Image pickup system for preventing image darkening due to the entrance of intense light

A signal processing apparatus for receiving a reset voltage and a differential voltage of each of a plurality of unit cells from an image pickup device, and processing the reset and the differential voltages, the reset voltage corresponding to an output voltage from a photoelectric converter at an initialization, and the differential voltage corresponding to a difference between the reset voltage and a read voltage according to an output voltage from the photoelectric converter corresponding to an amount of received light, the signal processing apparatus comprising:

• a designating unit operable to designate, from among the plurality of unit cells, two or more unit cells as correction targets based on a judgment of whether read voltages outputted from the image pickup device for the plurality of unit cells are respectively within a predetermined range;
• and
• an output unit operable to output, for a unit cell being not one of the designated unit cells, the differential voltage of the unit cell as luminance information corresponding to the unit cell, and output, for a unit cell being one of the designated unit cells, a predetermined voltage indicating high luminance as luminance information corresponding to the unit cells,
• wherein the designating unit includes:
• a judging unit operable to make the judgment;
• and
• a selecting unit operable to select, from among unit cells having read voltages judged as not being within the predetermined range, two or more unit cells as the correction targets based on differential voltages outputted by the image pickup device for the plurality of unit cells.

A signal processing method for receiving a reset voltage and a differential voltage of each of a plurality of unit cells from an image pickup device, and processing the reset and the differential voltages, the reset voltage corresponding to an output voltage from a photoelectric converter at an initialization, and the differential voltage corresponding to a difference between the reset voltage and a read voltage according to an output voltage from the photoelectric converter corresponding to an amount of received light, the signal processing method comprising the steps of:

• (a) designating, from among the plurality of unit cells, two or more unit cells as correction targets based on a judgment of whether read voltages outputted from the image pickup device for the plurality of unit cells are respectively within a predetermined range;
• and
• (b) outputting, for a unit cell being not one of the designated unit cells, the differential voltage of the unit cell as luminance information corresponding to the unit cell, and output, for a unit cell being one of the designated unit cells, a predetermined voltage indicating high luminance as luminance information corresponding to the unit cells,
• wherein the step (a) includes the sub-steps of:
• (c) making the judgment;
• and
• (d) selecting, from among unit cells having read voltages judged as not being within the predetermined range, two or more unit cells as the correction targets based on differential voltages outputted by the device output unit for the plurality of unit cells.