Photo-electric conversion device with accumulation time control and leakage current compensation
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsMasahiro Kawasaki, Harumi Aoki, Koji Suzuki
Life of this patent
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Abstract
A photo-electric conversion device is provided with a light receiving array and circuits serving to scan the same. A light receiving device separate from the array and connected in parallel therewith is used as a part of a control device for controlling the accumulation time of the array. A saturation detection circuit may be arranged to receive the output of the array and to vary the accumulation time by a suitable factor when array saturation occurs. The conversion device may also be provided with means for compensating for leak currents in the conversion block, so as to facilitate higher linearity at low illumination intensities.
Claims3
A photo-electric conversion device, comprising:
- a light receiving element array for accumulating information on incident light through an accumulation effect;
- means for scanning said light receiving element array;
- a first light receiving element provided adjacent said light receiving element array and providing an output signal;
- a second light receiving element provided adjacent said first light receiving element and providing an output signal, said second light receiving element being shielded from light;
- comparison means for comparing output signals from said first and second light receiving elements;
- and
- means for controlling an accumulation time of said light receiving element array in accordance with the comparison of output signals from said first and second light receiving elements to compensate for a leakage current in said first light receiving element.
Dependencies are inferred from the claim text.