Two-dimensional semiconductor image sensor and method of operating the same

Claim 1

In a two-dimensional image sensor of the type wherein a plurality of sensor elements are carried in columns and rows by a doped semiconductor body, wherein row lines are selected by way of assigned parallel outputs of a row shift register to selectively drive first switching transistors connected to the sensor elements for transmitting exposure-dependent sensor signals, formed in the sensor elements, over the first switching transistors to respective column lines, wherein the column lines are successively connected to a readout line connected to a read output for reading the sensor signals via respective column read-out second switching transistors driven by parallel outputs of a column shift register, the improvement therein comprising: a plurality of third switching transistors each connected in series with a respective first switching transistor and connected to and operated by a respective output of the column shift register; a plurality of clock-driven fourth switching transistors each connecting a respective row line to a respective output of the row shift register; and a difference-forming stage connected to the read-output and operable to produce a difference signal from two successive read sensor signals.

Claim 8

A method of operating a two-dimensional image sensor of the type wherein a plurality of sensor elements are carried in columns and rows by a doped semiconductor body, wherein row lines are selected by way of assigned parallel outputs of a row shift register to selectively drive first switching transistors connected to the sensor elements for transmitting exposure-dependent sensor signals, formed in the sensor elements, over the first switching transistors to respective column lines, wherein the column lines are successively connected to a read-out line connected to a read output for reading the sensor signals via respective column read-out second switching transistors driven by parallel outputs of a column shift register, wherein a plurality of third switching transistors is provided with each connected in series with a respective first switching transistor and connected to and operated by a respective output of the column shift register, wherein a plurality of clock-driven fourth switching transistors is provided with each connecting a respective row line to a respective output of the row shift register, and wherein a difference-forming stage is connected to the read output and operable to produce a difference signal from two successive read sensor signals, comprising the steps of: selecting a row of sensor elements by applying a selection potential to the respective fourth switching transistor and simultaneously maintaining that transistor blocked; sequentially selecting each column by sequentially applying an enabling potential to the respective second and third switching transistors to render the same conductive; transmitting the noise and interference voltages generated by such switching on the read-out line and the column line to the difference-forming stage and storing such signals with a first operational sign; driving the respective fourth switching transistor to render the first switching transistors of the selected row conductive and transmit the respective sensor signal to the difference-forming stage along with noise and interference signals generated and superimposing the same, with an opposite, second operational sign, on the stored noise and interference voltages to produce a difference signal as an image sensor output signal; and repeating the above steps sequentially for each row.

Claim 9

A method of operating a two-dimensional image sensor of the type wherein a plurality of sensor elements are carried in columns and rows by a doped semiconductor body, wherein row lines are selected by way of assigned parallel outputs of a row shift register to selectively drive first switching transistors connected to the sensor elements for transmitting exposure-dependent sensor signals, formed in the sensor elements, over the first switching transistors to respective column lines, wherein the column lines are successively connected to a read-out line connected to a read output for reading the sensor signals via respective column read-out second switching transistors driven by parallel outputs of a column shift register, wherein a plurality of third switching transistors is provided with each connected in series with a respective first switching transistor and connected to and operated by a respective output of the column shift register, wherein a plurality of clock-driven fourth switching transistors is provided with each connecting a respective row line to a respective output of the row shift register, and wherein a difference-forming stage is connected to the read output and operable to produce a difference signal from two successive read sensor signals, comprising the steps of: selecting a row of sensor elements by applying a selection potential to the respective fourth switching transistor and simultaneously maintaining that transistor blocked; sequentially selecting each column by sequentially applying an enabling potential to the respective second and third switching transistors to render the same conductive; transmitting the noise and interference voltages generated by such switching on the read-out line and the column line to the difference-forming stage and storing such signals with a first operational sign; driving the respective fourth switching transistor to render the first switching transistors of the selected row conductive and transmit the respective sensor signal to the difference-forming stage along with noise and interference signals generated and superimposing the same, with an opposite, second operational sign, on the stored noise and interference voltages to produce a difference signal as an image sensor output signal; and repeating the above steps sequentially for each row.