JPS595773A - Image detector - Google Patents
Image detectorInfo
- Publication number
- JPS595773A JPS595773A JP57113757A JP11375782A JPS595773A JP S595773 A JPS595773 A JP S595773A JP 57113757 A JP57113757 A JP 57113757A JP 11375782 A JP11375782 A JP 11375782A JP S595773 A JPS595773 A JP S595773A
- Authority
- JP
- Japan
- Prior art keywords
- image
- layer
- photoconductor
- photoconductor layer
- scanning
- 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
Links
- 238000001514 detection method Methods 0.000 claims abstract description 40
- 239000004020 conductor Substances 0.000 claims abstract description 20
- 230000000903 blocking effect Effects 0.000 claims description 11
- 239000010408 film Substances 0.000 claims description 8
- 239000010409 thin film Substances 0.000 claims description 4
- 229910021417 amorphous silicon Inorganic materials 0.000 claims description 3
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims description 2
- 239000011669 selenium Substances 0.000 claims description 2
- 229910052711 selenium Inorganic materials 0.000 claims description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims 1
- 230000001681 protective effect Effects 0.000 claims 1
- 239000003990 capacitor Substances 0.000 abstract description 18
- 230000003287 optical effect Effects 0.000 abstract description 15
- 238000007599 discharging Methods 0.000 abstract description 5
- 230000007246 mechanism Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 15
- 230000000694 effects Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 230000004888 barrier function Effects 0.000 description 8
- 230000005855 radiation Effects 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000005686 electrostatic field Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000002594 fluoroscopy Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910004613 CdTe Inorganic materials 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 206010047571 Visual impairment Diseases 0.000 description 1
- 238000002583 angiography Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical group [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 1
- 229910052601 baryte Inorganic materials 0.000 description 1
- 239000010428 baryte Substances 0.000 description 1
- UHYPYGJEEGLRJD-UHFFFAOYSA-N cadmium(2+);selenium(2-) Chemical compound [Se-2].[Cd+2] UHYPYGJEEGLRJD-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 238000002405 diagnostic procedure Methods 0.000 description 1
- 230000002526 effect on cardiovascular system Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 208000032839 leukemia Diseases 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/04—Scanning arrangements, i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versa
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Apparatus For Radiation Diagnosis (AREA)
- Closed-Circuit Television Systems (AREA)
- Fax Reproducing Arrangements (AREA)
- Photo Coupler, Interrupter, Optical-To-Optical Conversion Devices (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- Photoreceptors In Electrophotography (AREA)
- Combination Of More Than One Step In Electrophotography (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Facsimile Scanning Arrangements (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は像検出装置、とりわけ被検体を像露光し検出プ
レートに潜像を形成し、検出プレートをビーム走査する
ことによって時系列的に像検出する装置であって、煩雑
なプロセスを要せず検出時間を短縮した装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image detection device, and more particularly to an image detection device that exposes a subject to image light, forms a latent image on a detection plate, and detects an image in time series by scanning the detection plate with a beam. The present invention relates to a device that shortens detection time without requiring complicated processes.
一般に照射源からの露光により被写体像を形成せんとす
るとき、被写体からの反射光又は透過光を像面に伝送す
るものであるが、被写体への照射量が少ない方が種々の
点で常置が少ない。Generally, when trying to form an image of a subject by exposure from an irradiation source, the reflected light or transmitted light from the subject is transmitted to the image plane, but it is better in various respects to maintain a small amount of irradiation on the subject. few.
特に医療用X線撮影においては、人体にXMを照射しこ
れを透過したX線を検出するものであり、被爆線量が多
いと白血病や感性腫瘍等が生ずる。In particular, in medical X-ray photography, the human body is irradiated with XM and the X-rays that pass through the X-rays are detected, and if the exposure dose is high, leukemia, sensitive tumors, etc. will occur.
そこで従来、医療用X線撮影において、被検者の被爆線
量を減らすだめ、及び各種画像処理を施して診断能を向
上させるため、X線照射により光導電体に作られた潜像
を電気信号として取り出すことが考えられている。この
幕本プロセスは特開昭54−31219号公報等に知ら
れ、検出プレートは両端の導電体層を除いて、絶縁
゛体層、光導電体層の2層を有する。Conventionally, in medical X-ray photography, in order to reduce the radiation dose to the examinee and to improve diagnostic performance through various image processing, the latent image created on the photoconductor by X-ray irradiation has been converted into electrical signals. It is considered to be extracted as This Makumoto process is known from Japanese Patent Application Laid-Open No. 54-31219, etc., and the detection plate is insulated except for the conductive layer at both ends.
It has two layers: a body layer and a photoconductor layer.
この方法は他の周知の撮影法であるイメージインテンシ
ファイア及びTV撮像管による間接方法と、ゼロラジオ
グラフィ方法(電子X線写真法)と比較して、前者に対
しては解像度の点で、また後者に対しては撮影に要する
X線線量の少ない点で優れている。This method is compared with other well-known imaging methods, indirect methods using image intensifiers and TV image pickup tubes, and xeroradiography (electron X-ray photography). Moreover, it is superior to the latter in that the amount of X-rays required for imaging is small.
しかし上記方法は順次1次帯電、電荷分配。However, the above method uses sequential primary charging and charge distribution.
像露光、ビーム走査という煩雑なプロセスを要し像検出
に時間を要し、リアルタイムで連続透視を行なう場合や
、血管造影撮影での連続パルス撮影に適していない。It requires a complicated process of image exposure and beam scanning, and requires time for image detection, and is not suitable for continuous fluoroscopy in real time or continuous pulse imaging in angiography.
