Solid state sensor having logarithmic photovoltaic response, with pixel uniformity correction and white balance circuitry therefor

A solid-state image sensing apparatus comprising:

• a solid-state image sensing device having a plurality of pixels and a characteristic that an output voltage thereof natural-logarithmically varies in accordance with a light reception amount;
• first storing means for storing an image sensing output signal obtained from the solid-state image sensing device with respect to each pixel when a first light is irradiated to the solid-state image sensing device;
• second storing means for storing an image sensing output signal obtained from the solid-state image sensing device with respect to each pixel when a second uniform light of which light amount is different from that of the first uniform light is irradiated to the solid-state image sensing device;
• first calculating means for calculating a difference between the output signals which are stored, respectively, in the first and the second storing means with respect to each pixel;
• second storing means for calculating a difference between an image sensing output signal obtained with respect to each pixel in actual sensing and a stored image sensing output signal with respect to a pixel corresponding thereto which signal is stored in said second storing means;
• and
• third calculating means for calculating a ratio of the difference calculated by the first calculating means to the difference calculated by the second calculating means to form an image signal.

A solid-state image sensing apparatus comprising;

• a solid-state image sensing device having a plurality of pixels and a characteristic that an output voltage thereof natural-logarithmically varies in accordance with light reception amount;
• first calculating means for calculating with each pixel a difference between an image sensing output from the solid-state image sensing device when a first uniform light is irradiated to the solid-state image sensing device and an image sensing output signal from the solid-state image sensing device when a second uniform light of which light amount is different from that of the first light amount is irradiated to the solid-state image sensing device;
• second calculating means for calculating a difference between a sensing signal obtained with respect to each pixel in actual sensing and a stored image sensing output signal with respect to a pixel corresponding thereto obtained when the second uniform light is irradiated to the solid-state image sensing device;
• and
• third calculating means for calculating a ratio of the difference calculated by the first calculating means to the difference calculated by the second calculating means to form an image signal.

A solid-state image sensing apparatus comprising:

• a solid-state image sensing device having a plurality of pixels and a characteristic that an output voltage thereof natural-logarithmically varies in accordance with a light reception amount, the solid-state image sensing device is directed to generate voltage corresponding to respective three primary colors of light for sensing a color image;
• storing means for storing an image sensing output signal obtained from the solid-state image sensing device with respect to each pixel when white light is irradiated to the solid-state image sensing device;
• and
• calculating means for calculating a difference between an image sensing signal obtained with respect to each pixel in actual sensing and a stored image sensing output signal with respect to a pixel corresponding thereto which signal is stored in the storing means to realize a white balance of an image signal.