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: The disclosure concerns the reading of the photocharges generated by the illumination of a matrix of photosensitive dots. The dots are formed by a photosensitive diode in series with a reading diode, all between a row and a column of the matrix. To reduce the reading errors, there is provision to illuminate the photosensitive dots with a constant illumination which gets added to the illumination to be measured, thus creating driving charges that get added to the useful charge and facilitate its transfer to a reading register.

Abstract: The invention relates to a photosensitive matrix (2) permitting the simultaneous acquisition of two images, especially radiological images, and which offers at the same time a maximum sensitivity and a maximum image resolution. The matrix (2) of the invention includes photosensitive points (P1 to P9) disposed in lines and in columns. According to a feature of the invention, each photosensitive point (P1 to 9) includes two photosensitive cells (JA, JB), the first ends (3A, 3B) of which are connected to a same line conductor (L1 to L3), and the second ends (4A, 4B) of which are connected to different column conductors. FIG. 1.

Abstract: The invention relates to the processing of images, especially radiological images, by means of a photosensitive matrix (1) permitting the simultaneous acquisition of a plurality of images. The matrix (1) of the invention includes an array of line conductors (L1 to L3) and an array of column conductors (F1 to F3). Photosensitive points (P1 to P9) are formed at each crossing of a line conductor (L1 to L3) with a column conductor (F1 to F3); each photosensitive point having one end (10) connected to the line conductor and the other end (11) connected to the column conductor. According to a feature of the invention, each photosensitive point (P1 to P9) consists of two photosensitive elements (DA, DB) and a capacitor (CI) all connected in series, the two photosensitive elements (DA, DB) having opposite directions of conduction.

Abstract: The disclosure concerns photosensitive matrices and, more precisely, the read circuit connected to each of the output columns of the matrix. To reduce the noise of a transfer from a column to an output register, there is performed, N times successively, a transfer of the charge Qs to be read from the column to an intermediate storage zone, a duplication of this charge and a summation of the duplicated charges Qs*, and a restitution of the charge Qs to the column. If the transfer noises are decorrelated with respect to one another, the overall signal-to-noise ratio is improved in a ratio of N.sup.1/2. A fraction of the sum of the replica charges (for example the mean of the N replica charges) is transmitted to the output and constitutes the output signal of the read circuit.

Abstract: The disclosure concerns matrices of photosensitive elements. To avoid the need for a resetting light source using, as a photosensitive dot, a photodiode in series with a capacitor between a row conductor and a column conductor, it is proposed, according to the invention, to provide for a photosensitive dot comprising two diodes (a photosensitive diode and a reading diode) and a capacitor connected to a common floating node. The capacitor is connected to a row-addressing conductor giving a reading pulse to the selected line. The cathode of the reading diode is connected to the column conductor which collects the useful signal; and the anode of the photodiode is connected to a second row conductor (which, besides, may be the first conductor of a neighboring row) which receives a resetting pulse after the reading pulse. In another embodiment, the photodiode is simply connected to a reference voltage source.

Abstract: The disclosure concerns devices for the conversion of images into electronic signals with particular application to X-ray imaging. Instead of forming, on an insulating glass substrate, a strip or matrix of photosensitive elements (PIN diodes) which are then coated with a scintillating sheet bonded to or pressed against the upper surface of the photosensitive elements, a scintillating layer is deposited on the substrate before forming the photosensitive elements. Thus, a gain in sensitivity and definition is achieved. It is moreover possible to preserve, in addition to the scintillating layer deposited between the substrate and the photosensitive elements, a scintillating layer bonded to or pressed against the upper surface of the unit. The two scintillators may be identical or different in nature. If they are different, they may react to different wavelengths but may also emit in different wavelengths.

Abstract: A charge transfer device having a first storage gate above a first storage region and a second storage gate above a second storage region. The charge duplicator has a first charge injector having a first passage gate which introduces, below the first storage gate, the reference charge to be duplicated. A second charge injector having a second passage gate is located near the second storage gate. The first storage gate and second storage gate are connected to the two inputs of a voltage comparator, the output of the voltage comparator being connected to the second passage gate. The charge duplicator has a mechanism which initially is used to apply a reference voltage to the two inputs of the voltage comparator, thereby leaving the two inputs and the gates connected to them in a floating state. The voltage comparator outputs a high level or low level, depending on the value of the differential voltage between its inputs.