また上記方法では、走査ビームの波長が光導電物質の制
約を受け、He−Cdレーザ等の特定のものしか使用で
きない。Further, in the above method, the wavelength of the scanning beam is limited by the photoconductive material, and only a specific one such as a He-Cd laser can be used.
本発明は如上の点に鑑み、煩雑なプロセスを要すること
なく、検出時間を短縮し、また走査ビームの許容波長域
を拡大して、)le −Neレーザ等の使用を可能なら
しめ、装置の小形化、低コスト化を可能にした新規な像
検出装置を提供することを目的とする。In view of the above points, the present invention shortens the detection time without requiring complicated processes, expands the permissible wavelength range of the scanning beam, enables the use of )le-Ne laser, etc., and improves the efficiency of the device. The object of the present invention is to provide a new image detection device that can be made smaller and lower in cost.
本発明の特徴とするところは検出プレートが両端の導電
体層を除いて、第1光導電体層、第2光導電体層の2層
を有し、第2光導電体層を走査ビームによる光スィッチ
として作用させ、第1光導電体層を像露光中の電荷放電
回路(光スィッチがオフの場合)として、且つ、電荷充
電回路(光スィッチがオンの場合)として作用させるこ
とにある。A feature of the present invention is that the detection plate has two layers, a first photoconductor layer and a second photoconductor layer, excluding the conductor layers at both ends, and the second photoconductor layer is scanned by a scanning beam. By acting as a light switch, the first photoconductor layer acts as a charge discharge circuit during image exposure (when the light switch is off) and as a charge charging circuit (when the light switch is on).
これによって像露光量に応じて、一定時間経過後(例え
ば2次元走査における1フレ一ム時間後)の電荷量変化
分を、充電時の電流出力として信号検出するものである
。Thereby, a change in the amount of charge after a certain period of time (for example, after one frame time in two-dimensional scanning) is detected as a signal as a current output during charging according to the image exposure amount.
本発明によればビーム走査によって像検出と充電が自動
的に連続して行なわれ1次帯電及びこれに付随するプロ
セスが不要となり、また第2の光導電体層がアモルファ
スシリコンである場合、走査ビーム源として一般に普及
し信頼性が高く、低価格のHe −Neレーザ等が用い
られ得る。According to the present invention, image detection and charging are performed automatically and sequentially by beam scanning, eliminating the need for primary charging and associated processes. As a beam source, a commonly used, highly reliable, and low-cost He--Ne laser or the like may be used.
以下、本発明の詳細な説明すパる。The present invention will be described in detail below.
先ず、理解を容易にするため本発明に係わる像検出の原
理を第1図乃至第3図にて説明する。First, in order to facilitate understanding, the principle of image detection according to the present invention will be explained with reference to FIGS. 1 to 3.
第1図は1画素に和尚する部分の第1.第2光導体層の
各小領域の簡略された等価回路図を示す。Figure 1 shows the first part of the image that corresponds to one pixel. A simplified equivalent circuit diagram of each sub-region of the second optical conductor layer is shown.
ここで簡略さねたとけ、第2光導電体層は本来完全な光
スィッチとしてでなく、コンデンサ。For the sake of simplicity, the second photoconductor layer is not originally intended as a complete optical switch, but rather as a capacitor.
抵抗を成分として有する(これKついては後述)か、理
解を容易にするため完全な光スィッチとしてだけ機能す
ることを意味する。なおこの簡略された等価回路はTV
撮像管であるビジコン管がその光電面に結像された光の
像を蓄積し、その潜像を雷、子ビーム走査によって読み
出す場合と同様である。It means that it has a resistor as a component (K will be explained later) or that it functions only as a complete optical switch for ease of understanding. This simplified equivalent circuit is for TV
This is similar to the case where a vidicon tube, which is an image pickup tube, accumulates a light image formed on its photocathode, and the latent image is read out by lightning or laser beam scanning.
なお前述の各小領域とは時々刻々移動する走査レーザビ
ームのスポット領域をいう○第1図中tlは第1光導電
体層、t、は第2光導電体層であり、t+は像露光のだ
めの光(ここではX線)のみに、またt、は像読、出し
のだめの光(ここではレーザビーム)のみに感光するO
t、には一定電荷量Q0を充電するコンデンサと。Note that each of the above-mentioned small areas refers to a spot area of a scanning laser beam that moves moment by moment. In Figure 1, tl is the first photoconductor layer, t is the second photoconductor layer, and t+ is the image exposure layer. O is sensitive only to the initial light (in this case, X-rays), and t is sensitive to only the initial light (in this case, a laser beam) for image reading.
t is a capacitor that charges a constant amount of charge Q0.
X線線景に応じて可変の抵抗値を示す可変抵抗Rとが並
列配列される。この抵抗はX線照射によって電子−ホー
ルの対が生ずることに依存し露光量が少なければ大きな
抵抗値を示す。A variable resistor R having a variable resistance value depending on the X-ray scene is arranged in parallel. This resistance depends on the generation of electron-hole pairs by X-ray irradiation, and exhibits a large resistance value when the amount of exposure is small.
またt、には走査レーザビームによる光スィッチSがt
lと直列配列される。なお一定電圧Eは光スィッチSが
オンとなることにより印加される0
第1図囚CB) (C) (I))は走査レーザビーム
が該小領域をよぎった瞬間1=0から再び走査レーザビ
ームが該小領域をよぎる瞬間t=Tまでの電荷状態を示
す。厳密に言えば該小領域をビームが照射し始めてから
し終る迄の微かな時間Δtがあって、このLtの間にQ
。の充電が行なわれる。Also, at t, an optical switch S using a scanning laser beam is activated.
arranged in series with l. Note that the constant voltage E is applied when the optical switch S is turned on. It shows the charge state up to the moment t=T when the beam crosses the small area. Strictly speaking, there is a slight time Δt from when the beam starts irradiating the small area until it finishes, and during this Lt, Q
. Charging is performed.
