Patent ID: 6211914
Filing Date: 2001-04-03
Classification: H04N

Abstract:
An apparatus for reading a signal out of a solid-state image sensing device which includes a number of photoelectric transducers for storing signal charge in an amount conforming to an amount of irradiating light, and a floating diffusion amplifier circuit for amplifying a video signal component having a level conforming to the amount of signal charge that has accumulated in the photoelectric transducers, and for being reset by a reset pulse applied thereto, wherein a first signal component having a predetermined level is outputted by the floating diffusion amplifier circuit over a period of time during which the reset signal is being applied, a feed-through signal component having a reference level with respect to the video signal component is outputted by the floating diffusion amplifier circuit after the output of the first signal component, and the video signal component following amplification thereof is outputted by the floating diffusion amplifier circuit after output of the feed-through signal component, the apparatus comprising:a first gate circuit for outputting a signal component, which is outputted by said solid-state image sensing device, as a first extracted captured-image signal for a first period of time that includes the duration of the feed-through signal component;a second gate circuit for outputting a signal component, which is outputted by said solid-state image sensing device, as a second extracted captured-image signal for a second period of time that is different from the first period of time and includes part of the duration of the video signal component;a first averaging circuit for averaging the first extracted captured-image signal outputted by said first gate circuit and outputting the averaged signal as a first average captured-image signal;a second averaging circuit for averaging the second extracted captured-image signal outputted by said second gate circuit and outputting the averaged signal as a second average captured-image signal;a level adjusting device for adjusting the level of at least one of the first average captured-image signal, which is outputted by said first averaging circuit, and the second average captured-image signal, which is outputted by said second averaging circuit, at the ratio of the first period of time to the second period of time; anda difference signal detecting circuit for detecting and outputting a signal representing a difference between the first average captured-image signal and the second average captured-image signal the signal level of which has been adjusted by said level adjusting device.