Signal processing device

A signal processing device configured to use first characteristic data and pieces of another characteristic data, the first characteristic data being detected from a sheet-like detection target by a first detection element, the pieces of the another characteristic data respectively being detected from the detection target by other detection elements, each of the pieces of the another characteristic data being detected from the detection target by a corresponding other detection element included in the other detection elements and having (i) a characteristic that is different from a characteristic of the first characteristic data and (ii) a correlation with the first characteristic data, the signal processing device comprising:

• an evaluation value generator to generate an evaluation value determining whether an unnecessary portion is present using the correlations of the first characteristic data with the pieces of the another characteristic data, the unnecessary portion being included in the first characteristic data and being detected by the first detection element;
• and
• a correction amount determiner to determine, using the evaluation value, a correction amount for the first characteristic data to correct the data determined to be the unnecessary portion by the evaluation value generator.

A signal processing device configured to use first characteristic data and second characteristic data, the first characteristic data being detected from a sheet-like detection target by an element for detecting a change in capacitance, the second characteristic data being detected from the detection target by an image reading element and having a correlation with the first characteristic data, the signal processing device comprising:

• an evaluation value generator to generate an evaluation value determining whether an unnecessary portion is present using the correlation of the first characteristic data with the second characteristic data, the unnecessary portion being included in the first characteristic data and being detected by the first detection element;
• and
• a correction amount determiner to determine, using the evaluation value, a correction amount for the first characteristic data to correct the data determined to be the unnecessary portion by the evaluation value generator.