すなわちt=0 、 t=Tは共に完全にQ。が充電
された瞬間を意味するが理解を容易にするため、ここで
はレーザビームがよぎった瞬間を1=0とする。That is, both t=0 and t=T are completely Q. means the moment when the laser beam is charged, but for ease of understanding, the moment when the laser beam crosses is assumed to be 1=0.
まず第1図(4)において1=0のとき、光スィッチS
けオンとなり、t、のコンデンサに一定電荷量Q0が充
電される。First, in FIG. 1 (4), when 1=0, the optical switch S
is turned on, and the capacitor t is charged with a constant amount of charge Q0.
その後、走査ビームが該小領域を離れると光スィッチS
はオフとなり(第1図@)、コンデンサに充電された電
荷は像露光によシ抵抗Rを介して閉じたループ内で自己
放電し始める。電荷減少と経過時間の相関関係は第2図
に示されるがRの抵抗値が小さければ、すなわち明部の
場合、放電量が大きく、電荷減少量は大きく、一方、R
の抵抗値が大きければ、すなわち暗部の場合、放電量が
小さく、電荷減少量は小さい。Then, when the scanning beam leaves the small area, the optical switch S
is turned off (Fig. 1@), and the charges stored in the capacitor begin to self-discharge within a closed loop via the resistor R during image exposure. The correlation between charge reduction and elapsed time is shown in Figure 2. If the resistance value of R is small, that is, in the case of a bright area, the amount of discharge is large and the amount of charge reduction is large;
If the resistance value of is large, that is, in the case of a dark area, the amount of discharge is small and the amount of charge reduction is small.
一般にコンデンサと抵抗の並列回路での放電では電荷量
は時間とともにエクスポネンシャルに減少することとな
る。Generally, when discharging in a parallel circuit of a capacitor and a resistor, the amount of charge decreases exponentially over time.
第1図(C)は再びレーザビームが該小領域に達する寸
前の状況を示す。コンデンサに残る電荷量は、第2図に
おいて抵抗値が小さい場合(明部) 、 Qo−ΔQ1
となり、抵抗値が大きい場倣暗部)、Qo−△Q、とな
る。FIG. 1(C) again shows the situation just before the laser beam reaches the small area. The amount of charge remaining in the capacitor is Qo-ΔQ1 when the resistance value is small (bright part) in Figure 2.
If the resistance value is large, the dark area), Qo - ΔQ.
第1図0は再びレーザビームが該小領域に達丁
した瞬間t=%を示す。このとき再び光スイツチ下
Sはオンとなり1=0からt=%までの電荷減少量ΔQ
をコンデンサに充電することとなる。すなわち前述の明
部では△QI+暗部では△Q!たけ外部よねコンデンサ
に充電される。FIG. 10 again shows the moment t=% when the laser beam reaches the small area. At this time, the lower light switch S is turned on again, and the charge decrease amount ΔQ from 1=0 to t=%
will charge the capacitor. In other words, in the bright area mentioned above, △QI + in the dark area, △Q! The external capacitor is charged.
第1図C)では電荷減少量−△Qを外部検出できないが
、第1図0では電荷減少量−△Qと絶対値の等しい充電
電荷量+ΔQが外部検出され、これが信号出力となる。In FIG. 1C), the amount of charge decrease -ΔQ cannot be detected externally, but in FIG.
第3図は2つの光導電体層L+ t Lt の全体
的な等価回路図である。すなわち第1図に示した各小領
域におけるtll Atが複数個並列配列されるものと
等価となる。FIG. 3 is an overall equivalent circuit diagram of two photoconductor layers L+ t Lt . In other words, this is equivalent to arranging a plurality of tll At in parallel in each small area shown in FIG.
さて次に本発明の像検出装置の全体的説明を第4図にて
行なう。51はX線発生源であシ、52は被写体である
。ここでX線は連続して照射されている。被写体を通過
しない部分のX線54はわずかの減衰で検出プレート3
1の導電体層1を通過し、第1の光導電体層2に吸収さ
れる。被写体52を通過したX線は大きな減衰を生じわ
ずかな線量が導電体1を通過して第1の光導電体層2に
吸収され、光導電効果を生じさせる。55は暗箱であり
、レーザー光走査機構53からのレーザービーム56が
検出プレート31の透明導電体層4を走査する。レーザ
ーの走査はTVカメラと同様にX、Yの2次元走査と考
えてよい。レーザービーム56は透明導電体層4を透過
し、第2の光導電体3を照射しながら第5図の如く、2
次元移動する。なおレーザが1次元に走査され、検出プ
レートが走査方向に直交して移動することによっても結
果として2次元走査が可能である。第5図においてレー
ザービームが同じ小領域を再びよぎるまでの時間Tは1
フレ一ム分に相当する。すなわち第5図に示されるよう
に任意点Pに対し、該点に走査ビームが達してから、再
び該点に達するまでのPQ + RPだけ走査ビームが
進むのに要する時間は一定時間Tである。換言すれば検
出プレートの任意点を走査ビームが一定周期でよぎるこ
ととなる。Next, an overall explanation of the image detecting device of the present invention will be given with reference to FIG. 51 is an X-ray generation source, and 52 is an object. Here, X-rays are continuously irradiated. The portion of the X-ray 54 that does not pass through the object is slightly attenuated and is detected by the detection plate 3.
