US 6,410,898 B1Granted

Photosensitive device equipped with an illumination measurement device

AssigneeTrixell

InventorsThierry Ducourant, Christophe Chaussat

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Abstract

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.

Claims20

Dependent claims

A photosensitive device comprising:

addressing conductors;
read conductors;
a plurality of photosensitive cells arranged as a matrix, wherein the addressing conductors and the read conductors intersect between the cells of the matrix, each cell is connected to one of the addressing conductors and to one of the read conductors, and each cell includes:
a photosensitive diode connected to the one read conductor, and configured to generate a current in response to an illumination, and
a switching diode connected to the one addressing conductor, and configured to allow a fraction of the generated current to flow to the one read conductor and to the one addressing conductor, wherein the photosensitive diode and the switching diode share a common point;
addressing circuit directly connected to the addressing conductors;
charge-reading means connected to the read conductors for reading charges that accumulated in selected cells during the illumination;
first measuring means for measuring during the illumination an information element representative of a sum of the current flowing in the addressing conductors, wherein the addressing conductors include a pre-selected subset of addressing conductors, the addressing conductors of said subset being held to an in idle potential during the illumination in order to quantify the amount of illumination received by cells connected to the subset of addressing conductors so as to extract information pertaining to the illumination in real time;
and
second means for measuring during the illumination an information element representative of a sum of the current flowing in the read conductors, wherein the read conductors include a pre-selected subset of read conductors, the read conductors of said subset being held to a predetermined potential during the illumination in order to quantify the amount of illumination received by cells connected to the subset of read conductors so as to extract information pertaining to the illumination in real time.

7 more elements

A photosensitive device comprising:

addressing conductors;
read conductors;
a plurality of photosensitive cells arranged as a matrix, wherein the addressing conductors and the read conductors intersect between the cells of the matrix, each cell is connected to one of the addressing conductors and to one of the read conductors, and each cell includes:
a photosensitive diode connected to the one read conductor, and configured to generate a current in response to an illumination, and
a switching diode connected to the one addressing conductor, and configured to allow a fraction of the generated current to flow to the one read conductor and to the one addressing conductor, wherein the photosensitive diode and the switching diode share a common point;
an addressing circuit directly connected to the addressing conductors;
a charge-reading circuit connected to the read conductors and configured to read charges that accumulated in selected cells during the illumination;
a first measuring circuit configured to measure during the illumination an information element representative of a sum of the current flowing in the addressing conductors, wherein the addressing conductors include a pre-selected subset of addressing conductors, the addressing conductors of said subset being held to an in idle potential during the illumination in order to quantify the amount of illumination received by cells connected to the subset of addressing conductors so as to extract information pertaining to the illumination in real time;
and
a second measuring circuit configured to measure during the illumination an information element representative of a sum of the current flowing in the read conductors, wherein the read conductors include a pre-selected subset of read conductors, the read conductors of said subset being held to a predetermined potential during the illumination in order to quantify the amount of illumination received by cells connected to the subset of read conductors so as to extract information pertaining to the illumination in real time.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/198,531Filed 24 Nov 1998
Priority: FR 97 1476325 Nov 1997
Granted: 25 Jun 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04N 25/76
SSIS architectures; Circuits associated therewith: addressed sensors, e.g. MOS or CMOS sensors
H04N 23/30
Cameras or camera modules comprising electronic image sensors; Control thereof: for generating image signals from X-rays
H04N 23/71
Circuitry for compensating brightness variation in the scene: circuitry for evaluating the brightness variation
H04N 25/30
Circuitry of solid-state image sensors [SSIS]; Control thereof: for transforming X-rays into image signals