uses a thin glass substrate having a thickness of about 0.7 mm, it is difficult to say that it is mechanically robust. Still, in the case of the charge readout substrate 74, the mounting area of the semiconductor film 73 can be mechanically reinforced because the semiconductor film 73 can be resin-molded together with the semiconductor film 73, but the peripheral portion of the charge readout substrate 74 is formed by a flexible printed wiring board or the like. Since it is an electrical connection area or an integrated circuit mounting area and a resin mold cannot be applied for repair (repair) in the event of a connection abnormality or circuit failure, mechanical reinforcement cannot be performed, and the charge readout board 74 You must worry about the breakage at the periphery.

前記の間接変換タイプの検出器の場合のように、電荷読み出し用基板７４の裏側に基台を接着剤で接合して機械的に補強する方策が考えられはするが、直接変換タイプの検出器の場合、電荷読み出し用基板７４に接合した基台や接合用の接着剤で検出特性改善用の光の照射が妨げられるので、この方策を採ることは出来ない。 As in the case of the above-described indirect conversion type detector, a measure to mechanically reinforce the base by bonding the base to the back side of the charge readout substrate 74 with an adhesive may be considered, but the direct conversion type detector. In this case, since the irradiation of the light for improving the detection characteristics is hindered by the base or the bonding adhesive bonded to the charge readout substrate 74, this measure cannot be taken.

この発明は、このような事情に鑑みてなされたものであって、検出特性改善用の光照射を阻害しないと同時に電荷読み出し用基板の破損を招来しないかたちで検出器本体を筐体に対し固定することができる放射線検出器を提供することを目的とする。 The present invention has been made in view of such circumstances, and the detector main body is fixed to the housing in such a manner that it does not hinder light irradiation for improving detection characteristics and at the same time does not cause damage to the charge readout substrate. An object of the present invention is to provide a radiation detector that can be used.

この発明は、上記の目的を達成するために、次のような構成をとる。 In order to achieve the above object, the present invention has the following configuration.

即ち、請求項１に記載の発明に係る放射線検出器は、バイアス電圧印加用の共通電極が表面に形成されていると共に入射放射線を直接電荷に変換する放射線有感体が透光性を有する電荷読み出し用基板に搭載されている検出器本体と、電荷読み出し用基板を介して放射線有感体に向けて検出特性改善用の光を照射する光照射機構と、検出器本体と光照射機構との間で検出器本体を電荷読み出し用基板の裏側から支えていると共に検出特性改善用の光が通る光通路を有する支持台と、検出器本体および光照射機構と支持台を収容する筐体とを備えていて、検出器本体が支持台を介して筐体に対し固定されていることを特徴とするものである。 That is, in the radiation detector according to the first aspect of the present invention, the common electrode for applying the bias voltage is formed on the surface, and the radiation sensitive body that directly converts incident radiation into electric charge has translucency. A detector main body mounted on the readout substrate, a light irradiation mechanism for irradiating the radiation sensitive body with light for detection characteristic improvement via the charge readout substrate, and a detector main body and a light irradiation mechanism. A support base having a light path for supporting the detector main body from the back side of the charge readout substrate and through which light for detection characteristic improvement passes, and a housing for housing the detector main body, the light irradiation mechanism, and the support base. The detector main body is fixed to the housing via a support base.

［作用・効果］請求項１の発明の放射線検出器の場合、放射線の検出中、検出器本体における入射放射線を直接電荷に変換する放射線有感体に光照射機構からの照射光が支持台の光通路を通り透光性の電荷読み出し用基板を介して照射されるのに伴って放射線有感体に空間電荷が溜まるので、入射放射線によって発生した電荷の方は滞留せずに掃き出される結果、実効的な有感面積の変化が起こらなくなり、放射線検出器の検出感度の変動を回避できる。また入射放射線で発生した電荷の掃き出し後も、光照射機構による光照射を続けることによって光照射で生じた空間電荷は掃き出されずに留まり続けるので、残留出力の発生を回避できる。 [Operation / Effect] In the case of the radiation detector according to the first aspect of the present invention, during the radiation detection, the irradiation light from the light irradiation mechanism is applied to the radiation sensitive body that directly converts the incident radiation into the electric charge into the detector body. Space charge accumulates in the radiation sensitive body as it irradiates through the light-transmitting charge readout substrate through the optical path, so that the charge generated by the incident radiation is swept away without staying. As a result, the effective sensitive area does not change, and fluctuations in the detection sensitivity of the radiation detector can be avoided. Further, even after the charge generated by the incident radiation is swept out, the space charge generated by the light irradiation is kept without being swept out by continuing the light irradiation by the light irradiation mechanism, so that the generation of the residual output can be avoided.

また、請求項１の発明の放射線検出器の場合、検出器本体を電荷読み出し用基板の裏側から支えている支持台を介して検出器本体が筐体に対し固定されていて、検出器本体は支持台によって支えられているので、電荷読み出し用基板によって検出器本体全体を支える状態は解消される結果、電荷読み出し用基板の破損を招来せずに済む。さらに、検出器本体を支えている支持台は検出特性改善用の光が通る光通路を有するので、検出特性改善用の光照射を阻害することもない。 In the case of the radiation detector according to the first aspect of the invention, the detector main body is fixed to the housing via a support base that supports the detector main body from the back side of the charge readout substrate. Since it is supported by the support base, the state in which the entire detector body is supported by the charge reading substrate is eliminated, so that the charge reading substrate is not damaged. Furthermore, since the support that supports the detector body has a light path through which light for improving detection characteristics passes, it does not hinder light irradiation for improving detection characteristics.

また、請求項２の発明は、請求項１に記載の放射線検出器において、支持台は、検出特性改善用の光を透過させる透光性板状体であり、透光性板状体が表面全体で電荷読み出し用基板を受け止めているものである。 The invention according to claim 2 is the radiation detector according to claim 1, wherein the support base is a translucent plate that transmits light for improving detection characteristics, and the translucent plate is on the surface. As a whole, the charge readout substrate is received.

［作用・効果］請求項２の発明の放射線検出器の場合、検出特性改善用の光は透光性板状体を通り抜けて電荷読み出し用基板から放射線有感体に照射される。また、支持台の透光性板状体が表面全体で電荷読み出し用基板を受け止めるので、支持台は検出器本体をしっかり支えることができる。 [Operation / Effect] In the radiation detector according to the second aspect of the present invention, the light for improving the detection characteristics passes through the translucent plate and is irradiated from the charge readout substrate to the radiation sensitive body. Further, since the translucent plate-like body of the support base receives the charge readout substrate over the entire surface, the support base can firmly support the detector body.

また、請求項３の発明は、支持台は、請求項１に記載の放射線検出器において、支持台は、検出特性改善用の光が通る光通路となる中空領域を有する金属製枠体であり、金属製枠体が枠全体で電荷読み出し用基板を受け止めているものである。 According to a third aspect of the present invention, in the radiation detector according to the first aspect, the support base is a metal frame having a hollow region serving as an optical path through which light for improving detection characteristics passes. The metal frame receives the charge readout substrate over the entire frame.

［作用・効果］請求項３の発明の放射線検出器の場合、検出特性改善用の光は金属製枠状体の中空領域を通って電荷読み出し用基板から放射線有感体に照射される。また、支持台の金属製枠体が枠全体で電荷読み出し用基板を受け止めるので、支持台は検出器本体をしっかり支えることができる。 [Operation / Effect] In the case of the radiation detector according to the third aspect of the invention, the detection characteristic improving light is irradiated from the charge readout substrate to the radiation sensitive body through the hollow region of the metal frame. Further, since the metal frame of the support base receives the charge readout substrate over the entire frame, the support base can firmly support the detector body.

また、請求項４の発明は、請求項１から３のいずれかに記載の放射線検出器において、支持台が筐体に取り付けられることにより検出器本体が筐体に対し固定されているものである。 According to a fourth aspect of the present invention, in the radiation detector according to any one of the first to third aspects, the detector main body is fixed to the casing by attaching the support base to the casing. .

