Matrix of photosensitive elements and radiation detector including such a matrix, especially double-energy X-ray detector

Claim 3

The device as claimed in claim 1, wherein the photosensitive elements (DA., DB) are photodiodes.

Claim 4

The device as claimed in claim 1, wherein the photosensitive elements (DA, DB) are phototransistors of the NIPIN or PINIP type.

Claim 5

The device as claimed in claim 1, wherein the capacitor (CI) is placed in series between the photosensitive elements (DA, DB).

Claim 6

The device as claimed in claim 1, in which each photosensitive point (P1 to P9) includes a first and a second end (10, 11) which are connected respectively to a line conductor (L1 to L3) and to a column conductor (F1 to F3), wherein a photosensitive point (P1 to P9) further includes a first and a second zone of floating potential (A, B) where there are stored respectively a first and a second information item (QA., QB) which are produced respectively by the illumination of the first and of the second photosensitive elements (DA, DB).

Claim 7

The device as claimed in claim 5, wherein the line conductors (L1 to L3) and the column conductors (F1 to F3) are connected to means (3, G1, G2, G3) for biasing in reverse the photosensitive elements (DA, DB) before their illumination, and then for subsequently forward-biasing them in order to obtain two reading charges (Q1, Q2) associated with the information items (QA, QB) stored in the zones (A, B) of floating potential.

Claim 8

The device as claimed in claim 6, wherein the means for biasing the photosensitive elements (DA, DB) include a pulse generator (3).

Claim 9

The device as claimed in claim 7, wherein the pulse generator (3) delivers groups of two pulses of opposite polarities.

Claim 10

The device as claimed in claim 1, wherein the two scintillator substances (27, 55) constitute a first and a second scintillator layer (SA, SB), between which the photosensitive matrix (1) is situated, in such a manner as to construct a sandwich structure.

Claim 11

The device as claimed in claim 1, wherein the incident radiation is X-rays.

Claim 12

The device as claimed in claim 9, wherein the photosensitive matrix (1) includes a plurality of photosensitive points (PI to P9) each including a first and a second photosensitive element and a capacitor (DA, DB, CI) connected in series, the two photosensitive elements and the capacitor consisting of layers (30, 31, 32, 34, 40, 41, 42) which are superposed in the direction of a thickness (E) of the matrix included between the two scintillator layers (SA, SB).

Claim 13

The device as claimed in claim 11, wherein the matrix (1), in the direction of its thickness (E) is transparent to light which is visible or near visible.

Claim 14

The device as claimed in claim 12, which further includes a light source (60) serving to perform a reset to level (RAN) of the photosensitive elements (DA, DB).

Claim 15

The device as claimed in claim 13, wherein the light emitted by the light source (60) has a greater wavelength than the light emitted by the scintillator substances (27, 55).

Claim 16

The device as claimed in claim 11, wherein the photosensitive elements (D.A, DB) are photodiodes.

Claim 17

The device as claimed in claim 11, wherein the photosensitive elements (DA, DB) are phototransistors of the NIPIN or PINIP type.

Claim 18

The device as claimed in claim 1, wherein the photosensitive matrix (1) is formed on a substrate (26), and wherein a scintillator layer (SB) is deposited on the substrate (25) and intercalated between the substrate (26) and the photosensitive matrix (1).

Claim 19

The device as claimed in claim 17, wherein the substrate (26) is transparent, and wherein the light source (60) is situated on a face of the substrate which is opposite to the photosensitive matrix.

Claim 20

The device as claimed in claim 12, wherein the first and second photosensitive elements (DA, DB) have substantially equal thicknesses (E2, E3).

Claim 21

The device as claimed in claim 6, wherein the first and second information items (QA, QB) are linked respectively to the two reading charges (Q1, Q2) by the following two relations: ##EQU3## where QA and QD correspond respectively to the first and the second information items; CI is the capacitor which, in a photosensitive point, is in series with the two photosensitive elements DA and DB; CDA is the equivalent capacitance of the first photosensitive element DA; CDB is the equivalent capacitance of the second photosensitive element DB; α and γ are known respectively by the third and fourth relations which follow: ##EQU4##

Claim 22

A matrix of photosensitive elements including an array of line conductors (L1 to L3) and an array of column conductors (F1 to F3) and an array of photosensitive points (PI to P9), wherein each photosensitive point (PI to P9) includes, between a line conductor (11) and a column conductor (fl) two photosensitive elements (DA, DB) and a capacitor (CI), the two photosensitive elements (DA, DB) and the capacitor (CI) being connected in series, the two photosensitive elements being connected with directions of conduction which are opposite to one another, in order to constitute two floating-potential points to store separately the charges created by each of the photosensitive elements.

