公开(公告)号：EP0842541B1

公开(公告)日：2002-02-13

申请号：EP95926356.7

申请日：1995-07-31

申请人： iFire Technology Inc. ,  Sunnybrook Hospital

发明人： WAECHTER, David ,  ZHAO, Wei ,  ROWLANDS, John ,  HUANG, Zhong, Shou

IPC分类号： H01L27/146

CPC分类号： H01L27/14643

摘要： A flat panel detector (20) for radiation imaging includes an array of transistor switches (38) each of which is associated with a pixel electrode (36). A radiation transducer (CSE) including a top electrode (72) and a radiation conversion layer (70) is disposed over the array. Means are positioned over dead zones between adjacent pixel electrodes to inhibit the accumulation of charge in the radiation conversion layer at the dead zones when the top electrode is biased and the flat panel detector is exposed to radiation. In one embodiment, the inhibiting means is constituted by islands (64) formed of semiconductor material between the array and the radiation transducer. Each island is positioned over a dead zone between adjacent pixel electrodes and contacts a pixel electrode to allow charges accumulated on the islands to drift to the pixel electrodes.

公开(公告)号：EP0842541A1

公开(公告)日：1998-05-20

申请号：EP95926356.0

申请日：1995-07-31

申请人： LITTON SYSTEMS CANADA LIMITED ,  Sunnybrook Hospital

发明人： WAECHTER, David ,  ZHAO, Wei ,  ROWLANDS, John ,  HUANG, Zhong, Shou

IPC分类号： H01L27

CPC分类号： H01L27/14643

摘要： A flat panel detector (20) for radiation imaging includes an array of transistor switches (38) each of which is associated with a pixel electrode (36). A radiation transducer (CSE) including a top electrode (72) and a radiation conversion layer (70) is disposed over the array. Means are positioned over dead zones between adjacent pixel electrodes to inhibit the accumulation of charge in the radiation conversion layer at the dead zones when the top electrode is biased and the flat panel detector is exposed to radiation. In one embodiment, the inhibiting means is constituted by islands (64) formed of semiconductor material between the array and the radiation transducer. Each island is positioned over a dead zone between adjacent pixel electrodes and contacts a pixel electrode to allow charges accumulated on the islands to drift to the pixel electrodes.

公开(公告)号：EP0823132B1

公开(公告)日：1999-08-04

申请号：EP95916537.4

申请日：1995-04-28

申请人： Sunnybrook Hospital

发明人： ZHAO, Wei ,  ROWLANDS, John

IPC分类号： H01L27/146

CPC分类号： H01L27/14665

公开(公告)号：EP0823132A1

公开(公告)日：1998-02-11

申请号：EP95916537.0

申请日：1995-04-28

申请人： Sunnybrook Hospital

发明人： ZHAO, Wei ,  ROWLANDS, John

IPC分类号： H01L27 ,  H01L31 ,  H04N5

CPC分类号： H01L27/14665

摘要： A digital detector for radiography and fluoroscopy. The detector comprises a large area, flat panel which easily fits into the conventional X-ray room bucky tray. The detector utilizes a layer of photoconductor (i.e. a-Se in the preferred embodiment) to detect X-rays and convert the X-ray energy to charge, and an active matrix TFT array in the form of a very large area integrated circuit, for readout of the charge. A dual gate structure is used for the TFT array wherein the top gate is formed as an extension of the pixel electrode, so as to provide high voltage protection of the TFT. An integrated pixel storage capacitor is provided for enhanced absorption of X-ray energy with low pixel voltage, low leakage current and a large charge leakage time constant. In the preferred embodiment, the integrated pixel storage capacitor is created by overlapping the pixel electrode with an adjacent gate line or a separate groundline of the active matrix readout array. Image charge collection efficiency is enhanced in the imager of the present invention by manipulating the electric field distribution in the photoconductor layer so that image charges land on the pixel electrodes, and not on the TFT readout devices. Also, a photo-timer is integrated into the imaging detector for measuring X-ray exposure.