| 摘要 |
<p>PURPOSE:To prevent bar codes from being erroneously recognized by exactly judging whether the fetched bar codes are correct or not. CONSTITUTION:Based on a clock signal from a reference clock part 21, the edge width of a binary signal from a waveform shaping part 20 is counted by a first counter 22 and stored in a first memory 23, and the number of edges in the binary signal is counted by a second counter 24 and stored in a second memory 25. In this case, the processing of the second counter 24 can be executed in an extremely short time so as to exactly count the number of bar data without losing them even when any printing fault is generated in the bar code. Therefore, an ALU 26 can judge whether the fetched bar code is correct or not by comparing the number of data stored in the first memory 23 with the number of data stored in the second memory 25 and corresponding to this result, the wrong recognition of the bar code can be prevented without fail.</p> |
