Image sensor providing output image signal with reduced offset

An image sensor comprising:

• photo sensing elements, having charge storage capability, for transducing received light into electrical quantities;
• first switching elements, each having a first source electrode, a first gate electrode and a first drain electrode with the first source and drain electrodes overlapping the first gate electrode to provide overlap capacity, for transferring charge stored in the photo sensing elements;
• second switching elements, each having a second source electrode, a second gate electrode and a second drain electrode with the second source and drain electrodes overlapping the second gate electrode to provide overlap capacity for resetting the photo sensing elements by removing the charge still left in the photo sensing elements after the charge transfer;
• the first and second switching elements having the respective first electrodes and second electrodes thereof arrayed such that the first and second source electrodes of the first and second switching elements being aligned in a vertical scan direction, and the first and second drain electrodes also being aligned in the vertical scan direction;
• and
• the amplitude of the second pulse signal being different from that of the first pulse signal based on difference between the overlap capacity of the first switching elements and the overlap capacity of the second switching elements.

An image sensor comprising:

• photo sensing elements, having charge storage capability, for transducing received light into electrical quantities;
• first switching elements, having first source, gate and drain electrodes and having charge storage capability, for transferring the charge stored in the photo sensing elements;
• second switching elements, having second source, gate and drain electrodes and having charge storage capability, for resetting the photo sensing elements by removing the charge still left in the photo sensing elements after the charge transfer:
• wherein, in each of the first and second switching elements, the source electrode overlaps with the gate electrode, and the drain electrode also overlaps with the gate electrode, thereby forming overlap capacitance, and the overlap capacitance of the second switching element is larger than that of the first switching element.

An image sensor comprising:

• photo sensing elements, having charge storage capability, for transducing received light into electrical quantities;
• first switching elements, each having a first source electrode, a first gate electrode and a first drain electrode with the first source and drain electrodes overlapping the first gate electrode to provide overlapping capacity, for transferring charge stored in the photo sensing elements;
• second switching elements, each having a second source electrode, a second gate electrode and a second drain electrode with the second source and drain electrodes overlapping the second gate electrode to provide overlapping capacity for resetting the photo sensing elements by removing the charge still left in the photo sensing elements after the charge transfer;
• wherein a potential applied to the source electrodes of the second switching elements is not equal to the ground potential based on difference between the overlap capacity of the first switching elements and the overlap capacity of the second switching elements.