Abstract: A pixel matrix includes a sub-matrix of four adjacent pixels. Each of the pixels of the sub-matrix comprises: a set of a photoelectric-effect element and a memory point, a detection node, a transfer gate. The binning stage is connected to the set and is common with an adjacent pixel of the sub-matrix. At least one detection node per sub-matrix is common to two adjacent pixels of the sub-matrix. The pixel matrix furthermore comprises at least one readout stage per sub-matrix, connected to the common detection node.

Abstract: A circuit for reading a pixel matrix array comprises, for each column of pixels of the matrix array: voltage-to-delay converting circuits receiving, on an input, a voltage value representative of the voltage of a read conductor of a respective column of pixels of the matrix array and delivering as output a binary signal called a comparative signal, this signal switched at a time dependent on the input voltage value; frequency-multiplying circuits, one for each of the voltage-to-delay converting circuits, receiving as input a primary clock signal and delivering as output secondary clock signals of multiplied frequency; and binary counters, receiving, on a first input, a the secondary clock signal, and, on a second input, a the binary comparative signal and counting at a rate dictated by the secondary clock signal until the binary comparative signal switches. An image sensor comprising a matrix array of pixels, in particular active pixels, and a read circuit is also provided.

Abstract: Ramp analog-digital converters used in matrix image sensors to provide a digital value representative of a level of illumination of a pixel are provided. Two voltage samples are applied to a comparator, a counter is used to count pulses at a frequency F from a starting instant of the ramp until a toggling of the comparator. Two other voltage samples, one of which is added to a linear voltage ramp having an identical starting instant and slope to the first ramp, are applied to a second comparator, a half counting frequency F/2 is applied to the counter from the toggling of one of the comparators, and the content of the counter at the moment of toggling of the other comparator is stored. Two measurements of samples of the same signal or of two different signals are averaged without undergoing a digital conversion for each signal and a digital addition.

Abstract: An active pixel image sensor comprising a matrix of pixels organized in rows and columns and a read circuit comprising a distinct read pathway for each column of pixels, comprises: a photodiode, a storage node, a transfer transistor, a storage node reset transistor, a row select transistor and a transistor mounted as voltage follower; each read pathway comprises a subtraction block connected to receive, first, voltage at the terminals of the storage node of a pixel of the corresponding column and, second, a reference voltage of value substantially equal to the reset voltage of the pixels of the matrix seen at the input of the read pathway; the sensor comprises a controller for driving the transistors of pixels and the read circuit to perform an image acquisition in global shutter mode with subtraction of the reset noise and non-destructive reading of the pixels. A method for acquiring images is provided.

Abstract: An N-bit Gray counter, with N an integer greater than 1, comprises a string of N logic cells connected in cascade, wherein each logic cell comprises an input port for a succession of clock pulses, a circuit for generating a Gray count bit having an output port for the Gray count bit and a circuit for generating a clock signal having a clock output port linked to the input port of the following logic cell. An analog-digital converter of ramp type using such a Gray counter is also provided.

Abstract: Integrated circuits of large size produced by photorepetition of several mutually identical partial patterns are provided, more precisely to the compensation of propagation delays of signals (notably of clock signals) from one partial circuit to the following whereas the signals concerned must reach the various partial circuits simultaneously for proper operation of the whole. The compensation circuit provided in each partial circuit comprises a main transmission line for a master clock signal and a compensation line with multiple outputs, as well as a multiplexer for selecting one of the outputs, the output selected being different in the various partial circuits. The multiplexer provides a local clock signal in each partial circuit and these clock signals are synchronous despite the propagation delays.