Interline CCD image sensor with an antiblooming structure

A ⅔-in 384 (H) × 490 (V) element interline CCD image sensor with a new antiblooming structure was developed. Blooming was suppressed without sacrificing photosensitivity and dynamic range by means of a vertical overflow drain positioned under (rather than beside) a photodiode. For 10-percent vertical height illumination the smear signal was reduced to 0.05 percent of the illumination signal. Well-balanced performance, namely, large dynamic range (72 dB), low random noise (65 rms noise electrons per charge packet), high-contrast transfer functions for horizontal and vertical directions, and a spectral response similar to the luminous efficiency curve were obtained under moderate operating conditions.