［作用・効果］請求項４の発明の放射線検出器の場合、支持台が直に筐体に取り付けられているので、支持台は検出器本体をしっかり支えることができる。 [Operation / Effect] In the case of the radiation detector according to the fourth aspect of the present invention, since the support base is directly attached to the casing, the support base can firmly support the detector body.

また、請求項５の発明は、請求項２に記載の放射線検出器において、支持台は透光性板状体の側周面に沿って取り囲んで透光性板状体と組み付けられている取付枠を具備していて、支持台が取付枠で筐体に取り付けられることにより検出器本体が筐体に対し固定されているものである。 According to a fifth aspect of the present invention, in the radiation detector according to the second aspect, the support base surrounds the side surface of the translucent plate and is assembled with the translucent plate. The detector main body is fixed with respect to a housing | casing by comprising the frame and attaching a support stand to a housing | casing with an attachment frame.

［作用・効果］請求項５の発明の放射線検出器の場合、支持台が取付枠で筐体に取り付けられるので、透光性板状体には取り付けの効かないものも用いることができるのに加え、支持台が直に筐体側に取り付けられているので、支持台は検出器本体をしっかり支えることができる。 [Operation / Effect] In the case of the radiation detector according to the invention of claim 5, since the support base is attached to the casing by the mounting frame, a translucent plate-like body that does not work can be used. In addition, since the support base is directly attached to the housing side, the support base can firmly support the detector body.

また、請求項６の発明は、請求項１から５のいずれかに記載の放射線検出器において、光照射機構の前面に光拡散用の拡散板を有するものである。 According to a sixth aspect of the present invention, in the radiation detector according to any one of the first to fifth aspects, a light diffusing plate is provided in front of the light irradiation mechanism.

［作用・効果］請求項６の発明の放射線検出器の場合、検出特性改善用の光が拡散板によって均一化されるので、検出特性改善用の光の照射むらが抑えられる。 [Operation / Effect] In the case of the radiation detector according to the sixth aspect of the present invention, since the light for improving the detection characteristics is made uniform by the diffusion plate, unevenness in the irradiation of the light for improving the detection characteristics can be suppressed.

請求項１の発明の放射線検出器の場合、検出器本体を電荷読み出し用基板の裏側から支えている支持台を介して検出器本体が筐体に対し固定されていて、検出器本体は支持台によって支えられているので、電荷読み出し用基板によって検出器本体全体を支える状態は解消される結果、電荷読み出し用基板の破損を招来せずに済む。さらに、検出器本体を支えている支持台は検出特性改善用の光が通る光通路を有しているので、透光性の電荷読み出し用基板を介して行なわれる検出特性改善用の光照射を阻害することもない。 In the case of the radiation detector according to the first aspect of the invention, the detector main body is fixed to the housing via a support base that supports the detector main body from the back side of the charge readout substrate, and the detector main body is a support base. As a result, the state of supporting the entire detector body by the charge readout substrate is eliminated, so that the charge readout substrate is not damaged. Furthermore, since the support base that supports the detector body has a light path through which light for detection characteristic improvement passes, light irradiation for detection characteristic improvement performed through a translucent charge readout substrate is performed. There is no hindrance.

よって、請求項１の発明の放射線検出器によれば、検出特性改善用の光照射を阻害しないと同時に電荷読み出し用基板の破損を招来しないかたちで検出器本体を筐体に対し固定することができる。 Therefore, according to the radiation detector of the first aspect of the invention, the detector main body can be fixed to the housing in such a manner that the light irradiation for improving the detection characteristics is not hindered and at the same time the damage of the charge readout substrate is not caused. it can.

この発明の放射線検出器の実施例を図面を参照しながら説明する。図１は実施例１にかかる直接変換タイプのフラットパネル型の二次元放射線検出器（以下、適宜「検出器」と略記）の検出器本体の取り付け構造を示す断面図、図２は実施例１の検出器の検出器本体の要部構成を示す平面図、図３は実施例１の検出器を用いた医用の放射線撮像装置を検出器の要部構成を中心に示したブロック図である。 An embodiment of the radiation detector of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a mounting structure of a detector main body of a direct conversion type flat panel type two-dimensional radiation detector (hereinafter abbreviated as “detector” as appropriate) according to the first embodiment, and FIG. FIG. 3 is a block diagram showing a medical radiation imaging apparatus using the detector of Example 1 with a focus on the configuration of the main part of the detector.

実施例１の検出器１は、図１および図２に示すように、バイアス電圧印加用の共通電極３が表面に形成されていると共に入射放射線を直接電荷に変換する放射線有感体４が、透光性を有する電荷読み出し用基板５に搭載されている検出器本体２と、透光性の電荷読み出し用基板５を介して放射線有感体４に向けて検出特性改善用の光を照射する光照射機構（光源）６とを備えている他に、検出器本体２と光照射機構６との間で検出器本体２を電荷読み出し用基板５の裏側から支えていると共に検出特性改善用の光が通る光通路を有する支持台７と、検出器本体２および光照射機構６と支持台７を収容する平箱状の筐体８とを備えていて、検出器本体２が支持台７を介して筐体８に対し固定された構成とされている。 As shown in FIGS. 1 and 2, the detector 1 of the first embodiment has a radiation sensitive body 4 that has a common electrode 3 for applying a bias voltage formed on the surface thereof and converts incident radiation directly into charges. The detector body 2 mounted on the light-transmitting charge readout substrate 5 and the light for improving detection characteristics are irradiated toward the radiation sensitive body 4 through the light-transmitting charge readout substrate 5. In addition to the light irradiation mechanism (light source) 6, the detector main body 2 is supported from the back side of the charge readout substrate 5 between the detector main body 2 and the light irradiation mechanism 6 and is used for improving detection characteristics. A support base 7 having a light path through which light passes, a detector main body 2, a light irradiation mechanism 6, and a flat box-shaped housing 8 that accommodates the support base 7 are provided. It is set as the structure fixed with respect to the housing | casing 8 via this.

さらに、検出器１は、図３に示すように、検出器本体２から取り出した電荷を増幅処理する電気信号処理回路９を備えている他に、光照射機構６の照射する特性改善用の光強度をコントロールする光強度制御部１０や電荷読み出し用基板５の電荷読み出し動作を司るゲートドライバ１１などを備えている。 Further, as shown in FIG. 3, the detector 1 includes an electric signal processing circuit 9 for amplifying the electric charge taken out from the detector main body 2, and light for improving characteristics irradiated by the light irradiation mechanism 6. A light intensity control unit 10 for controlling the intensity, a gate driver 11 for controlling the charge reading operation of the charge reading substrate 5, and the like are provided.

また、実施例１の検出器１を用いた放射線撮像装置の場合、図３に示すように、検出器１の電気信号処理回路９で増幅処理された電気信号に基づいて被検体（図示省略）の放射線画像を作成する画像処理回路１２と、画像処理回路１２で作成された放射線画像を表示する画像表示モニタ１３と、撮像実行に必要な入力操作を行う操作部１４と、操作部１４による入力操作や撮影プロセスの進行状況に応じて必要な演算および制御を行う中央演算制御処理部１５とを備え、Ｘ線管などの放射線源（図示省略）による被検体への放射線曝射に伴って検出器１に投影される被検体の透過放射線像に対応する放射線画像が画像表示モニタ１３に映し出されるように構成されている。 In the case of the radiation imaging apparatus using the detector 1 of the first embodiment, as shown in FIG. 3, the subject (not shown) is based on the electrical signal amplified by the electrical signal processing circuit 9 of the detector 1. An image processing circuit 12 for generating a radiographic image, an image display monitor 13 for displaying a radiographic image generated by the image processing circuit 12, an operation unit 14 for performing an input operation necessary for execution of imaging, and an input by the operation unit 14 And a central processing control processing unit 15 that performs necessary computation and control according to the progress of the operation and the imaging process, and is detected along with radiation exposure to the subject by a radiation source (not shown) such as an X-ray tube. A radiographic image corresponding to the transmitted radiographic image of the subject projected on the instrument 1 is displayed on the image display monitor 13.