Claim 23

A matrix of photosensitive elements including an array of line conductors (L1 to L3) and an array of column conductors (F1 to F3) and an array of photosensitive points (PI to P9), wherein each photosensitive point (PI to P9) includes, between a line conductor (11) and a column conductor (fl) two photosensitive elements (DA, DB) and a capacitor (CI), the two photosensitive elements (DA, DB) and the capacitor (CI) being connected in series, the two photosensitive elements being connected with directions of conduction which are opposite to one another, in order to constitute two floating-potential points to store separately the charges created by each of the photosensitive elements.

Claim 24

The device as claimed in claim 21, wherein for each photosensitive point (P1 to P9) the two photosensitive elements and the capacitor (DA, DB, CI) consist of layers (30, 31, 32, 34, 40, 41, 42) which are all superposed.

Claim 25

A matrix of photosensitive elements including an array of line conductors (L1 to L3) and an array of column conductors (F1 to F3) and an array of photosensitive points (P1 to P9), wherein each photosensitive point (P1 to P9) includes, between a line conductor (L1) and a column conductor (F1) two photosensitive elements (DA, DB) and a capacitor (CI), the two photosensitive elements (DA, DB) and the capacitor (CI) being connected in series, the two photosensitive elements being connected with directions of conduction which are opposite to one another, each photosensitive point (PI to P9) includes a first and a second end (10, 11) which are connected respectively to a line conductor (L1 to L3) and to a column conductor (F1 to F3), a first and a second one of floating potential (A, B) where there are stored respectively a first and a second information item (QA, QB) which are produced respectively by the illumination of the first and of the second photosensitive elements (DA, DB), the line conductors (L1 to L3) and the column conductors (F1 to F3) are connected to means (3, G1, G2, G3) for biasing in reverse the photosensitive elements (DA, DB) before their illumination, and then for subsequently forward-biasing them in order to obtain two reading charges (Q1, Q2) associated with the information items (QA, QB) stored in the zones (A, B) of floating potential, and the first and second information items (QA, QB) are linked respectively to the two reading charges (Q1, Q2) by the following two relations: ##EQU5## where QA and QB correspond respectively to the first and the second information items; CI is the capacitor which, in a photosensitive point, is in series with the two photosensitive elements DA and DB; CDA is the equivalent capacitance of the first photosensitive element DA; CDB is the equivalent capacitance of the second photosensitive element DB; α and γ are known respectively by the third and fourth relations which follow: ##EQU6##

Claim 26

A matrix of photosensitive elements including an array of line conductors (L1 to L3) and an array of column conductors (F1 to F3) and an array of photosensitive points (P1 to P9), wherein each photosensitive point (P1 to P9) includes, between a line conductor (L1) and a column conductor (F1) two photosensitive elements (DA, DB) and a capacitor (CI), the two photosensitive elements (DA, DB) and the capacitor (CI) being connected in series, the two photosensitive elements being connected with directions of conduction which are opposite to one another, each photosensitive point (PI to P9) includes a first and a second end (10, 11) which are connected respectively to a line conductor (L1 to L3) and to a column conductor (F1 to F3), a first and a second one of floating potential (A, B) where there are stored respectively a first and a second information item (QA, QB) which are produced respectively by the illumination of the first and of the second photosensitive elements (DA, DB), the line conductors (L1 to L3) and the column conductors (F1 to F3) are connected to means (3, G1, G2, G3) for biasing in reverse the photosensitive elements (DA, DB) before their illumination, and then for subsequently forward-biasing them in order to obtain two reading charges (Q1, Q2) associated with the information items (QA, QB) stored in the zones (A, B) of floating potential, and the first and second information items (QA, QB) are linked respectively to the two reading charges (Q1, Q2) by the following two relations: ##EQU5## where QA and QB correspond respectively to the first and the second information items; CI is the capacitor which, in a photosensitive point, is in series with the two photosensitive elements DA and DB; CDA is the equivalent capacitance of the first photosensitive element DA; CDB is the equivalent capacitance of the second photosensitive element DB; α and γ are known respectively by the third and fourth relations which follow: ##EQU6##