Photosensitive cell reading method and device
AssigneeSTMicroelectronics S.r.l.
InventorJosep Segura
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Abstract
A method for reading from a cell of a network of photosensitive cells arranged in rows and in columns, each cell being adapted to providing an image voltage or a reference voltage, comprising the steps of charging, simultaneously for all the cells in the row of said cell, at least one capacitor with a resulting charge which is a function of the difference between a reference current and an image current respectively corresponding to the conversion, by an amplifying factor greater than one, of the reference voltage and of the image voltage, and measuring for the cell column the capacitor charge.
Drawings
Claims9
A method for reading a cell (10) of an array of photosensitive cells arranged in rows and columns, each cell being adapted to provide an image voltage (VPIX) or a reference voltage (VREF), comprising the steps of:
- a) charging, simultaneously for all the cells in the row of said cell, at least one capacitor (63, 80, 84) with a resulting charge which is a function of the difference between a reference current and an image current respectively corresponding to the conversion of the reference voltage and of the image voltage;
- and
- b) measuring the capacitor charge for the cell column.
A device for reading cells (10) of an array of photosensitive cells arranged in lines and columns, each cell being adapted to provide an image voltage (VPIX) or a reference voltage (VREF), comprising for each column:
- a voltage-to-current converter (61) having an input terminal (100) connected to all the column cells and receiving the voltages provided by one of the column cells;
- and
- at least one capacitor (63, 80, 84) charged under the current provided by the converter.
Dependencies are inferred from the claim text.