放射線有感体４は、図３に示すように、放射線に有感な半導体層４Ａおよび半導体層４Ａにおける共通電極３の反対側に設けられているキャリア選択性の中間層４ａからなる。半導体層４Ａおよびキャリア選択性の中間層４ａは、通常、半導体厚膜や半導体薄膜の他に半導体結晶をスライスした半導体薄体なども利用可能である。但し中間層４ａを機能させる為に、半導体層４Ａと中間層４ａは異なる材料とする。 As shown in FIG. 3, the radiation sensitive body 4 includes a semiconductor layer 4A sensitive to radiation and a carrier-selective intermediate layer 4a provided on the opposite side of the common electrode 3 in the semiconductor layer 4A. As the semiconductor layer 4A and the carrier selective intermediate layer 4a, a semiconductor thin body obtained by slicing a semiconductor crystal in addition to a semiconductor thick film or a semiconductor thin film can be used. However, in order to make the intermediate layer 4a function, the semiconductor layer 4A and the intermediate layer 4a are made of different materials.

なお、中間層４ａは、共通電極３の反対側に設ける代わりに、共通電極３の直下に設けてもよい。さらに共通電極３の反対側と共通電極３の直下の両方に中間層４ａを設けてもよく、この際、各中間層４ａの材料は、同じである必要はない。 The intermediate layer 4 a may be provided directly below the common electrode 3 instead of being provided on the opposite side of the common electrode 3. Further, the intermediate layer 4a may be provided both on the opposite side of the common electrode 3 and directly below the common electrode 3, and in this case, the material of each intermediate layer 4a is not necessarily the same.

また、具体的な半導体層４Ａや中間層４ａとしては、ノンドープのＳｅ、ノンドープのＳｅ化合物のアモルファス体、ＡｓまたはＴｅをドープしたＳｅ、Ｓｅ化合物のアモルファス体、アルカリ金属やハロゲンを１種または複数種ドープしたＳｅ、アルカリ金属やハロゲンを１種または複数種ドープしたＳｅ化合物のアモルファス体などが好ましい。 Further, as the specific semiconductor layer 4A and intermediate layer 4a, non-doped Se, amorphous body of non-doped Se compound, Se doped with As or Te, amorphous body of Se compound, one or more of alkali metals and halogens A seed-doped Se, an amorphous body of a Se compound doped with one or more alkali metals and halogens, and the like are preferable.

また、半導体層４Ａには、ＣｄＴｅ、ＣｄＺｎＴｅ、ＰｂＩ₂、ＨｇＩ₂、ＴｌＢｒ、ＧａＡｓの化合物半導体のいずれかの多結晶体、またはハロゲンをドープした前記化合物半導体の多結晶体も好ましい。中間層４ａには、Ｓｂ₂Ｓ₃、ＣｅＯ₂、ＣｄＳ、ＣｄＳｅ、ＣｄＴｅ、ＣｄＺｎＴｅ、ＺｎＳｅ、ＺｎＴｅ、ＺｎＳ、ＰｂＩ₂、ＨｇＩ₂、ＴｌＢｒ、ＧａＡｓの化合物半導体のいずれかの多結晶体、またはこれらの多結晶体を組み合わせて多層にしたものも好ましい。 In addition, the semiconductor layer _{4A, CdTe, CdZnTe, PbI 2} , HgI 2, TlBr, either polycrystal GaAs compound semiconductor, or a compound doped with a halogen semiconductor polycrystal is preferred. The intermediate layer 4a includes a polycrystalline body of a compound semiconductor of Sb ₂ S ₃ , CeO ₂ , CdS, CdSe, CdTe, CdZnTe, ZnSe, ZnTe, ZnS, PbI ₂ , HgI ₂ , TlBr, and GaAs, or these A multi-layered combination of these polycrystals is also preferred.

電荷読み出し用基板５は、厚み０．７ｍｍ程度の薄い透明ガラス基材５Ａが用いられていて、ＩＴＯ膜等の透明性を有する多数個の個別電極（分割電極）１６が放射線有感体４の裏面側となる表面に縦横の２次元マトリックス配列で形成されているのに加え、個別電極１６毎に薄膜トランジスタ・スイッチ（以下、適宜「ＴＦＴ」という）１７とコンデンサ１８が放射線画像の各画素と対応付けられて形成されている。すなわち、電荷読み出し用基板５は透明ガラス基材５Ａと電荷読み出し回路用の薄膜とからなり、事実上、透明性を有しており、光照射機構６により照射される検出特性改善用の光を透過させることができる。電荷読み出し用基板５の透光性を良くするという観点から個別電極（分割電極）１６は透明性を有する電極（透明電極）であることが好ましい。 A thin transparent glass substrate 5A having a thickness of about 0.7 mm is used for the charge readout substrate 5, and a large number of individual electrodes (divided electrodes) 16 having transparency such as an ITO film are included in the radiation sensitive body 4. In addition to being formed in a vertical and horizontal two-dimensional matrix arrangement on the front surface, a thin film transistor switch (hereinafter referred to as “TFT” as appropriate) 17 and a capacitor 18 correspond to each pixel of the radiation image for each individual electrode 16. It is attached and formed. That is, the charge readout substrate 5 comprises a transparent glass substrate 5A and a thin film for a charge readout circuit, and is practically transparent, so that light for improving detection characteristics irradiated by the light irradiation mechanism 6 can be obtained. Can be transmitted. From the viewpoint of improving the translucency of the charge readout substrate 5, the individual electrodes (divided electrodes) 16 are preferably transparent electrodes (transparent electrodes).

そして、電荷読み出し用基板５の場合、放射線入射に伴って個別電極１６経由でコンデンサ１８に放射線入射強度に応じた量の電荷が蓄積されるとともに、走査信号によってゲートドライバ１１がＴＦＴスイッチ１７に順次Ｏｎ・Ｏｆｆの切り替えを行なわせて各コンデンサ１８に蓄積された電荷を読み出す構成となっている。つまり、検出器１は、個別電極１６は画素電極として２次元マトリックスの配列で設置され、個別電極１６毎に検出電荷が取得される二次元検出器となっている。 In the case of the charge readout substrate 5, an amount of charge corresponding to the radiation incident intensity is accumulated in the capacitor 18 via the individual electrode 16 with the radiation incident, and the gate driver 11 is sequentially applied to the TFT switch 17 by the scanning signal. The charge accumulated in each capacitor 18 is read by switching between On and Off. That is, the detector 1 is a two-dimensional detector in which the individual electrodes 16 are arranged in a two-dimensional matrix array as pixel electrodes, and the detected charges are acquired for each individual electrode 16.

電気信号処理回路９は、取り出した電荷を中央演算制御処理部１５によるセッティングによって設定されるゲイン値（ゲイン設定値）に従って増幅処理すると共にゲイン設定値の増加、減少がおこなえる構成とされている。通常、ゲイン設定値は想定入射放射線の強度が増えればゲイン設定値が減り、想定入射放射線の強度が減ればゲイン設定値が増す（つまり入射放射線の強度とゲイン設定値が反比例の関係となる）ように設定される。 The electric signal processing circuit 9 is configured to amplify the extracted charge according to a gain value (gain setting value) set by setting by the central processing control processing unit 15 and to increase or decrease the gain setting value. Normally, the gain setting value decreases as the assumed incident radiation intensity increases, and the gain setting value increases as the assumed incident radiation intensity decreases (that is, the incident radiation intensity and the gain setting value are inversely related). Is set as follows.