1 conductor layer 1 and is absorbed by the first photoconductor layer 2 . The X-rays passing through the object 52 undergo a large attenuation and a small dose passes through the conductor 1 and is absorbed by the first photoconductor layer 2, producing a photoconductive effect. 55 is a dark box, in which a laser beam 56 from a laser beam scanning mechanism 53 scans the transparent conductor layer 4 of the detection plate 31. Laser scanning can be thought of as two-dimensional X and Y scanning, similar to a TV camera. The laser beam 56 passes through the transparent conductor layer 4 and irradiates the second photoconductor 3, as shown in FIG.
Move dimensionally. Note that two-dimensional scanning is also possible by scanning the laser one-dimensionally and moving the detection plate orthogonally to the scanning direction. In Figure 5, the time T until the laser beam crosses the same small area again is 1
Equivalent to one frame. In other words, as shown in FIG. 5, for an arbitrary point P, the time required for the scanning beam to travel by PQ + RP from when it reaches that point to when it reaches that point again is a constant time T. . In other words, the scanning beam crosses any point on the detection plate at a constant period.
なお第4図中、像露光光(X線)と像検出光(レーザー
ビーム)は互いに反対方向より照射されているが、これ
を同一方向とすることもできる。すなわち、X線源をレ
ーザ光源側に設定し、X線が第2の光導電体層3に吸収
されることなく通過し、第1の光導電体層2に吸収する
ものであれば良い。In FIG. 4, the image exposure light (X-rays) and the image detection light (laser beam) are irradiated from opposite directions, but they can also be irradiated from the same direction. That is, it is sufficient if the X-ray source is set on the laser light source side, the X-rays pass through the second photoconductor layer 3 without being absorbed, and are absorbed by the first photoconductor layer 2.
いずれにしても走査ビームが照射される側の導電体層は
、走査ビームに対し透明であり、金属薄膜例えば第2の
光導電体層が非結晶シリコンの場合には可視に透明なネ
サガラスSnO,、Auの薄膜等が選ばれる。In any case, the conductor layer on the side irradiated with the scanning beam is transparent to the scanning beam, and the metal thin film, for example, when the second photoconductor layer is made of amorphous silicon, the conductor layer on the side irradiated with the scanning beam is visibly transparent Nesa Glass SnO, , Au thin film, etc. are selected.
ところで前述の第1図の等価回路図では理解を容易にす
るだめ、第2の光導電体層に対して素に相当する各小領
域は第6図に示されるように光スィッチ24と直列に導
通抵抗25が、またこれらと並列にコンデンサ23.暗
抵抗26が配置される回路となる。ここで暗抵抗26と
はレーザ光が第2の光導電体に照射されない場合の抵抗
をいう。なお27128は電極、33は増幅器32の出
力端子、34はアースである。By the way, in the equivalent circuit diagram of FIG. 1 described above, for ease of understanding, each small region that corresponds to the second photoconductor layer is connected in series with the optical switch 24 as shown in FIG. A conduction resistor 25 is also connected in parallel with a capacitor 23 . This is a circuit in which a dark resistor 26 is arranged. Here, the dark resistance 26 refers to the resistance when the second photoconductor is not irradiated with laser light. Note that 27128 is an electrode, 33 is an output terminal of the amplifier 32, and 34 is a ground.
ところで導通抵抗25は充分なビーム光量によって充分
低くなることが要求される。By the way, the conduction resistance 25 is required to be sufficiently low due to a sufficient amount of beam light.
この第1の理由は、X線量の変化によって抵抗22は変
化するが、この程度の変化で静電容量21の充電、電圧
が大巾に変化するのを避けるためである。これは静電容
量21の充電完了時の電圧は抵抗22と導通抵抗26と
の分圧によって与えられるからである。第2の理由は導
゛通抵抗25と静電容量21及び23との時定数
を小さくするためである。これは走査ビームがこの1画
素を走査する時間内に、できるだけ完全に静電容量21
の充電と静電容[23の放電を完了させるだめである。The first reason for this is to avoid large changes in the charge and voltage of the capacitor 21 due to changes in the resistance 22 due to changes in the X-ray dose. This is because the voltage when charging of the capacitor 21 is completed is given by the voltage division between the resistor 22 and the conduction resistor 26. The second reason is to reduce the time constant of the conduction resistance 25 and the capacitances 21 and 23. This means that the capacitance 21 is completely filled as much as possible within the time that the scanning beam scans this one pixel.
It is impossible to complete the charging and discharging of the capacitance [23].
この非件は本方式の走査速度、及び残像に関して重要で
ある。静電容量21の他の側は電極27を通じて増巾器
32の入力に接続されている。従ってs?Ix容量21
の充1!電流は増dJ器32の入力に流れ込む。増巾器
32の入力インピーダンスは充分低いことが望ましい。This issue is important regarding the scanning speed and afterimage of this method. The other side of capacitance 21 is connected through electrode 27 to the input of amplifier 32. Therefore s? Ix capacity 21
Full 1! The current flows into the input of the dJ amplifier 32. It is desirable that the input impedance of the amplifier 32 is sufficiently low.
これは導通抵抗25と直列であり、前記における導通抵
抗25が低いことを要求されることと同じ理由である。This is in series with the conduction resistance 25, and is for the same reason that the conduction resistance 25 described above is required to be low.
