Commissariat a L'energie Atomique

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Gilles Chamming's

Jean-Luc Martin

Patrick Villard

Bertrand Dupont

The invention relates to matrix image sensors, and more particularly to a method for correcting the spatial noise caused by the dispersion of the physical properties of the various pixels of the matrix. According to the invention, a signal X(L) is established pixel by pixel that corresponds to the illumination of a pixel Pby a luminance L; a fixed reference Kis defined for this signal, the value Kbeing chosen such that, for a given luminance L, the pixels all supply an identical signal X(L) that is equal to K; and a corrected signal X*(L) is established by applying to the duly referenced signal X(L)&#x2212;Ka multiplying correcting coefficient specific to the pixel concerned, the correcting coefficient being determined from the signal X(Lr) supplied by the pixel Pfor a determined reference luminance Lr which is the same for all the pixels. The correcting coefficient is preferably stored in an initialization register REGspecific to the pixel, which contains a value dTfor modulating the integration time of a counting frequency representing the luminance.

Method of correcting sensitivity and matrix image sensor for implementing this method

The invention relates to matrix image sensors, and it relates more particularly to a method for correcting the spatial noise generated by the dispersion of the physical properties of the different individual sensitive dots, or pixels, of the matrix. For each pixel, in an individual electronic circuit associated with the pixel, a recursively digital method is used to determine an approximate value (M) of an average of the signal Sobtained from the pixel during this large number of images; the signal obtained from each pixel is corrected according to the determined approximate average value and according to a reference average value (M0), and a corrected signal S*is transmitted from the circuit associated with the pixel.

Method for correcting the spatial noise of a matrix image sensor

Embodiments of the present disclosure relate to an electronic sensor including capture means producing a signals comprising x pulses during a given capture time, such that a'&#x3c;x&#x3c;b&#x2032;, wherein a&#x2032;, b&#x2032; and x are non-null natural integers, and counting means receiving the signals, which are incremented with each pulse received, including a maximum counting capacity equal to z such that (b&#x2032;&#x2212;a&#x2032;)&#x2266;z&#x3c;a&#x2032;, where z is a non-null natural integer, resetting the counting, when the maximum counting capacity z is exceeded and outputting, at the end of the capture time, a number representative of the number of pulses x of the signals, wherein a&#x2032; is the minimum value and b&#x2032; is the maximum value of the number of pulses that can be produced by the capture means.

Electronic sensor with optimized counting capacity

The present invention relates to a device for measuring an electric charge in digitized form. The digitized value is coded on N bits. The device has at least a battery of N capacitors () integrating the charge. The capacitors have a common electrode linked to a current source providing the charge. Each capacitor has an individual electrode. The values of the capacitances of the capacitors are in geometric progression. A capacitor corresponds to a bit of the digitized value. Switches () are connected to each individual electrode operating according to two phases, connecting the capacitors in parallel in an integration phase so as to integrate the charge in the capacitors () and making it possible in a digitization phase to take each of the individual electrodes to two distinct potentials, corresponding to the two logic states of the bit, so as to transfer or not transfer the charge carried by the capacitor to all the other capacitors of the battery. The device has a logic unit () making it possible to determine in the second mode the combination of capacitors which, containing the same quantity of charge, is at a defined potential, the combination representing the digitized value.

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Grenoble, France

Gilles Chamming's