電気信号処理回路９は、電荷（電流）−電圧変換器９Ａとマルチプレクサ９ＢとＡ／Ｄ変換器９Ｃ等を有し、電荷−電圧変換器９Ａにゲイン設定値がセットされる。図２の放射線撮像装置の場合、放射線源（図示省略）の放射強度も中央演算制御処理部１５によってコントロールされ、中央演算制御処理部１５が放射線源の放射強度に合わせて電気信号処理回路９のゲイン設定値をセットする。勿論、別途に放射線の強度を検出すると共に検出された放射線強度に見合ったゲイン設定値が自動的にセットされる構成でもよい。 The electric signal processing circuit 9 includes a charge (current) -voltage converter 9A, a multiplexer 9B, an A / D converter 9C, and the like, and a gain setting value is set in the charge-voltage converter 9A. In the case of the radiation imaging apparatus of FIG. 2, the radiation intensity of the radiation source (not shown) is also controlled by the central processing control processing unit 15, and the central processing control processing unit 15 performs the electrical signal processing circuit 9 according to the radiation intensity of the radiation source. Set the gain setting value. Of course, a configuration in which the intensity of radiation is separately detected and a gain setting value corresponding to the detected radiation intensity is automatically set may be employed.

画像処理回路１２は、放射線画像作成用の電気信号毎に検出器１の検出系統の場所的不均一性に起因する各電気信号間のオフセットの場所的バラツキを補正するオフセット補正係数および各電気信号間の感度の場所的バラツキを補正する感度補正係数を登録する補正係数登録部１２Ａを有しており、画像処理回路１２による処理の実行時に予め登録されているオフセット補正係数および感度補正係数に基づき各電気信号間のオフセットや感度のバラツキ補正処理が行われる。 The image processing circuit 12 includes an offset correction coefficient and each electrical signal for correcting a local variation in offset between each electrical signal caused by the locational non-uniformity of the detection system of the detector 1 for each electrical signal for creating a radiographic image. And a correction coefficient registration unit 12A for registering a sensitivity correction coefficient for correcting a local variation in sensitivity between the two, and based on an offset correction coefficient and a sensitivity correction coefficient registered in advance when the processing by the image processing circuit 12 is executed. Correction processing for offset and sensitivity variation between the electrical signals is performed.

そして、検出器１の場合、光強度制御部１０のコントロールにより電気信号処理回路９のゲイン設定値の減少、増加に応じて光照射機構６が照射する光の強度が増加、減少する構成となっている。電気信号処理回路９のゲイン設定値が減少すれば、光照射機構６が照射する光の強度が増大し、逆にゲイン設定値が増加すれば、光照射機構６が照射する光の強度が減少する（つまりゲイン設定値と光の強度が反比例の関係となる）。 In the case of the detector 1, the intensity of light emitted from the light irradiation mechanism 6 increases or decreases as the gain setting value of the electric signal processing circuit 9 decreases or increases as controlled by the light intensity controller 10. ing. If the gain setting value of the electric signal processing circuit 9 decreases, the intensity of light emitted by the light irradiation mechanism 6 increases. Conversely, if the gain setting value increases, the intensity of light emitted by the light irradiation mechanism 6 decreases. (That is, the gain setting value and the light intensity are in an inversely proportional relationship).

したがって、本実施例の場合、普通、入射放射線の強度とゲイン設定値は反比例の関係となるように操作されると共に、ゲイン設定値と光の強度とは反比例の関係にあるので、結果的に、光強度制御部１０は光照射機構６の照射光の強度と入射放射線の強度が正比例関係にあるように光照射機構６をコントロールする。 Therefore, in the case of the present embodiment, normally, the intensity of the incident radiation and the gain setting value are operated so as to be in an inversely proportional relationship, and the gain setting value and the light intensity are in an inversely proportional relationship. The light intensity control unit 10 controls the light irradiation mechanism 6 so that the intensity of the irradiation light of the light irradiation mechanism 6 and the intensity of the incident radiation are in a direct proportional relationship.

図３の放射線撮像装置の場合、例えば、予め各ゲイン設定値について適当な照射光の強度を実験的に求めて、この照射光の強度を各ゲイン設定値と対応させて登録しておき、ゲイン設定値をセットする時に対応する照射光の強度を読み出して光強度制御部１０にセット（設定）する。なお、もし使用放射線の強度が予め幾つかに限定されている場合、放射線の強度毎に適当なゲイン設定値および適当な照射光の強度を対応付けて登録しておき、放射線の強度を設定すると、自動的にゲイン設定値および適当な照射光の強度のセットが行われる構成としてもよい。 In the case of the radiation imaging apparatus shown in FIG. 3, for example, an appropriate irradiation light intensity is experimentally obtained in advance for each gain setting value, and the irradiation light intensity is registered in association with each gain setting value. When the set value is set, the intensity of the corresponding irradiation light is read out and set (set) in the light intensity control unit 10. If the intensity of the radiation used is limited to several in advance, an appropriate gain setting value and an appropriate intensity of irradiation light are registered in association with each radiation intensity, and the radiation intensity is set. Alternatively, the gain setting value and the appropriate irradiation light intensity may be automatically set.

具体的な光照射機構６としては、図３に示すように、例えば、透明アクリル樹脂製の導光板１９と、導光板１９の側端面に設置された発光ダイオードや冷陰極管等の発光体２０とを有し、更に導光板１９の光放射面には微細加工（表面粗化加工）が施されているのに加えて、光拡散用の拡散板２１が取り付けられている一方、導光板１９の裏面には反射シート２２が取り付けられている構成が挙げられる。発光体２０の光は、反射シート２２で反射しながら導光板１９を通り、導光板１９の表面の微細加工および拡散板２１を経て照射されるので、検出特性改善用の光を効率よく均一にむらなく照射することができる。なお、発光体２０として面発光ダイオードを電荷読み出し用基板５の側に発光面を向けるようにして使うこともできる。 As a specific light irradiation mechanism 6, as shown in FIG. 3, for example, a light guide plate 19 made of transparent acrylic resin, and a light emitting body 20 such as a light emitting diode or a cold cathode tube installed on a side end surface of the light guide plate 19. Further, the light emitting surface of the light guide plate 19 is finely processed (surface roughening), and a light diffusion plate 21 is attached to the light guide plate 19. A configuration in which a reflective sheet 22 is attached to the back surface of the lens is mentioned. The light emitted from the light emitter 20 passes through the light guide plate 19 while being reflected by the reflection sheet 22 and is irradiated through the fine processing of the surface of the light guide plate 19 and the diffusion plate 21, so that the light for improving the detection characteristics can be efficiently and uniformly distributed. Irradiate evenly. Note that a surface light emitting diode may be used as the light emitter 20 with the light emitting surface facing the charge reading substrate 5 side.

また光強度制御部１０は、発光体２０の光強度がゲイン設定値の減少、増加に応じて増加、減少するように発光体２０の発光量をコントロールするとともに、光照射機構６による光照射が放射線の検出中だけでなく放射線の検出前あるいは検出後でも行えるようにコントロールする。 The light intensity controller 10 controls the light emission amount of the light emitter 20 so that the light intensity of the light emitter 20 increases or decreases as the gain setting value decreases or increases, and the light irradiation mechanism 6 performs light irradiation. Control is performed not only during radiation detection but also before or after radiation detection.

検出器１の場合、個別電極１６の側から放射線有感体４に光照射機構６により光が照射されるのに伴って、放射線有感体４における個別電極１６間のスペースの領域に光照射で生じた空間電荷が溜まってしまうので、放射線の入射によって発生した電荷の方は溜まらずに掃き出される。その結果、実効的な有感面積の変化が起こらず、検出器１の検出感度の変動が回避できる。また、放射線の入射停止後も光照射機構６による光照射を続ければ、個別電極１６間のスペースの領域に溜まった空間電荷は掃き出されずに留まり続けるので、残留出力の発生を回避できる。 In the case of the detector 1, as the radiation sensitive body 4 is irradiated with light from the individual electrode 16 side by the light irradiation mechanism 6, light irradiation is performed on the region of the space between the individual electrodes 16 in the radiation sensitive body 4. As a result, the space charge generated by the radiation is accumulated, and the charge generated by the incidence of radiation is swept out without accumulating. As a result, the effective sensitive area does not change, and fluctuations in the detection sensitivity of the detector 1 can be avoided. Further, if the light irradiation by the light irradiation mechanism 6 is continued even after the radiation incidence is stopped, the space charge accumulated in the space area between the individual electrodes 16 continues to stay without being swept out, so that the generation of a residual output can be avoided.

