Image sensing apparatus using calibration sequences stored in extended portions of shift registers

An image sensing apparatus comprising:

• an array of image sensing elements;
• a first shift register having a plurality of stages divided into first and second sections, the stages of the first section corresponding respectively to odd-numbered elements of said array;
• a second shift register having a plurality of stages divided into first and second sections, the stages of the first section corresponding respectively to even-numbered elements of said array;
• gate means responsive to a transfer command pulse for transferring image signals developed in the odd-numbered elements of said array to the corresponding stages of said first shift register and transferring image signals developed in the even-numbered elements of said array to the corresponding stages of said second shift register;
• means for generating a calibration sequence of equal pulse amplitude;
• control means for generating said transfer command pulse during a line scan interval, causing said calibration sequence to be stored into the second section of each of said first and second shift registers when said gate means is in a turn-off state, and alternately driving said first and second shift registers for delivering the image signals and the calibration sequences therefrom;
• means for combining the image signals delivered from the first and second shift registers;
• means for detecting a difference in amplitude between the calibration sequences delivered from the first and second shift registers;
• and
• compensation means responsive to the detected difference for controlling the amplitude of the image signals delivered from said shift registers.