SIGNAL PROCESSING DEVICE, SIGNAL PROCESSING METHOD AND INFORMATION READING APPARATUS

摘要

A pattern presence/absence evaluation value generation unit (41) determines the presence or absence of a pattern by comparing sensing data (d3) and correction data (d44). Operating according to a pattern presence/absence evaluation value (d41) obtained from the pattern presence/absence evaluation value generation unit (41), a correction data updating unit (42) outputs correction data (d42) updated by weighted addition of the sensing data (d3) and the correction data (d44), increasing the weighting of the correction data (d44) when an image pattern is present and increasing the weighting of the sensing data (d3) when the image pattern is absent. A correction data subtraction unit (43) subtracts the correction data (d42) from the sensing data (d3) and outputs output sensing data (d4). It consequently becomes possible to reduce the effect of sensing signal level variations of the sensing signal generated within the interval of reading of the object being sensed, and read the pattern accurately.

主权项

1. A signal processing device comprising:
a pattern presence/absence evaluation value generation unit for calculating, on a basis of sensing data which includes a signal component of an object being sensed and which is obtained by sequential sensing, by a sensing element, of the object being scanned, a degree of inclusion of the signal component in the sensing data; a correction data updating unit for taking a weighted sum of correction data representing a direct current component of the sensing data and the sensing data to generate updated correction data, with weight given to the correction data being greater as said degree increases, and weight given to the sensing data being greater as said degree decreases; and a correction data subtraction unit for subtracting the updated correction data from the sensing data to generate corrected sensing data.