一方、光照射機構６による光照射は、電気信号に暗電流分として加わる電気信号の増加を伴う。光照射機構６による光照射に伴う暗電流分は、照射光の強度の増減に応じて増減し、照射光の強度が増すほど暗電流分が増える。他方、電気信号処理回路９では光照射に伴う暗電流分も一緒にゲイン設定値に応じて増幅処理される結果、増幅処理後の暗電流分が電気信号処理回路９の出力範囲を占める分だけ電気信号処理回路９のダイナミックレンジが狭められることになるが、ゲイン設定値が増えると暗電流分の増幅度が増すので、同一量の暗電流分に対してはゲイン設定値が増すとダイナミックレンジの狭められる度合いも増える。 On the other hand, the light irradiation by the light irradiation mechanism 6 is accompanied by an increase in the electric signal added as a dark current component to the electric signal. The amount of dark current accompanying light irradiation by the light irradiation mechanism 6 increases / decreases according to the increase / decrease of the intensity of irradiation light, and the dark current increases as the intensity of irradiation light increases. On the other hand, in the electrical signal processing circuit 9, the dark current due to light irradiation is also amplified according to the gain setting value, so that the dark current after amplification occupies the output range of the electrical signal processing circuit 9. The dynamic range of the electric signal processing circuit 9 is narrowed. However, when the gain setting value is increased, the amplification factor of the dark current is increased. Therefore, when the gain setting value is increased for the same amount of dark current, the dynamic range is increased. The degree of narrowing increases.

しかし、前述したように、検出器１では、電気信号処理回路９のゲイン設定値が増す場合、光照射機構６により照射する光の強度が減らされて暗電流分が減るので、ゲイン設定値の増加が暗電流分の減少で相殺され、ゲイン設定値の増加でダイナミックレンジが狭められるのが抑えられる。逆に電気信号処理回路９のゲイン設定値が減る場合、光照射機構６により照射する光の強度が増して暗電流分が増えるけれども、暗電流分の増加がゲイン設定値の減少で相殺され、照射光の強度増加でダイナミックレンジが狭められるのが抑えられる。したがって、検出器１の場合、検出感度の変動や残留出力の発生を回避する為の光照射に伴って発生する暗電流分が電気信号処理回路９の出力範囲を広く占めてしまうことは解消され、ダイナミックレンジが大きく狭められる事態は起こらない。 However, as described above, in the detector 1, when the gain setting value of the electric signal processing circuit 9 is increased, the intensity of light irradiated by the light irradiation mechanism 6 is reduced and the dark current is reduced. The increase is offset by the decrease in dark current, and the dynamic range is prevented from being narrowed by increasing the gain setting value. Conversely, when the gain setting value of the electrical signal processing circuit 9 decreases, the intensity of light irradiated by the light irradiation mechanism 6 increases and the dark current component increases, but the increase in the dark current component is offset by the decrease in the gain setting value, It is possible to prevent the dynamic range from being narrowed by increasing the intensity of irradiation light. Therefore, in the case of the detector 1, it is solved that the dark current generated due to the light irradiation for avoiding the fluctuation of the detection sensitivity and the generation of the residual output occupies a wide output range of the electric signal processing circuit 9. The situation where the dynamic range is greatly narrowed does not occur.

一方、検出器１の検出器本体２は、図１に示すように、電荷読み出し用基板５の上に放射線有感体４を取り囲むかたちで配置されたスペーサ用のフレーム枠２３と、フレーム枠２３を蓋するかたちで配置された上面ガラス板２４と、スペーサ用フレーム枠２３と上面ガラス板２４の内側空間を埋めるかたちでエポキシ系樹脂を用いて形成された対環境性改善および耐圧性改善の為の樹脂モールド２５とを備えているが、フレーム枠２３の外側となる電荷読み出し用基板５の周縁部はフレキシブルプリント配線板等による電気接続域や集積回路搭載域となっていて、接続異常時や回路故障時のリペア（補修）などのために樹脂モールドは施されていない。 On the other hand, as shown in FIG. 1, the detector main body 2 of the detector 1 includes a frame frame 23 for spacers arranged on the charge readout substrate 5 so as to surround the radiation sensitive body 4, and a frame frame 23. In order to improve environmental resistance and pressure resistance, which is formed by using an epoxy-based resin so as to fill the inner space of the upper glass plate 24, the spacer frame frame 23, and the upper glass plate 24, which are arranged in the form of a lid. However, the peripheral portion of the charge readout substrate 5 on the outside of the frame frame 23 is an electrical connection area or an integrated circuit mounting area by a flexible printed wiring board, etc. Resin molds are not applied to repair (repair) in case of circuit failure.

他方、検出器本体２を支えている支持台７は、光照射機構６が照射する検出特性改善用の光を透過させる透光性板状体７Ａと、透光性板状体７Ａの側周面に沿って取り囲むかたちで透光性板状体７Ａと組み付けられている金属製取付枠７Ｂとを具備している。透光性板状体７Ａはエポキシ系樹脂を用いた樹脂モールド７Ａ１と透明な下面ガラス板７Ａ２とからなり、金属製取付枠７Ｂの下面には取り付け用のネジ孔７Ｂ１が設けられている。樹脂モールド７Ａ１および下面ガラス板７Ａ２と金属製取付枠７Ｂは樹脂モールド７Ａ１の強力な接着力で相互にしっかりと接着されている。 On the other hand, the support 7 that supports the detector body 2 includes a translucent plate-like body 7A that transmits light for improving detection characteristics irradiated by the light irradiation mechanism 6, and a side periphery of the translucent plate-like body 7A. It includes a metal mounting frame 7B assembled with a translucent plate-like body 7A so as to surround the surface. The translucent plate 7A is composed of a resin mold 7A1 using an epoxy resin and a transparent lower glass plate 7A2, and a screw hole 7B1 for attachment is provided on the lower surface of the metal attachment frame 7B. The resin mold 7A1, the lower glass plate 7A2, and the metal mounting frame 7B are firmly bonded to each other by the strong adhesive force of the resin mold 7A1.

そして、支持台７は金属製取付枠７Ｂで筐体８に取り付けられることにより検出器本体２が筐体８に対し固定されている。即ち、筐体８は内壁面の中程の高さの処に水平内向きに突き出した支持台取り付けの為の突出部８Ａを有しており、この突出部８Ａに貫通孔８Ａ１が形成されていて、止めネジ２６を貫通孔８Ａ１を通して金属製取付枠７Ｂの下面のネジ孔７Ｂ１にネジ込むことで支持台７が筐体８に取り付けられている。金属製取付枠７Ｂを用いた場合、漏光防止や電気的シールドによるノイズ低減効果もある。 The detector base 2 is fixed to the housing 8 by attaching the support base 7 to the housing 8 with a metal mounting frame 7B. That is, the housing 8 has a protruding portion 8A for attaching a support base that protrudes horizontally inward at the middle height of the inner wall surface, and a through hole 8A1 is formed in the protruding portion 8A. The support base 7 is attached to the housing 8 by screwing the set screw 26 into the screw hole 7B1 on the lower surface of the metal mounting frame 7B through the through hole 8A1. When the metal mounting frame 7B is used, there are also noise reduction effects due to light leakage prevention and electrical shielding.