走査ビームがとの画紫の個所を離れると光スィッチ25
はOFFされる。第1の光導電体層にはX線が照射され
ておシX線にする光導電効果によって低下した抵抗22
は充電された静電容量21を放電させ始める。又同時に
静電容量23を充電させ始める。もしX線の照射が次の
ビームの走査迄持続すればその間静電容−i:21は放
電を続ける。もしX線の照射が次のビームの走査が行わ
れる迄に中止された場合は、その時点で放電が停止され
る。それは抵抗22が暗抵抗として非常に大きくなった
ことを意味している。When the scanning beam leaves the purple part of the picture, the light switch 25
is turned off. The first photoconductor layer is irradiated with X-rays and has a reduced resistance 22 due to the photoconductive effect of X-rays.
begins to discharge the charged capacitance 21. At the same time, charging of the capacitance 23 begins. If the X-ray irradiation continues until the next beam scan, the capacitor -i:21 continues to discharge during that time. If the X-ray irradiation is stopped before the next beam scan, the discharge is stopped at that point. This means that the resistance 22 has become very large as a dark resistance.
静電容量21の表面電位はその電荷が放電されればそれ
に比例して低下する。もしX線照射線量がビームの1フ
レーム走査期間で時間的に変化なく一定であれば、この
表面電位は時間と共にエクスポネンシャルに低下するこ
とになる。The surface potential of the capacitor 21 decreases in proportion to the discharge of its charge. If the X-ray irradiation dose is constant with no change over time during one frame scanning period of the beam, this surface potential will decrease exponentially with time.
内部電荷も同様に減少する。そしてこの放電された電荷
量は次のビームが走査されたとき、再びそれと同量補充
される。すなわち放電電荷の総量は次の走査時の充電電
荷の総量と等しい。The internal charge decreases as well. This amount of discharged charge is replenished by the same amount again when the next beam is scanned. That is, the total amount of discharged charges is equal to the total amount of charged charges during the next scan.
この充電電流は増巾器32に入力電流として走査毎に流
れ、その出力に電圧として取出される。This charging current flows into the amplifier 32 as an input current for each scan, and is taken out as a voltage at its output.
第7図は透明導電層をアースした別の実施例である。第
1の光導電層の静電容量はビーム走査時に光スィッチ2
4によって充電されるがこの充電電流は増巾器入力から
供給される。この供給電流が信号電流となるので、前記
の動作と原理的には全く同じである。但し、信号電流の
向きは逆になる。FIG. 7 shows another embodiment in which the transparent conductive layer is grounded. The capacitance of the first photoconductive layer is controlled by the optical switch 2 during beam scanning.
This charging current is supplied from the amplifier input. Since this supplied current becomes a signal current, the operation is exactly the same in principle as described above. However, the direction of the signal current is reversed.
第8図は第1の光導電体層2と第2の光導電体層3の間
にブロッキングコンタクト5を設けた場合の実施例であ
る。ブロッキングコンタクトはP−N接合等のバリテで
あって障壁電位を有している。FIG. 8 shows an embodiment in which a blocking contact 5 is provided between the first photoconductor layer 2 and the second photoconductor layer 3. In FIG. The blocking contact is a barite such as a PN junction and has a barrier potential.
第9図はこの場合の等価回路である。ブロッキングコン
タクトはP−N接合としてのダイオード30と障壁電位
としての電池29として表される。この電池29で示さ
れる障壁電位は第1の光導電体層に感度がある放射線又
は光に対するものであり、第2の光導電体層に感度があ
る光ビームに対しては障壁電位が無視できる程に小さい
ので、第2の光導電体層を通過する若干の光ビームによ
って、その照射時にONとなる光スィッチ24に直列で
あるダイオード30のみとして示される。FIG. 9 shows an equivalent circuit in this case. The blocking contact is represented by a diode 30 as a PN junction and a battery 29 as a barrier potential. The barrier potential exhibited by this cell 29 is for radiation or light to which the first photoconductor layer is sensitive, and the barrier potential is negligible for light beams to which the second photoconductor layer is sensitive. It is so small that it is only shown as a diode 30 in series with the optical switch 24 which is turned on by some light beam passing through the second photoconductor layer.
第8.9図の検出プレートは検出プレートの7図と第9
図を用いて説明する。The detection plate in Figure 8.9 is
This will be explained using figures.
第2の光導電体層に光ビームが照射されると2個の光ス
イッチ24.24’はONと々す、静電界4123は放
電され、第1の静電容量21にはダイオード30′を通
じて電圧が加えられ容量21は充電される。光ビーム照
射が終るとX線照射の効果により第1の光導電体の導電
率が増加し等側内部抵抗22を通じて容量21の電荷は
放電を始め、第1の光導電体の表面電位は低下を始める
。もしこの電圧の低下分が電池29で示される障壁電位
を超えるとダイオード30は導通することになる。しか
しこの表面電位の低下が障壁電位より小さい範囲であれ
ば、第1の光導電体層の内部抵抗はこの容量21の放電
では前述のように静電界t23の充電電流、暗抵抗26
の電流も第1の光導電体層の内部抵抗を通じ流れるが、
もしこの値が大聞いと、大きいエネルギー損失となり、
光電変換効率の低下となる。すなわち第2の光導電体層
の容量に次の走査迄に充電された電荷は、次走査時放電
され、熱として失われるものであり、これは第゛1の光
導電体が受けた放射エネルギーの1部と考えることがで
きる。When the second photoconductor layer is irradiated with a light beam, the two optical switches 24 and 24' are turned on, the electrostatic field 4123 is discharged, and the first capacitance 21 is connected to the first capacitor 21 through the diode 30'. A voltage is applied and the capacitor 21 is charged. When the light beam irradiation ends, the conductivity of the first photoconductor increases due to the effect of the X-ray irradiation, the charge in the capacitor 21 begins to discharge through the isolateral internal resistance 22, and the surface potential of the first photoconductor decreases. Start. If this voltage drop exceeds the barrier potential exhibited by battery 29, diode 30 will become conductive. However, if this decrease in surface potential is within a range smaller than the barrier potential, the internal resistance of the first photoconductor layer will be reduced by the charging current of the electrostatic field t23 and the dark resistance 26 as described above in discharging this capacitor 21.
