Eastman-kodak Company

Qiang Luo

Christina P Phan

Caron Yvonne Thor

Chris Papalias

Eric Staton

Edith Kwong

A charge diffusion crosstalk reduction process is provided for image signals from, for example, a CMOS image sensor. Charge diffusion crosstalk processing can be used in accordance with aspects of the present invention to reduce charge diffusion crosstalk caused by electrons migrating from adjacent pixels. Crosstalk effects can be determined by color gain and color offset. By adjusting the color gain and color offset, crosstalk can be cancelled to the first order. Charge diffusion crosstalk processing in accordance with aspects of the present invention can be relatively easily integrated with color correction processing during the post processing of image sensors. Color correction and cross talk cancellation processing can use the same circuitry as previously used before by color correction process only. The input coefficients for color correction and cross talk cancellation processing can be determined from the results of the multiplication of color correction matrixand crosstalk cancellation matrix.

Charge diffusion crosstalk reduction for image sensors

The electrical cross talk in color solid-state image sensor is estimated or characterized by acquiring image data from an array of imaging cells which is a portion of a much larger array, extracting cross talk data from the acquired image data, and characterizing the cross talk based on the extracted coefficients.

Method of estimating electrical cross talk in an array of imaging cells

A horizontal scan circuit comprises a column selector and a plurality of block selectors. A column selector is used to address particular columns of pixels within blocks. A block selector is used to select a particular block and to select the particular columns of the selected block that are addressed by the column selector. Each block selector typically comprises a single D-type flip-flop that is associated with a block of pixel columns. The block selectors are arranged such that the blocks can be scanned from left-to-right or right-to-left. The column selector comprises an asynchronous counter and a decoder that are further arranged to provide sub-sampling and horizontal adding functions. The use of block and column selectors reduces the number of relatively large D-type flip-flops (which conserves die area) and reduces the parasitic capacitance associated with the otherwise required relatively large number of inputs of the column selection circuit drivers.

Bidirectional horizontal scan circuit with sub-sampling and horizontal adding functions

An array of active pixel sensor cells is operated to substantially reduce the gate induced drain leakage (GIDL) current component of the dark current. In addition, the array is tested to determine the number of cells in the array that are bad, and discards the array of active pixel sensor cells when the number of bad cells exceeds a predefined limit.

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Santa Clara, CA, United States of America

Qiang Luo