光照射機構６は別に筐体８に取り付けられて固定されている。即ち、筐体８は内壁面の底に近い高さの処に水平に内側へ突き出した光照射機構取り付けの為の突出部８Ｂを有しており、この突出部８Ｂに受け座８Ｂ１が形成されていて、受け座８Ｂ１に光照射機構６が据え付けられている。光照射機構６は受け座８Ｂ１に据え置かれた後、ネジ止め等や接着等の適当な仕方で取り付けられている。放射線有感体４には検出特性改善用の光が光通路としての透光性板状体７Ａを通り透光性の電荷読み出し用基板５を介して照射される。 The light irradiation mechanism 6 is separately attached and fixed to the housing 8. That is, the housing 8 has a protruding portion 8B for attaching a light irradiation mechanism that protrudes inward horizontally at a height near the bottom of the inner wall surface, and a receiving seat 8B1 is formed on the protruding portion 8B. The light irradiation mechanism 6 is installed on the receiving seat 8B1. The light irradiation mechanism 6 is mounted on the receiving seat 8B1 and then attached by an appropriate method such as screwing or bonding. The radiation sensitive body 4 is irradiated with light for improving detection characteristics through a translucent charge readout substrate 5 through a translucent plate 7A as an optical path.

したがって、検出器１の場合、光照射機構６は支持台７の側に組み付けられておらず、別途に筐体８に対し固定されている。その結果、光照射機構６が支持台７を受け止めて支える必要も、逆に支持台７が光照射機構６を吊り下げて支える必要もなく、光照射機構６と支持台７の間の相互干渉を避けることができる。また、光照射機構６は光拡散用の拡散板２１は支持台７に接触しないかたちで取り付けられていることが好ましい。支持台７と拡散板２１の接触によって拡散板２１の光拡散機能の低下を防ぐことができる。 Therefore, in the case of the detector 1, the light irradiation mechanism 6 is not assembled to the support base 7 side and is separately fixed to the housing 8. As a result, there is no need for the light irradiation mechanism 6 to receive and support the support base 7, and conversely, the support base 7 does not need to suspend and support the light irradiation mechanism 6, and mutual interference between the light irradiation mechanism 6 and the support base 7. Can be avoided. Moreover, it is preferable that the light irradiation mechanism 6 is attached so that the light diffusion plate 21 does not contact the support base 7. The contact between the support base 7 and the diffusion plate 21 can prevent the light diffusion function of the diffusion plate 21 from being lowered.

このように、実施例１の検出器１の場合、検出器本体２を電荷読み出し用基板５の裏側から支えている支持台７を介して検出器本体２が筐体８に対し固定されており、検出器本体２全体が支持台７で支えられていて、電荷読み出し用基板５で検出器本体２全体を支える状態は解消されるので、電荷読み出し用基板５の破損を招来せずに済む。さらに、光照射機構６が照射する検出特性改善用の光が通る光通路としての透光性板状体７Ａを有する支持台７によって検出器本体２が支えられているので、検出特性改善用の光照射を阻害することもない。加えて、支持台７を取り外せば、検出器本体２が取り出せるので、リペアなどの為に検出器本体２を取り出さなければならない時でも取り出し易い。 Thus, in the case of the detector 1 according to the first embodiment, the detector main body 2 is fixed to the housing 8 via the support base 7 that supports the detector main body 2 from the back side of the charge readout substrate 5. Since the entire detector body 2 is supported by the support 7 and the state of supporting the entire detector body 2 by the charge readout substrate 5 is eliminated, the charge readout substrate 5 can be prevented from being damaged. Furthermore, since the detector body 2 is supported by the support base 7 having the light-transmitting plate-like body 7A as a light path through which the light for improving the detection characteristics irradiated by the light irradiation mechanism 6 passes, It does not interfere with light irradiation. In addition, since the detector main body 2 can be taken out by removing the support base 7, it is easy to take out the detector main body 2 even when the detector main body 2 has to be taken out for repair or the like.

また、実施例１の検出器１の場合、透光性板状体７Ａの表面全体および金属製取付枠７Ｂの枠全体の双方で電荷読み出し用基板５を受け止めて検出器本体２をしっかり支えるのに加え、支持台７が直に筐体８に取り付けられているので、支持台７による検出器本体２の支持が確かなものになる。さらに、支持台７が金属製取付枠７Ｂで筐体８に取り付けられているので、透光性板状体７Ａには取り付けの効かないものも用いることができる。
である。それに、検出器１はフラットパネル型の二次元検出器であるので、薄型・軽量の検出器であるのに加え、放射線有感体４に投影される二次元放射線像を一度に検出できる。 In the case of the detector 1 according to the first embodiment, both the entire surface of the translucent plate 7A and the entire frame of the metal mounting frame 7B receive the charge readout substrate 5 and firmly support the detector body 2. In addition, since the support base 7 is directly attached to the housing 8, the support of the detector main body 2 by the support base 7 is ensured. Furthermore, since the support base 7 is attached to the housing 8 with a metal attachment frame 7B, it is also possible to use a non-attachable one for the translucent plate-like body 7A.
It is. In addition, since the detector 1 is a flat panel type two-dimensional detector, in addition to being a thin and light detector, a two-dimensional radiation image projected on the radiation sensitive body 4 can be detected at a time.

続いて、実施例２の検出器を図面を参照して説明する。図４は実施例２に係る直接変換タイプの検出器の検出器本体の取り付け構造を示す断面図である。 Next, the detector of Example 2 will be described with reference to the drawings. FIG. 4 is a cross-sectional view illustrating a mounting structure of the detector main body of the direct conversion type detector according to the second embodiment.

実施例２の検出器２７は、支持台２８が検出特性改善用の光が通る光通路となる中空領域２８Ｂを有する金属製枠体２８Ａのみからなる他は、実施例１と同様のものであるので、共通点は省略し、相違点のみを説明する。 The detector 27 of the second embodiment is the same as that of the first embodiment except that the support base 28 comprises only a metal frame 28A having a hollow region 28B that serves as a light path through which light for improving detection characteristics passes. Therefore, common points are omitted, and only differences are described.

支持台２８である金属製枠体２８Ａは中空領域２８Ｂが検出特性改善用の光の通過域に一致するように位置決めされたかたちで電荷読み出し用基板５の裏面に接着されている。金属製枠体２８Ａの接着は金属製枠体２８Ａの上面を両面粘着テープ等の接着剤で電荷読み出し用基板５の裏面に接着させること等により行なわれる。なお、その際、両面粘着テープ等の接着剤が検出特性改善用の光の通過域にかからないように注意する。また支持台２８は金属製枠体２８Ａの下面に取り付け用のネジ孔２８Ａ１が設けられている。金属製枠体２８Ａは実質的に金属製取付枠７Ｂと同じものである。 A metal frame 28A, which is the support base 28, is adhered to the back surface of the charge readout substrate 5 in such a manner that the hollow region 28B is positioned so as to coincide with the light passing region for improving detection characteristics. The metal frame 28A is bonded by bonding the upper surface of the metal frame 28A to the back surface of the charge readout substrate 5 with an adhesive such as a double-sided adhesive tape. At that time, care should be taken so that the adhesive such as the double-sided adhesive tape does not enter the light passage area for improving detection characteristics. The support base 28 is provided with a screw hole 28A1 for attachment on the lower surface of the metal frame 28A. The metal frame 28A is substantially the same as the metal mounting frame 7B.

検出特性改善用の光は金属製枠体２８Ａの光通路としての中空領域２８Ｂを通り抜けて電荷読み出し用基板５から放射線有感体４に照射される。また、支持台２８である金属製枠体２８Ａは枠全体で電荷読み出し用基板５を受け止めて検出器本体２をしっかり支える。金属製枠体２８Ａは強固であるから金属製枠体２８Ａだけでも検出器本体２を十分に支えられる。また、支持台２８は、支持台７と比べると樹脂モールド７Ａ１と下面ガラス板７Ａ２がない分だけ検出特性改善用の透過率が良くなるし、支持台２８の作製も容易である。 The detection characteristic improving light passes through the hollow region 28B as an optical path of the metal frame 28A and is irradiated from the charge readout substrate 5 to the radiation sensitive body 4. Further, the metal frame 28A, which is the support base 28, receives the charge readout substrate 5 over the entire frame and firmly supports the detector body 2. Since the metal frame 28A is strong, the detector main body 2 can be sufficiently supported by the metal frame 28A alone. In addition, the support base 28 has improved transmittance for detecting characteristics as much as the resin mold 7A1 and the lower glass plate 7A2 are absent, and the support base 28 can be easily manufactured.