The current also flows through the internal resistance of the first photoconductor layer, but
If this value is too large, it will result in a large energy loss.
This results in a decrease in photoelectric conversion efficiency. In other words, the charge that has been charged in the capacitance of the second photoconductor layer until the next scan is discharged during the next scan and is lost as heat, and this is due to the radiant energy received by the first photoconductor. It can be considered as a part of
従ってこのブロッキングコンタクトを設け、障壁電位を
越えないように作動させればこの損失が生じないので信
号電流の増大すなわちシへ比、感度が向上できる。洩れ
電流が減少することにより、少くとも1走査期間中の電
荷の保持が容易に可能となるので、1画面を読み出す場
合にはシエーデングや出力信号の変動が減少し、精度が
向上する。さらに又静電界t23には充電々流が流れ込
まないため、ビーム照射の際の放電々流はわずかになり
、従って1画素内の走査時間を短縮できる、すなわち読
取ビームの高速走査を可能にする効果がある0
尚、このブロッキングコンタクトは第2の光導電体層と
透明導電体層の間に設けても同様な効果を得ることがで
きる。Therefore, if this blocking contact is provided and the device is operated so as not to exceed the barrier potential, this loss will not occur, so that the signal current can be increased, that is, the shear ratio and sensitivity can be improved. By reducing the leakage current, it becomes possible to easily hold charge for at least one scanning period, so when reading one screen, shading and fluctuations in the output signal are reduced, and accuracy is improved. Furthermore, since no charge current flows into the electrostatic field t23, the discharge current during beam irradiation becomes small, and therefore the scanning time within one pixel can be shortened, which has the effect of enabling high-speed scanning of the reading beam. Note that the same effect can be obtained even if this blocking contact is provided between the second photoconductor layer and the transparent conductor layer.
第10図は検出プレートの第2の光導電体層に固着され
た透明導電体層4の外側に反射防止膜6をコーティング
その他の手段によって設けたものを示している。FIG. 10 shows an antireflection film 6 provided by coating or other means on the outside of the transparent conductor layer 4 fixed to the second photoconductor layer of the detection plate.
第11図は第1θ図の部分的拡大図であυ、レーザーか
らのビームは透明導電体層4の表面で反射される損失を
防ぎ、透過率を高め、レーザー光の出力効率を向上でき
る。又第2の光導電体層3の表面に達したビームが反射
されても、透明導電体層表面の反射防止膜を透過する効
率が良いので、この部分での再反射が少く等制約にビー
ムスポット径を小さくシ、解像度を向上させる効果があ
る。FIG. 11 is a partially enlarged view of FIG. 1θ. The beam from the laser is prevented from being lost due to reflection on the surface of the transparent conductor layer 4, increasing the transmittance and improving the output efficiency of the laser beam. In addition, even if the beam that reaches the surface of the second photoconductor layer 3 is reflected, it is efficiently transmitted through the anti-reflection film on the surface of the transparent conductor layer, so there is little re-reflection at this part and the beam is This has the effect of reducing the spot diameter and improving resolution.
第12図は像投影側の導電体層1を透明導電体層に置き
換えた場合の実施例である。もし投影像が可視光である
場合には導電体層1を透明導電体層1例えばネサ膜に置
き換えるだけで良いが、X線その他の放射線である場合
にはこの放射線を受けてケイ光を発するケイ元板7を貼
付けることによって第1の光導電体2に作用させること
ができる。当然この場合、第1の光導電体がケイ光の波
長に感度を有する場合に効果が有るのであって、投影像
の放射線に感度を持たない場合も成立つ。もし放射線に
も感度を有する場合には増感作用と1〜で用いられるこ
とになる。FIG. 12 shows an embodiment in which the conductor layer 1 on the image projection side is replaced with a transparent conductor layer. If the projected image is visible light, it is sufficient to simply replace the conductive layer 1 with a transparent conductive layer 1, such as a Nesa film, but if the projected image is X-rays or other radiation, it emits fluorescent light upon receiving this radiation. The first photoconductor 2 can be acted upon by pasting the silicon base plate 7. Naturally, in this case, the effect is obtained when the first photoconductor is sensitive to the wavelength of fluorescent light, but it also holds true when the first photoconductor is not sensitive to the radiation of the projected image. If it is sensitive to radiation, it will be used as a sensitizing agent.
第13図は第12図の部分拡大図で大矢56はケイ光で
あることを示している。FIG. 13 is a partially enlarged view of FIG. 12, showing that the large arrow 56 is fluorescent.
ところで前記実施例では連続読取りの方式について述べ
たが第1の光電導体と第2の光導電体に1次帯電してお
き、像賞光、読取りを行うことも可能である。この場合
、第2の光導電体層は単に絶縁体と働かせることもで^
、又、第1の光導電体だけに帯電を行う場合には光照射
して光スィッチとして働かせることもできる。Incidentally, in the above embodiment, a continuous reading system has been described, but it is also possible to perform image recognition light and reading by primary charging the first photoconductor and the second photoconductor. In this case, the second photoconductor layer can also simply act as an insulator.
Alternatively, when charging only the first photoconductor, it can be irradiated with light to function as a light switch.
又潜像を完全消滅させる場合には開光してスイッチとし
て働かせることもできる。In addition, when the latent image is to be completely eliminated, the light can be opened and used as a switch.
第′1の光導電体層として非結晶セレン板の代りにPB
O等を用いても良く、又、第2の光導電体として非結晶
シリコンの代りにCdSeやCdTe等を用いても良い
。PB instead of an amorphous selenium plate as the '1st photoconductor layer.
