Abstract: In a matrix array of photosensitive elements, each photosensitive point is provided with a photosensitive element (pin photodiode) in series with a capacitor between a row lead and a column lead. It is proposed to make use of a simplified photosensitive element in which an end semiconductor layer is suppressed such as, for example, the n-layer of a pin photodiode or the n-layer of a five-layer phototransistor of the nipin type. The dielectric of the capacitor then comes directly into contact with an intrinsic semiconductor layer in which electrons accumulate. These electrons reconstitute the equivalent of an n-type doped layer.

Abstract: The disclosure concerns photosensitive matrices, and especially those using NIPIN or PINIP type phototransistors made of amorphous silicon. To prevent problems of remanence, due to the collecting of holes in the base after an illumination stage, it is proposed to follow the step for reading the illumination signal by a remanence erasure step in which the phototransistor is made conductive in forward or reverse bias, so as to inject, into the base, electrons which will eliminate the holes by recombination. Switching on by reverse bias proves to be more efficient than switiching on by forward bias. The invention is applicable notably to a matrix structure of rows and columns of photosensitive sites in which each site is formed by a NIPIN transistor made of amorphous silicon in series with a reading diode that may be put into reverse conduction.

Abstract: Disclosed is a matrix of photosensitive elements for imaging. This matrix comprises, in series between a row conductor and a column conductor, a capacitor in series with a NIPIN or PINIP type phototransistor. This phototransistor can be made conductive, for the reading of the charges stored in the memory, as easily as a photodiode, even in darkness. The phototransistor is preferably formed by a stacking of N type, intrinsic type, P type, intrinisic type and N type semiconducting layers.

Abstract: When the capacitance of the conductive columns of the line-transfer photosensitive device is higher than that of the photosensitive elements and of the read register, use is made of a reading circuit provided in the case of each conductive column with a plurality of charge storage capacitors separated by an MOS transistor. These MOS transistors operate in the saturating mode and pass signal charges derived from each conductive column from one capacitor to the next up to the read register. The storage capacitors have decreasing values as the distance from the read register becomes shorter. Transfer of the signal charges is accompanied by transfer of polarization charge quantities which decrease in value as the distance from the register becomes shorter. Once the transfer operations have been performed, these quantities of polarization charges are returned to their initial capacitors.

Abstract: An improved line-transfer photosensitive device and particularly a device which operates with a double drive charge comprises on at least one semiconductor substrate a photosensitive region made up of M lines of N photosensitive points. The photosensitive points of the different lines are connected in parallel by means of conductive columns to a line memory which carries out at least the transfer of the signal charges integrated on any one line of the phtosensitive region to a read register consisting of a charge-coupled shift register of the volume transfer type. The line memory is formed on a semiconductor substrate region having an impurity implantation of opposite type with respect to the substrate in order to produce a volume charge transfer. The region in which the line memory is formed has a dopant concentration which is lower than or equal to that of the region in which the shift register is formed.

Abstract: The present invention pertains to a large-sized X-ray photography panel. This panel comprises several modules placed end to end. Each module comprises a network of photosensitive detectors with the same number of columns as the panels but with a smaller number of rows. Each module has its own addressing and reading means. The addressing means are located on an edge of the insulating substrate that bears the detectors. The reading means are located on the other side of the substrate from the detectors. A screen, which is opaque to the radiation to be detected, is interposed between the substrate and these means. These means are liked to the column connections coming from the opposite side of the substrate by connections along one of the side surfaces of the substrate.

Abstract: A method for reading a photosensitive element having a photodiode and a capacitor as applicable in particular to reading a low-level analog signals consists in introducing a biasing charge background, for example by means of calibrated uniform illumination prior to each read operation in order to cause forward biasing of the photodiode substantially beyond its knee voltage at the time of application of a control read pulse which reliably restores the voltage at the photodiode terminals to the knee voltage value, the current during the read operation being such that all the charges are then reliably transmitted via the capacitor to the integrating read amplifier.

Abstract: The invention provides a matrix of photosensitive elements in which each photosensitive element is reduced to the association of a diode and a capacity. The method for manufacture thereof is therefore easy particularly from amorphous silicon. The method for reading same uses multiplexed reading of the columns: the n columns are distributed in groups of n/M successive columns controlled simultaneously by M horizontal shift registers, each associated with a reading integrator. To ensure correct reading of the useful signal, whatever their level, the level of the voltages at the terminals of the diodes of the photosensitive elements is reset so that the starting voltage at the beginning of each reading pulse applied to a line is such that only this pulse, and even with a maximum useful illumination signal, can bias the diode forwardly, and so that with a column addressing pulse, the diode is biased forwardly even in the absence of the useful signal.

Abstract: An analog image memory device using charge transfer and comprising:a memory zone of N lines of M memory points, each memory point being formed by the integration on the same semiconductor substrate of an MIS capacity separated from a diode by a screen grid,means for selecting each memory point,means for writing in each memory point a charge amount corresponding to the analog signal to be stored andmeans for reading the memory zone line by line after writing.

Abstract: A charge transfer analog comparator comprising two adjacent MIS capacities coupled together by a passage gate and connected respectively to the input and to the output of an amplifier as well as the means for initializing the comparison connected to the input of an amplifier and means for introducing under each capacity respectively the signal charge and the reference charge.