Abstract: The disclosure concerns matrices of photosensitive elements. To prevent the need for a resetting light source in matrices using, as a photosensitive dot, a photodiode in series with a capacitor between a row conductor and a column conductor, a photosensitive dot is proposed, formed by a photodiode in series with a reading diode between a row conductor and a column conductor, it being possible to put the reading diode into forward or reverse conduction. To read the photoelectrical charges generated, a reading pulse, which makes the reading diode forward conductive, is applied. To then reset the potential of the floating node A, at which the photoelectrical charges accumulate, at a constant starting level, a reverse resetting pulse is applied, thus making the reading diode conductive (but this time in reverse conduction).

Abstract: According to the invention, each light-sensitive element is made up by the series-connection of a capacitor, a photodiode and an electronic switch. The light signal to be read is applied to the device after the photodiodes have been reverse polarized by a voltage pulse with an amplitude V.sub.P1. The device is read row by row, by the application of a voltage pulse with an amplitude V.sub.P2 greater than V.sub.P1 to each row read. The switches of the read row are closed while the switches of the other rows are open. Once the device is read, the photodiodes are zeroized.

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: The present invention relates to an improvement to solid state photosensible devices of the type having a charge storing capacitor preceding the charge--voltage conversion stage. The photosensitive device of the invention comprises photosensitive detectors, each detector being connected to a charge integration cell, which is itself connected via a multiplexer to a charge--voltage conversion stage, preceded by a first storage capacitor connected to a resetting means with a supplementary storage capacitor located upstream of the first capacitor. The bias voltage of the supplementary capacitor can be brought to a high or a low level, as a function of the charge quantity to be integrated, for modifying the value of the capacitor receiving the charges.

Abstract: Each integration cell is surrounded by means imposing, at least during the charge integration time, a given surface potential. The detectors and integration cells are integrated onto semiconductor substrates receiving different biasing voltages and such that in the case of overillumination, each detector is biased at its open circuit voltage and supplies no further current until the surface potential of the integration cell has reached the given surface potential, which produces an anti-blooming effect.

Abstract: A device for the optical abutment of photosensitive detectors using an optical system comprising two prisms joined together by a semireflecting face. The detectors are disposed on two right angle faces each belonging to a prism. The arrangement of the strips of detectors is such that they are as close as possible to each other and that the junction of two strips on one of the faces does not correspond to the junction of two strips on the other face. Means provide summation of the information from two detectors, situated on each of the two faces and receiving the same signal.

Abstract: A method of operating a solid state photodetector device which has N photodetectors formed on a first substrate portion connected to a readout stage, through a transition zone having at least one storage zone and a transfer gate, and a multiplexer of the charges transfer type which are on a second substrate portion. The second substrate portion is biased to a voltage which is negative with respect to that of the first substrate portion. Then, after integration of the charges from the photodetectors and tansfer thereof into the multiplexer in the usual way by leaving a charge Qo in the storage zone, the transfer gate is biased so that the voltage under this gate is less than the biasing voltage of the first substrate portion. Then the gate in the storage zone is biased so that the potential under this gate is between the bias voltage of the first substrate portion and the potential under the transfer gate so as to remove the charge Qo.

Abstract: The present invention concerns a process for correcting the output level of a charge-transfer device, as well as a device for operating the same. Said process comprises different steps, respectively a first step where the quantities of charges corresponding to a reference signal that are stored in N stages are read successively and the values being function of the different quantities of charges read, are stored in a memory; and a second step, where before each read-out of a charges quantity, the precharge level of the output stage is modulated in function of the value of the same rank stored in the memory.

Abstract: A photosensitive device for the infrared range wherein each detector is connected to a first and a second MOS transistor. The second MOS transistors are addressed, column by column, by a first shift register. The first MOS transistors are connected, line by line, to a charge storage capacity and to a third charge reading MOS transistor addressed by a second shift register. The whole of the device is placed in a cryostat which only has a single output.

Abstract: A solid state photosensitive device according to the invention comprises at least one photonic and charges integration cell connected to a reading stage constituted by voltage reading means each connected to a cell through the intermediary of means allowing to read the potential corresponding to the quantity of charge in the integration zone of the said cell, at least one addressing means in order to address sequentially one of the reading means and means for return to zero of the previously read detection and integration cell.