O, etc. may be used, and CdSe, CdTe, etc. may be used instead of amorphous silicon as the second photoconductor.
以上、本発明によれば以下の効果が顕らかである。As described above, according to the present invention, the following effects are obvious.
1 連続的X線照射を行い、繰返し走査を行うととによ
ってTV等のモニター表示が可能となり、透視と撮影の
機能を備えた装置が構成できる。1. By performing continuous X-ray irradiation and repeated scanning, display on a monitor such as a TV becomes possible, and a device with fluoroscopy and imaging functions can be constructed.
2 イメージインテンシファイアとTV方式によるX線
透視装置では得られない被写範囲が大きく、高品位のX
線像が映像信号として得られる効果がある。2 A large field of view and high-quality X-rays that cannot be obtained using an image intensifier and TV system
This has the effect that a line image can be obtained as a video signal.
3、連続高速撮影での映像信号化が可能となり、画像処
理を併用して循環器診断法に於いても診断のし易いX線
像を提供できる効果がある。3. Continuous high-speed imaging allows video signals to be converted, and when used in combination with image processing, it has the effect of providing X-ray images that are easy to diagnose even in cardiovascular diagnostic methods.
4 銅塩フィルム以外の素材の複写装置にも画像信号を
供給できる。4 Image signals can also be supplied to copying devices made of materials other than copper salt film.
ところで以上、像露光光はX線として説明しだがこれに
限らず、可視光、赤外光、紫外光その他電磁波一般に適
用できるものである。By the way, although the image exposure light has been described above as X-rays, it is not limited to this, and can be applied to visible light, infrared light, ultraviolet light, and other electromagnetic waves in general.
また走査ビームもレーザービームに限られず本発明を逸
脱しない範囲で適宜選択可能である。Furthermore, the scanning beam is not limited to the laser beam, and can be selected as appropriate without departing from the scope of the present invention.
第1図乃至第3図は本発明の詳細な説明図で、第1図は
、検出プレートの各小領域の簡略化された等価回路図、
第2図は、蓄積電荷量の時間変化を示す図、第3図は、
検出プレート全体の等価回路図、第4図は、本発明に係
わる像検出器の全体説明図、
第5図は、レーザービームによる2次元走査読み出しの
説明図、
第6図は、検出グレートの各小領域の実際の等価回路図
、
第7図は、第6図における電気接続を変形した説明図、
第8図、第9図はブロッキングコンタクトを有する検出
プレートの構成図1等価回路図、第10図、第11図は
反射防止膜を設けた検出プレートの構成図、特性説明図
、
第12図、第13図は螢光膜を設けた検出プレートの構
成図9%性説明図、
図中
t、 、 L、は第1の光導電体層。
t21 L!は第2の光導電体層。
1は導電体層、2け第1の光導電体層、3は第2の光導
電体層、4は透明導電体層、5はブロッキングコンタク
ト層、6は反射防止膜、7は螢光層、21は第1の光導
電体の静電容量、22は等側内部抵抗、23は傘2の光
導電体の静電容量、24は第2の光導電体の光スィッチ
、25゛は第2の光導電体の光スィッチONの場合の導
通抵抗、26は第2の光導電体の暗抵抗、27は導電体
の電極、28は透明導電体の電極、29けブロッキング
コンタクトの等価障壁電位、3゜はブロッキングコンタ
クトによるダイオード、31は検出プレート、32は電
流増巾器、33は増巾器の出力端子、34はアース、5
1はX線発生源、52はX線被写体、53はレーザー走
査機構、54はX線、′55は暗箱、56はレーザービ
ームである。Figures 1 to 3 are detailed explanatory diagrams of the present invention, with Figure 1 being a simplified equivalent circuit diagram of each small region of the detection plate, and Figure 2 showing changes over time in the amount of accumulated charge. Figure 3 is
4 is an explanatory diagram of the entire image detector according to the present invention; FIG. 5 is an explanatory diagram of two-dimensional scanning readout using a laser beam; and FIG. 6 is an illustration of each of the detection plates. Actual equivalent circuit diagram of a small area; Figure 7 is an explanatory diagram with modified electrical connections in Figure 6; Figures 8 and 9 are configuration diagrams of a detection plate with blocking contacts; Figure 1 is an equivalent circuit diagram; Figures 11 and 11 are configuration diagrams and characteristics explanatory diagrams of a detection plate provided with an antireflection film. Figures 12 and 13 are configuration diagrams and characteristic diagrams of a detection plate provided with a fluorescent film. , , L is the first photoconductor layer. t21 L! is the second photoconductor layer. 1 is a conductor layer, 2 is a first photoconductor layer, 3 is a second photoconductor layer, 4 is a transparent conductor layer, 5 is a blocking contact layer, 6 is an antireflection film, and 7 is a fluorescent layer. , 21 is the capacitance of the first photoconductor, 22 is the isolateral internal resistance, 23 is the capacitance of the photoconductor of the umbrella 2, 24 is the optical switch of the second photoconductor, and 25 is the second photoconductor. 2 is the conduction resistance of the photoconductor when the optical switch is ON, 26 is the dark resistance of the second photoconductor, 27 is the electrode of the conductor, 28 is the electrode of the transparent conductor, and 29 is the equivalent barrier potential of the blocking contact. , 3° is a diode with a blocking contact, 31 is a detection plate, 32 is a current amplifier, 33 is an output terminal of the amplifier, 34 is ground, 5
1 is an X-ray generation source, 52 is an X-ray object, 53 is a laser scanning mechanism, 54 is an X-ray, '55 is a dark box, and 56 is a laser beam.