続いて、実施例３の検出器を図面を参照して説明する。図５は実施例３に係る直接変換タイプの検出器の検出器本体の取り付け構造を示す断面図である。 Subsequently, the detector of Example 3 will be described with reference to the drawings. FIG. 5 is a cross-sectional view illustrating a mounting structure of a detector main body of a direct conversion type detector according to the third embodiment.

実施例３の検出器２９は、支持台３０が検出特性改善用の光を透過させる透光性板状体３０Ａと、透光性板状体３０Ａの側周面に沿って取り囲むかたちで透光性板状体３０Ａと組み付けられている金属製取付枠３０Ｂとからなる他は、実施例１と同様のものであるので、共通点は省略し、相違点のみを説明する。なお、透光性板状体３０Ａは実質的に樹脂モールド７Ａ１と同じものであり、金属製取付枠３０Ｂは実質的に金属製取付枠７Ｂと同じものである。 The detector 29 according to the third embodiment has a translucent plate 30 A through which the support 30 transmits light for improving detection characteristics, and the translucent plate 30 A is surrounded along the side peripheral surface of the translucent plate 30 A. Since it is the same as that of Example 1 except for comprising the metallic plate-like body 30A and the metal mounting frame 30B, the common points are omitted, and only the differences will be described. The translucent plate 30A is substantially the same as the resin mold 7A1, and the metal attachment frame 30B is substantially the same as the metal attachment frame 7B.

透光性板状体３０Ａと金属製取付枠３０Ｂおよび電荷読み出し用基板５は透光性板状体３０Ａの強力な接着力によって相互にしっかり接着されている。また支持台３０の場合も、金属製取付枠３０Ｂの下面に設けられた取り付け用のネジ孔３０Ｂ１で筐体８にネジ止めされて取り付けられている。なお、検出器２９の場合、透光性板状体３０Ａの樹脂モールドが完全に固化しないうちは、光照射機構６の拡散板２１が触れると照射光の均一化が阻害される恐れがあるので注意する必要がある。 The translucent plate 30A, the metal mounting frame 30B, and the charge readout substrate 5 are firmly bonded to each other by the strong adhesive force of the translucent plate 30A. Also, in the case of the support base 30, it is attached to the housing 8 by being screwed to the housing 8 through an attachment screw hole 30B1 provided on the lower surface of the metal attachment frame 30B. In the case of the detector 29, if the resin mold of the translucent plate 30A is not completely solidified, if the diffusion plate 21 of the light irradiation mechanism 6 is touched, the uniformity of the irradiated light may be hindered. You need to be careful.

検出特性改善用の光は光通路としての透光性板状体３０Ａを透過して電荷読み出し用基板５から放射線有感体４に照射される。支持台３０の場合、透光性板状体３０Ａの表面全体と金属製取付枠３０Ｂの枠全体で電荷読み出し用基板５を受け止めて検出器本体２をしっかり支える。支持台３０は、支持台７と比べると下面ガラス板７Ａ２のない分だけ検出特性改善用の透過率が良くなる。 The detection characteristic improving light passes through the translucent plate 30 A as an optical path and is irradiated from the charge readout substrate 5 to the radiation sensitive body 4. In the case of the support table 30, the entire surface of the translucent plate 30 A and the entire frame of the metal mounting frame 30 B receive the charge readout substrate 5 and firmly support the detector body 2. Compared with the support base 7, the support base 30 has a better transmittance for detecting characteristics than the lower glass plate 7A2.

続いて、実施例４の検出器を図面を参照して説明する。図６は実施例４に係る直接変換タイプの検出器の検出器本体の取り付け構造を示す断面図である。 Subsequently, the detector of Example 4 will be described with reference to the drawings. FIG. 6 is a cross-sectional view illustrating a mounting structure of a detector main body of a direct conversion type detector according to the fourth embodiment.

実施例４の検出器３１は、支持台３２が光照射機構６が照射する検出特性改善用の光を透過させる樹脂製の透光性板状体３２Ａのみからなる他は、実施例１と同様のものであるので、共通点は省略し、相違点のみを説明する。 The detector 31 of the fourth embodiment is the same as the first embodiment except that the support base 32 includes only a resin-made translucent plate-like body 32A that transmits the light for detection characteristic improvement irradiated by the light irradiation mechanism 6. Therefore, common points are omitted, and only differences are described.

支持台３２である透光性板状体３２Ａは電荷読み出し用基板５の裏面に接着されている。透光性板状体３２Ａは別途に樹脂シートを裁断した樹脂プレートであってもよいし、樹脂モールドであってもよい。樹脂プレートの場合、検出特性改善用の光の通過域外となる透光性板状体３２Ａの表面周縁域と電荷読み出し用基板５の裏面周縁域を接着剤や両面粘着テープで貼り付ければよい。樹脂モールドの場合、電荷読み出し用基板５を裏向けにした状態でシリコン板等で型枠を組み付けておいてエポキシ樹脂を注入することで形成してもよい。後者の場合、支持台３２は透光性板状体３２Ａの強力な接着力で電荷読み出し用基板５にしっかりと接着する。さらに、透光性板状体３２Ａの下面には取り付け用のネジ孔３２Ｂが設けられていて、支持台３２は取り付け用のネジ孔３２Ｂで筐体８にネジ止めされて取り付けられている。 A translucent plate 32 A that is the support base 32 is bonded to the back surface of the charge readout substrate 5. The translucent plate-like body 32A may be a resin plate obtained by cutting a resin sheet separately, or may be a resin mold. In the case of a resin plate, the surface peripheral area of the translucent plate-like body 32A that is outside the light transmission area for improving detection characteristics and the back peripheral area of the charge readout substrate 5 may be attached with an adhesive or a double-sided adhesive tape. In the case of a resin mold, it may be formed by injecting an epoxy resin after assembling a mold with a silicon plate or the like with the charge readout substrate 5 facing back. In the latter case, the support base 32 is firmly adhered to the charge readout substrate 5 by the strong adhesive force of the translucent plate-like body 32A. Further, a screw hole 32B for attachment is provided on the lower surface of the translucent plate-like body 32A, and the support base 32 is attached to the housing 8 by being screwed to the housing 8 through the screw hole 32B for attachment.

検出特性改善用の光は光通路としての透光性板状体３２Ａを透過して電荷読み出し用基板５から放射線有感体４に照射される。支持台３２の場合、透光性板状体３２Ａの表面全体で電荷読み出し用基板５を受け止めて検出器本体２をしっかり支える。 The detection characteristic improving light passes through the translucent plate-like body 32A as an optical path and is irradiated from the charge readout substrate 5 to the radiation sensitive body 4. In the case of the support base 32, the entire surface of the translucent plate-like body 32A receives the charge readout substrate 5 and firmly supports the detector main body 2.

この発明は、上記実施の形態に限られることはなく、下記のように変形実施することができる。 The present invention is not limited to the above-described embodiment, and can be modified as follows.

（１）実施例１〜４の各検出器では、光照射機構６が照射する特性改善用の光強度をコントロールする光強度制御部１０は検出器に内蔵されていたが、光強度制御部１０は必ずしも検出器に内蔵されている必要はなく外付けであってもよい。 (1) In each detector of Examples 1 to 4, the light intensity control unit 10 for controlling the light intensity for improving the characteristics irradiated by the light irradiation mechanism 6 is built in the detector, but the light intensity control unit 10 Need not be built in the detector, but may be external.

