US 5,396,072 AGranted

X-ray image detector

AssigneeU. S. Philips Corporation

InventorsUlrich Schiebel, Herfried Wieczorek, Andreas Brauers

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Abstract

The invention relates to an X-ray image detector, comprising a plurality of X-ray-sensitive sensors and having the following features: each sensor comprises a collecting electrode and a switching element which connects the collecting electrode to an output lead; a photoconductor layer is provided between the individual collecting electrodes and a bias electrode; the collecting electrodes form, in conjuction with reference electrodes, capacitances which can be charged by charge carriers generated in the photoconductor. The invention improves the effectiveness of such an X-ray image detector in that either the surface area of the collecting electrodes is increased or the electric field is distorted by a semiconductor layer so that the majority of the charge carriers generated in the photoconductor flow to the collecting electrodes.

Claims13

Dependent claims

An X-ray image detector, comprising a plurality of X-ray sensitive sensors and having the following features:

each sensor comprises a collecting electrode (11), a reference electrode (10) and a switching element (1) which connects the collecting electrode to an output lead (7);
a photoconductor layer (3) is provided between the individual collecting electrodes (11) and a bias electrode (4);
and
in conjunction with the reference electrodes, the collecting electrodes form capacitances (2) which are chargeable by charge carriers generated in the photoconductor;
characterized in that each of the collecting electrodes comprises two electrically contacting electrode portions (11, 14), the first electrode portion (11) being arranged in a respective area adjoining the associated output lead (7), the second electrode portion (14) having a surface area which is greater than that of the first electrode portion and being situated between the first electrode portion and the bias electrode, an insulating layer being provided between the second electrode portion (14) and the output lead (7).

2 more elements

An X-ray image detector, comprising a plurality of X-ray-sensitive sensors and having the following features:

each sensor comprises a collecting electrode (11), a reference electrode (10) and a switching element (1) which connects the collecting electrode to an output lead (7);
a photoconductor layer (3) is provided between the individual collecting electrodes (11) and a bias electrode (4);
and
in conjunction with the reference electrodes, the collecting electrodes form capacitances (2) which can be charged by charge carriers generated in the photoconductor;
characterized in that each sensor also has the following features:
the collecting electrode (11) is arranged adjacent the output lead (7);
the switching element (1) and the output lead are covered by an insulating layer (13);
the insulating layer (13) and the collecting electrode (11) are covered by a semiconductor layer (35);
and
the semiconductor layer (35) is doped so that for the charge carriers flowing in the direction of the collecting electrode it has a conductivity which is high in comparison with its conductivity for charge carriers of opposite polarity.

7 more elements

Dependencies are inferred from the claim text.