Trixell S.a.s.

Thomson Tubes Electroniques

Christophe Chaussat

Thierry Ducourant

Christophe Barnichon

Robert Neyret

Clément Atoyan

Paul Apard

Clement Atoyan

A process for controlling a photosensitive device including at least one photosensitive point with a photodiode connected to a switching element. The process submits the photosensitive point to successive imaging cycles. Between a first imaging cycle and a second imaging cycle, the process produces a holding phase terminating at the start of the second imaging cycle. During this holding phase, whose duration is equal to several equal time intervals that are as short as possible, the photosensitive point is exposed to an optical flash at the start of each time interval. Between successive optical flashes, the photodiode is reverse biased. The junction region between the photodiode and the switching element has substantially the same potential at the end of each time interval.

Process for controlling a photosensitive device including a photosensitive point produced by techniques for depositing semiconductor materials

A drive process for an array of photosensitive points produced on a semiconductor material. Each of the points has a photodiode connected in series with a switch element. The photodiode is reverse-biased and produces charges when it is exposed to a light signal during an imaging phase. Before the imaging phase, the photosensitive points are illuminated with an additional light flux whose intensity causes the photodiode to conduct in the forward direction and then in applying a biasing pulse to the photosensitive points in order to return the photodiode to reverse bias. Thus, a current is produced which has the effect of reducing a remanence effect in the semiconductor material.

Method for controlling a photosensitive device with low image retention, and photosensitive device implementing same

A photosensitive device comprises: photosensitive cells located at the intersection of at least one addressing conductor and one read conductor, a cell comprising a photosensitive diode connected to a read conductor and to at least one diode having a switching function connected to an addressing conductor, these diodes having a common point; addressing means connected to at least one addressing conductor; charge-reading means connected to at least one read conductor. The device furthermore comprises first measurement means capable of the measurement, in real time, of an information element representing a current flowing in at least one addressing conductor, this conductor being taken to an idle potential during the illumination so as to be capable of quantifying the illumination received by the cells located on the conductor concerned by the measurement; and second measurement means capable of the measurement of an information element representing a current flowing, during the illumination, in at least one read conductor, this read conductor being taken, during the illumination, to a specific potential so as to be capable of quantifying the illumination received by the cells located on the conductor concerned by the measurement. Application especially to the detection of radiological images.

Photosensitive device equipped with an illumination measurement device

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St Nizier, France

Christophe Chaussat