（２）実施例１〜４の各検出器では、支持台が筐体８に直に取り付けられた構成であったが、例えば、図７に示すように、支持台は筐体８に直に取り付けられずに、支持台３０が光照射機構６の上に載置され、支持台３０は筐体８に間接的に取り付けられた構成である他は、実施例３と同一の構成を有する検出器３３が変形実施例として挙げられる。但し、変形実施例の場合、金属製取付枠３０Ｂにはネジ孔３０Ｂ１を設ける必要はない。 (2) In each of the detectors of Examples 1 to 4, the support base is directly attached to the housing 8. For example, as shown in FIG. 7, the support base is directly attached to the housing 8. A detection having the same configuration as that of the third embodiment except that the support 30 is mounted on the light irradiation mechanism 6 without being attached and the support 30 is indirectly attached to the housing 8. A device 33 is given as a variant embodiment. However, in the modified embodiment, it is not necessary to provide the screw hole 30B1 in the metal mounting frame 30B.

検出器３３の場合、光照射機構６が検出器本体２と支持台３０の両方を支えることになり、拡散板２１が支持台３０に接触すると光拡散機能が損なわれる可能性が高いので、拡散板２１は若干の隙間を隔てて支持台３０の裏面に対面させる。光照射機構６と支持台３０の接着は、光照射機構６と支持台３０の周縁部の検出特性改善用の光の通過域外で両面粘着テープ等を用いて接着することで行なうことができる。 In the case of the detector 33, the light irradiation mechanism 6 supports both the detector body 2 and the support base 30, and if the diffusion plate 21 comes into contact with the support base 30, the light diffusion function is likely to be impaired. The plate 21 faces the back surface of the support base 30 with a slight gap. The light irradiation mechanism 6 and the support table 30 can be bonded together by using a double-sided adhesive tape or the like outside the light passing area for improving detection characteristics at the peripheral portions of the light irradiation mechanism 6 and the support table 30.

（３）実施例１〜４の各検出器の場合、支持台を構成する透光性板状体の材料が樹脂やガラスであったが、透光性板状体の材料として結晶体（例えばダイヤモンド）を用いることもできる。 (3) In the case of each detector of Examples 1 to 4, the material of the translucent plate-like body constituting the support was resin or glass. Diamond) can also be used.

（４）実施例１〜４の各検出器は、医用の放射線撮像装置に用いられるものであったが、この発明の放射線検出器は、医用以外に工業用や原子力用に用いることもできる。 (4) Although each detector of Examples 1-4 was used for a medical radiation imaging device, the radiation detector of this invention can also be used for industrial use and nuclear power besides medical use.

実施例１の検出器の検出器本体の取り付け構造を示す断面図である。It is sectional drawing which shows the attachment structure of the detector main body of the detector of Example 1. FIG. 実施例１の検出器の検出器本体の要部構成を示す平面図である。FIG. 3 is a plan view illustrating a main configuration of a detector main body of the detector according to the first embodiment. 実施例１の検出器を用いた医用の放射線撮像装置を検出器の要部構成を中心に示したブロック図である。It is the block diagram which showed centering around the principal part structure of the medical radiation imaging device using the detector of Example 1 centered on the detector. 実施例２の検出器の検出器本体の取り付け構造を示す断面図である。It is sectional drawing which shows the attachment structure of the detector main body of the detector of Example 2. FIG. 実施例３の検出器の検出器本体の取り付け構造を示す断面図である。It is sectional drawing which shows the attachment structure of the detector main body of the detector of Example 3. 実施例４の検出器の検出器本体の取り付け構造を示す断面図である。It is sectional drawing which shows the attachment structure of the detector main body of the detector of Example 4. 変形実施例の検出器の検出器本体の取り付け構造を部分的に示す断面図である。It is sectional drawing which shows partially the attachment structure of the detector main body of the detector of a modification. 従来の間接変換タイプの検出器の基本構成を示す模式図である。It is a schematic diagram which shows the basic composition of the conventional indirect conversion type detector. 従来の直接変換タイプの検出器の基本構成を示す模式図である。It is a schematic diagram which shows the basic composition of the conventional direct conversion type detector.

符号の説明Explanation of symbols

１，２７，２９，３１，３３ …検出器
２ …検出器本体
３ …共通電極
４ …放射線有感体
５ …電荷読み出し用基板
６ …光照射機構
７，２８，３０，３２ …支持台
７Ａ，３０Ａ，３２Ａ …透光性板状体
７Ｂ，３０Ｂ …金属製取付枠
８ …筐体
１６ …個別電極
２１ …拡散板
２８Ａ …金属製枠体
２８Ｂ …（光通路としての）中空領域
1, 27, 29, 31, 33 ... detector 2 ... detector main body 3 ... common electrode 4 ... radiation sensitive body 5 ... substrate for charge readout 6 ... light irradiation mechanism 7, 28, 30, 32 ... support base 7A, 30A, 32A ... Translucent plate-like body 7B, 30B ... Metal mounting frame 8 ... Housing 16 ... Individual electrode 21 ... Diffusion plate 28A ... Metal frame 28B ... Hollow area (as light path)

Claims

バイアス電圧印加用の共通電極が表面に形成されていると共に入射放射線を直接電荷に変換する放射線有感体が透光性を有する電荷読み出し用基板に搭載されている検出器本体と、電荷読み出し用基板を介して放射線有感体に向けて検出特性改善用の光を照射する光照射機構と、検出器本体と光照射機構との間で検出器本体を電荷読み出し用基板の裏側から支えていると共に検出特性改善用の光が通る光通路を有する支持台と、検出器本体および光照射機構と支持台を収容する筐体とを備えていて、検出器本体が支持台を介して筐体に対し固定されていることを特徴とする放射線検出器。 A detector body on which a common electrode for applying a bias voltage is formed on the surface and a radiation sensitive body for directly converting incident radiation into charges is mounted on a light-transmitting charge-reading substrate; A light irradiation mechanism that emits light for improving detection characteristics toward the radiation sensitive body through the substrate, and the detector body is supported from the back side of the charge readout substrate between the detector body and the light irradiation mechanism. And a support base having a light path through which light for improving detection characteristics passes, and a detector main body, a light irradiation mechanism, and a housing for housing the support base. The detector main body is attached to the housing via the support base. A radiation detector characterized in that it is fixed.

請求項１に記載の放射線検出器において、支持台は、検出特性改善用の光を透過させる透光性板状体であり、透光性板状体が表面全体で電荷読み出し用基板を受け止めている放射線検出器。 The radiation detector according to claim 1, wherein the support base is a translucent plate-like body that transmits light for improving detection characteristics, and the translucent plate-like body receives the charge readout substrate over the entire surface. Radiation detector.

請求項１に記載の放射線検出器において、支持台は、検出特性改善用の光が通る光通路となる中空領域を有する金属製枠体であり、金属製枠体が枠全体で電荷読み出し用基板を受け止めている放射線検出器。 2. The radiation detector according to claim 1, wherein the support base is a metal frame body having a hollow region serving as an optical path through which light for detection characteristic improvement passes, and the metal frame body is a charge readout substrate as a whole of the frame. The radiation detector that is receiving.

請求項１から３のいずれかに記載の放射線検出器において、支持台が筐体に取り付けられることにより検出器本体が筐体に対し固定されている放射線検出器。 4. The radiation detector according to claim 1, wherein the detector main body is fixed to the casing by attaching the support base to the casing.

請求項２に記載の放射線検出器において、支持台は透光性板状体の側周面に沿って取り囲んで透光性板状体と組み付けられている取付枠を具備していて、支持台が取付枠で筐体に取り付けられることにより検出器本体が筐体に対し固定されている放射線検出器。 The radiation detector according to claim 2, wherein the support base includes a mounting frame that surrounds the side peripheral surface of the translucent plate-like body and is assembled with the translucent plate-like body. Is a radiation detector in which the detector main body is fixed to the housing by being attached to the housing with a mounting frame.

請求項１から５のいずれかに記載の放射線検出器において、光照射機構の前面に光拡散用の拡散板を有する放射線検出器。
The radiation detector in any one of Claim 1 to 5 WHEREIN: The radiation detector which has a diffusion plate for light diffusion in the front surface of a light irradiation mechanism.