Abstract: Use is made of a row memory and a read register, in which charge transfer takes place in volume. The threshold voltage of the negative feedback amplifiers is adjusted so that the operating point of the assembly constituted by each amplifier, the diode and the gate of the memory to which it is connected is located in the high gain zone of the transfer characteristic of the amplifier. It is possible to adjust the threshold voltage by an enhancement in its own type of impurities of the zone of the substrate located beneath the gate of one of the MOS transistors constituting the amplifier.

Abstract: A charge transfer multi-linear strip comprising several lines of photosensitive detectors, each line receiving successively the radiation to be detected and comprising charge transfer shift registers which provide in phase summing of the information collected at the detectors occupying the same position in the different lines, and wherein:said strip is adapted to radiology, the photosensitive detectors being photodiodes with a scintillator before these photodiodes and a screen being disposed to protect from the x rays the whole strip, except the photodiodes and their connections;there is a device for charge injection of the information between each connection connected to a detector and an input of a charge transfer shift register, said device comprising especially a charge injection diode connected to one of the connections and a screen grid brought to a constant potential, said grid providing biasing of the detector.

Abstract: In order to modulate the sensitivity of a photosensitive device by modulating the integration time, a first reading of each line of a photosensitive zone of the device is followed by a second reading at an adjustable time interval. The charges resulting from the first reading operation are removed to the drain while the parasitic charges and the signal charges resulting from the second reading operation are transferred to the read register at the same time. Modulation of the time interval which elapses between two readings of one line is carried out by varying the time which elapses between the injection of one drive pulse into the two registers which control respectively the first reading and the second reading of the lines.

Abstract: In a device for current-reading of a quantity of electric charges, the control circuit for the first and second MOS transistors receives a constant potential and comprises:a third transistor, the drain and gate of which are connected to the constant potential and the source of which is connected to the drain and to the gate of the second transistor;a second capacitor connected through one of its terminals to the nodal point of the second and the third transistor.The device is employed for reading quantities of charges which arrive under the storage electrodes of charge-transfer filters.

Abstract: A charge transfer photosensitive device, having a plurality of photosensitive zones (20) fabricated on a single conducting substrate, and having N lines and M columns, and insulated from one another. In the photosensitive zones electrical charges are created depending upon light received. Each of these zones is formed by a MOS capacitance (3) and a charge collecting diode (8). A plurality of reading diodes (5) read the charges collected in the photosensitive zones; and a screen grid (4) is placed between the reading diodes (5) and the photosensitive zones (20).

Abstract: A device for electrically analyzing color light images includes:a matrix of photosensitive points each able to receive a colored filter,an assembly of two line memories receiving in parallel the electric charges from a line of the matrix,two shift registers receiving in parallel respectively the charges supplied by the two line memories. This device applies more particularly to a television camera.

Abstract: This analog-ditigal coder determines the coefficients a.sub.o . . . a.sub.n in two stages:during the first stage, the generator processes voltages V.sub.R and V.sub.Ri with i=1 to k-1;during the second stage, the generator processes the voltages V.sub.R and V.sub.Ri with i=1 to n-k.A capacitive voltage divider (2.sup.k C, C) preceded by two sample and hold means (S.sub.3, C.sub.3, S.sub.4, C.sub.4) assures the division by 2.sup.k of the voltages processed during the second stage and their summation with the final voltage V.sub.R(k-1) produced during the first stage.

Abstract: A switched-capacity amplifier formed from integrated capacities has undesirable parasitic capacities that are large and variable on only one terminal of each of the capacities. A voltage-follower stage is connected to this terminal of each of the capacities (except those capacities which are grounded) to offset the parasitic capacity. The amplifier is also connected in a switched-capacity filter and a charge-transfer filter.

Abstract: A switched capacity filter having capacities formed by MOS technology on a semiconductor substrate. The connection between two capacities whose first plates are formed by the semiconductor substrate are periodically connected by providing transfer of charges in the substrate on which these two capacities are integrated. The external or other plate of each capacity receives, the input voltage, or a reference voltage, or the surface potential under another capacity which is provided by a reinjection and reading device formed from a diode and a voltage follower stage.

Abstract: Successive two-trip traversals of charges between gates G.sub.0 and G.sub.2 make it possible to obtain beneath gates G.sub.1 and G.sub.2 quantities of charges equal to Q.sub.R, Q.sub.R /2, Q.sub.R /2.sup.2 . . . Q.sub.R /2.sup.i. A readout device for reading charges and connected to gates G.sub.2 and G.sub.4 generates voltages V.sub.R and V.sub.Ri =a.sub.0 .multidot.V.sub.R +a.sub.1 .multidot.V.sub.R /2+ . . . +a.sub.i-1 .multidot.V.sub.R /2.sup.i-1 +V.sub.R /2.sup.i which are compared with a voltage sample V.sub.x to be coded in order to determine by successive approximations the coefficients a.sub.0 . . . a.sub.n which are equal to 0 or to 1 such that V.sub.x =a.sub.0 .multidot.V.sub.R +a.sub.1 .multidot.V.sub.R /2+ . . . +a.sub.n .multidot.V.sub.R /2.sup.n. Depending on the value of a.sub.i, each quantity of charges Q.sub.R /2.sup.i stored beneath gate G.sub.1 is removed beneath diode D.sub.e or stored beneath gate G.sub.3 and then transferred beneath gate G.sub.4.