Claims (1)
・ 該検出プレートをビーム走査することによって時系列的
に像検出する装置において、検出プレートが第1の導電
体層と、該導電体層の一方の面側に設けられ像露光によ
り潜像を形成する第1の光導電体層と、該第1の光導電
体層の他方の面側に設けられ走査ビームを受ける第2の
光導電体層と、該第2の光導電体層の他方の面側に設け
られる第2の導電体層とを有することを特徴とする像検
出装置0 2、像露光光がX線である特許請求の範囲第1項記載の
像検出装置。 3、像露光と走査ビームが異なる方向から照射される特
許請求の範囲第1項記載の像検出装置。 4、像露光と走査ビームが同じ方向から照射される特許
請求の範囲第1項記載の像検出装置。 5、 走査ビームが照射される側の導電体層が走査ビー
ムに対して透明である特許請求の範囲” 第3項又は第
4項記載の像検出装置。 6、透明導電体層の表面に反射防止膜を有する特許請求
の範囲第5項記載の像検出装置。 7、導電体層表面に螢光体層が設けられ、像露光光と異
なる波長の光を第1の光導電体層が受ける特許請求の範
囲第1項記載の像検出装置。 8 第1の光導電体層と、第2の光導電体層との間に像
露光後の潜像に対してのみブロッキングコンタクトとし
て作用するブロッキングコンタクト層を有する特許請求
の範囲第1項記載の像検出装置。 9、第1の光導電体層が非結晶セレンの薄膜であり、第
2の光導電体層が非結晶シリコンの薄膜である特許請求
の範囲第1項記載の像検出装置。 10. 検出プレートの任意点を走査ビームが一定周
期でよぎる特許請求の範囲第1項記載の像検出装置。[Claims] 1. Imagewise exposing a subject to form a latent image on a detection plate; 1.
- In a device that detects images in time series by scanning the detection plate with a beam, the detection plate is provided on a first conductive layer and on one side of the conductive layer, and forms a latent image by image exposure. a first photoconductor layer provided on the other side of the first photoconductor layer and receiving the scanning beam; 2. The image detecting device according to claim 1, wherein the image detecting device has a second conductive layer provided on the surface side, and the image exposing light is X-rays. 3. The image detection device according to claim 1, wherein the image exposure and scanning beams are irradiated from different directions. 4. The image detection device according to claim 1, wherein the image exposure and the scanning beam are irradiated from the same direction. 5. The image detection device according to claim 3 or 4, wherein the conductive layer on the side to which the scanning beam is irradiated is transparent to the scanning beam. 6. Reflection on the surface of the transparent conductive layer. The image detection device according to claim 5, which has a protective film. 7. A phosphor layer is provided on the surface of the conductor layer, and the first photoconductor layer receives light of a wavelength different from the image exposure light. Image detection device according to claim 1. 8. A blocking layer between the first photoconductor layer and the second photoconductor layer that acts as a blocking contact only for the latent image after image exposure. The image detection device according to claim 1, having a contact layer. 9. The first photoconductor layer is a thin film of amorphous selenium, and the second photoconductor layer is a thin film of amorphous silicon. 10. An image detection device according to claim 1. 10. An image detection device according to claim 1, in which the scanning beam crosses any point on the detection plate at a constant period.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57113757A JPS595773A (en) | 1982-06-30 | 1982-06-30 | Image detector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57113757A JPS595773A (en) | 1982-06-30 | 1982-06-30 | Image detector |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS595773A true JPS595773A (en) | 1984-01-12 |
Family
ID=14620362
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP57113757A Pending JPS595773A (en) | 1982-06-30 | 1982-06-30 | Image detector |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS595773A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60192230U (en) * | 1984-05-31 | 1985-12-20 | 三菱自動車工業株式会社 | Control mechanism of variable nozzle vane type turbo |
JPS6170136A (en) * | 1984-09-13 | 1986-04-10 | Mitsubishi Heavy Ind Ltd | Controller of supercharger |
JPS6228044U (en) * | 1985-08-02 | 1987-02-20 | ||
JPS6275039A (en) * | 1985-09-30 | 1987-04-06 | Isuzu Motors Ltd | Internal combustion engine with variable capacity supercharger |
EP0338091A1 (en) * | 1987-10-21 | 1989-10-25 | Hitachi, Ltd. | Light-receiving element and method of operating the same |
JPH0237118A (en) * | 1988-07-27 | 1990-02-07 | Toyota Motor Corp | Two-axle-type gas turbine engine |
JPH058250U (en) * | 1991-06-24 | 1993-02-05 | 株式会社ニチリン | oil cooler |
-
1982
- 1982-06-30 JP JP57113757A patent/JPS595773A/en active Pending
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60192230U (en) * | 1984-05-31 | 1985-12-20 | 三菱自動車工業株式会社 | Control mechanism of variable nozzle vane type turbo |
JPH0318665Y2 (en) * | 1984-05-31 | 1991-04-19 | ||
JPS6170136A (en) * | 1984-09-13 | 1986-04-10 | Mitsubishi Heavy Ind Ltd | Controller of supercharger |
JPS6228044U (en) * | 1985-08-02 | 1987-02-20 | ||
JPS6275039A (en) * | 1985-09-30 | 1987-04-06 | Isuzu Motors Ltd | Internal combustion engine with variable capacity supercharger |
EP0338091A1 (en) * | 1987-10-21 | 1989-10-25 | Hitachi, Ltd. | Light-receiving element and method of operating the same |
JPH0237118A (en) * | 1988-07-27 | 1990-02-07 | Toyota Motor Corp | Two-axle-type gas turbine engine |
JPH058250U (en) * | 1991-06-24 | 1993-02-05 | 株式会社ニチリン | oil cooler |
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