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 three diodes (a photosensitive diode, a reading diode and a resetting diode) connected to a common floating node. In one embodiment, the anode of the photosensitive diode 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 resetting diode is connected to a second row conductor (which, besides, may be the first conductor of a neighbouring row) which receives a resetting pulse after the reading pulse. In another embodiment, the photosensitive diode is turned back, its cathode being then connected to a row conductor; the resetting diode is simply connected to a reference voltage source.
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:
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. A very steep transition occurs between the two levels, which is as close to zero as possible.
Abstract:
This device comprises a MOS transistor of the tetrode type operating under triode conditions. The storage of charges corresponding to each input voltage sample is realised beneath the MOS capacitor, whose plate is the longer insulating gate of the MOS transistor. The various gates of the transistor are half-rings with an increasing surface area. The diode connected to the input voltage of the device is placed in the center of circles defining the rings. The diode connected to the voltage follower stage supplying the output voltage of the device is positioned on the periphery of the longer insulating gate.
Abstract:
This device incorporates a photosensitive (1) constituted by a matrix of photosensitive points. Each photosensitive point has a charge reading diode D.sub.1. Metallic connections (C.sub.1 to C.sub.4) connect the reading diodes of the same column to a single diode (D.sub.2), followed by a grid G.sub.2 raised to a constant potential (V.sub.2). The operation of the device involves the repetition of two stages, i.e. stage T.sub.1 and stage T.sub.2. During stage T.sub.1 parasitic charges, due for example to too intense illumination, are transferred from diodes D.sub.1 to diodes D.sub.2 and are removed by a diode (D.sub.5). During stage T.sub.2 the signal charges stored by the points of one line of the matrix are transferred into a memory and then into a charge transfer read register (R.sub.2). The register reads these charges during the following stages T.sub.1 and T.sub.2 until the time when the register receives the charges corresponding to the reading of the following line.
Abstract:
A device for reading a quantity of electric charges arriving at a point B. Two MOS transistors Q2 and Q3 are connected in series and with one terminal to point B. A capacitor C.sub.A is connected to a common point A of the two transistors. A transistor control circuit charges the capacitor C.sub.A from a low potential V.sub.DD. The capacitor C.sub.A and the transistors Q2 and Q3 maintain a constant potential at the point B at the time of charge inflow. This results is a variation of potential at the common point A in accordance with the incoming charges at B. Thus, the variations of potential at point A is a measure of the charges arriving at point B.
Abstract:
Disclosed is a solid state photosensitive device having photosensitive dots, each of which achieves an amplification of the useful signal by means of a transistor obtained by a technology enabling the making photosensitive devices with large areas. To this end, according to the disclosure, each photosensitive diode has at least one photosensitive element that generates electrical charges stored at a point at floating potential, and has a transistor, the control gate of which is connected to the floating point. The transistor thus fulfils an amplifier function, but does not fulfill a photodetection function, so that it can be made of amorphous silicon, amorphous silicon being a material that can be used in thin layers or thin films on large areas.
Abstract:
A device for the electric scanning of luminous images. It includes a matrix of N lines and M columns of photosensitive points. A system incorporating a line memory of M points receives in parallel the electric charges supplied by the M points of the same line parasitic charge are removed by diodes. The system insures the injection of the same predetermined quantity of charges between each of the photosensitive points and the output of the device. An output shift register receives in parallel the charges supplied by the line memory and supplies in series a picture scanning electric signal. This device is particularly intended for use in a television camera.
Abstract:
The switched-capacitance amplifier comprises n capacitors C.sub.11 to C.sub.1n which are periodically switched in parallel and in series, the n parallel-switched capacitors being charged simultaneously by the same voltage V.sub.E. An amplified voltage n.times.V.sub.E is obtained between the end terminals A and B of the n series-switched capacitors. Periodic switching of the n capacitors in parallel and in series is performed by means of MOS transistors T.sub.11 to T.sub.1(2n-1) and T.sub.21 to T.sub.2(n-1) which operate in the switching mode. The n capacitors and the MOS transistors are integrated on the same semiconductor substrate.
Abstract:
A differential charge-transfer device for transversal filtering or delay line applications. It comprises: two charge-transfer channels which respectively receive the two signals, the difference between which is to be formed; an electrode common to both channels; means for sampling the signals in each channel, this sampling taking place at the same instants in both channels; a set of electrodes in each channel which, on the application of potentials of period T, propagate the samples to the common electrode with a relative delay equal to T/2 from one channel to the other. The signal representing the difference between the input signals is extracted at the common electrode.