Patent ID: 9235745
Filing Date: 2016-01-12
CPC Classification: G06K

Claim Text:
1. A signal processing device comprising: a variable amplifier configured to output a signal, as an output signal thereof, corresponding to an input signal, an offset and a gain of the variable amplifier being able to be adjusted; a comparing means configured to compare a level of the output signal of the variable amplifier with a plurality of thresholds; a detecting means configured to detect either or both of a shift of the offset of the variable amplifier and an excess or deficiency of the gain of the variable amplifier based on the result of the comparison executed in the comparing means; and an adjusting means configured to adjust either or both of the offset and the gain of the variable amplifier based on the result of the detection executed in the detecting means, wherein the detecting means is also configured to utilize, as the result of the comparison for each of the plurality of thresholds, a number of times selected from a group consisting of a first number of times that the level of the output signal changes from a level below the threshold to a level over the threshold in a predetermined period, the second number of times that the level of the output signal changes from the level over the threshold to the level below the threshold in the predetermined period, and a third number of times which is a sum of the first number of times and the second number of times, said number of times being similarly selected among the plurality of thresholds.