Solid state image sensor device and its driving method

A method of driving a solid state image sensor which comprises

• a step of reading first signal charges corresponding to a first aspect ratio including second signal charges corresponding to a second aspect ratio from a first image segment of a matrix of photosensitive elements adapted to accumulate said first signal charges to vertical shift registers, said second signal charges accumulated in a second image segment situated centrally in said first image segments,
• a step of transferring said first signal charges from said vertical shift registers to a first horizontal shift register which is disposed under said first image segment,
• a step of transferring horizontally said first signal charges to a first buffer amplifier, when reading out said first signal charges, and
• a step of transferring only said second signal charges included in said first signal charges without horizontal transfer in said first horizontal shift register from said first horizontal shift register to a second horizontal shift register, and transferring horizontally said second signal charges to a second buffer amplifier, when reading out said second signal charges, said second horizontal shift register having the same number of transfer stages as the number of said photosensitive elements in one row of said second image segment, disposed in parallel with said first horizontal shift register, and disposed just under said second image segment through said first horizontal shift register.

A method of driving a solid state image sensor which comprises

• a step of reading first signal charges corresponding to a first aspect ratio including second signal charges corresponding to a second aspect ratio from a first image segment of a matrix of photosensitive elements adapted to accumulate said first signal charges to vertical shift registers, said second signal charges accumulated in a second image segment situated centrally in said first image segment,
• a step of transferring said first signal charges from said vertical shift registers to a storage region, said storage region comprising a first storage segment to store said first signal charges, a second storage segment to store said second signal charges situated centrally in said first storage segment, and a group of transfer gate electrodes wherein either the last transfer gate electrode or a plurality of transfer gate electrodes including said last transfer gate electrode are electrically independent of the remainder of transfer gate electrodes,
• a step of applying a high-speed driving pulse to either said last transfer gate electrode or said plurality of transfer gate electrodes including said last transfer gate electrode, the width of said high-speed driving pulse being narrower than the width of driving pulses to be applied to said remainder of transfer gate electrodes, to thereby transfer said first signal charges from said first storage segment to a horizontal shift register,
• a step of applying a first high-speed transfer pulse to said horizontal shift register during a horizontal blanking interval to sweep a first unnecessary signal charges included said first signal charges when reading out said second signal charges, said first unnecessary signal charges stored in one of two segments situated in both sides of said second storage segment,
• a step of transferring said second signal charges from said horizontal shift register to a buffer amplifier after sweeping said first unnecessary signal charges, and
• a step of applying a second high-speed transfer pulse to said horizontal shift register during the next horizontal blanking interval to sweep a second unnecessary signal charges included said first signal charges after transferring said second signal charges to said buffer amplifier, said second unnecessary signal charges stored in the other.