| 摘要 |
<p>PURPOSE:To detect a similar pattern as well as identical pattern by using plural constant current circuits and analog synthesis circuits to compare an input digital code string and a reference digital code string quantitatively. CONSTITUTION:An input digital code string Din is inputted to a shift register 1. The shift register 1 compares the input digital code string Din with the reference digital code string (set by selecting a positive logical output +Q or a negative logical output -Q of each shift register), and the presence of coincidence is outputted in parallel at each bit. A coincidence signal generated at each unit code becomes a control signal of a switch array 2. Constant current sources Ic1-Ic8 are connected respectively to switches S1-S8 and opposite terminals are connected in common. Since a voltage in response to the coincidence of the input digital string and the reference digital string is obtained on a line 10, it is compared with a reference value by a comparator CP so as to detect a similar pattern in addition to a completely coincident pattern.</p> |
